1.Facilitators and barriers to work-related musculoskeletal disorder prevention behaviors among healthcare professionals: A comprehensive review
Haijing MA ; Su’e YUAN ; Hui ZHU ; Yujia CHEN ; Ping SONG ; Huiqin YU ; Yunxia LI
Journal of Environmental and Occupational Medicine 2026;43(3):387-394
Work-related musculoskeletal disorders (WMSDs) represent a significant occupational health challenge among healthcare professionals globally, posing substantial threats to physical and mental well-being as well as work sustainability. Adopting preventive behaviors—including ergonomic postural adjustments, optimized work-rest scheduling, proper use of protective and assistive equipment, and regular physical activity—is essential for mitigating the risk of WMSDs. Guided by the social ecological model, the review synthesized current evidence on the determinants of WMSDs preventive behaviors across four levels: intrapersonal characteristics, work environment conditions, interpersonal support, and policy/institutional factors. The findings suggest that higher educational attainment, favorable health-related behavioral patterns, optimized ergonomic work environments, adoption of supportive collaborative systems, strong organizational support, as well as policy safeguards facilitate preventive behavior adoption. Conversely, limited prevention-related knowledge, low risk perception, insufficient physical activity, excessive workload, lack of appropriate protective equipment, inadequate ergonomic training, a prevailing culture of presenteeism, and inadequate policy implementation constitute significant barriers. Multi-dimensional intervention strategies targeting these determinants are warranted to enhance preventive behaviors, reduce the risk of WMSDs, and strengthen occupational health protection for healthcare professionals.
2.Volatile Component Differences in Xihuangwan Prepared with Natural and Artificial Musk Based on Non-targeted and Targeted Metabolomics
Jing WANG ; Fangzhu XU ; Li MENG ; Qizhen ZHU ; Huanjun ZHAO ; Caina YU ; Xuelian CHEN ; Hui GAO ; Zimin YUAN
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(8):194-201
ObjectiveHeadspace solid-phase microextraction-gas chromatography-mass spectrometry(HS-SPME-GC-MS) and GC-triple quadrupole MS(GC-QqQ-MS) in combination with non-targeted and targeted metabolomics were employed to systematically analyze the chemical composition differences of Xihuangwan prepared with natural musk and artificial musk, and establish an identification system for them. MethodsThe volatile components of 9 batches of Xihuangwan samples from 8 manufacturers were analyzed by HS-SPME-GC-MS non-targeted metabolomics, and identified by comparing their MS data with the National Institute of Standards and Technology(NIST) spectral library. Orthogonal partial least squares-discriminant analysis(OPLS-DA) was used to identify differential volatile components of Xihuangwan prepared with natural musk and artificial musk. Additionally, GC-QqQ-MS targeted metabolomics was applied to quantify the levels of α-pinene, β-elemene, muscone, dehydroepiandrosterone, bornyl acetate, and octyl acetate in 27 batches of samples from 9 manufacturers. Cluster analysis, principal component analysis(PCA), and partial least squares-discriminant analysis(PLS-DA) were conducted to further explore the differences in volatile components between Xihuangwan samples prepared with natural musk and artificial musk. ResultsNon-targeted metabolomics identified 291 volatile compounds in Xihuangwan, including alkanes, esters, alkanes, alcohols, ketones, naphthalenes and others. OPLS-DA analysis revealed distinct separation between Xihuangwan samples containing artificial musk(A1, C1, D1, E1, F1, G1, I1) and those containing natural musk(H1, H3). A total of 30 differential metabolites were identified. The relative contents of these 30 differential metabolites were visualized using a radar chart, revealing significant differences in the levels of octanol, borneol acetate and muscone. Cluster analysis and PCA results from targeted metabolomics indicated that Xihuangwan could be classified into two distinct groups:one composed of natural musk(H1, H3) and the other of artificial musk, sample H2. PLS-DA identified muscone, octyl acetate, and dehydroepiandrosterone as key differential volatile components. Although no significant difference was observed in the content of octyl acetate between the two groups, statistically significant differences were found for muscone and dehydroepiandrosterone(P<0.05). ConclusionMuscone and dehydroepiandrosterone can be used for the differentiation of Xihuangwan samples containing natural musk from those containing artificial musk. This study systematically and comprehensively analyzed the differences in the types and contents of major volatile components in Xihuangwan prepared with natural musk and artificial musk, providing a scientific basis for quality evaluation and control of Xihuangwan.
