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Numerical investigation of production performance of challenging gas hydrates from deposits with artificial fractures and impermeable barriers

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Title: Numerical investigation of production performance of challenging gas hydrates from deposits with artificial fractures and impermeable barriers
Authors: Shuaishuai Nie, Ke Liu, Xiuping Zhong, Yafei Wang, Yalu Han, Kangtai Xu, Jian Song, Jiangfei Li
Source: Scientific Reports, Vol 15, Iss 1, Pp 1-17 (2025)
Publisher Information: Nature Portfolio, 2025.
Publication Year: 2025
Collection: LCC:Medicine
LCC:Science
Subject Terms: Gas hydrate, Reservoir stimulation, Artificial fracture, Impermeable barrier, Water control, Medicine, Science
More Details: Abstract In this research, a novel reservoir stimulation scheme combining impermeable artificial barriers and high-conductivity artificial fractures was introduced for gas hydrate extraction from clayey silt deposits, and the injection-production performance was numerically investigated using hydrates at the Shenhu SH2 site as the typical case scenario. The results indicated that impermeable barriers effectively addressed the challenges including boundary water intrusion, decomposition gas leakage, and injected hot fluid loss. Especially, artificial barriers and fractures exert a synergistic stimulation effect of “1 + 1 > 2”. The average gas production rate increased logarithmically as fracture conductivity increased, whereas the gas-to-water ratio and energy ratio, presented an opposite trend. The impact of injection pressure and production pressure on productivity was limited relative to hot water temperature, whereas low-temperature and low-pressure injection were more conducive to water control and energy utilization. Furthermore, parameter optimization based on multivariate nonlinear models suggested that commercial productivity and the Class II development standard for offshore gas reservoirs were expected to be achieved. Therefore, the combination of artificial fractures and impermeable boundaries is promising for clayey silt hydrate reservoir stimulation, offering a viable development mode for marine challenging hydrate.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2045-2322
Relation: https://doaj.org/toc/2045-2322
DOI: 10.1038/s41598-025-87460-3
Access URL: https://doaj.org/article/e42c424bb5fa465ea632fe149908effe
Accession Number: edsdoj.42c424bb5fa465ea632fe149908effe
Database: Directory of Open Access Journals
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  Value: <anid>AN0183578297;[fkqs]10mar.25;2025Mar12.06:47;v2.2.500</anid> <title id="AN0183578297-1">Exploring the influence of polysaccharide on gastrointestinal stability, drug release and formation mechanism of nanoparticles in Zhimu and Huangbai herb pair decoction </title> <p>Natural polysaccharides with multiple biological activities from traditional Chinese medicine (TCM) can be self-assembled. Natural nanoparticles have been found to exist in TCM decoctions. However, the influence of polysaccharides in TCM decoctions on the formation mechanism, drug release and gastrointestinal stability of nanoparticles remains unclear. Therefore, using Zhimu and Huangbai herb pair decoction (ZBD) as an example, this study aimed to reveal the effects of polysaccharides on the formation, gastrointestinal stability and in vitro release of nanoparticles (N-ZBD) in ZBD. First, N-ZBD was successfully isolated by high-speed centrifugation with an average particle size of 225.9 nm, PDI of 0.53 and zeta potential of -13.00 mV, and N-ZBD is mainly composed of small active compounds and polysaccharides. Interestingly, gastrointestinal stability results showed that N-ZBD had good stability while and the nanoparticles after polysaccharide removal (RPN-ZBD) were degraded within 4 h, indicating that polysaccharide can protect the stability of nanoparticles in the gastrointestinal environment. Moreover, in vitro drug release results showed that compared with free drugs and RPN-ZBD, N-ZBD has obvious slow-release behavior in simulated gastric fluid and simulated intestinal fluid, suggesting that polysaccharides contribute to the slow release of N-ZBD. The critical micelle concentration (CMC) of polysaccharides was 0.63 mg/mL, which could self-assemble with small active compounds to form N-ZBD. In conclusion, polysaccharides of ZBD were essential for N-ZBD formation, and could protect the stability of N-ZBD in the gastrointestinal environment and contribute to its slow drug release.</p> <p>Keywords: Nanoparticles; Polysaccharide; Gastrointestinal stability; Drug release; Zhimu and Huangbai herb pair decoction</p> <p>Supplementary Information The online version contains supplementary material available at https://doi.org/10.1038/s41598-024-82130-2.</p> <hd id="AN0183578297-2">Introduction</hd> <p>Traditional Chinese medicines (TCM) are widely used in the prevention and treatment of various diseases due to their complex active components and remarkable therapeutic effects. The separation of active components from TCM by modern methods such as preparative liquid chromatography systems, has long been conducted and those isolated monomer compounds are widely used to reveal the therapeutic mechanism of decoction[<reflink idref="bib1" id="ref1">1</reflink>],[<reflink idref="bib2" id="ref2">2</reflink>]. However, a series of studies have shown that the bioavailability of purified form of compounds is less than that of decoctions[<reflink idref="bib3" id="ref3">3</reflink>]. For example, the blood concentration of mangiferin in Rhizoma Anemarrhena (Zhimu) decoction and Rhizoma Anemarrhena and Phellodendri Chinensis Cortex (Zhimu and Huangbai) decoction was significantly higher than the corresponding values of free mangiferin at the same dose level[<reflink idref="bib4" id="ref4">4</reflink>]. After oral administration of free gentiopicroside, the area under the concentration time curve (AUC) of gentiopicroside was significantly lower than that of Gentianae decoctions[<reflink idref="bib5" id="ref5">5</reflink>]. Therefore, the interaction of coexisting components in decoctions may affect the oral absorption of drugs.</p> <p>Natural self-assembled nanoparticles are widely found in the TCM decoctions[<reflink idref="bib3" id="ref6">3</reflink>],[<reflink idref="bib6" id="ref7">6</reflink>], [<reflink idref="bib7" id="ref8">7</reflink>], [<reflink idref="bib8" id="ref9">8</reflink>], [<reflink idref="bib9" id="ref10">9</reflink>]–[<reflink idref="bib10" id="ref11">10</reflink>]. Our previous research found that nanoparticles (N-XBSD) with size of 100 nm existed in Xie-bai-san decoction (XBSD), and N-XBSD could obviously enhance the oral bioavailability of active compounds[<reflink idref="bib11" id="ref12">11</reflink>]. Importantly, natural polysaccharides derived from TCM, have outstanding biological activity with low immunogenicity, low toxicity and degradability. Numerous studies have shown that plant polysaccharides are amphiphilic and capable of self-assembly[<reflink idref="bib12" id="ref13">12</reflink>], [<reflink idref="bib13" id="ref14">13</reflink>]–[<reflink idref="bib14" id="ref15">14</reflink>]. Thus, polysaccharides may be involved in the formation of nanoparticles in decoctions. Moreover, the gastrointestinal tract is accompanied by a highly acidic environment (pH = 1.2-2.0) and digestive enzymes, which often cause significant denaturation and degradation of the nanoparticles, reducing their biological activity. Carrier materials in modern pharmaceuticals, such as liposomes, are unstable in acidic environments, leading to early drug release and low bioefficacy. In order to improve the release pattern and biological efficacy of liposomes, complex modifications of liposomes are required, which limits their application in oral administration[<reflink idref="bib15" id="ref16">15</reflink>]. Therefore, the ability of nanoparticles in decoction to remain stable in the gastrointestinal tract is a prerequisite for their ability to promote drug absorption. Among the common polysaccharides, gum arabic (GA), guar gum (GG), pectin (PE), and xanthan gum (XG) have better acid and alkaline resistance, which may have advantages in protecting the stability of nanoparticles[<reflink idref="bib16" id="ref17">16</reflink>]. Polysaccharide nanocarriers have been shown to improve the mechanical strength and stability of liposomes during drug delivery[<reflink idref="bib17" id="ref18">17</reflink>]. However, whether polysaccharides are involved in the formation of nanoparticles and the effect of polysaccharides on the gastrointestinal stability and drug release behaviour of nanoparticles in decoctions has not been systematically investigated.</p> <p>Herb pairs are the most fundamental and the simplest form of multi-herb formula. Zhimu and Huangbai herb pair decoction (ZBD): Rhizoma Anemarrhena and Phellodendri Chinensis Cortex, has long been used in TCM for the treatment of type 2 diabetes mellitus (T2DM)[<reflink idref="bib18" id="ref19">18</reflink>]. Based on phytochemical research, ZBD contains many constituents, such as flavonoids[<reflink idref="bib19" id="ref20">19</reflink>], alkaloids[<reflink idref="bib20" id="ref21">20</reflink>],[<reflink idref="bib21" id="ref22">21</reflink>], saponins[<reflink idref="bib22" id="ref23">22</reflink>], organic acids[<reflink idref="bib23" id="ref24">23</reflink>] and polysaccharide[<reflink idref="bib24" id="ref25">24</reflink>]. Berberine (Fig. 1F), mangiferin (Fig. 1D), neomangiferin (Fig. 1A), phellodendrine (Fig. 1C), jatrorrhizine (Fig. 1E), timosaponin BII (Fig. 1H), obacunone (Fig. 1G) and polysaccharide have been proven to be the active anti-diabetic substances[<reflink idref="bib14" id="ref26">14</reflink>],[<reflink idref="bib24" id="ref27">24</reflink>], [<reflink idref="bib25" id="ref28">25</reflink>], [<reflink idref="bib26" id="ref29">26</reflink>], [<reflink idref="bib27" id="ref30">27</reflink>], [<reflink idref="bib28" id="ref31">28</reflink>], [<reflink idref="bib29" id="ref32">29</reflink>]–[<reflink idref="bib30" id="ref33">30</reflink>]. Studies have shown that Zhimu contains mangiferin, neomangiferin, saponin and a large number of polysaccharides[<reflink idref="bib31" id="ref34">31</reflink>], all of which are amphiphilic components that are prone to self-assembly. However, current research on ZBD has focused on the individual components, and few studies have investigated self-assembly between the active components.