1.Efficacy and safety of Babaodan Capsule in patients with chronic hepatitis B virus infection comorbid with gallbladder polyps
Qianqian NIU ; Huan CHEN ; Ying ZHENG ; Chunyan GOU ; Chen XU ; Li LI ; Xinxin WANG ; Jianping LIU ; Zhaolan LIU ; Xiuhui LI
Journal of Clinical Hepatology 2026;42(2):304-311
ObjectiveTo investigate the efficacy and safety of Babaodan Capsule (BBD) in the treatment of patients with chronic hepatitis B virus (HBV) infection with damp-heat in the liver and gallbladder comorbid with gallbladder polyps. MethodsA randomized, double-blinded, placebo-controlled single-center trial was conducted among 120 patients with chronic HBV infection who were admitted to Beijing YouAn Hospital, Capital Medical University, from August 2020 to April 2023, and they were divided into treatment group (BBD) and control group (placebo), with 60 patients in each group. The course of treatment was 24 weeks, and follow-up assessments were conducted every 4 weeks. The primary outcome measures were the number and maximum diameter of gallbladder polyps (assessed by ultrasound), and the secondary outcome measures included traditional Chinese medicine (TCM) syndrome score, blood lipid levels, and liver function parameters. The independent-samples t test or the Wilcoxon rank-sum test was used for comparison of continuous data between two groups, and the chi-square test or the Fisher’s exact test was used for comparison of categorical data between two groups; the Wilcoxon rank-sum test was used for comparison of ranked data between two groups; the generalized estimating equation was used to analyze repeated measures data. ResultsAfter 8 weeks of treatment, the treatment group had a significantly smaller diameter of polyps and a significantly lower number of polyps than the control group (Z=-1.76 and -1.80, both P<0.05), and after 24 weeks of treatment, the treatment group had a significantly higher polyp reduction rate than the control group (30.51% vs 10.91%, P<0.05). The subgroup analysis showed that patients receiving combined antiviral therapy, male patients, patients with a diameter of polyps of <5 mm, and patients with multiple polyps tended to achieve significantly greater benefits. At week 8 of treatment, the treatment group had a significantly better TCM syndrome score than the control group (Z=-2.35, P<0.05); after treatment, compared with the control group, the treatment group had a significantly greater increase in high-density lipoprotein (Z=-1.85, P<0.05) and significantly lower levels of alanine aminotransferase (Z=-2.06, P <0.05), aspartate aminotransferase (Z=-2.13, P<0.05), total bilirubin (Z=-2.12, P<0.05), and direct bilirubin (Z=-3.09, P<0.05). No serious adverse events were reported in either group. ConclusionBBD can effectively reduce the size of gallbladder polyps, improve TCM syndrome score, and reduce the level of bilirubin in patients with chronic HBV infection with damp-heat in the liver and gallbladder, with a favorable safety profile, and it may be more suitable for patients receiving combined antiviral therapy and specific subgroups (male patients, patients with a diameter of polyps of <5 mm, and patients with multiple polyps.
