BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

Background: Malignant vasovagal syncope (VVS) is characterized by cardiac arrest lasting more than 3 seconds during a syncope episode or head-up tilt test (HUTT). We aim to conduct a risk assessment for potential malignant VVS before the HUTT by using economic, simple and convenient demographic data, in order to prevent adverse outcomes for pediatric VVS.Purpose: To explore the correlation between demographic factors and pediatric malignant VVS, and verify the value of these factors in early risk assessment for malignant VVS before HUTT, so as to optimize test safety and reduce adverse events. Methods: We conducted a retrospective analysis of the clinical data of 3,734 children who were initially diagnosed with VVS due to unexplained syncope and presyncope. Finally, 122 children who met the diagnostic criteria for malignant VVS were included in the malignant VVS group, and 661 children who did not meet the criteria during the same period were matched as the control group. By analyzing demographic data and other factors, we attempted to clarify the association between these factors and malignant VVS. Results: Linear relationship: age and body mass index (BMI) have independent protective effects on malignant VVS. For every 1-year increase in age and every 1 kg/m2 increase in BMI, the risk of malignant VVS decreases by 12% and 9%, respectively. Nonlinear relationship: When the age is <12.9 years old, for every additional year of age, the risk of malignant VVS decreases by 20%. For ages 12.9 years and above, the efficacy is not significant. There is no significant nonlinear relationship between BMI and malignant VVS. Conclusion Age and BMI are independent protective factors for pediatric malignant VVS. Before the age of 12.9 years, the incidence of malignant VVS gradually decreases with the increase in age, and thereafter there is no significant impact.

Osteoporosis and cardiovascular calcification,two major age-related chronic diseases that China is confronting today,pose serious threats to public health.Previous studies have reported overlapping connections in the pathological processes and molecular mechanisms of these two diseases,particularly concerning inflammation,oxidative stress,and dysregulation of mineral metabolism,and that these two diseases tend to share common pathogenic factors.However,research exploring the comorbidity mechanisms of the two diseases remains limited in both depth and scope,largely due to the lack of widely accepted comorbidity animal models.Herein,we analyzed the latest research findings on the comorbidity mechanisms of vascular calcification and osteoporosis,focusing on summarizing the animal disease models currently in extensive use and the relevant evaluation criteria.We aim to provide new references for comorbidity research models and offer scientific evidence for future studies on pathological mechanisms and the development of new therapeutic strategies.

Objective To evaluate the effects of Yiqi Huayu Jiedu Decoction combined with chemotherapy on disease-free survival rate and disease-free survival(DFS)of patients with stage Ⅱ and Ⅲ postoperative gastric cancer.Methods Totally 102 patients with stage Ⅱ and Ⅲ postoperative gastric cancer treated by Affiliated Hospital of Nanjing University of Chinese Medicine and Nanjing Drum Tower Hospital were selected.The patients were divided into control group(52 cases)and test group(50 cases)with block random method.The control group received conventional postoperative adjuvant chemotherapy for 4-6 cycles.The test group was treated with Chinese materia medica for 6 months on the basis of chemotherapy.Continue follow-up until the patients had recurrence,metastasis or death.DFS was analyzed by Kaplan-Meier method,and the average DFS of the two groups was estimated.Log Rank test was used to test the significance of differences in survival distribution between groups.Univariate and multivariate analyses of variables affecting prognosis were conducted using the Cox regression model.Adverse reactions of both groups were monitored.Results The recurrence and metastasis rate of the test group was 12.0%(6/50),while that of the control group was 34.6%(18/52),which was lower in the test group than in the control group(P<0.05).The 1-year and 2-year DFS rates and DFS of the control group were 86.5%,72.2%and 25.8 months respectively,while those of the test group were 95.6%,84.1%and 33.9 months respectively,with statistical significance(P=0.012).Cox-regression analysis suggested:The independent factors influencing the disease-free survival time of patients with gastric cancer were the test group(P=0.022),surgical methods of subtotal gastrectomy(P=0.038)and clinical stages Ⅱ(P=0.040).No adverse reactions related to Chinese materia medica were reported in the two groups.Conclusion Yiqi Huayu Jiedu Decoction combined with chemotherapy can improve the 1-year and 2-year DFS rate,prolong DFS,reduce the recurrence and metastasis rate,and improve the prognosis.