</p> <p>Accordingly, using ZBD as an example, the purpose of this study was to reveal whether there are nanoparticles in ZBD, the composition of nanoparticles, and the effects of polysaccharides on the formation, gastrointestinal stability and in vitro release of nanoparticles. This study not only attempted to discover new orally self-assembled nanocarriers through polysaccharides, but also further explored the important role of polysaccharides in herbal decoctions.</p> <hd id="AN0183578297-3">Method</hd> <p></p> <hd id="AN0183578297-4">Chemicals and reagents</hd> <p>Anemarrhenae Rhizoma (Batch number: 20210526, Shanghai, China), Phellodendri Chinensis Cortex (Batch number: 20211007, Shanghai, China) were from Shanghai Kangqiao traditional Chinese medicine Co. Ltd. The standards which included neomangiferin (Catalog: B21397, ≥ 98% purity), chlorogenic acid (Catalog: B20782, ≥ 98% purity, Fig. 1B), phellodendrine (Catalog: B20552, ≥ 98% purity), mangiferin (Catalog: B20837, ≥ 98% purity), jatrorrhizine (Catalog: B21476, ≥ 98% purity), berberine (Catalog: B21379, ≥ 98% purity), obacunone (Catalog: B20553, ≥ 98% purity) and Timosaponin BII (Catalog: B21657, ≥ 98% purity) were all purchased from Shanghai Yuanye Biotechnology Co., Ltd (https://<ulink href="http://www.shyuanye.com">www.shyuanye.com</ulink>). 3500Da dialysis bag was purchased from Shanghai Yuanye Biotechnology Co., Ltd (https://www.shyuanye.com, catalog: SP132594). The Gastrointestinal simulating fluid was purchased from Phygene Biotechnology Co., Ltd (<ulink href="http://phygene.com">http://phygene.com</ulink>).</p> <p>Graph: Fig. 1 Chemical structures of main pharmacodynamic compounds: neomangiferin (A), chlorogenic acid (B), phellodendrine (C), mangiferin (D), jatrorrhizine (E), berberine (F), obacunone (G), Timosaponin BII (H).</p> <hd id="AN0183578297-5">Preparation of ZBD and separation of the phase states in ZBD</hd> <p>The preparation of ZBD was performed as follows: Anemarrhenae Rhizoma (30 g), Phellodendri Chinensis (30 g), were soaked in 600 mL distilled water for 30 min. Then boil for 60 min. Lastly, filter with four layers of gauze to get ZBD.</p> <p>The 50 mL ZBD (I) was centrifuged for 30 min (4000 rpm). The supernatant was tightly sealed in a dialysis bag, and then submerged into 500 mL of water and dialyzed at 37 °C for 1 h (120 rpm). Finally, the liquid in the dialysis bag was centrifuged for 30 min (<reflink idref="bib13" id="ref35">13</reflink>,000 rpm). The dialysis and centrifugation were repeated twice. By the above operation, all centrifuged precipitates were collected, i.e., the sediment phase state (S-ZBD, II), the dialysis outer liquid was the true solution phase state (T-ZBD, III), and the liquid inside the dialysis bag was the nanoparticles (N-ZBD, IV) (Fig. 2)[<reflink idref="bib12" id="ref36">12</reflink>].</p> <p>Graph: Fig. 2 Isolation method of N-ZBD.</p> <hd id="AN0183578297-6">UPLC-DAD and HPLC-ELSD quantitative analysis</hd> <p></p> <hd id="AN0183578297-7">Chromatographic conditions of UPLC-DAD and HPLC-ELSD analysis</hd> <p>Quantitative analysis of neomangiferin, chlorogenic acid, phellodendrine, mangiferin, jatrorrhizine, berberine and obacunone was performed on an ultra-high performance liquid chromatography-diode array detector (UPLC-DAD) system (Agilent, USA), using an SB-AQ column (3.0 mm × 150 mm, 2.7 μm). The mobile phase consisted of 0.2% sodium pyrophosphate (A) and acetonitrile (B), using a gradient elution. The elution conditions were as follows: 0–4 min, 2% B; 4–6 min, 2–8% B; 6–20 min, 8–10% B; 20–30 min, 10–40% B; 30–35 min, 40–95% B. The flow rate was 0.6 mL/min. The column temperature was 25 °C, and the injection volume was 1 µL. The detection wavelengths of the DAD detector were performed as follows: 214 nm for 0–8 min, 340 nm for 8–16 min, 240 nm for 16–20 min, 340 nm for 20–31 min and 214 nm for 31–40 min.</p> <p>Quantitative analysis of timosaponin BII were performed on a high-performance liquid: chromatography- evaporative light scattering detector (HPLC-ELSD) system (Agilent, USA), using an Ultimate XB-C18 (4.6 mm×250 mm, 5 μm) column. The mobile phase consisted of water (A) and acetonitrile (B), using a gradient elution. The elution conditions were as follows: 0–11 min, 25–26% B; 11–15 min, 26–60% B; 15–20 min, 60–95% B; 20–25 min, 95% B. The flow rate was 1 mL/min. The column temperature was 25 °C, and the injection volume was 20 µL. The drift tube temperature was 60 °C and the carrier gas flow rate was 1.5 L/min.</p> <hd id="AN0183578297-8">Method validation</hd> <p>The developed method underwent validation for specificity, limit of detection (LOD) and lowest limit of quantification (LLOQ), precision, accuracy, recovery, and stability in accordance with ICH Technical Requirements for Pharmaceuticals for Human Use and USP guidelines.</p> <hd id="AN0183578297-9">Specificity</hd> <p>Method selectivity was determined by comparing chromatograms of negative samples without the measured compounds to those of all analyte samples.</p> <hd id="AN0183578297-10">Linearity and LLOQ</hd> <p>To establish linearity and LLOQ, a series of diluted mixed standard solutions with known concentrations of each standard were prepared. The LOD and LLOQ for the standards were set at the minimum concentrations of which the signal-to-noise ratios (S/N) could be determined as 3:1 and 10:1, respectively.</p> <hd id="AN0183578297-11">Precision and accuracy</hd> <p>Precision was evaluated in two aspects: intraday and interday precisions for standards, and precision for determination of analytes in samples. Relative standard deviations (RSD) in the detected analytes were calculated to assess the method's precision. Accuracy was determined using the standard addition method.</p> <hd id="AN0183578297-12">Recovery</hd> <p>Samples with known quantities of each of the standards were spiked with approximately 50%, 100%, and 150%. The percentage of recovery was calculated by comparing the spiked and unspiked samples to the actual amount added.</p> <hd id="AN0183578297-13">Stability</hd> <p>The ZBD sample stored at room temperature was analyzed at 0, 2, 4, 6, 8, and 12 h, and the variation was expressed by the RSDs of the contents of each analyte.</p> <hd id="AN0183578297-14">Determination of the chemical composition of ZBD, S-ZBD, T-ZBD and N-ZBD by UPLC-DAD and HPLC...</hd> <p>Primary stock solutions of neomangiferin (487.00 µg/mL), chlorogenic acid (498.00 µg/mL), phellodendrine (516.00 µg/mL), mangiferin (610.00 µg/mL), jatrorrhizine (177.00 µg/mL), berberine (2030.00 µg/mL), obacunone (200.00 µg/mL) and timosaponin BII (2050.00 µg/mL) were prepared in 50% methanol. After gradient dilution, calibration curves were obtained for five concentration levels. By comparing retention times (RT) and UV spectra with those of standard compounds (neomangiferin, chlorogenic acid, phellodendrine, mangiferin, jatrorrhizine, berberine, obacunone and timosaponin BII), chromatographic peaks were identified. 5 mL of ZBD, N-ZBD and T-ZBD were respectively placed in 10 mL volumetric bottles, 5 mL methanol was added to the scale, swirled for 10 min, and then filtered by 0.22 μm organic filter membrane for UPLC-DAD and HPLC-ELSD analysis. The S-ZBD was taken from 50 mL of the decoction and added into 10 mL of 50% methanol solution, then ultrasonicated for 20 min and filtered by 0.22 μm organic filter membrane for UPLC-DAD and HPLC-ELSD analysis.</p> <hd id="AN0183578297-15">Total carbohydrates determination</hd> <p>Four times the volume of anhydrous ethanol was added to N-ZBD, shaken well, leave overnight, centrifuge for 15 min (2000 rpm), discard the supernatant, and the precipitate was washed twice with 80% ethanol, and after evaporation of the ethanol, the total carbohydrate content was determined by the phenol-concentrated sulfuric acid method[<reflink idref="bib32" id="ref37">32</reflink>].</p> <hd id="AN0183578297-16">Removal of polysaccharides from N-ZBD</hd> <p>Total polysaccharides in N-ZBD were removed by ethanol precipitation. Briefly, 4 times the volume of ethanol was added to the ZBD and left to stand for 24 h, then the ethanol in the supernatant was recovered by rotary evaporation at 50 °C, and the ethanol precipitation operation was repeated twice to obtain the polysaccharide-removed ZBD, and finally the removed-polysaccharide nanoparticles (RPN-ZBD) was obtained by separating the nanoparticles according to the method "2.2". In order to exclude the effect of recycling ethanol after adding ethanol on N-ZBD, we set up a blank control, i.e., recovering ethanol after adding ethanol without removing polysaccharides, and then the split phase was performed to obtain the control nanoparticles (CN-ZBD). The flowchart is shown in Fig. S1.</p> <hd id="AN0183578297-17">Isolation of total polysaccharides from ZBD</hd> <p>The total polysaccharide (TPS) in ZBD was obtained by ethanol precipitation. In brief, The ZBD was centrifuged at 4000 rpm for 30 min to remove the insoluble precipitate. After adding 4-fold volume of absolute ethanol, centrifugation, the precipitate was collected. It was then dialyzed in a 10,000 D molecular weight dialysis bag for 12 h to remove the pigment and small molecules. Next, deproteinization was performed with TCA reagent, and the resulting polysaccharide solution was precipitated with 4-fold volume of ethanol, centrifuged at 8000 rpm, and freeze-dried. The freeze-dried TPS was used for subsequent experiments. The flowchart is shown in Fig. S1.</p> <hd id="AN0183578297-18">In vitro release study</hd> <p>The membrane dialysis method was used to determine the eight compounds release of ZBD, N-ZBD, RPN-ZBD and free drugs in simulated gastric fluid (SGF) (pH 1.2), simulated intestinal fluid (SIF) (pH 6.8), respectively. Briefly, the sink condition was used and 30 mL of ZBD, N-ZBD, RPN-ZBD and free drugs solution were transferred into MWCO 3500 Da dialysis bags followed by immersion into 500 mL SGF and SIF, respectively, maintained at 37.0 °C in a shaking incubator at 120 rpm. The concentration of the eight compounds of the free drugs was the same as that of N-ZBD. 0.2 mL of sample solution was drawn at 0 h, 1 h, 2 h, 4 h, 6 h, 8 h and 12 h. After high-speed centrifugation (12000 rpm, 10 min), the drug release amount was determined by UPLC-DAD and HPLC-ELSD.