3.Volatile Component Differences in Xihuangwan Prepared with Natural and Artificial Musk Based on Non-targeted and Targeted Metabolomics
Jing WANG ; Fangzhu XU ; Li MENG ; Qizhen ZHU ; Huanjun ZHAO ; Caina YU ; Xuelian CHEN ; Hui GAO ; Zimin YUAN
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(8):194-201
ObjectiveHeadspace solid-phase microextraction-gas chromatography-mass spectrometry(HS-SPME-GC-MS) and GC-triple quadrupole MS(GC-QqQ-MS) in combination with non-targeted and targeted metabolomics were employed to systematically analyze the chemical composition differences of Xihuangwan prepared with natural musk and artificial musk, and establish an identification system for them. MethodsThe volatile components of 9 batches of Xihuangwan samples from 8 manufacturers were analyzed by HS-SPME-GC-MS non-targeted metabolomics, and identified by comparing their MS data with the National Institute of Standards and Technology(NIST) spectral library. Orthogonal partial least squares-discriminant analysis(OPLS-DA) was used to identify differential volatile components of Xihuangwan prepared with natural musk and artificial musk. Additionally, GC-QqQ-MS targeted metabolomics was applied to quantify the levels of α-pinene, β-elemene, muscone, dehydroepiandrosterone, bornyl acetate, and octyl acetate in 27 batches of samples from 9 manufacturers. Cluster analysis, principal component analysis(PCA), and partial least squares-discriminant analysis(PLS-DA) were conducted to further explore the differences in volatile components between Xihuangwan samples prepared with natural musk and artificial musk. ResultsNon-targeted metabolomics identified 291 volatile compounds in Xihuangwan, including alkanes, esters, alkanes, alcohols, ketones, naphthalenes and others. OPLS-DA analysis revealed distinct separation between Xihuangwan samples containing artificial musk(A1, C1, D1, E1, F1, G1, I1) and those containing natural musk(H1, H3). A total of 30 differential metabolites were identified. The relative contents of these 30 differential metabolites were visualized using a radar chart, revealing significant differences in the levels of octanol, borneol acetate and muscone. Cluster analysis and PCA results from targeted metabolomics indicated that Xihuangwan could be classified into two distinct groups:one composed of natural musk(H1, H3) and the other of artificial musk, sample H2. PLS-DA identified muscone, octyl acetate, and dehydroepiandrosterone as key differential volatile components. Although no significant difference was observed in the content of octyl acetate between the two groups, statistically significant differences were found for muscone and dehydroepiandrosterone(P<0.05). ConclusionMuscone and dehydroepiandrosterone can be used for the differentiation of Xihuangwan samples containing natural musk from those containing artificial musk. This study systematically and comprehensively analyzed the differences in the types and contents of major volatile components in Xihuangwan prepared with natural musk and artificial musk, providing a scientific basis for quality evaluation and control of Xihuangwan.
4.Disease burden and changing trends of bladder cancer in China and globally in 1992 - 2021
Zhengnan LI ; Zhuang LI ; Yuanyuan LUO ; Bo YU ; Hao SU ; GuangYong CAO ; Kai YIN ; Dongbo YUAN ; Jianguo ZHU
Journal of Public Health and Preventive Medicine 2026;37(3):8-13
Objective To analyze the disease burden and trends of bladder cancer in China and globally from 1992 to 2021. Methods Using the GBD 2021 database, the incidence, prevalence, mortality, and disability-adjusted life years (DALYs) rates of bladder cancer in China and globally from 1992–2021 were analyzed. Average annual percentage change (AAPC) was calculated using Joinpoint regression. Subgroup analyses by sex and age were conducted, and a Bayesian age-period-cohort (BAPC) model was used to predict trends in age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) for the next 15 years. Results In 2021, China reported 106 000 new cases (ASIR: 5.14/100 000), 571 000 prevalent cases (age-standardized prevalence rate, ASPR: 26.61/100 000), 43 000 deaths (ASMR: 2.34/100 000), and a DALY rate of 45.31/100 000. From 1992–2021, China showed upward trends in ASIR and ASPR but declines in ASMR and DALYs, while global ASIR, ASMR, and DALYs decreased overall with slow ASPR growth. The peak cases in China and globally were both concentrated in the 65-79 age group, with a significantly higher burden on males than females. In China, smoking-related ASMR and ASDR exceeded global averages and rose, whereas high glucose-related indexes were lower and declined. Projections for 2021–2036 indicated that the global incidence and mortality rates would be rising, but ASIR/ASPR would be declining, while in China, the incidence rate would continue to rise, and the mortality rate will stabilize, with a significant increase in ASIR and a gradual decrease in ASPR. Conclusion From 1992 to 2021, the incidence of bladder cancer in China has shown a continuous upward trend and is projected to persist in the future, with significant gender and age differences. Particular attention should be given to elderly males aged 85-89. The disease burden of bladder cancer attributable to smoking continues to rise, highlighting the urgent need to strengthen tobacco control policies.