Objective:A mineralized gelatin methacryloyl/hyaluronic acid methacryloyl (GelMA/HAMA) double network hydrogel was constructed, its performance was characterized, and its cell compatibility was studied.Methods:The hydrogel was constructed by photocrosslinking technology, and the biomimetic mineralized hydrogel was prepared by alternating mineralization with calcium and phosphorus solution. The hydrogel was mineralized for three times, for 24 h each time. The control groups were the non-mineralized groups, named the GelMA-0 group and GelMA/HAMA-0 group, respectively. The experimental groups were the mineralized treatment groups. The GelMA hydrogel and GelMA/HAMA double network hydrogel mineralized for 1, 2 and 3 times were named the GelMA-1, 2 and 3 group and GelMA/HAMA-1, 2 and 3 group, respectively. The microstructure of the mineralized hydrogel was characterized by scanning electron microscope and energy dispersive X-ray spectroscopy. The chemical composition of the mineralized hydrogel was characterized by Fourier transform infrared spectroscopy and X-ray diffraction. The mineralization rate of the mineralized hydrogel was evaluated by the ashing method. The compressive strength of the mineralized hydrogel was evaluated by a compression test. The cell compatibility of bone marrow mesenchymal stem cells (BMSCs) on the mineralized hydrogel surface was evaluated by a cell counting kit-8 assay and living/dead cell staining experiment. The datas were analyzed by one-way analysis of variance and Tukey test.Results:With the increase in the number of mineralization cycles, the mineralized layer gradually thickened, and the mineral layer on the cross section of the hydrogel uniformly penetrated into the interior of the hydrogel, with the amount of internal mineral deposition increased. The microstructure of the hydrogel and the distribution of inorganic particles also changed. The surface of the GelMA-3 group and the GelMA/HAMA-3 group contained Ca and P elements, and the distribution was consistent. The inorganic particles generated by mineralization may be immature hydroxyapatite (HAP) crystal precursors. To further verify the chemical composition of inorganic particles, the GelMA-0 and 3 groups as well as the GelMA/HAMA-0 and 3 groups of hydrogels showed GelMA amide Ⅰ, Ⅱ and Ⅲ bands. The GelMA-3 group and GelMA/HAMA-3 group hydrogels contained phosphate, and the diffraction peaks confirmed that the inorganic particles are mainly HAP crystal precursors with low crystallinity. The mineralization rates of the GelMA-1, 2 and 3 groups were (12.48±1.06)%, (21.12±0.62)% and (27.31±0.45)%, while those of the GelMA/HAMA-1, 2 and 3 groups were (15.54±1.03)%, (23.39±0.25)% and (32.26±0.62)%, and the compressive elastic modulus of the GelMA-0, 1, 2 and 3 groups were (69.01±1.04, 91.76±2.05, 105.16±2.95, 131.65±2.21) kPa, and those of the GelMA/HAMA-0, 1, 2 and 3 groups were (270.76±4.56, 347.47±4.60, 388.98±6.96, 430.6±15.47) kPa. Under the same cyclic mineralization times, the mineralization rates and compressive elastic modulus of the GelMA/HAMA double network hydrogel were significantly higher than those of the GelMA hydrogel (all P<0.01). The cell proliferation rates of BMSCs on the GelMA/HAMA-0, 1, 2 and 3 hydrogel surfaces were (49.80±3.38)%, (52.32±1.28)%, (58.00±4.64)% and (62.46±2.74)% on the first day of culture, (58.86±3.36)%, (58.26±3.45)%, (73.08±2.61)% and (76.40±3.45)% on the third day of culture, and (85.89±4.23)%, (90.75±3.21)%, (103.35±4.11)% and (113.42±3.40)% on the fifth day of culture. The cell proliferation rates of the GelMA/HAMA-3 group were significantly higher than those of GelMA/HAMA-0 and 1 groups (all P<0.01). Living/dead cell staining experiment showed that BMSCs on the surface of the GelMA/HAMA-0, 1, 2 and 3 groups were dominated by living cells on the third and fifth days of culture. Conclusions:The mineralized GelMA/HAMA double network hydrogel was constructed, which significantly improved the mineralization rate, mechanical performance and cell compatibility of the biomimetic mineralized hydrogel.