</p> <hd id="AN0183578297-19">The storage stability and gastrointestinal stability</hd> <p>The N-ZBD, RPN-ZBD, CN-ZBD were placed in closed transparent ampoule at 37 °C, 50% humidity and the storage stability of N-ZBD, RPN-ZBD and CN-ZBD was examined at each time point. The 1 mL of N-ZBD, RPN-ZBD and CN-ZBD were incubated in 5 mL of simulated gastric fluid (SGF, pH = 1.2), simulated intestinal fluid (SIF, pH = 6.8) at 37 °C for 12 h, respectively. The particle size of the N-ZBD, RPN-ZBD and CN-ZBD at 2, 4, 8 and 12 h was detected to access the storage stability and gastrointestinal stability of N-ZBD, RPN-ZBD and CN-ZBD.</p> <hd id="AN0183578297-20">TEM and particle size analyser</hd> <p>One drop of N-ZBD, RPN-ZBD and CN-ZBD, was spread uniformly on a copper mesh coated with carbon film, respectively, dried, stained with 2.0% phosphotungstic acid for 2 min, dried again and the morphology of the nanoparticles was observed under transmission electron microscopy (TEM, Tokyo, Japan). A Zetasizer Nano ZSE (Malvern Zetasizer Nano-ZS ZEN 3600, Marvin, England) was used to determine the particle size distribution and surface potential of N-ZBD [<reflink idref="bib12" id="ref38">12</reflink>].</p> <hd id="AN0183578297-21">Study of the mechanism of N-ZBD formation</hd> <p></p> <hd id="AN0183578297-22">Formation of self-assembly between small molecules</hd> <p>Berberine was combined with chlorogenic acid (CGA) and mangiferin (MGF), respectively, and phellodendrine (PDD) was combined with MGF in the ratio of 1:1 (0.1 mM) at 120 °C, respectively. The solution was heated and stirred at 600 rpm for 2 h without reflux condensation until the concentration increased to 4 mM.</p> <hd id="AN0183578297-23">The determination of critical micelle concentration of TPS</hd> <p>Pyrene was prepared with acetone in a solution of 5 × 10<sups>− 3</sups>M, and 100 µL was transferred to a series of 10 mL brown volumetric flasks. The TPS solution was configured with water at a concentration of 3 mg/mL, and different volumes of TPS solution were absorbed and added to each brown volumetric flask, and the final concentration of pyrene was 5 × 10<sups>− 5</sups>M. Water bath ultrasound for 40 min (180 W) and 40℃ water bath for 12 h. The fluorescence spectrum of pyrene was measured with a fluorescence spectrophotometer. The excitation wavelength was 334 nm, the slit width of emission and excitation were 2.5 and 5.0 nm, respectively, and the scanning speed was set to 240 nm/min. The fluorescence spectra of pyrene in TPS solutions with different concentrations were recorded. The I1/I3 intensity ratio of pyrene at different concentrations was plotted with the logarithmic value of TPS concentration as the horizontal coordinate and the value of I(373 nm)/I(384 nm) as the vertical coordinate, and the critical micelle concentration (CMC) of TPS was calculated.</p> <hd id="AN0183578297-24">Formation of small molecules with polysaccharide self-assembly</hd> <p>After berberine and mangiferin were heated and stirred according to 2.10.1, polysaccharide was added so that the concentration of polysaccharide in the solution reached 2 mg/mL, and heating and stirring were continued for 1 h.</p> <hd id="AN0183578297-25">Statistical analysis</hd> <p>Data were expressed as mean ± SD. Differences among groups were performed with a one-way analysis of variance (ANOVA) test. <emph>p</emph> < 0.05 was considered statistically significant.</p> <hd id="AN0183578297-26">Results</hd> <p></p> <hd id="AN0183578297-27">Separation and characteristic of N-ZBD from ZBD</hd> <p>N-ZBD was isolated using a combination of dialysis and high-speed centrifugation, a common method for separating nanoparticles from herbal decoctions [<reflink idref="bib37" id="ref39">37</reflink>],[<reflink idref="bib38" id="ref40">38</reflink>]. In this process, dialysis removed free drugs from the decoction, while subsequent high-speed centrifugation eliminated micron-sized particles, resulting in the formation of N-ZBD. The N-ZBD particles were spherical, with diameters between 30 and 500 nm (Fig. 3A). The average particle size was 225.9 ± 5.03 nm (Fig. 3D), with a polydispersity index (PDI) of 0.53 ± 0.03 and zeta potential of -13.00 ± 0.43 mV (Fig. 3G).</p> <p>In order to elucidate the role of polysaccharides in N-ZBD, we used ethanol precipitation to remove polysaccharides from N-ZBD and obtained RPN-ZBD. In order to exclude the effect of adding ethanol to N-ZBD and then recycling ethanol to N-ZBD on N-ZBD, we set up a blank control, i.e., adding ethanol to N-ZBD and then recycling ethanol, and CN-ZBD was obtained without removing polysaccharides. The TEM morphology, particle sizes and potentials of N-ZBD and CN-ZBD are close to each other (Fig. 3A,C,D,F,G,I), indicating that the addition of ethanol and then recycling of ethanol has less effect on the particle size, potential and morphology of N-ZBD, which made it possible to continue the experiment. In contrast, the particle sizes of N-ZBD and RPN-ZBD were 225.90 ± 5.03 nm (Fig. 3D) and 361.50 ± 2.49 nm (Fig. 3E), respectively, and the potentials were − 13.00 ± 0.34 mV (Fig. 3G) and − 6.94 ± 0.54 mV (Fig. 3H), respectively. TEM images also showed the morphology of N-ZBD was composed of black nanoparticles as the inner core and white material as the shell (Fig. 3A), whereas, interestingly, only the inner core was seen after the polysaccharides were removed from N-ZBD (Fig. 3B). This suggests that the inner core may be a self-assembled nanoparticle of small molecular compounds, while the outer shell is a self-assembled nanoparticle of polysaccharides. At the same time, there are white quasi-spherical nanoparticles in Fig. 3A and C, but they are not seen in RPN-ZBD after the removal of the polysaccharide (Fig. 3B), indicating that the white self-assembled nanoparticles may be formed by the self-assembly of the polysaccharide alone.</p> <p>Graph: Fig. 3 (A) TEM of N-ZBD (bright field image). (B) TEM of RPN-ZBD (dark field image). (C) TEM of CN-ZBD (bright field image). (D) Particle size distribution of N-ZBD. (E) Particle size distribution of RPN-ZBD. (F) Particle size distribution of CN-ZBD. (G) The zeta potential of N-ZBD. (H) The zeta potential of RPN-ZBD. (I) The zeta potential of CN-ZBD.</p> <hd id="AN0183578297-28">Validation of the quantitative method</hd> <p>Flavonoids, alkaloids, saponins, organic acids and polysaccharide are the main compounds of ZBD in anti-T2DM. In order to clarify whether N-ZBD contains active components, the neomangiferin, chlorogenic acid, phellodendrine, mangiferin, jatrorrhizine, berberine, obacunone and timosaponin BII of ZBD, S-ZBD, T-ZBD and N-ZBD were analyzed by UPLC-DAD and HPLC-ELSD and the total carbohydrates was determined by the phenol-concentrated sulfuric acid method. The chromatogram is shown in Fig. 4. Table 1 provides a summary of the linearity, sensitivity, precision, accuracy, and stability of the UPLC-DAD and HPLC-ELSD assays used for the quantitative analysis of the eight analytes. The data indicated a good relationship between concentrations and peak areas of the analytes within the test ranges (<emph>R</emph> ≥ 0.9995). The LOD ranged from 0.019 to 2.067 µg/mL and the LLOQ ranged from 0.057 to 6.204 µg/mL. The overall RSDs for precision and repeatability were below 2.45% and 2.90%, respectively. The method demonstrated good accuracy, with recoveries ranging from 96.14 to 103.68% for all analytes. Stability tests showed that the RSDs for the concentration of each analyte within 12 h were less than 2.67%. These results showed that the developed method has excellent linearity, sensitivity, precision, accuracy, recovery and stability, making it suitable for the quantitative analysis of the eight compounds in ZBD.</p> <p>Graph: Fig. 4 (A) A representative UPLC-DAD chromatogram. (B) A representative HPLC-ELSD chromatogram. From top to bottom: mixture of standard compounds, ZBD, N-ZBD, RPN-ZBD, CN-ZBD, T-ZBD and S-ZBD. (a) Neomangiferin; (b) chlorogenic acid; (c) phellodendrine; (d) mangiferin; (e) jatrorrhizine; (f) berberine; (g) limonin; (h) obacunone; (i) timosaponin BII.</p> <p>Table 1 Linearity, LOD, LLOQ, stability, precision, repeatability, accuracy of the assay.</p> <p> <ephtml> <table frame="hsides" rules="groups"><thead><tr><th align="left" rowspan="2"><p>Compound</p></th><th align="left" colspan="3"><p>Linearity</p></th><th align="left" rowspan="2"><p>LOD</p><p>(µg/mL)</p></th><th align="left" rowspan="2"><p>LLOQ</p><p>(µg/mL)</p></th><th align="left" rowspan="2"><p>Stability</p><p>(RSD, %, <italic>n</italic> = 6)</p></th><th align="left" colspan="2"><p>Precision (RSD, %, <italic>n</italic> = 6)</p></th><th align="left" rowspan="2"><p>Repeatability</p><p>(RSD, %, <italic>n</italic> = 6)</p></th><th align="left" colspan="3"><p>Recovery (%, <italic>n</italic> = 3)</p></th></tr><tr><th align="left"><p>Range (µg/mL)</p></th><th align="left"><p>Regressive equation</p></th><th align="left"><p><italic>R</italic></p></th><th align="left"><p>Intra-</p><p>day</p></th><th align="left"><p>Inter-</p><p>day</p></th><th align="left"><p>80%</p></th><th align="left"><p>100%</p></th><th align="left"><p>120%</p></th></tr></thead><tbody><tr><td align="left"><p>Neomangiferin</p></td><td char="." align="char"><p>15.22–487.00</p></td><td align="left"><p> A = 1.280c + 0.985</p></td><td char="." align="char"><p>0.9999</p></td><td char="." align="char"><p>1.048</p></td><td char="." align="char"><p>3.144</p></td><td char="." align="char"><p>1.41</p></td><td char="." align="char"><p>0.30</p></td><td char="." align="char"><p>0.63</p></td><td char="." align="char"><p>2.61</p></td><td char="." align="char"><p>97.40</p></td><td char="." align="char"><p>96.14</p></td><td char="." align="char"><p>98.00</p></td></tr><tr><td align="left"><p>Chlorogenic acid</p></td><td char="." align="char"><p>15.56–498.00</p></td><td align="left"><p> A = 3.542c + 2.554</p></td><td char="." align="char"><p>0.9999</p></td><td char="." align="char"><p>0.255</p></td><td char="." align="char"><p>0.764</p></td><td char="." align="char"><p>2.67</p></td><td char="." align="char"><p>0.32</p></td><td