5.Effect and mechanism of composite hydrogel loaded with human umbilical cord mesenchymal stem cell-derived exosomes in promoting knee cartilage regeneration
Yanchi BI ; Ding YUAN ; Liang ZHU ; Haibo ZHAO ; Fan JIANG ; Xiao XIAO ; Tengbo YU
Chinese Journal of Trauma 2025;41(8):778-788
Objective:To investigate the effect and mechanism of injectable photopolymerizable porous gelatin methacrylate anhydride (Porous GelMA)/methacrylated silk fibroin (SilMA) composite hydrogel (PSE) loaded with human umbilical cord mesenchymal stem cell-derived exosomes (hUCMSC-Exos) in promoting knee joint cartilage regeneration.Methods:The porous GelMA solution (60 g/L) was mixed with SilMA solution (200 g/L) at a volume ratio of 6∶1 . The mixture was ultraviolet-irradiated for 30 seconds to form a cured Porous GelMA/SilMA hydrogel (P/S6). The hUCMSC-Exos was isolated via differential centrifugation coupled with ultrafiltration and then was incorporated into the Porous GelMA/SilMA composite solution at 200 μg/ml, followed by ultraviolet irradiation for 30 seconds to generate Exos-loaded PSE. Primary rat chondrocytes (P1) were divided into control group, P/S6 group, and PSE group to characterize the porosity, compressive strength, and sustained exosome release kinetics of PSE hydrogel. Chondrocytes were allocated to control group, interleukin-1β (IL-1β) group, P/S6 group, and PSE group, among which the last three groups were preconditioned with 10 ng/ml IL-1β for 24 hours, and then cultured in complete medium, P/S6 extract and PSE extract for 3 days, respectively, to establish in vitro cartilage defect models, while the control group remained untreated. Western blot and qRT-PCR analysis were conducted to quantify the expression levels of antibody to aggrecan core protein (ACAN), sex-determining region Y-box transcription factor 9 (SOX9), matrix metalloproteinase-13 (MMP13) and collagen type II (COL II). Murine monocyte-macrophage leukemia cells (RAW264.7) were divided into control group, P/S6 group, and PSE group, which were then cultured in complete medium, PSE extract, and PSE extract medium for 3 days, respectively. qRT-PCR was employed to detect the expression levels of recombinant arginase-1 protein (ARG1), mannose receptor (CD206), and inducible nitric oxide synthase (iNOS). Transcriptomic sequencing was used to identify differentially expressed genes during PSE-mediated chondrocyte regeneration, followed by functional enrichment analysis of key signaling pathways. Twenty-four SD rats were selected to establish cartilage defect models and assigned to injury control group, P/S6 group, and PSE group according to the random number table (8 rats per group). The right knee joints of the rats were surgically exposed, and cylindrical osteochondral defects (a diameter of 2.0 mm× a depth of 1.0 mm) were surgically created in the center of the femoral trochlear groove using a drill bit. The injury control group received phosphate-buffered saline, while the P/S6 group and PSE group were injected with corresponding hydrogels followed by photo-crosslinking. Incisions then were closed in layers. At 6 and 10 weeks after injury, specimens were harvested for HE staining and safranin O-fast green staining to evaluate cartilage regeneration and immunohistochemistry staining to quantify the positive area fractions for COL II, MMP13, ARG1, and CD206 in the defect areas. Results:PSE hydrogel exhibited compressive strength matching native cartilage (0.41 MPa), high porosity (85%), and sustained exosome release capacity (cumulative release rate of approximately 85% over 14 days). In chondrocyte repair experiments, compared to the IL-1β group, the PSE group demonstrated significantly upregulated expression of anabolic markers of cartilage (COL II expression increased by 2.1-fold, ACAN by 1.8-fold, and SOX9 by 1.5-fold) ( P<0.01) as well as significantly suppressed expression of catabolic markers (MMP13 expression decreased by 52%) ( P<0.01). In