2.Quality evaluation of Heat-clearing and symptom-relieving formula based on multi-component quantification and screening of marker components
Jiahui CHEN ; Qiong LUO ; Lijun WEI ; Yuewu WANG ; Jun LI ; Chengdong LIU ; Jiajia HAO ; Liwen NIU
China Pharmacy 2026;37(6):740-745
OBJECTIVE To systematically evaluate the quality of the Heat-clearing and symptom-relieving formula and screen potential marker components that influence the quality of the formula. METHODS The contents of 11 components (calycosin-7- O - β -D-glucoside, ononin, hyperoside, isoquercitrin, baicalin, baicalein, cryptotanshinone, tanshinone Ⅱ A , tanshinone Ⅰ, senkyunolide A, ferulic acid) in the Heat-clearing and symptom-relieving formula were determined by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Using the contents of the aforementioned components as variables, cluster analysis (CA), principal component analysis (PCA), and orthogonal partial least squares-discriminant analysis (OPLS-DA) were conducted using OriginPro 2024 software and SIMCA 14.1 software; marker components affecting the quality of the Heat-clearing and symptom-relieving formula were then screened based on the criteria of variable importance in the projection (VIP) value>1 and P <0.05. The comprehensive evaluation of 20 batches of samples was carried out using the entropy weight-technique for order preference by similarity to ideal solution(TOPSIS) and grey correlation analysis (GCA) methods. RESULTS The contents of the above 11 components were 7.993-72.866, 4.542-31.228, 727.666-1 901.884, 496.846-1 293.279, 1 995.501-6 779.150, 54.500-241.280, 150.302-304.339, 79.698-189.206, 257.118-682.418, 5.498-21.687, 7.524-26.935 μg/g. CA, PCA and OPLS-DA results showed that 20 batches of samples were grouped into 2 categories. Q1, Q3, Q4, Q7-Q9, Q12, Q15, Q16 were grouped into one category, and the rest were grouped into another category; VIP values of ferulic acid, tanshinone Ⅱ A , baicalin, cryptotanshinone, calycosin-7- O - β -D-glucoside and ononin were all greater than 1 ( P <0.05). Both the entropy weight-TOPSIS and GCA methods showed that the samples ranked in the top 11 according to the euclidean distance and relative correlation degree were Q2, Q5, Q6, Q10, Q11, Q13, Q14, Q17-Q20. CONCLUSIONS The established HPLC-MS/MS method is rapid, accurate and highly sens itive. Combined with chemical pattern recognition analysis, entropy weight-TOPSIS and GCA methods, this method can be used to evaluate the quality of the Heat-clearing and symptom-relieving formula. Ferulic acid, tanshinone Ⅱ A , baicalin, cryptotanshinone, calycosin-7- O - β -D-glucoside and ononin may be the marker components that affect the quality of this formula. The overall quality of 11 batches of the Heat-clearing and symptom-relieving formula, including Q17, is relatively superior.
3.Prevalence and associated factors of work-related musculoskeletal disorders among workers in a manganese enterprise
Tianzi SHAN ; Junxiang MA ; Tian CHEN ; Kang NONG ; Yucheng SUN ; Xueting WANG ; Gaoman ZHANG ; Teng MA ; Zhuoran XIA ; Fengtao CUI ; Li CHEN ; Yanyan ZHENG ; Piye NIU
Journal of Environmental and Occupational Medicine 2026;43(3):333-340
Background Work-related musculoskeletal disorders (WMSDs) are a major occupational health concern, particularly among workers exposed to adverse ergonomic conditions. Manganese production involves heavy physical demands, yet research on WMSDs among manganese workers remains limited. Objective To investigate the prevalence and influencing factors of WMSDs among manganese workers in a manganese enterprise in Guangxi. Methods A cross-sectional survey was conducted from May to June 2024 on workers at a manganese factory in Guangxi. The Chinese Musculoskeletal Disorders Questionnaire was used to collect information on demographic characteristics, distribution of musculoskeletal symptoms, and work-related exposures. χ2 test was applied to compare differences in positive WMSDs rates across groups, and logistic regression analysis was performed to identify associated factors. Results A total of 1476 workers were enrolled in the study after pre-determined inclusion and exclusion criteria. The overall prevalence of WMSDs was 34.15%. The most commonly affected body regions were the lower back (17.28%), neck (16.67%), and shoulders (13.82%). The results of logistic regression analysis indicated that female, older age, and education level of college or above were associated with a higher risk of WMSDs (P<0.05). Awkward working postures were significantly associated with WMSDs in corresponding body regions; in particular, awkward postures of the neck, upper limbs, trunk, and lower limbs were related to an increased risk of WMSDs in multiple body sites (P<0.05). In addition, poor lighting conditions, high workplace temperature, frequent or sustained arm support during work, and high job demands were associated with an increased risk of overall or site-specific WMSDs (P<0.05). Conclusion The high prevalence of WMSDs among manganese workers is closely associated with demographic characteristics, working postures, and work environment and organizational factors. Targeted ergonomic interventions focusing on high-risk body regions and key ergonomic exposures are warranted to reduce the risk of WMSDs among manganese workers.