In vivo, cells exist within the mechanical microenvironment of the extracellular matrix (ECM), and their biological processes are regulated by various mechanical factors. However, existing technology limits the direct study of the interaction between cells and ECM in vivo. Using hydrogel to mimic the natural ECM and to construct a suitable mechanical microenvironment for isolated cells, which indirectly reflects the cell-ECM interactions in real organisms through in vitro studies. Thus, in this review, the effects of mechanical factors in hydrogel on different types of cells were summarized, and the development of cell mechanical detection technology using hydrogel as carriers was introduced. Moreover, the future work of using hydrogel to study cell mechanical behavior and related detection technology, as well as standardized preparation, was discussed.

Dynamic hydrogel is three-dimensional networks of hydrophilic polymer formed by dynamic reversible cross-linked bonds. It is widely used in the field of bone repair therapy. The dynamic reversible cross-linked bonds in the dynamic hydrogel endows it with shear-thinning rheological properties, resulting in excellent self-healing, injectability and tunable mechanical properties. In this review, the formation mechanism of dynamic hydrogel was summarized, including non-covalent interaction and dynamic covalent interaction. The advantages and disadvantages of the various cross-linked methods used to form dynamic hydrogel were discussed. The applications of dynamic hydrogel in bone repair therapy were summarized, including haemostasis for filling bone defects, drug delivery, modulation of stem cell behavior, and biomimetic mineralization, to provide a reference for the future development of dynamic hydrogel for bone repair therapy.

BACKGROUND:Socket-shield technique can effectively maintain labial soft and hard tissues,but the incidence of postoperative complications such as exposure and displacement of root shield is relatively high.It is speculated that the root shield may be exposed and displaced due to excessive load after long-term function of dental implants. OBJECTIVE:Through three-dimensional finite element analysis,we aim to study the influence of varying root shield thicknesses on the stress distribution,equivalent stress peaks,and displacement in the root shield,periodontal ligaments,implant,and surrounding alveolar bone under normal occlusal loading.We also attempt to analyze the correlation between the thickness of the root shield and occurrence of mechanical events such as root shield exposure,displacement,and fracture. METHODS:Cone-beam CT data of a patient who met the indication standard of socket-shield technique for maxillary central incisor were retrieved from database.Reverse engineering techniques were used to build models of the maxillary bone and root shield,while forward engineering was used to create models for the implant components based on their parameters.Models depicting various root shield thicknesses(0.5,1.0,1.5,and 2.0 mm)were created using Solidworks 2022 software.ANSYS Workbench 2021 software was then used to simulate and analyze the effects of varying root shield thicknesses on stress distribution,equivalent stress peaks,and displacement of the root shields,periodontal ligaments,implants,and surrounding alveolar bone under normal occlusion. RESULTS AND CONCLUSION:(1)In all root shield models,the stress was concentrated on the palatal cervical side,both sides of the edges and the lower edge of the labial side.As the thickness of the root shield increased,the equivalent stress peak and displacement showed a decreasing trend.The 0.5 mm thickness model produced a stress concentration of 176.20 MPa,which exceeded the yield strength(150 MPa)of tooth tissue.(2)The periodontal ligament stress in each group was concentrated in the neck margin and upper region.With the increase of root shield thickness,the equivalent stress peak and displacement of periodontal ligament showed a decreasing trend.(3)Implant stress in all models was concentrated in the neck of the implant and the joint of the implant-repair abutment,and the labial side was more concentrated than the palatal side.With the increase of root shield thickness,the equivalent stress peak of the implant in the model showed an increasing trend.(4)In each group of models,stress of cortical bone concentrated around the neck of the implant and the periphery of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the equivalent stress peak around the root shield decreased;the peak value of the equivalent stress of the bone around the neck of the implant showed an increasing trend.In the model,the stress of cancellous bone was mainly concentrated around the neck of the lip of the implant,the top of the thread,the root tip and the lower margin of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the peak value of the equivalent stress of the bone around the root shield in the model showed a decreasing trend.The minimum principal stress of cortical bone in each group of models was concentrated around the neck of the implant,exhibiting a fan-shaped distribution.As the thickness of the root shield increased,the minimum principal stress of cortical bone showed an increasing trend.(5)These results indicate that different thicknesses of the root shield have different biomechanical effects.The root shield with a thickness of 0.5 mm is easy to fracture.For patients with sufficient bone width,the root shield with a thickness of 2.0 mm is an option to reduce the risk of complications such as root shield exposure,fracture,and displacement.Meanwhile,it should be taken into account to protect the periodontal ligament in the preparation process,and rounding treatments ought to be carried out on both sides and the lower edge of the root shield.