char="." align="char"><p>0.66</p></td><td char="." align="char"><p>2.35</p></td><td char="." align="char"><p>99.04</p></td><td char="." align="char"><p>100.76</p></td><td char="." align="char"><p>100.77</p></td></tr><tr><td align="left"><p>Phellodendrine</p></td><td char="." align="char"><p>16.13–516.00</p></td><td align="left"><p> A = 1.603c + 6.277</p></td><td char="." align="char"><p>0.9999</p></td><td char="." align="char"><p>1.003</p></td><td char="." align="char"><p>3.008</p></td><td char="." align="char"><p>2.18</p></td><td char="." align="char"><p>0.26</p></td><td char="." align="char"><p>1.39</p></td><td char="." align="char"><p>2.90</p></td><td char="." align="char"><p>98.72</p></td><td char="." align="char"><p>101.04</p></td><td char="." align="char"><p>103.68</p></td></tr><tr><td align="left"><p>Mangiferin</p></td><td char="." align="char"><p>19.06–610.00</p></td><td align="left"><p> A = 5.565c + 8.342</p></td><td char="." align="char"><p>0.9999</p></td><td char="." align="char"><p>0.336</p></td><td char="." align="char"><p>1.007</p></td><td char="." align="char"><p>1.42</p></td><td char="." align="char"><p>0.31</p></td><td char="." align="char"><p>0.42</p></td><td char="." align="char"><p>2.30</p></td><td char="." align="char"><p>99.35</p></td><td char="." align="char"><p>99.22</p></td><td char="." align="char"><p>99.56</p></td></tr><tr><td align="left"><p>Jatrorrhizine</p></td><td char="." align="char"><p>5.53–177.00</p></td><td align="left"><p> A = 7.149c + 4.834</p></td><td char="." align="char"><p>0.9999</p></td><td char="." align="char"><p>0.060</p></td><td char="." align="char"><p>0.181</p></td><td char="." align="char"><p>1.82</p></td><td char="." align="char"><p>0.35</p></td><td char="." align="char"><p>0.51</p></td><td char="." align="char"><p>2.26</p></td><td char="." align="char"><p>98.55</p></td><td char="." align="char"><p>98.22</p></td><td char="." align="char"><p>101.02</p></td></tr><tr><td align="left"><p>Berberine</p></td><td char="." align="char"><p>63.44–2030.0</p></td><td align="left"><p> A = 5.149c + 27.232</p></td><td char="." align="char"><p>0.9999</p></td><td char="." align="char"><p>0.084</p></td><td char="." align="char"><p>0.251</p></td><td char="." align="char"><p>1.41</p></td><td char="." align="char"><p>0.33</p></td><td char="." align="char"><p>0.53</p></td><td char="." align="char"><p>2.31</p></td><td char="." align="char"><p>96.76</p></td><td char="." align="char"><p>99.45</p></td><td char="." align="char"><p>99.83</p></td></tr><tr><td align="left"><p>Obacunone</p></td><td char="." align="char"><p>6.25–200.00</p></td><td align="left"><p> A = 2.991c + 1.778</p></td><td char="." align="char"><p>0.9999</p></td><td char="." align="char"><p>0.019</p></td><td char="." align="char"><p>0.057</p></td><td char="." align="char"><p>1.42</p></td><td char="." align="char"><p>1.58</p></td><td char="." align="char"><p>2.45</p></td><td char="." align="char"><p>1.75</p></td><td char="." align="char"><p>102.41</p></td><td char="." align="char"><p>103.18</p></td><td char="." align="char"><p>102.90</p></td></tr><tr><td align="left"><p>Timosaponin BII</p></td><td char="." align="char"><p>64.06–2050.00</p></td><td align="left"><p> A = 1.3893c – 0.609</p></td><td char="." align="char"><p>0.9999</p></td><td char="." align="char"><p>2.067</p></td><td char="." align="char"><p>6.204</p></td><td char="." align="char"><p>1.41</p></td><td char="." align="char"><p>0.30</p></td><td char="." align="char"><p>0.63</p></td><td char="." align="char"><p>2.61</p></td><td char="." align="char"><p>99.82</p></td><td char="." align="char"><p>97.79</p></td><td char="." align="char"><p>101.88</p></td></tr></tbody></table> </ephtml> </p> <hd id="AN0183578297-29">Determination of polysaccharide and main active compounds in N-ZBD</hd> <p>As shown in Table 2, there was a significant difference in the content of active components among the four phases. The percentages of neomangiferin, chlorogenic acid, phellodendrine, mangiferin, jatrorrhizine, berberine, obacunone and timosaponin BII in N-ZBD were 85.67, 75.32, 73.46, 84.49, 84.59, 83.70, 88.63 and 86.65%, respectively, of the total contents in ZBD. These results indicate that the active compounds in ZBD are mainly distributed in N-ZBD. In every 50 mL of ZBD, the weight of N-ZBD obtained by separation is 0.604 g. The polysaccharide content of N-ZBD was determined by phenol-concentrated sulfuric acid method. The data indicated a good relationship between concentrations and absorbance of the glucose within the test ranges (R<sups>2</sups> ≥ 0.995) (Fig. S2). The results showed that N-ZBD contained 16.77% polysaccharides, while N-ZBD contained 22.63% small molecule compounds (Fig. 5). This indicates that N-ZBD contains a lot of polysaccharides and small molecules. Other components may include tannins, trace elements, plant pigments and proteins, etc. Studies have shown that these components have little effect on the efficacy of ZBD. Therefore, they were not quantified in this study.</p> <p>Table 2 Determination of the chemical composition of ZBD, N-ZBD, S-ZBD and T-ZBD.</p> <p> <ephtml> <table frame="hsides" rules="groups"><thead><tr><th align="left"><p>Compounds</p></th><th align="left"><p>ZBD(µg mL<sup>− 1</sup>)</p></th><th align="left"><p>Percentage content of <italic>N</italic>-ZBD(%)</p></th><th align="left"><p>Percentage content of S-ZBD(%)</p></th><th align="left"><p>Percentage content of T-ZBD(%)</p></th></tr></thead><tbody><tr><td align="left"><p>Neomangiferin</p></td><td align="left"><p>443.36</p></td><td align="left"><p>85.67</p></td><td align="left"><p>1.42</p></td><td align="left"><p>12.91</p></td></tr><tr><td align="left"><p>Chlorogenic acid</p></td><td align="left"><p>198.98</p></td><td align="left"><p>75.32</p></td><td align="left"><p>1.49</p></td><td align="left"><p>23.19</p></td></tr><tr><td align="left"><p>Phellodendrine</p></td><td align="left"><p>239.52</p></td><td align="left"><p>73.46</p></td><td align="left"><p>1.31</p></td><td align="left"><p>25.23</p></td></tr><tr><td align="left"><p>Mangiferin</p></td><td align="left"><p>339.92</p></td><td align="left"><p>84.49</p></td><td align="left"><p>2.11</p></td><td align="left"><p>13.40</p></td></tr><tr><td align="left"><p>Jatrorrhizine</p></td><td align="left"><p>8.92</p></td><td align="left"><p>84.59</p></td><td align="left"><p>2.54</p></td><td align="left"><p>12.87</p></td></tr><tr><td align="left"><p>Berberine</p></td><td align="left"><p>1691.53</p></td><td align="left"><p>83.70</p></td><td align="left"><p>1.89</p></td><td align="left"><p>14.41</p></td></tr><tr><td align="left"><p>Obacunone</p></td><td align="left"><p>7.88</p></td><td align="left"><p>88.63</p></td><td align="left"><p>9.69</p></td><td align="left"><p>1.68</p></td></tr><tr><td align="left"><p>Timosaponin BII</p></td><td align="left"><p>2084.5</p></td><td align="left"><p>86.65</p></td><td align="left"><p>1.28</p></td><td align="left"><p>12.07</p></td></tr></tbody></table> </ephtml> </p> <p>Graph: Fig. 5 The proportion of each compound in N-ZBD.</p> <hd id="AN0183578297-30">Effect of polysaccharides on the storage stability and gastrointestinal stability of N-ZBD</hd> <p>The gastrointestinal tract is accompanied by a highly acidic environment (pH = 1.2-2.0) and digestive enzymes, which often cause significant denaturation and degradation of the nanoparticles, reducing their biological activity. In order to investigate whether N-ZBD can remain stable in the water and gastrointestinal tract, and the effect of polysaccharides on N-ZBD stability. We compared the storage stability and gastrointestinal stability of N-ZBD and RPN-ZBD. In the storage stability study, N-ZBD had good stability under storage conditions for 12 h, while the storage stability of RPN-ZBD was significantly inferior to that of N-ZBD (Fig. 6A). In the gastrointestinal stability study, N-ZBD was able to stabilize in SGF and SIF for 12 h (Fig. 6B,C), which indicated that N-ZBD was able to tolerate the decomposition of strong acids and proteases after oral administration. In contrast, after removing polysaccharides from N-ZBD, the storage stability and gastrointestinal stability of RPN-ZBD was significantly inferior to that of N-ZBD (Fig. 6B,C), especially in SGF, where the particle size of RPN-ZBD exceeded 1000 nm at 8 h (Fig. 6B). This suggests that polysaccharides are the key compounds in maintaining the stability of particle size of N-ZBD in the gastrointestinal tract.</p> <hd id="AN0183578297-31">Effect of polysaccharides on the drug release of N-ZBD</hd> <p>Drug release behavior affects drug absorption, metabolism and excretion. In order to investigate the in vitro release differences among decoctions, nanoparticles in decoctions and free drugs, and to investigate the role of polysaccharides in drug release, we compared the cumulative release behavior of ZBD, RPN-ZBD, N-ZBD, and free drugs in SGF and SIF as the release media. The release curves are shown in Fig. 6D and E and the release media are shown in Tables S2 and S3. Compared with the free drugs group, the eight compounds in the N-ZBD group showed a significantly slower release behavior in SGF and SIF, e.g., in SGF, berberine in the free drugs group released 89.58% at 6 h, while berberine in the N-ZBD group released only 74.77% at 6 h. In SIF, 88.80% of berberine was released at 6 h in the free drugs group, while only 72.84% of berberine was released at 6 h in the N-ZBD group. This suggests that there may be interaction forces between the compounds of the N-ZBD and that these interaction forces prevent the release of drugs from the dialysis bag. The release rate of all eight compounds in RPN-ZBD was faster than that of the N-ZBD group, e.g., in SGF, berberine in the RPN-ZBD group was released 87.22% at 6 h, which is close to 89.58% in the free drugs group, while berberine in the N-ZBD group was only released at 74.77% in 6 h. This may be due to the fact that after removing the polysaccharide from the N-ZBD, the nanoparticles were disrupted by the medium, which led to a faster drug release. This also indirectly demonstrates the ability of polysaccharides to stabilize nanoparticles in the gastrointestinal tract. The release behavior of the eight compounds in the ZBD was similar in SGF and SIF compared to the N-ZBD group, which may be related to the fact that most of the eight compounds were distributed in the N-ZBD. The other compounds had similar release trends to berberine between the ZBD, RPN-ZBD, N-ZBD and free drugs groups. The slow-release behavior of N-ZBD in SGF and SIF may be due to the electrostatic interaction between molecules slowed the release of the drug, and polysaccharide can protect the stability of nanoparticles in the gastrointestinal environment. Compared with free drugs, sustained-release formulations can reduce the frequency of administration and improve the oral bioavailability of drugs. The slow-release preparation can keep the blood concentration stable, reduce the frequency of administration and improve the oral bioavailability of drug and has greater advantages than the ordinary preparation in prolonging the action time and reducing the toxic and side effects. A series of studies have shown that the bioavailability of purified form of compounds is less than that of decoctions [<reflink idref="bib3" id="ref41">3</reflink>], and the slow-release effect of nanoparticles in the decoction may be the reason for this phenomenon.