macrophage polarization assays, the PSE group exhibited ARG1 expression increased by 68% when compared to the control group ( P<0.01), thus promoting M2 polarization of macrophages. Transcriptomic analysis revealed that PSE enhanced extracellular matrix (ECM) synthesis by activating the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathway and ECM-receptor interaction pathway, as well as by suppressing inflammation-related gene expression. Histological evaluation in animal experiments revealed regeneration of hyaline cartilage with smooth, continuous surfaces in the defect areas in the PSE group. At 10 weeks after surgery, the neocartilage-positive area in the PSE group was (9.94±0.26)%, significantly larger than (1.67±0.11)% in the injury control group ( P<0.01). Besides, the CD206? M2 macrophage-positive area reached (14.44±0.23)% in the PSE group, significantly larger than (3.41±0.36)% in the injury control group ( P<0.01). Conclusions:The PSE hydrogel successfully engineered in the study can significantly promote regenerative repair of knee cartilage defects through a dual mechanism of enhanced ECM anabolism and remodeled inflammatory microenvironment. The core mechanisms involve specific activation of the PI3K/Akt pathway (boosting chondrocyte proliferation and survival) and ECM-receptor interaction pathway (driving ECM synthesis and assembly) by exosome-loaded PSE, while effectively polarizing macrophages toward an anti-inflammatory M2 phenotype so as to coordinately regulate cartilage ECM metabolism and suppress inflammatory responses.
6.Clinical observation of coiling dragon needling plus chin tuck against resistance training for post-stroke deglutition disorders
Liying TANG ; Lili ZHU ; Ying ZHOU ; Mei YU ; Yuan ZHANG ; Fuqing ZHANG
Journal of Acupuncture and Tuina Science 2025;23(1):49-55
Objective:To explore the clinical efficacy of coiling dragon needling plus chin tuck against resistance(CTAR)training for post-stroke deglutition disorders and its impact on surface electromyography.Methods:A total of 100 patients with post-stroke deglutition disorders were randomly divided into two groups,with 50 cases in each group.Both groups received the same CTAR training,and the observation group was treated with additional coiling dragon needling.Both groups were treated for 2 weeks.The clinical efficacy,swallowing function,average value of the maximum amplitude of surface electromyography,quality of life,and the difference in adverse reactions were compared between the two groups.Results:The total effective rate of the observation group was higher than that of the control group(P<0.05).After treatment,the standardized swallowing assessment(SSA),aspiration score,and deglutition disorders score of the videofluoroscopic swallowing study(VFSS)in both groups were significantly lower than those before treatment(P<0.05).The average value of the maximum amplitude of surface electromyography in the relaxed state,dry swallowing state,and the state of swallowing water,and the swallowing quality of life questionnaire(SWAL-QOL)score were all significantly higher than those before treatment in the two groups(P<0.05).After treatment,the SSA score,VFSS aspiration score,and VFSS deglutition disorders score in the observation group were lower than those in the control group(P<0.05),and the average value of the maximum amplitude of surface electromyography in the relaxed state,dry swallowing state,and the state of swallowing water,and the SWAL-QOL score in the observation group were higher than those in the control group(P<0.05).There was no significant difference in the incidence of adverse reactions between the two groups(P>0.05).Conclusion:Compared to CTAR treatment alone,coiling dragon needling plus CTAR treatment can enhance the clinical efficacy in treating patients with post-stroke deglutition disorders,enhancing the contraction ability of swallowing muscles and improving their swallowing function and quality of life.