4.Peyton's Four-Step Teaching Method for Intestinal Ultrasound Training: Efficacy and Practical Implications
Zihan NIU ; Xiaoyan ZHANG ; Zhaojue WANG ; Qingli ZHU ; Mengsu XIAO ; Li MA ; Yudi HE ; Wenbo LI
Medical Journal of Peking Union Medical College Hospital 2026;17(2):591-596
To evaluate the application value of the Peyton four-step teaching method in the standardized training of intestinal ultrasound and compare it with traditional teaching methods, so as to provide an optimized approach for clinical ultrasound training. Participants from the Department of Ultrasound at Peking Union Medical College Hospital between September 2024 and March 2025 were randomly assigned to either the traditional group or Peyton group. The traditional group followed the conventional "lecture- demonstration-practice" model, while the Peyton group implemented the standardized "demonstration-deconstruction-comprehension-execution" four-step approach. All training focused on standard intestinal ultrasound scanning techniques. After the training, the operational skills were independently evaluated by the instructors. To verify the reproducibility of the teaching method, the participants in traditional teaching group received additional Peyton method training after the initial assessment and underwent a second evaluation. A total of 18 participants were included in this study, with 9 in the traditional teaching group and 9 in the Peyton teaching group. Participants in the Peyton group demonstrated significantly higher scores than those in the traditional group at every anatomical site assessed (all The Peyton four-step method is significantly more effective than traditional teaching in improving residents' intestinal ultrasound skills, demonstrating its suitability as the preferred approach for standardized training programs.
5.Influence of Antigen Type on the Establishment of an Induced Sjögren Syndrome Mouse Model
Wenshuang RONG ; Yuanfei NIU ; Meiting LIU ; Mengyuan YANG ; Shuang CUI ; Lina MA ; Yao FU ; Lianmei WANG ; Junling CAO
Laboratory Animal and Comparative Medicine 2026;46(2):178-190
ObjectiveThis study aims to compare the modeling effects of submaxillary gland antigen and salivary gland antigen in the establishment of Sjögren syndrome (SS) mouse models, and to characterize the phenotypic and immunological features of these models in comparison with spontaneous SS-prone non-obese diabetic (NOD)/LtJ mice. MethodsAdult C57BL/6J mice (equal numbers of males and females) were immunized with submaxillary gland antigen or salivary gland antigen, respectively, combined with Freund's adjuvant to induce SS models. Mice immunized with phosphate-buffered saline (PBS) combined with Freund's adjuvant served as the control group. Immunization was induced via multiple subcutaneous injections in the back with antigen combined with Freund's complete adjuvant (FCA) on Days 1 and 7. A booster immunization was administered via multiple subcutaneous injections in the back with antigen combined with Freund's incomplete adjuvant (FIA) on Day 14. Female NOD/LtJ mice were used as the spontaneous SS model group, with ICR mice as the corresponding control strain for comparative analysis. Body weight, water intake, and salivary flow rate of mice were dynamically monitored for 4 weeks. At the end of the experiment, tissue and serum samples were collected, the weights of submaxillary glands, thymus, and spleen were measured, and organ indices (organ-to-body weight ratios) were calculated. Pathological morphological analysis of the submaxillary gland and spleen was performed with hematoxylin and eosin (HE) staining. Serum interleukin-17 (IL-17) level was detected using enzyme-linked immunosorbent assay (ELISA). Real-time quantitative polymerase chain reaction was used to detect the mRNA expression levels of SS type A (SSA) and SS type B (SSB) in submaxillary gland tissues. ResultsFemale mice in the submaxillary