</p> <p>Graph: Fig. 6 (A) The stability of N-ZBD, RPN-ZBD, CN-ZBD in water. (B) The stability of N-ZBD, RPN-ZBD, CN-ZBD in SGF (pH = 1.2). (C) The stability of N-ZBD, RPN-ZBD, CN-ZBD in SIF (pH = 6.8). (D) The cumulative release curve of the eight compounds in SGF. (E) The cumulative release curve of the eight compounds in SIF. (<reflink idref="bib1" id="ref42">1</reflink>) neomangiferin; (<reflink idref="bib2" id="ref43">2</reflink>) chlorogenic acid; (<reflink idref="bib3" id="ref44">3</reflink>) phellodendrine; (<reflink idref="bib4" id="ref45">4</reflink>) mangiferin; (<reflink idref="bib5" id="ref46">5</reflink>) jatrorrhizine; (<reflink idref="bib6" id="ref47">6</reflink>) berberine; (<reflink idref="bib7" id="ref48">7</reflink>) obacunone; (<reflink idref="bib8" id="ref49">8</reflink>) timosaponin BII. **p < 0.01 which compared with N-ZND; ***p < 0.001 which compared with N-ZND; ****p < 0.0001 which compared with N-ZND.</p> <hd id="AN0183578297-32">The mechanism of N-ZBD formation</hd> <p>Chlorogenic acid, mangiferin, phellodendrine and berberine are the main active constituents of ZBD. It is noteworthy that the content of chlorogenic acid, mangiferin, phellodendrine and berberine was significantly higher in N-ZBD than in other phases. At the same time, N-ZBD contains 16.77% polysaccharides and its significantly affects the gastrointestinal stability and release of N-ZBD in vitro, indicating that polysaccharide might be involved in the formation of N-ZBD. Therefore, we hypothesized that self-assembly may occur between them.</p> <hd id="AN0183578297-33">Mechanism of formation of self-assembly between small molecules</hd> <p>Berberine was heated and stirred with chlorogenic acid and mangiferin forming CGA-BBR NPs (self-assembled nanoparticles of CGA and BBR) (Fig. 7A) and MGF-BBR NPs (self-assembled nanoparticles of MGF and BBR) (Fig. 7B), respectively. Mangiferin was heated and stirred with phellodendrine forming MGF-PDD NPs (self-assembled nanoparticles of MGF and PDD) (Fig. 7C). The particle sizes of CGA-BBR NPs, MGF-BBR NPs and MGF-PDD NPs are 353.30 ± 9.27, 342.40 ± 5.52 and 168.20 ± 7.56 nm, respectively. The zeta potential of CGA-BBR NPs, MGF-BBR NPs and MGF-PDD NPs are 3.67 ± 0.22 mV (Fig. 7D), -17.40 ± 0.61 mV (Fig. 7E) and − 19.3 ± 0.66 mV (Fig. 7F), respectively. FT-IR and HRMS analyses were used to explore the formation mechanism of nanoparticles in ZBD. In the CGA-BBR physical mixture, the peak of 3373.83 cm<sups>− 1</sups> was attributed to the phenolic hydroxyl group's stretching vibrations on chlorogenic acid's benzene rings. However, this peak shifted to 3424.88 cm<sups>− 1</sups> in CGA-BBR NPs. Likewise, the peak of 1231.77 cm<sups>− 1</sups> was attributed to the C-N stretching vibration in berberine, moved to a higher wavenumber (1234.14 cm<sups>− 1</sups>) in CGA-BBR NPs (Fig. 7G). These results indicated that the carboxyl group of CGA, the ammonium ion of BBR significantly changed after self-assembly, which may be due to the electrostatic interaction between the carboxyl group in CGA and the ammonium ion in BBR leding to changes in electron cloud density. In HRMS, a deprotonated chlorogenic acid/berberine complex with a binding ratio of 1:1 (<emph>m/z</emph> 689.2054) was observed in the ESI- mode, and its secondary fragment mass of <emph>m/z</emph> 353.0871 corresponded to chlorogenic acid (Fig. 7J). The results of HRMS clearly displayed the self-assembled unit of the CGA-BBR NPs. This may be due to the electrostatic interaction between the phenolic hydroxyl in chlorogenic acid and the ammonium ions in berberine. The peak at 3366.28 cm<sups>− 1</sups> in mangiferin was attributed to phenolic hydroxyl group's stretching vibrations, shifting to a higher wavenumber (3419.67 cm<sups>− 1</sups>) in MGF-PDD nanoparticles. Similarly, the peak at 1329.21 cm<sups>− 1</sups> was attributed to C-N stretching in berberine. However, this peak shifted to 1340.28 cm<sups>− 1</sups> in MGF-PDD nanoparticles (Fig. 7H). These results indicated that the phenolic hydroxyl group of MGF, the ammonium ion of BBR significantly changed after self-assembly, which may be due to the electrostatic interaction between the phenolic hydroxyl group in MGF and the ammonium ion in BBR leding to changes in electron cloud density. In HRMS, a deprotonated mangiferin/berberine complex with a binding ratio of 1:1 (<emph>m/z</emph> 756.1922) was observed in the ESI- mode, and its secondary fragments of <emph>m/z</emph> 421.0767 correspond to mangiferin, respectively (Fig. 7K). The results of HRMS clearly displayed the self-assembled unit of the MGF-BBR NPs. This may be due to the electrostatic interaction between the phenolic hydroxyl in mangiferin and the ammonium ions in berberine. The results observed in the self-assembly of mangiferin and phellodendrine are also consistent (Fig. 7C,F,I,L). FT-IR and HRMS directly confirmed the self-assembly between the three groups of molecules.</p> <p>Graph: Fig. 7 (A) Particle size of CGA-BBR NPs. (B) Particle size of MGF-BBR NPs. (C) Particle size of MGF-PDD NPs. (D) The zeta potential of CGA-BBR NPs. (E) The zeta potential of of MGF-BBR NPs. (F) The zeta potential of of MGF-PDD NPs. (G) FT-IR of CGA-BBR NPs, their monomers and their mixtures. (H) FT-IR of MGF-BBR NPs, their monomers and their mixtures. (I) FT-IR of MGF-PDD NPs, their monomers and their mixtures. (J) ESI-HRMS spectrum of CGA-BBR NPs. (K) ESI-HRMS spectrum of MGF-BBR NPs. (L) ESI-HRMS spectrum of MGF-PDD NPs.</p> <hd id="AN0183578297-34">The mechanism of formation of self-assembly between small molecules and polysaccharides</hd> <p>By heating and stirring the polysaccharide, we found that polysaccharides able to form nanoparticles by itself with a particle size of 252.07 ± 5.27 nm, a PDI of 1 (Fig. 8E) and a potential of -2.66 ± 0.61 mV (Fig. 8H). The TEM result show that the morphology was irregular spheroidal (Fig. 8B). CMC is one of the important parameters to measure whether amphiphilic polymers can form nanoparticle, so it is necessary to determine the CMC value of TPS in this study. The result show that CMC of TPS was 0.63 mg/mL (Fig. 8K), indicating that TPS is able to self-assemble to form nanoparticles.</p> <p>The particle size and potential of MGF-BBR NPs were 342.40 ± 5.52 nm (Fig. 8D) and − 17.40 ± 0.61 mV (Fig. 8G), respectively. By co-decocting the MGF-BBR NPs with TPS, we found that it could form new nanoparticles (MGF-BBR-TPS NPs) with a particle size of 254.17 ± 15.53 nm, a PDI of 1 (Fig. 8F) and a potential of -19.3 ± 0.66 mV (Fig. 8I). The TEM result shows that the morphology of MGF-BBR NPs was black spherical nanoparticles (Fig. 8A), however, after MGF-BBR NPs co-frying with polysaccharides, the MGF-BBR-TPS NPs had a bilayer membrane structure (Fig. 8C), which indicated that polysaccharides were able to wrap onto the small-molecule self-assembled nanoparticles to form new nanoparticles. Combined with the TEM results of N-ZBD (Fig. 4A) and RPN-ZBD (Fig. 4B), it is further proof that polysaccharides are successfully coated on the outer layer of small-molecule self-assembled nanoparticles. The FT-IR results (Fig. 8J) showed that the telescopic vibrational absorption peak of hydroxyl of TPS at 3388.79 cm<sups>− 1</sups>, the vibrational absorption peak of methylated carboxyl group in galacturonic acid of TPS at 1730.36 cm<sups>− 1</sups>, and the vibrational absorption peak of the free carboxyl group in galacturonic acid of TPS at 1608.68 cm<sups>− 1</sups>, whereas in the MGF-BBR-TPS NPs, the peak at 3388.79 cm<sups>− 1</sups> was shifted to 3419.94 cm<sups>− 1</sups>; the absorption peak at 1730.36 cm<sups>− 1</sups> was shifted to 1728.64 cm<sups>− 1</sups>; and the absorption peak at 1608.68 cm<sups>− 1</sups> was shifted to 1614.12 cm<sups>− 1</sups>. These results indicated that the hydroxyl band, the methylated carboxyl group band in galacturonic acid, and the methylated free carboxyl group band in galacturonic acid of TPS significantly changed after assembly, which suggest that self-assembly occurs between polysaccharides and MGF-BBR NPs. The above results show that the formation of N-ZBD may be due to the self-assembly of small molecules and the self-assembly of small molecules and polysaccharides together.</p> <p>Graph: Fig. 8 (A) TEM images of MGF-BBR NPs (dark field image). (B) TEM images of TPS NPs (bright field image). (C) TEM images of MGF-BBR-TPS NPs (bright field image). (D) Particle size distribution of MGF-BBR NPs. (E) Particle size distribution of TPS NPs. (F) Particle size distribution of MGF-BBR-TPS NPs. (G) The zeta potential of MGF-BBR NPs. (H) The zeta potential of TPS NPs. (I) The zeta potential of MGF-BBR-TPS NPs. (J) FT-IR of MGF-BBR NPs, TPS and MGF-BBR-TPS NPs. (K) CMC values of TPS.