OBJECTIVE: To assess the association between the single nucleotide polymorphisms (SNP) rs174575 and rs2845574 of the fatty acid desaturase 2 (FADS2) gene and gestational diabetes mellitus (GDM). METHODS: A total of 1 514 pregnant women who visited West China Second University Hospital of Sichuan University between January 1, 2013 and December 31, 2021 were enrolled in this study. Among them, 583 were diagnosed with gestational diabetes mellitus (GDM group), and 931 had normal pregnancies (control group). The SNPs rs174575 and rs2845574 of the FADS2 gene were analyzed using Sanger DNA sequencing. Plasma levels of insulin (INS), apolipoprotein A1 (apoA1) and apolipoprotein B (apoB) were measured using enzymatic methods, chemiluminescence and immunoturbidimetry. This study was approved by the Medical Ethics Committee of the West China Second University Hospital of Sichuan University (Ethics No.: 2020-036). RESULTS: The main genotype at the rs174575 C/G and rs2845574 C/T loci were CC in both GDM and control groups. No significant difference was found between the GDM and control groups regarding the genotypic or allelic frequencies of rs174575 and rs2845574 sites (P > 0.05). Among the GDM group, individuals with the GG genotype at the rs174575 site had lower plasma HDL-C levels compared to those with the CC genotype (P < 0.05), and had higher atherogenic indices (AI) compared with the CC and CG genotype (P < 0.05; P < 0.05). Individuals with the TT genotype at the rs2845574 site had higher AI compared with the CT genotype (P < 0.05). Among the control group, individuals with the GG genotype had lower diastolic blood pressure (DBP) compared to those with the CC genotype (P < 0.05). Additional subgroup analysis demonstrated that the rs174575 polymorphism was associated with AI levels in obesity subgroup of GDM, TG levels in non-obese subgroup of control and DBP levels in the obese subgroup of control (P < 0.05; P < 0.05; P < 0.05). CONCLUSION The FADS2 rs174575 and rs2845574 polymorphisms in GDM patients are associated wit HDL-C and AI levels, and the FADS2 rs174575 polymorphisms was also associated with DBP levels in normal pregnant women. The AI and DBP levels have a BMI-dependent effect.
Humans ; Female ; Pregnancy ; Fatty Acid Desaturases/genetics* ; Polymorphism, Single Nucleotide ; Adult ; Diabetes, Gestational/blood* ; Blood Pressure/genetics* ; Lipids/blood* ; Genotype ; Genetic Predisposition to Disease