gland antigen group exhibited significantly increased water intake (P<0.05) and reduced salivary flow rate (P<0.05) compared with the female control group. No statistically significant differences were observed in the submaxillary gland index, thymus index and spleen index (P>0.05). Focal lymphocytic infiltration was observed in the submaxillary glands, and the splenic marginal zone was enlarged. Serum IL-17 levels were significantly increased (P<0.05). There was no significant difference in submaxillary gland SSA/SSB expression levels (P>0.05). Compared with the female control group, female mice in the salivary gland antigen group showed no statistically significant differences in water intake, salivary flow rate, submaxillary gland index, and spleen index (P>0.05), whereas the thymus index was significantly reduced (P<0.01). Mild inflammatory cell infiltration and glandular atrophy were observed in the submaxillary glands, and the splenic white pulp and marginal zone were slightly enlarged. Serum IL-17 levels and submaxillary gland SSB mRNA expression levels were significantly increased (P<0.01), whereas no significant change was observed in submaxillary gland SSA expression levels (P>0.05). Compared with the male control group, mild submaxillary gland atrophy was observed in male mice in the submaxillary gland antigen group, whereas no obvious changes were found in other modeling-related indicators (P>0.05). Compared with the ICR control group, NOD/LtJ model mice exhibited elevated water intake (P<0.05), significantly reduced salivary flow rate (P<0.01), no significant differences in the submaxillary gland index or spleen index (P>0.05), but a significantly increased thymus index (P<0.05). Marked focal infiltration was observed in the submaxillary glands, the splenic marginal zone was obviously enlarged, and serum IL-17 concentrations as well as submaxillary gland SSA/SSB expression levels were significantly increased (P<0.05). ConclusionSubmaxillary gland antigen and salivary gland antigen can induce SS-related features in female C57BL/6J mice. The SS-related phenotype is more pronounced in the submaxillary gland antigen group than in the salivary gland antigen group, but weaker than that in spontaneously SS-prone female NOD/LtJ mice. Immunization of male C57BL/6J mice with submaxillary or salivary gland antigens fails to induce an obvious SS phenotype.
6.LU Fang's Clinical Experience in Differentiation and Treatment of Systemic Lupus Erythematosus from the Perspective of Heat-Toxin and Blood-Stasis in the Collaterals
Yingchao NIU ; Yongzhu PIAO ; Xiang GENG ; Zhihui GAO ; Yan ZHANG ; Huibin WU ; Zhilong WANG ; Shuangshuang GE ;
Journal of Traditional Chinese Medicine 2026;67(1):16-20
This paper summarizes Professor LU Fang's clinical experience in treating systemic lupus erythematosus (SLE) based on the differentiation and treatment of heat-toxin and blood-stasis in the collaterals. SLE is generally characterized by deficiency in origin with excess in manifestation. The core pathogenesis is heat-toxin obstructing the collaterals. During the acute active stage, the predominant pattern is blazing heat-toxin causing blood stasis, while in the chronic remitting stage, the main pattern is toxic stasis blocking the collaterals with qi and yin deficiency. Clinical treatment follows the basic principle that treat with salty-cold herbs, when heat invades internally and that assist with acrid-dispersing herbs when stasis obstructs the collaterals. The self-formulated Yimian Decoction (抑免汤) serves as the base formula and is applied in stages. During the acute active stage, it is often combined with herbs for clearing heat and detoxifying, cooling blood and resolving stasis, and unblocking the collaterals. In the chronic remitting stage, it is often combined with herbs for activating blood circulation and unblocking the collaterals, as well as tonifying qi and nourishing yin.