</p> <hd id="AN0183578297-35">Discussion</hd> <p>It is generally accepted that dialysis bags are permeable to low-molecular-weight compounds. Therefore, the dialysis bag with a molecular weight cutoff of 3500 D was sufficient to permeate the free drugs, but interestingly, it is unusual to detect neomangiferin, chlorogenic acid, phellodendrine, mangiferin, jatrorrhizine, berberine, obacunone and timosaponin BII in the dialysis bags. All are small molecules with the molecular masses of 584.5, 342.4, 342.0, 422.3, 338.4, 336.4, 454.5 and 921.1 D, respectively, suggesting that these compounds may be attached or embedded in the nanoparticles and involved in the formation of nanoparticles. Interestingly, the solubility of mangiferin in water is only 110 µg/mL[<reflink idref="bib33" id="ref50">33</reflink>], but the content of mangiferin in the ZBD is 333.92 µg/mL, which is a three-fold increase in the solubility; berberine has a solubility of 1200 to 1400 µg/mL in water[<reflink idref="bib34" id="ref51">34</reflink>], and the content of berberine in the ZBD is 1691.53 µg/mL, the solubility increased significantly. This may be due to the formation of nanoparticles in the ZBD which acted as solubilizers for mangiferin and berberine.</p> <p>During the decoction process, complex interactions often occur[<reflink idref="bib35" id="ref52">35</reflink>],[<reflink idref="bib36" id="ref53">36</reflink>]. Most importantly, they can form nanoparticles[<reflink idref="bib7" id="ref54">7</reflink>]. Self-assembled nanoparticles discovered in natural plants may be used as carriers for other drugs, which opens up another avenue for the research of medicinal plants and provides a new perspective. However, the current understanding of the formation mechanism of nanoparticles in decoctions is not yet mature. We have discovered for the first time the existence of self-assembled nanoparticles in N-ZBD and explored the self-assembly of high-content compounds in N-ZBD. Interestingly, we found that mangiferin and berberine can form nanoparticles (MGF-BBR NPs), chlorogenic acid and berberine can form nanoparticles (CGA-BBR NPs), and mangiferin and phellodendrine can also form nanoparticles (MGF-PDD NPs). Fourier transform infrared spectroscopy (FT-IR) and mass spectrometry analysis (HRMS) revealed that they self-assemble through electrostatic complexation. In addition, N-ZBD contains a large amount of polysaccharides. In a study on the solubilizing effect of vinegar-roasted chai hu polysaccharides on insoluble drugs in traditional Chinese medicine, the polysaccharides self-assembled into micelles that encapsulated water-insoluble compounds through the interplay of hydrogen bonding and hydrophobic forces, which improved the bioavailability of baicalein and safranin[<reflink idref="bib37" id="ref55">37</reflink>]. Studies have also found that starch can form self-assembled nanosystems with lipophilic drugs[<reflink idref="bib38" id="ref56">38</reflink>]; and the size of starch granules could be reduced to nanometer size by ball milling method[<reflink idref="bib39" id="ref57">39</reflink>]. Therefore, we hypothesised that polysaccharides may play an important role in the formation of nanoparticles and explored the mechanism of nanoparticle formation by polysaccharides. Our results showed that the formation of N-ZBD was formed by the encapsulation of small molecular components by polysaccharides. In this study, we have discovered for the first time that polysaccharides can form a self-assembled nano-system with small molecule components in decoctions, indicating that polysaccharides may act as drug carriers in prescriptions and encapsulate most active compounds to form nanoparticles during the boiling process. This study not only provides ideas for revealing the formation mechanism of nanoparticles in TCM decoctions but also provides a reference for discovering new nanocarriers from TCM decoctions.</p> <p>In modern pharmaceuticals, carrier materials like liposomes are unstable in gastrointestinal tract, resulting in premature drug release and low biological efficacy[<reflink idref="bib40" id="ref58">40</reflink>]. To enhance the release profile and biological effectiveness of liposomes, complex modifications are needed, which restricts their application in oral administration[<reflink idref="bib15" id="ref59">15</reflink>]. Hence, the stability of nanoparticles in decoctions within the gastrointestinal tract is a prerequisite for their role in promoting drug absorption. In this study, we found that N-ZBD can maintain stability in the gastrointestinal tract and has the effect of promoting the sustained release of active components. However, RPN-ZBD after removing polysaccharides is destroyed in the gastrointestinal tract and has no sustained release effect. In general, smaller nanoparticles (less than 500 nm) with neutral or negative surfaces can help the permeation of the mucous surface in the stomach and intestines, which is important for intestinal absorption. Therefore, negatively charged N-ZBD has good intestinal permeation properties. Research has indicated that caveolae play a role in the endocytosis of nanoparticles and that this process bypasses lysosomal degradation[<reflink idref="bib41" id="ref60">41</reflink>], suggesting that nanoparticles can enter the body's circulation after being absorbed by intestinal epithelial cells. Therefore, polysaccharides that enable nanoparticles in decoctions to remain stable in the gastrointestinal tract are promising natural nanocarriers for orally administered drugs.</p> <p>Nanoparticles in decoctions have received increasing attention in recent years. However, current research has mainly focused on the isolation of nanoparticles and their biological activities[<reflink idref="bib6" id="ref61">6</reflink>],[<reflink idref="bib7" id="ref62">7</reflink>],[<reflink idref="bib42" id="ref63">42</reflink>]. In this study, we found that N-ZBD contains a large amount of active components and polysaccharides, and discovered for the first time that polysaccharides are the key component for making nanoparticles in decoctions stable in the gastrointestinal tract. The formation mechanism of N-ZBD was further explored. However, the complex chemical composition of decoctions leads to the interaction forces between components that may not only include electrostatic interaction. Hydrogen bonds and van der Waals forces may also play a role in the formation of nanoparticles. The mechanism of self-assembly among multiple components is very complex, and whether there are other forces between components and whether changes in pH value or ionic strength will affect the formation of nanoparticles is a research direction worthy of exploration. Considering the widespread presence of nanoparticles in traditional Chinese medicine decoctions, we believe that this study will promote more research on nanoparticles in decoctions to gain a more comprehensive understanding of their medicinal value.</p> <hd id="AN0183578297-36">Conclusions</hd> <p>In this study, the phases of ZBD were separated by dialysis combined with centrifugation, and three phases, S-ZBD, T-ZBD and N-ZBD, were obtained. An UPLC-DAD and HPLC-ELSD method was established for the determination of the content of 8 compounds in ZBD, and most of the main active compounds in ZBD could be found in N-ZBD. The morphology and particle size distribution of N-ZBD and RPN-ZBD were characterized by using TEM and Malvern particle size apparatus. N-ZBD can remain stable in the gastrointestinal environment, whereas removal of polysaccharides from N-ZBD resulted in inferior stability. The results of in vitro release of N-ZBD in SGF and SIF showed that N-ZBD had a significant sustained release effect compared with free drugs, while the release behavior of N-ZBD after polysaccharide removal was similar to that of free drugs. The mechanism of N-ZBD formation is a combination of self-assembly between small molecule compounds and self-assembly between small molecules and polysaccharides. The slow-release behavior of N-ZBD in SGF and SIF may due to the electrostatic interaction between molecules, and polysaccharide can protect the stability of nanoparticles in the gastrointestinal environment. In conclusion, our methodology and findings may inspire further studies on the interaction of active phytochemicals with nanoparticles in TCM decoctions.</p> <hd id="AN0183578297-37">Acknowledgements</hd> <p>This study was supported by Programs of the National Natural Science Foundation of China [grant number 82274066, 82374002 and 82204777]; National Key Research and Development Program of China [grant number 2022YFC3501705], Youth Talent Program from the Shanghai Municipal Health Commission [grant number 2022YQ030]; Natural Science Foundation of Shanghai [grant number 22ZR1459000]; China Postdoctoral Science Foundation [grant number 2022M712155].</p> <hd id="AN0183578297-38">Author contributions</hd> <p>Wen-long Nie: Investigation, Writing - Original Draft, Methodology. Xin-yu Zhang: Investigation, Writing - Original Draft, Methodology. Ping Kang: Writing - Original Draft. Jin-shuai Lan: Investigation, Writing - Original Draft. Zhe Li: Investigation. Dong-hao Gu: Investigation. Rui Zhou: Investigation. Yue Ding: Project administration, Funding acquisition. Tong Zhang: Writing - Review & Editing, Project administration.</p> <hd id="AN0183578297-39">Data availability</hd> <p>The data supporting the findings of this study are available from the corresponding author upon reasonable request.</p> <hd id="AN0183578297-40">Declarations</hd> <p></p> <hd id="AN0183578297-41">Competing interests</hd> <p>The authors declare no competing interests.</p> <hd id="AN0183578297-42">Electronic supplementary material</hd> <p>Below is the link to the electronic supplementary material.</p> <p>Graph: Supplementary Material 1</p> <hd id="AN0183578297-43">Publisher's note</hd> <p>Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.</p> <ref id="AN0183578297-44"> <title> References </title> <blist> <bibl id="bib1" idref="ref1" type="bt">1</bibl> <bibtext> Fan Y. Purification of flavonoids from licorice using an off-line preparative two-dimensional normal-phase liquid chromatography/reversed-phase liquid chromatography method. J. Sep. Sci. 2016; 39: 2710-2719. 1:CAS:528:DC%2BC28XhtVSjt73M. 10.1002/jssc.201501393. 27214649. 1181.68260</bibtext> </blist> <blist> <bibl id="bib2" idref="ref2" type="bt">2</bibl> <bibtext> Xu H. Glycyrrhizic acid alters the hyperoxidative stress-induced differentiation commitment of MSCs by activating the Wnt/β-catenin pathway to prevent SONFH. Food Funct. 2023; 14: 946-960. 1:CAS:528:DC%2BB38XjtFGqsbzP. 10.1039/d2fo02337g. 36541285. 