7.Effects of nuciferine on neuroinflammation and ferroptosis in mice with chronic hypoperfusion-induced white matter injury
Ting-ting DUAN ; Gui-min JIN ; Yuan-yuan ZHU ; Yu-hao XU ; Yue-feng LI ; Chen QIAO ; Ming YU
Chinese Pharmacological Bulletin 2025;41(10):1931-1940
Aim To explore the effects of nuciferine on cognitive behavior and the underlying mechanisms,white matter injury(WMI),neuroinflammation,and ferroptosis in mice with chronic ischemic WMI.Meth-ods Sixty C57BL/6 mice were divided into a control group,a bilateral common carotid artery stenosis(BCAS)model group,and low/high-dose nuciferine groups(20/40 mg·kg-1).A chronic ischemic WMI model was established using BCAS surgery.Following eight weeks of treatment,cognitive behavior(Y-maze,novel object recognition,Morris water maze),white matter integrity(LFB/MBP staining),microglial acti-vation(Iba-1 immunofluorescence),inflammatory cy-tokines(ELISA for TNF-α,IL-1β,IL-6),ferroptosis markers(Fe2+,ROS,MDA,GSH),mitochondrial ultrastructure(electron microscopy),and protein ex-pression of the PI3K/Akt and NRF2/xCT/GPX4 signa-ling pathways(Western blot)were evaluated.Results Compared with the control group,the BCAS group showed significant cognitive decline(P<0.05),re-duced myelin density,elevated inflammatory cytokines and ferroptosis markers(Fe2+,ROS,MDA),shrunk-en mitochondria,and downregulated PI3K/Akt and NRF2/xCT/GPX4 pathway proteins(P<0.05).Nu-ciferine intervention significantly ameliorated these in-juries in BCAS mice,with the high-dose group exhibi-ting superior effects(P<0.05).Conclusions Nu-ciferine exerts protective effects against chronic ische-mic WMI and cognitive impairment by activating the PI3K/Akt and NRF2/xCT/GPX4 signaling pathways,thereby suppressing neuroinflammation and ferroptosis.
8.Development and validation of a machine learning-based prognostic model for portal vein thrombosis in liver cirrhosis
Junqi YUAN ; Sa LYU ; Jun LING ; Yiwen XU ; Hui FENG ; Shaoli YOU ; Fuquan LIU ; Limei YU ; Bing ZHU
Chinese Journal of Hepatobiliary Surgery 2025;31(7):497-502
Objective:To analyze the prognostic factors of patients with liver cirrhosis and portal vein thrombosis (PVT), and to construct a prognostic prediction model based on machine learning methods.Methods:The clinical data of 388 patients with liver cirrhosis and PVT admitted to the Fifth Medical Center of PLA General Hospital from January 2022 to April 2024 were retrospectively collected and analyzed, including 243 males and 145 females, aged (56.9±10.9) years. A total of 388 patients were randomly divided into the training set ( n=310) and the testing set ( n=78) in a 4∶1 ratio. The Boruta algorithm was used to screen the key features in the training set, and then four machine learning algorithms, including random forest, support vector machine, generalized linear model and Bayesian, were used to establish a survival prediction model. Model performance was evaluated by the receiver operating characteristic (ROC) curves of the test set and the training set. The patients were followed up for 1 year for survival. Sort the importance of features based on the SHAP value. Results:There were 250 patients (80.6%) who survived and 60 (19.4%) who died. The model for end-stage liver disease score, total bilirubin, serum creatinine, prothrombin time, international normalized ratio, D-dimer, white blood cell count, severe ascites ratio, and Child-Pugh grade C ratio of liver function in the death group were higher than those in the survival group, and the red blood cell count and hematocrit were lower than those in the survival group, and the differences were statistically significant (all P<0.05). The areas under the ROC curve for predicting survival by random forest, support vector machine, generalized linear model and Bayesian model were 0.92, 0.78, 0.81 and 0.71 in the training set, and the area under the ROC curve in the testing set were 0.81, 0.72, 0.67 and 0.68, respectively. Random forest had the best prediction performance, with an accuracy of 81.7%, a sensitivity of 84.6%, and a specificity of 76.9% in the testing set. In the analysis of the importance of characteristic parameters of the random forest model, total bilirubin, red blood cells, hematocrit, serum creatinine, ascites classification, etc. had a relatively high contribution to the model. Conclusion:In the survival prediction model of patients with liver cirrhosis and PVT based on machine learning algorithm, the random forest model had high prediction performance, and total bilirubin may be the most important factor affecting the survival prognosis of patients.