7.Construction and in vitro osteogenic activity study of magnesium-strontium co-doped hydroxyapatite mineralized collagen
WANG Meng ; SUN Yifei ; CAO Xiaoqing ; WEI Yiyuan ; CHEN Lei ; ZHANG Zhenglong ; MU Zhao ; ZHU Juanfang ; NIU Lina
Journal of Prevention and Treatment for Stomatological Diseases 2026;34(1):15-28
Objective:
To investigate the efficacy of magnesium-strontium co-doped hydroxyapatite mineralized collagen (MSHA/Col) in improving the bone repair microenvironment and enhancing bone regeneration capacity, providing a strategy to address the insufficient biomimetic composition and limited bioactivity of traditional hydroxyapatite mineralized collagen (HA/Col) scaffolds.
Methods:
A high-molecular-weight polyacrylic acid-stabilized amorphous calcium magnesium strontium phosphate precursor (HPAA/ACMSP) was prepared. Its morphology and elemental distribution were characterized by high-resolution transmission electron microscopy (TEM) and energy-dispersive spectroscopy. Recombinant collagen sponge blocks were immersed in the HPAA/ACMSP mineralization solution. Magnesium-strontium co-doped hydroxyapatite was induced to deposit within collagen fibers (experimental group: MSHA/Col; control group: HA/Col). The morphological characteristics of MSHA/Col were observed using scanning electron microscopy (SEM). Its crystal structure and chemical composition were analyzed by X-ray diffraction and Fourier transform infrared spectroscopy, respectively. The mineral phase content was evaluated by thermogravimetric analysis. The scaffold's porosity, ion release, and in vitro degradation performance were also determined. For cytological experiments, CCK-8 assay, live/dead cell staining, alkaline phosphatase staining, alizarin red S staining, RT-qPCR, and western blotting were used to evaluate the effects of the MSHA/Col scaffold on the proliferation, viability, early osteogenic differentiation activity, late mineralization capacity, and gene and protein expression levels of key osteogenic markers [runt-related transcription factor 2 (Runx2), collagen type Ⅰ (Col-Ⅰ), osteopontin (Opn), and osteocalcin (Ocn)] in mouse embryonic osteoblast precursor cells (MC3T3-E1).
Results:
HPAA/ACMSP appeared as amorphous spherical nanoparticles under TEM, with energy spectrum analysis showing uniform distribution of carbon, oxygen, calcium, phosphorus, magnesium, and strontium elements. SEM results of MSHA/Col indicated successful complete intrafibrillar mineralization. Elemental analysis showed the mass fractions of magnesium and strontium were 0.72% (matching the magnesium content in natural bone) and 2.89%, respectively. X-ray diffraction revealed characteristic peaks of hydroxyapatite crystals (25.86°, 31°-34°). Infrared spectroscopy results showed characteristic absorption peaks for both collagen and hydroxyapatite. Thermogravimetric analysis indicated a mineral phase content of 78.29% in the material. The scaffold porosity was 91.6% ± 1.1%, close to the level of natural bone tissue. Ion release curves demonstrated sustained release behavior for both magnesium and strontium ions. The in vitro degradation rate matched the ingrowth rate of new bone tissue. Cytological experiments showed that MSHA/Col significantly promoted MC3T3-E1 cell proliferation (130% increase in activity at 72 h, P < 0.001). MSHA/Col exhibited excellent efficacy in promoting osteogenic differentiation, significantly upregulating the expression of osteogenesis-related genes and proteins (Runx2, Col-Ⅰ, Opn, Ocn) (P < 0.01).
Conclusion
The MSHA/Col scaffold achieves dual biomimicry of natural bone in both composition and structure, and effectively promotes osteogenic differentiation at the genetic and protein levels, breaking through the functional limitations of pure hydroxyapatite mineralized collagen. This provides a new strategy for the development of functional bone repair materials
8.Fabrication and evaluation of an inositol hexaphosphate-zinc hydrogel with dual capabilities of self-mineralization and osteoinduction
LIU Mingyi ; MIAO Xiaoyu ; CAI Yunfan ; WANG Yan ; SUN Xiaotang ; KANG Jingrui ; ZHAO Yao ; NIU Lina
Journal of Prevention and Treatment for Stomatological Diseases 2026;34(1):29-40
Objective:
To fabricate a hydrogel loaded with inositol hexaphosphate-zinc and preliminarily evaluate its performance in self-mineralization and osteoinduction, thereby providing a theoretical basis for the development of bone regeneration materials.