1313.28017</bibtext> </blist> <blist> <bibl id="bib3" idref="ref3" type="bt">3</bibl> <bibtext> Zhao J. Natural nano-drug delivery system in Coptidis Rhizoma extract with modified berberine hydrochloride pharmacokinetics. Int. J. Nanomed. 2021; 16: 6297-6311. 10.2147/ijn.S323685. 1499.26176</bibtext> </blist> <blist> <bibl id="bib4" idref="ref4" type="bt">4</bibl> <bibtext> Liu Y. Application of a liquid chromatography/tandem mass spectrometry method to pharmacokinetic study of mangiferin in rats. J. Chromatogr. B Analyt Technol. Biomed. Life Sci. 2010; 878: 3345-3350. 1:CAS:528:DC%2BC3cXhsFarsLfO. 10.1016/j.jchromb.2010.10.014. 21081292. 1190.34049</bibtext> </blist> <blist> <bibl id="bib5" idref="ref5" type="bt">5</bibl> <bibtext> Wang CH. Pharmacokinetics and bioavailability of gentiopicroside from decoctions of Gentianae and Longdan Xiegan Tang after oral administration in rats–comparison with gentiopicroside alone. J. Pharm. Biomed. Anal. 2007; 44: 1113-1117. 1:CAS:528:DC%2BD2sXpt1Kmu7w%3D. 10.1016/j.jpba.2007.04.036. 17560062. 1150.93426</bibtext> </blist> <blist> <bibl id="bib6" idref="ref7" type="bt">6</bibl> <bibtext> Zhou J. Chromatographic isolation of nanoparticles from Ma-Xing-Shi-Gan-Tang decoction and their characterization. J. Ethnopharmacol. 2014; 151: 1116-1123. 1:CAS:528:DC%2BC2cXhtlGqsL8%3D. 10.1016/j.jep.2013.12.029. 24384378. 1349.34284</bibtext> </blist> <blist> <bibl id="bib7" idref="ref8" type="bt">7</bibl> <bibtext> Zhang YL. Traditional chinese medicine formulae QY305 reducing cutaneous adverse reaction and diarrhea by its nanostructure. Adv. Sci. (Weinh). 2024; 11: e2306140. 1:CAS:528:DC%2BB3sXis1Smsr3M. 10.1002/advs.202306140. 38044276</bibtext> </blist> <blist> <bibl id="bib8" idref="ref9" type="bt">8</bibl> <bibtext> Gao, G. et al. Polysaccharide nanoparticles from Isatis Indigotica Fort. Root Decoction: Diversity, cytotoxicity, and antiviral activity. Nanomaterials (Basel). 12https://doi.org/10.3390/nano12010030 (2021).</bibtext> </blist> <blist> <bibl id="bib9" idref="ref10" type="bt">9</bibl> <bibtext> Lin, D. et al. Antidiabetic micro-/nanoaggregates from Ge-Gen-Qin-Lian-Tang decoction increase absorption of baicalin and cellular antioxidant activity in vitro. Biomed. Res. Int. 9217912 (2017). https://doi.org/10.1155/2017/9217912 (2017).</bibtext> </blist> <blist> <bibtext> Ping Y. A study of nanometre aggregates formation mechanism and antipyretic effect in Bai-Hu-Tang, an ancient Chinese herbal decoction. Biomed. Pharmacother. 2020; 124: 109826. 1:CAS:528:DC%2BB3cXhsVSntr4%3D. 10.1016/j.biopha.2020.109826. 31978766. 1490.37112</bibtext> </blist> <blist> <bibtext> Nie W. Self-assembled nanoparticles from Xie-Bai-San Decoction: Isolation, characterization and enhancing oral bioavailability. Int. J. Nanomed. 2024; 19: 3405-3421. 10.2147/IJN.S449268. 07875076</bibtext> </blist> <blist> <bibtext> Yang B. A multi-component nano-co-delivery system utilizing astragalus polysaccharides as carriers for improving biopharmaceutical properties of astragalus flavonoids. Int. J. Nanomed. 2023; 18: 6705-6724. 1:CAS:528:DC%2BB3sXisVejsrfK. 10.2147/ijn.S434196. 1524.90058</bibtext> </blist> <blist> <bibtext> Zhu S. Creating burdock polysaccharide-oleanolic acid-ursolic acid nanoparticles to deliver enhanced anti-inflammatory effects: Fabrication, structural characterization and property evaluation. Food Sci. Hum. Wellness. 2023; 12: 454-466. 1:CAS:528:DC%2BB38XisFKnsbfN. 10.1016/j.fshw.2022.07.047</bibtext> </blist> <blist> <bibtext> Zheng W, Yang S, Chen X. The pharmacological and pharmacokinetic properties of obacunone from citrus fruits: A comprehensive narrative review. Fitoterapia. 2023; 169: 105569. 1:CAS:528:DC%2BB3sXht12hsL%2FP. 10.1016/j.fitote.2023.105569. 37315716. 1520.93391</bibtext> </blist> <blist> <bibtext> Moss DM, Curley P, Kinvig H, Hoskins C, Owen A. The biological challenges and pharmacological opportunities of orally administered nanomedicine delivery. Expert Rev. Gastroenterol. Hepatol. 2018; 12: 223-236. 1:CAS:528:DC%2BC2sXhslyru7vK. 10.1080/17474124.2018.1399794. 29088978</bibtext> </blist> <blist> <bibtext> Cheng Z. Oral polysaccharide-coated liposome-modified double-layered nanoparticles containing anthocyanins: Preparation, characterization, biocompatibility and evaluation of lipid-lowering activity in vitro. Food Chem. 2024; 439: 138166. 1:CAS:528:DC%2BB3sXis1SgtLfN. 10.1016/j.foodchem.2023.138166. 38091786</bibtext> </blist> <blist> <bibtext> Mokgehle TM, Madala N, Gitari WM, Tavengwa NT. Advances in the development of biopolymeric adsorbents for the extraction of metabolites from nutraceuticals with emphasis on Solanaceae and subsequent pharmacological applications. Carbohydr. Polym. 2021; 264: 118049. 1:CAS:528:DC%2BB3MXptVSqtLY%3D. 10.1016/j.carbpol.2021.118049. 33910751</bibtext> </blist> <blist> <bibtext> Zhang J. Reversal of muscle atrophy by Zhimu-Huangbai herb-pair via Akt/mTOR/FoxO3 signal pathway in streptozotocin-induced diabetic mice. PLoS One. 2014; 9: e100918. 2014PLoSO.9j0918Z. 1:CAS:528:DC%2BC2cXhs1elsrzK. 10.1371/journal.pone.0100918. 24968071. 4072704</bibtext> </blist> <blist> <bibtext> Li YJ, Bi KS. RP-HPLC determination and pharmacokinetic study of mangiferin in rat plasma after taking traditional Chinese medicinal-preparation: Zhimu decoction. Chromatographia. 2003; 57: 767-770. 1:CAS:528:DC%2BD3sXltlCisbY%3D. 10.1007/BF02491763</bibtext> </blist> <blist> <bibtext> Chan CO, Chu CC, Mok DK, Chau FT. Analysis of berberine and total alkaloid content in cortex phellodendri by near infrared spectroscopy (NIRS) compared with high-performance liquid chromatography coupled with ultra-visible spectrometric detection. Anal. Chim. Acta. 2007; 592: 121-131. 1:CAS:528:DC%2BD2sXlsFKrtbg%3D. 10.1016/j.aca.2007.04.016. 17512816</bibtext> </blist> <blist> <bibtext> Li CY, Lu HJ, Lin CH, Wu TS. A rapid and simple determination of protoberberine alkaloids in cortex phellodendri by 1H NMR and its application for quality control of commercial traditional Chinese medicine prescriptions. J. Pharm. Biomed. Anal. 2006; 40: 173-178. 1:CAS:528:DC%2BD28XksFCiug%3D%3D. 10.1016/j.jpba.2005.06.017. 16061339. 1422.37078</bibtext> </blist> <blist> <bibtext> Liu YW. Total saponins from Rhizoma Anemarrhenae ameliorate diabetes-associated cognitive decline in rats: Involvement of amyloid-beta decrease in brain. J. Ethnopharmacol. 2012; 139: 194-200. 1:CAS:528:DC%2BC3MXhs1Ght7rF. 10.1016/j.jep.2011.11.004. 22101084</bibtext> </blist> <blist> <bibtext> Xie YY. Metabolism and pharmacokinetics of major polyphenol components in rat plasma after oral administration of total flavonoid tablet from Anemarrhenae Rhizoma. J. Chromatogr. B Analyt Technol. Biomed. Life Sci. 2016; 1026: 134-144. 3546949. 1:CAS:528:DC%2BC28XhtVOgu7jJ. 10.1016/j.jchromb.2015.12.003. 26698235. 1342.34017</bibtext> </blist> <blist> <bibtext> Chen J. Structural characteristics and antioxidant and hypoglycemic activities of a heteropolysaccharide from Anemarrhena asphodeloides Bunge. Int. J. Biol. Macromol. 2023; 236: 123843. 1:CAS:528:DC%2BB3sXltlKlsrk%3D. 10.1016/j.ijbiomac.2023.123843. 36858093. 1448.46045</bibtext> </blist> <blist> <bibtext> Xiong W. Brij-functionalized chitosan nanocarrier system enhances the intestinal permeability of P-glycoprotein substrate-like drugs. Carbohydr. Polym. 2021; 266: 118112. 1:CAS:528:DC%2BB3MXhtVelt77N. 10.1016/j.carbpol.2021.118112. 34044929</bibtext> </blist> <blist> <bibtext> Wang M. The management of diabetes mellitus by mangiferin: Advances and prospects. Nanoscale. 2022; 14: 2119-2135. 1:CAS:528:DC%2BB38Xit1ert7k%3D. 10.1039/d1nr06690k. 35088781. 1175.93117</bibtext> </blist> <blist> <bibtext> Zhang FX, Yuan YL, Cui SS, Li M, Li RM. Characterization of metabolic fate of phellodendrine and its potential pharmacological mechanism against diabetes mellitus by ultra-high-performance liquid chromatography-coupled time-of-flight mass spectrometry and network pharmacology. Rapid Commun. Mass. Spectrom. 2021; 35: e9157. 1:CAS:528:DC%2BB3MXhsl2ls7nP. 10.1002/rcm.9157. 34182613</bibtext> </blist> <blist> <bibtext> Zhou, Y. et al. Jatrorrhizine improves endothelial function in diabetes and obesity through suppression of endoplasmic reticulum stress. Int. J. Mol. Sci.23https://doi.org/10.3390/ijms232012064 (2022).</bibtext> </blist> <blist> <bibtext> Li X. Rhizome of Anemarrhena asphodeloides counteracts diabetic ophthalmopathy progression in streptozotocin-induced diabetic rats. Phytother Res. 2013; 27: 1243-1250. 1:CAS:528:DC%2BC3sXhtFOlurfN. 10.1002/ptr.4866. 23148017. 1292.35167</bibtext> </blist> <blist> <bibtext> Shi K. Lipidomics analysis of timosaponin BII in INS-1 cells induced by glycolipid toxicity and its relationship with inflammation. Chem. Biodivers. 2020; 17: e1900684. 1:CAS:528:DC%2BB3cXmtFyrtLw%3D. 10.1002/cbdv.201900684. 32064755</bibtext> </blist> <blist> <bibtext> Huang, Q, Wang, J, Zong, R, Wu, D. & Jin, C. A water-soluble polysaccharide from the fibrous root of Anemarrhena asphodeloides Bge. And its immune enhancement effect in vivo and in vitro. Evid. Based Complement. Alternat Med.2022, 8723119. https://doi.org/10.1155/2022/8723119 (2022).</bibtext> </blist> <blist> <bibtext> Ye G. Structural characterization and antitumor activity of a polysaccharide from Dendrobium wardianum. Carbohydr. Polym. 2021; 269: 118253. 1:CAS:528:DC%2BB3MXht1Ghs7zM. 10.1016/j.carbpol.2021.118253. 34294290</bibtext> </blist> <blist> <bibtext> Lü S. Isolation and characterization of nanometre aggregates from a Bai-Hu-Tang decoction and their antipyretic effect. Sci. Rep. 2018; 8: 12209. 2018NatSR.812209L. 1:CAS:528:DC%2BC1MXkt1Kmug%3D%3D. 10.1038/s41598-018-30690-5. 30111786. 6093970. 1436.03318</bibtext> </blist> <blist> <bibtext> Lu Y. Progress in the formulation of berberine and its salts. Chin. J. Drug Evaluation. 2022; 39: 140-147. 2022rcod.book..L. 1297.11080</bibtext> </blist> <blist> <bibtext> Chen M. Comprehensive analysis of Huanglian Jiedu decoction: Revealing the presence of a self-assembled phytochemical complex in its naturally-occurring precipitate. J. Pharm. Biomed. Anal. 2021; 195: 113820. 1:CAS:528:DC%2BB3cXisFahsr7I. 10.1016/j.jpba.2020.113820. 33303266. 1506.65170</bibtext> </blist> <blist> <bibtext> Wang Z. Revealing the active ingredients of the traditional Chinese medicine decoction by the supramolecular strategies and multitechnologies. J. Ethnopharmacol. 2023; 300: 115704. 1:CAS:528:DC%2BB38XisFyrs7bM. 10.1016/j.jep.2022.115704. 