9.Predictive value of changes in body mass index and blood glucose indicators in early pregnancy for gestational diabetes mellitus
Yu WANG ; Weiying ZHU ; Haiyan YUAN
Chinese Journal of Primary Medicine and Pharmacy 2025;32(6):829-834
Objective:To investigate the predictive value of changes in body mass index (BMI) and blood glucose indicators in early pregnancy for gestational diabetes mellitus (GDM).Methods:A total of 126 pregnant women with GDM who were admitted to the Department of Obstetrics at Jiaxing Maternity and Child Health Care Hospital from January 2022 to December 2023 were retrospectively analyzed and included in the GDM group. Additionally, 140 healthy pregnant women were included in the non-GDM group. Changes in BMI and levels of blood glucose indicators [fasting blood glucose (FBG), 1-hour postprandial blood glucose, 2-hour postprandial blood glucose (2hPG), and glycated hemoglobin during early pregnancy were compared between the two groups. Influential factors for GDM were analyzed using a multivariate logistic regression model. The predictive value of changes in BMI and blood glucose indicators during early pregnancy for GDM was assessed using receiver operating characteristic curves.Results:The BMI at 10 [(24.60 ± 0.82) kg/m2] and 14 weeks of pregnancy [(23.50 ± 0.85) kg/m2] in the GDM group was significantly higher compared with the non-GDM group (both P < 0.05). The levels of FBG [(5.98 ± 0.36) mmol/L], 1-hour postprandial blood glucose [(10.95 ± 0.83) mmol/L], and 2hPG [(8.60 ± 0.82) mmol/L] in the GDM group were also significantly higher than those in the non-GDM group ( t = 12.25, 23.90, 5.98, all P < 0.001). The levels of total cholesterol [(6.35 ± 1.10) mmol/L] and triglycerides [(3.23 ± 0.60) mmol/L] in the GDM group were significantly higher compared with the non-GDM group ( t = 6.45, 7.45, both P < 0.001). The number of cesarean sections ( n = 69 cases) and the incidence of adverse delivery outcomes [26.98% (34/126)] in the GDM group were significantly higher than those in the non-GDM group ( χ2 = 16.72, 12.71, both P < 0.001). Multivariate logistic regression analysis indicated that BMI at 10 weeks of pregnancy, BMI at 14 weeks of pregnancy, FBG, and 2hPG were independent risk factors for GDM ( OR = 1.292, 6.514, 2.601, 1.784, all P < 0.05). According to Receiver Operating Characteristic curve analysis, the area under the curve (AUC) (95% CI) for BMI at 10 and 14 weeks of pregnancy were 0.717 (0.630-0.795) and 0.719 (0.631-0.796), respectively. The AUC (95% CI) for FBG and 2hPG levels were 0.731 (0.635-0.813) and 0.802 (0.712-0.873), respectively. The AUC (95% CI) for the combined evaluation of these indicators was 0.911 (0.839-0.958), indicating that the combined evaluation had a higher predictive value for GDM than the use of a single indicator ( P < 0.05). Conclusions:The changes in BMI and blood glucose indicators during early pregnancy are closely related to the occurrence of GDM. The combination of these measurements has a high predictive value for GDM and is of significant importance for its prevention.