Methods:
The hydrogel framework (designated DF0) was formed by copolymerizing methacryloyloxyethyltrimethylammonium chloride and four-armed poly(ethylene glycol) acrylate, followed by sequentially loading inositol hexaphosphate anions via electrostatic interaction and zinc ions via chelation. The hydrogel loaded only with inositol hexaphosphate anions was named DF1, while the co-loaded hydrogel was named DF2. The self-mineralization efficacy of the DF0 , DF1 and DF2 hydrogels was characterized using scanning electron microscopy, transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and selected area electron diffraction (SAED). The biocompatibility was assessed via live/dead cell staining and a CCK-8 assay. The osteoinductive capacity of the DF0 , DF1 and DF2 hydrogels on MC3T3-E1 cells was assessed via alkaline phosphatase (ALP) and Alizarin Red S (ARS) staining. In the aforementioned cell experiments, cells cultured in standard medium served as the control group
Results:
The DF0, DF1, and DF2 hydrogels were successfully synthesized. Notably, DF1 and DF2 exhibited distinct self-mineralization within 6 days. Results from TEM, EDS, and SAED confirmed that the mineralization products were amorphous calcium phosphate in group DF1, and amorphous calciumzinc phosphate in group DF2. Biocompatibility tests revealed that none of the hydrogels (DF0, DF1, and DF2) adversely affected cell viability or proliferation. In osteogenic induction experiments, both ALP and ARS staining were intensified in the DF1 and DF2 groups, with the most profound staining observed in the DF2 group.
Conclusion
The developed inositol hexaphosphate-zinc hydrogel (DF2) demonstrates the dual capacity to generate calcium-phosphate compounds through self-mineralization while exhibiting excellent osteoinductive properties. This biocompatible, dual-promoting osteogenic hydrogel presents a novel strategy for bone regeneration.
9.A study on the preparation of a BGN-loaded thermosensitive adhesive and its performance in barrier membrane fixation
WANG Yuzhu ; GU Junting ; LI Zhiting ; BAI Que ; DANG Gaopeng ; WANG Yifei ; SUN Xiaotang ; NIU Lina ; FANG Ming
Journal of Prevention and Treatment for Stomatological Diseases 2026;34(1):41-53
Objective:
To investigate the barrier membrane fixation performance and enhanced guided bone regeneration (GBR) capability of a thermosensitive adhesive containing bioactive glass nanoparticles in order to provide a novel solution for membrane fixation during GBR procedures.
Methods:
M2NP@BGN (methoxyethyl acrylate-co-N-isopropylacrylamide-co-protocatechuic acid@Bioactive glass nanoparticle), a thermosensitive adhesive, was synthesized via free radical polymerization by compositing methoxyethyl acrylate, N-isopropylacrylamide, and protocatechuic acid into a basic adhesive that was modified with bioactive glass nanoparticle (BGN). The successful fabrication of basic adhesive M2NP was characterized by attenuated total reflection-Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The thermosensitive adhesive M2NP@BGN (BGN concentration of 1 mg/mL) was characterized by scanning electron microscopy and a rheometer. By adjusting the BGN concentration (0.1 mg/mL, 0.5 mg/mL, 1 mg/mL, and 2 mg/mL), the adhesive and mechanical strengths were investigated with a universal testing machine. Biocompatibility was evaluated with a cell counting kit-8 assay and hemolysis test to identify the optimal formulation. The optimal material’s extract was co-cultured with mouse bone marrow mesenchymal stem cells, and its osteogenic activity was examined in vitro by quantitative real-time PCR, alkaline phosphatase, and alizarin red S staining. The rat mandibular defect model was established, filled with bone graft, and divided into 3 groups based on membrane fixation method: M2NP@BGN (BGN concentration of 1 mg/mL) fixation group (M2NP@BGN), titanium nail fixation group (Nail), and unfixed control group (Negative). Bone regeneration was analyzed after 8 weeks by micro computed tomography and histological staining.