36096345. 1536.92025</bibtext> </blist> <blist> <bibtext> Zhao Y. Polysaccharide from vinegar baked radix bupleuri as efficient solubilizer for water-insoluble drugs of Chinese medicine. Carbohydr. Polym. 2020; 229: 115473. 1:CAS:528:DC%2BC1MXitFansb%2FP. 10.1016/j.carbpol.2019.115473. 31826443. 1523.60147</bibtext> </blist> <blist> <bibtext> Zhang Z. Porous starch based self-assembled nano-delivery system improves the oral absorption of lipophilic drug. Int. J. Pharm. 2013; 444: 162-168. 1:CAS:528:DC%2BC3sXhvFegtrc%3D. 10.1016/j.ijpharm.2013.01.021. 23340325. 1263.35140</bibtext> </blist> <blist> <bibtext> Jhan F. Characterisation and utilisation of nano-reduced starch from underutilised cereals for delivery of folic acid through human GI tract. Sci. Rep. 2021; 11: 4873. 2021NatSR.11.4873J. 1:CAS:528:DC%2BB3MXlslSjsL8%3D. 10.1038/s41598-021-81623-8. 33649366. 7921593. 1484.47177</bibtext> </blist> <blist> <bibtext> Wu H, Nan J, Yang L, Park HJ, Li J. Insulin-loaded liposomes packaged in alginate hydrogels promote the oral bioavailability of insulin. J. Control. Release. 2023; 353: 51-62. 1:CAS:528:DC%2BB38XivFegsbvM. 10.1016/j.jconrel.2022.11.032. 36410613. 1291.30203</bibtext> </blist> <blist> <bibtext> Sahay G, Alakhova DY, Kabanov AV. Endocytosis of nanomedicines. J. Control. Release. 2010; 145: 182-195. 1:CAS:528:DC%2BC3cXosF2ntbY%3D. 10.1016/j.jconrel.2010.01.036. 20226220. 2902597. 1520.11080</bibtext> </blist> <blist> <bibtext> Ma BL. Naturally occurring proteinaceous nanoparticles in Coptidis Rhizoma extract act as concentration-dependent carriers that facilitate berberine absorption. Sci. Rep. 2016; 6: 20110. 2016NatSR.620110M. 1:CAS:528:DC%2BC28XhslOmt78%3D. 10.1038/srep20110. 26822920. 4731763</bibtext> </blist> </ref> <aug> <p>By Wenlong Nie; Xinyu Zhang; Ping Kang; Jinshuai Lan; Zhe Li; Donghao Gu; Rui Zhou; Yue Ding and Tong Zhang</p> <p>Reported by Author; Author; Author; Author; Author; Author; Author; Author; Author</p> </aug> <nolink nlid="nl1" bibid="bib10" firstref="ref11"></nolink> <nolink nlid="nl2" bibid="bib11" firstref="ref12"></nolink> <nolink nlid="nl3" bibid="bib12" firstref="ref13"></nolink> <nolink nlid="nl4" bibid="bib13" firstref="ref14"></nolink> <nolink nlid="nl5" bibid="bib14" firstref="ref15"></nolink> <nolink nlid="nl6" bibid="bib15" firstref="ref16"></nolink> <nolink nlid="nl7" bibid="bib16" firstref="ref17"></nolink> <nolink nlid="nl8" bibid="bib17" firstref="ref18"></nolink> <nolink nlid="nl9" bibid="bib18" firstref="ref19"></nolink> <nolink nlid="nl10" bibid="bib19" firstref="ref20"></nolink> <nolink nlid="nl11" bibid="bib20" firstref="ref21"></nolink> <nolink nlid="nl12" bibid="bib21" firstref="ref22"></nolink> <nolink nlid="nl13" bibid="bib22" firstref="ref23"></nolink> <nolink nlid="nl14" bibid="bib23" firstref="ref24"></nolink> <nolink nlid="nl15" bibid="bib24" firstref="ref25"></nolink> <nolink nlid="nl16" bibid="bib25" firstref="ref28"></nolink> <nolink nlid="nl17" bibid="bib26" firstref="ref29"></nolink> <nolink nlid="nl18" bibid="bib27" firstref="ref30"></nolink> <nolink nlid="nl19" bibid="bib28" firstref="ref31"></nolink> <nolink nlid="nl20" bibid="bib29" firstref="ref32"></nolink> <nolink nlid="nl21" bibid="bib30" firstref="ref33"></nolink> <nolink nlid="nl22" bibid="bib31" firstref="ref34"></nolink> <nolink nlid="nl23" bibid="bib32" firstref="ref37"></nolink> <nolink nlid="nl24" bibid="bib37" firstref="ref39"></nolink> <nolink nlid="nl25" bibid="bib38" firstref="ref40"></nolink> <nolink nlid="nl26" bibid="bib33" firstref="ref50"></nolink> <nolink nlid="nl27" bibid="bib34" firstref="ref51"></nolink> <nolink nlid="nl28" bibid="bib35" firstref="ref52"></nolink> <nolink nlid="nl29" bibid="bib36" firstref="ref53"></nolink> <nolink nlid="nl30" bibid="bib39" firstref="ref57"></nolink> <nolink nlid="nl31" bibid="bib40" firstref="ref58"></nolink> <nolink nlid="nl32" bibid="bib41" firstref="ref60"></nolink> <nolink nlid="nl33" bibid="bib42" firstref="ref63"></nolink>
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Items – Name: Title
  Label: Title
  Group: Ti
  Data: Numerical investigation of production performance of challenging gas hydrates from deposits with artificial fractures and impermeable barriers
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Shuaishuai+Nie%22">Shuaishuai Nie</searchLink><br /><searchLink fieldCode="AR" term="%22Ke+Liu%22">Ke Liu</searchLink><br /><searchLink fieldCode="AR" term="%22Xiuping+Zhong%22">Xiuping Zhong</searchLink><br /><searchLink fieldCode="AR" term="%22Yafei+Wang%22">Yafei Wang</searchLink><br /><searchLink fieldCode="AR" term="%22Yalu+Han%22">Yalu Han</searchLink><br /><searchLink fieldCode="AR" term="%22Kangtai+Xu%22">Kangtai Xu</searchLink><br /><searchLink fieldCode="AR" term="%22Jian+Song%22">Jian Song</searchLink><br /><searchLink fieldCode="AR" term="%22Jiangfei+Li%22">Jiangfei Li</searchLink>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: Scientific Reports, Vol 15, Iss 1, Pp 1-17 (2025)
– Name: Publisher
  Label: Publisher Information
  Group: PubInfo
  Data: Nature Portfolio, 2025.
– Name: DatePubCY
  Label: Publication Year
  Group: Date
  Data: 2025
– Name: Subset
  Label: Collection
  Group: HoldingsInfo
  Data: LCC:Medicine<br />LCC:Science
– Name: Subject
  Label: Subject Terms
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Gas+hydrate%22">Gas hydrate</searchLink><br /><searchLink fieldCode="DE" term="%22Reservoir+stimulation%22">Reservoir stimulation</searchLink><br /><searchLink fieldCode="DE" term="%22Artificial+fracture%22">Artificial fracture</searchLink><br /><searchLink fieldCode="DE" term="%22Impermeable+barrier%22">Impermeable barrier</searchLink><br /><searchLink fieldCode="DE" term="%22Water+control%22">Water control</searchLink><br /><searchLink fieldCode="DE" term="%22Medicine%22">Medicine</searchLink><br /><searchLink fieldCode="DE" term="%22Science%22">Science</searchLink>
– Name: Abstract
  Label: Description
  Group: Ab
  Data: Abstract In this research, a novel reservoir stimulation scheme combining impermeable artificial barriers and high-conductivity artificial fractures was introduced for gas hydrate extraction from clayey silt deposits, and the injection-production performance was numerically investigated using hydrates at the Shenhu SH2 site as the typical case scenario. The results indicated that impermeable barriers effectively addressed the challenges including boundary water intrusion, decomposition gas leakage, and injected hot fluid loss. Especially, artificial barriers and fractures exert a synergistic stimulation effect of “1 + 1 > 2”. The average gas production rate increased logarithmically as fracture conductivity increased, whereas the gas-to-water ratio and energy ratio, presented an opposite trend. The impact of injection pressure and production pressure on productivity was limited relative to hot water temperature, whereas low-temperature and low-pressure injection were more conducive to water control and energy utilization. Furthermore, parameter optimization based on multivariate nonlinear models suggested that commercial productivity and the Class II development standard for offshore gas reservoirs were expected to be achieved. Therefore, the combination of artificial fractures and impermeable boundaries is promising for clayey silt hydrate reservoir stimulation, offering a viable development mode for marine challenging hydrate.
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  Data: article
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  Data: electronic resource
– Name: Language
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  Data: English
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  Data: 2045-2322
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  Group: SrcInfo
  Data: https://doaj.org/toc/2045-2322
– Name: DOI
  Label: DOI
  Group: ID
  Data: 10.1038/s41598-025-87460-3
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  Label: Access URL
  Group: URL
  Data: <link linkTarget="URL" linkTerm="https://doaj.org/article/e42c424bb5fa465ea632fe149908effe" linkWindow="_blank">https://doaj.org/article/e42c424bb5fa465ea632fe149908effe</link>
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  Label: Accession Number
  Group: ID
  Data: edsdoj.42c424bb5fa465ea632fe149908effe
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RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1038/s41598-025-87460-3
    Languages:
      – Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 17
        StartPage: 1
    Subjects:
      – SubjectFull: Gas hydrate
        Type: general
      – SubjectFull: Reservoir stimulation
        Type: general
      – SubjectFull: Artificial fracture
        Type: general
      – SubjectFull: Impermeable barrier
        Type: general
      – SubjectFull: Water control
        Type: general
      – SubjectFull: Medicine
        Type: general
      – SubjectFull: Science
        Type: general
    Titles:
      – TitleFull: Numerical investigation of production performance of challenging gas hydrates from deposits with artificial fractures and impermeable barriers
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Shuaishuai Nie
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            NameFull: Ke Liu
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            NameFull: Xiuping Zhong
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            NameFull: Yafei Wang
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            NameFull: Yalu Han
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            NameFull: Kangtai Xu
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            NameFull: Jian Song
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            NameFull: Jiangfei Li
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          Dates:
            – D: 01
              M: 02
              Type: published
              Y: 2025
          Identifiers:
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              Value: 20452322
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              Value: 15
            – Type: issue
              Value: 1
          Titles:
            – TitleFull: Scientific Reports
              Type: main
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