10.Effect and mechanism of composite hydrogel loaded with human umbilical cord mesenchymal stem cell-derived exosomes in promoting knee cartilage regeneration
Yanchi BI ; Ding YUAN ; Liang ZHU ; Haibo ZHAO ; Fan JIANG ; Xiao XIAO ; Tengbo YU
Chinese Journal of Trauma 2025;41(8):778-788
Objective:To investigate the effect and mechanism of injectable photopolymerizable porous gelatin methacrylate anhydride (Porous GelMA)/methacrylated silk fibroin (SilMA) composite hydrogel (PSE) loaded with human umbilical cord mesenchymal stem cell-derived exosomes (hUCMSC-Exos) in promoting knee joint cartilage regeneration.Methods:The porous GelMA solution (60 g/L) was mixed with SilMA solution (200 g/L) at a volume ratio of 6∶1 . The mixture was ultraviolet-irradiated for 30 seconds to form a cured Porous GelMA/SilMA hydrogel (P/S6). The hUCMSC-Exos was isolated via differential centrifugation coupled with ultrafiltration and then was incorporated into the Porous GelMA/SilMA composite solution at 200 μg/ml, followed by ultraviolet irradiation for 30 seconds to generate Exos-loaded PSE. Primary rat chondrocytes (P1) were divided into control group, P/S6 group, and PSE group to characterize the porosity, compressive strength, and sustained exosome release kinetics of PSE hydrogel. Chondrocytes were allocated to control group, interleukin-1β (IL-1β) group, P/S6 group, and PSE group, among which the last three groups were preconditioned with 10 ng/ml IL-1β for 24 hours, and then cultured in complete medium, P/S6 extract and PSE extract for 3 days, respectively, to establish in vitro cartilage defect models, while the control group remained untreated. Western blot and qRT-PCR analysis were conducted to quantify the expression levels of antibody to aggrecan core protein (ACAN), sex-determining region Y-box transcription factor 9 (SOX9), matrix metalloproteinase-13 (MMP13) and collagen type II (COL II). Murine monocyte-macrophage leukemia cells (RAW264.7) were divided into control group, P/S6 group, and PSE group, which were then cultured in complete medium, PSE extract, and PSE extract medium for 3 days, respectively. qRT-PCR was employed to detect the expression levels of recombinant arginase-1 protein (ARG1), mannose receptor (CD206), and inducible nitric oxide synthase (iNOS). Transcriptomic sequencing was used to identify differentially expressed genes during PSE-mediated chondrocyte regeneration, followed by functional enrichment analysis of key signaling pathways. Twenty-four SD rats were selected to establish cartilage defect models and assigned to injury control group, P/S6 group, and PSE group according to the random number table (8 rats per group). The right knee joints of the rats were surgically exposed, and cylindrical osteochondral defects (a diameter of 2.0 mm× a depth of 1.0 mm) were surgically created in the center of the femoral trochlear groove using a drill bit. The injury control group received phosphate-buffered saline, while the P/S6 group and PSE group were injected with corresponding hydrogels followed by photo-crosslinking. Incisions then were closed in layers. At 6 and 10 weeks after injury, specimens were harvested for HE staining and safranin O-fast green staining to evaluate cartilage regeneration and immunohistochemistry staining to quantify the positive area fractions for COL II, MMP13, ARG1, and CD206 in the defect areas. Results:PSE hydrogel exhibited compressive strength matching native cartilage (0.41 MPa), high porosity (85%), and sustained exosome release capacity (cumulative release rate of approximately 85% over 14 days). In chondrocyte repair experiments, compared to the IL-1β group, the PSE group demonstrated significantly upregulated expression of anabolic markers of cartilage (COL II expression increased by 2.1-fold, ACAN by 1.8-fold, and SOX9 by 1.5-fold) ( P<0.01) as well as significantly suppressed expression of catabolic markers (MMP13 expression decreased by 52%) ( P<0.01). In macrophage polarization assays, the PSE group exhibited ARG1 expression increased by 68% when compared to the control group ( P<0.01), thus promoting M2 polarization of macrophages. Transcriptomic analysis revealed that PSE enhanced extracellular matrix (ECM) synthesis by activating the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathway and ECM-receptor interaction pathway, as well as by suppressing inflammation-related gene expression. Histological evaluation in animal experiments revealed regeneration of hyaline cartilage with smooth, continuous surfaces in the defect areas in the PSE group. At 10 weeks after surgery, the neocartilage-positive area in the PSE group was (9.94±0.26)%, significantly larger than (1.67±0.11)% in the injury control group ( P<0.01). Besides, the CD206? M2 macrophage-positive area reached (14.44±0.23)% in the PSE group, significantly larger than (3.41±0.36)% in the injury control group ( P<0.01). Conclusions:The PSE hydrogel successfully engineered in the study can significantly promote regenerative repair of knee cartilage defects through a dual mechanism of enhanced ECM anabolism and remodeled inflammatory microenvironment. The core mechanisms involve specific activation of the PI3K/Akt pathway (boosting chondrocyte proliferation and survival) and ECM-receptor interaction pathway (driving ECM synthesis and assembly) by exosome-loaded PSE, while effectively polarizing macrophages toward an anti-inflammatory M2 phenotype so as to coordinately regulate cartilage ECM metabolism and suppress inflammatory responses.


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