Results:
M2NP@BGN (BGN concentration of 1 mg/mL) was successfully synthesized and demonstrated rapid gelation under warm, humid conditions. The adhesive with a BGN concentration of 1 mg/mL exhibited the highest adhesive strength (P < 0.001) and significantly enhanced mechanical strength (P < 0.001) under 37℃ wet conditions. All formulations showed excellent biocompatibility, with cell viability > 80% and hemolysis ratio < 5%. M2NP@BGN (BGN concentration of 1 mg/mL) significantly upregulated the expression of Runx2 and Col I (P < 0.001) and enhanced the activity of osteogenic differentiation markers (P < 0.05). In the animal model, the M2NP@BGN group (BGN concentration of 1 mg/mL) achieved significantly higher bone volume fraction and better bone maturity compared to the negative and nail groups (P < 0.05).
Conclusion
M2NP@BGN (BGN concentration of 1 mg/mL) combines excellent wet adhesion with potent osteogenic activity, enhances the bone augmentation efficacy of membranes, and presents a novel fixation strategy with significant clinical translation potential for GBR therapy.
10.Identification of autoinducer-2 in Streptococcus mutans membrane vesicles and effect of membrane vesicles on biofilm formation
TU Ye ; HUANG Zhengwei ; CHEN Zhanyi ; NIU Chenguang
Journal of Prevention and Treatment for Stomatological Diseases 2026;34(2):119-128
Objective:
To investigate whether membrane vesicles (MVs) of Streptococcus mutans (S.mutans) contain autoinducer-2 (AI-2) and to preliminarily explore the effects of these MVs on the growth and biofilm formation of S. mutans.
Methods:
MVs were isolated from the S. mutans UA159 strain using differential centrifugation. The isolated MVs were characterized by nanoparticle tracking analysis for particle size and concentration and observed by transmission electron microscopy. The presence of AI-2 was identified using the Vibrio harveyi BB170 bioluminescence assay: the BB170 diluent was supplemented with AB medium (control group), MV extract (MVs group), pre-ultrafiltration supernatant (Sup group), or post-ultrafiltration supernatant (Sup-af group). The effects of MVs on growth and biofilm formation were assessed using the S.mutans UA159 strain or a luxS deletion mutant as the control group, compared with experimental groups stimulated with gradient concentrations of MVs (MVs-2.0E+7, MVs-2.0E+8, and MVs-2.0E+9 groups). Growth curves, MTT assay, and colony-forming unit (CFU) counts were used to determine changes in growth capacity. Biofilm formation was evaluated using crystal violet staining, confocal laser scanning microscopy, and the anthrone method for polysaccharide quantification.
Results:
Enriched S. mutans MVs were successfully obtained, with an average particle size of approximately 94.19 nm and a concentration of 1.87E+11 particles/mL. The bioluminescence assay showed that the luminescence intensity of the Sup group was higher than that of the Sup-af group, and the MVs group exhibited higher intensity than the control group. Assessments via growth curves, MTT assay, and CFU counts indicated no significant differences in the growth capacity of the various S. mutans strains after treatment with different concentrations of MVs. Crystal violet staining quantification and confocal laser scanning microscopy observations revealed that high-concentration MV treatment (2.0E+9 particles/mL group) resulted in lower biofilm mass compared to the control. The anthrone method showed that the production of both water-soluble and water-insoluble polysaccharides was significantly lower in the high-concentration MV group than in the control.
Conclusion
S. mutans MVs contain the quorum sensing signal molecule AI-2. These MVs do not significantly affect the growth of S. mutans, but they can regulate biofilm formation and exhibit an inhibitory effect at high concentrations.


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