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published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating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:Curcumin is the main active ingredient of turmeric and has significant medicinal value in anti-tumor,anti-inflammatory,antioxidant and other aspects.However,its poor water solubility,unstable chemical properties and easy decomposition lead to difficulty in extracting curcumin and low extraction yield.Therefore,it is particularly important to optimize the curcumin extraction method.OBJECTIVE:To enhance the extraction yield and utilization value of curcumin and optimize the curcumin extraction process and curcumin nanoparticle preparation process.METHODS:Curcumin was extracted from turmeric by ethanol extraction,ultrasonic extraction,ionic liquid extraction,enzyme extraction,and ionic liquid combined with ultrasonic assisted enzyme extraction.The curcumin extraction yield was detected by high performance liquid chromatography;the best extraction method was determined,and subsequent process optimization experiments were carried out.The curcumin extraction yield was the response value with the type of ionic liquid,reaction temperature,ultrasonic time,liquid-to-solid ratio,ionic liquid concentration,and enzyme-drug mass ratio as parameters.The optimal production process of ionic liquid combined with ultrasonic assisted enzyme extraction was determined by single factor combined response surface experiment.The optimal process for preparing curcumin nanoparticles by ionic crosslinking method was determined by single factor combined response surface experiment with acetic acid concentration,chitosan to sodium tripolyphosphate mass ratio,stirring rate,curcumin mass concentration,sodium tripolyphosphate mass concentration,and chitosan mass concentration as parameters,and drug encapsulation efficiency as response value.Curcumin nanoparticles were prepared under the optimal process,and the particle size,polydispersity index,Zata potential value,drug loading,stability,hemolysis rate,and antioxidant capacity in vivo and in vitro of the nanoparticles were detected.RESULTS AND CONCLUSION:(1)Among the five extraction methods,the curcumin yield of ionic liquid combined with ultrasound-assisted enzyme extraction was the highest,and this method was selected as the curcumin extraction method for subsequent experiments.The results of single factor combined response surface experiment showed that the optimal process for curcumin extraction was:ionic liquid selected 1-hexyl-3-methylimidazolium chloride,reaction temperature 55 ℃,liquid-to-solid ratio 40 mL/g,ultrasound time 57 minutes,ionic liquid concentration 57％,enzyme-drug mass ratio 3.5:10,and the obtained turmeric extraction yield was 3.10％.The optimal preparation process of curcumin nanoparticles was:glacial acetic acid concentration 0.5％,chitosan and sodium tripolyphosphate mass ratio 5.0:1,stirring speed 150 r/min,curcumin mass concentration 2.23 mg/mL,sodium tripolyphosphate mass concentration 1.45 mg/mL,chitosan mass concentration 3.63 mg/mL,and the obtained drug encapsulation efficiency was 90.61％.(2)The drug loading of curcumin nanoparticles was(14.49±0.23)％,the average particle size was(76.95±1.65)nm,the polydispersity coefficient was 0.15±0.02,and the Zata potential value was(32.37±1.46)mV.The curcumin nanoparticles had good stability and blood compatibility,did not induce hemolysis,and had stronger antioxidant capacity in vivo and in vitro than free curcumin.(3)The results show that the process optimization not only solves the problems of low extraction yield,poor solubility,and low bioavailability of curcumin,but also enhances its antioxidant activity in vivo and in vitro.

BACKGROUND:Nanocell vesicles possess functions such as re-epithelialization,antioxidation,anti-inflammation,and regulation of extracellular matrix remodeling.Meanwhile,apoptotic bodies have the immunomodulatory effects.Therefore,the combination of the two to form nanofusion vesicles can synergistically promote the healing of diabetic skin wounds.OBJECTIVE:To elucidate the impact of nanofusion vesicles on skin wound healing in a diabetic murine model.METHODS:(1)Material preparation and characterization:The primary bone marrow mesenchymal stem cells of C57BL/6J neonatal mice and the neutrophil apoptotic bodies of C57BL/6J mice were isolated and extracted.The nanofusion vesicles were prepared by micro-extrusion mechanism.(2)In vitro experiment:MTT assay was used to detect the proliferative effect of different concentrations of nanofusion vesicles on NIH-3T3 cells and human umbilical vein endothelial cells.Reactive oxygen species fluorescence probe was used to detect the antioxidant effect of nano-fusion vesicles on NIH-3T3 cells treated with hydrogen peroxide(H2O2).The inhibitory effect of nanofusion vesicles on RAW 264.7 macrophage inflammation induced by lipopolyside was detected by real-time quantitative RT-qPCR.(3)In vivo experiment:36 male C57BL/6J mice were employed to develop a murine model of diabetes mellitus.Following the successful induction of diabetes,two circular full-thickness wounds,each with a diameter of 6 mm,were created on either side of the diabetic mice's spine using a skin punch.The mice were divided into three groups by random number table method.The control group was injected with 0.1 mL of phosphate buffer solution.The nanovesicle group was injected with 0.1 mL nanovesicles(25 μg/mL).The nanofusion vesicle group was injected with 0.1 mL nanofusion(25 μg/mL)vesicles.After treatment for three consecutive days,the wound healing and histomorphological changes were observed.RESULTS AND CONCLUSION:(1)In vitro experiment:nanofusion vesicles,when administered at concentrations ranging from 0 to 100 μg/mL,exhibited no toxic effects and promoted the proliferation of NIH-3T3 and HUVEC cell lines.Notably,a concentration of 25 μg/mL nanofusion vesicle significantly enhanced the proliferation of NIH-3T3 cells.Furthermore,the survival rate of human umbilical vein endothelial cells was observed to increase in correlation with escalating concentrations of nanofusion vesicles.Nanofusion vesicles had a good antioxidant effect.In comparison to the H2O2 group,the fluorescence signal indicative of reactive oxygen species was progressively diminished in both the nanovesicle group and the nanofusion vesicle group.Furthermore,nanofusion vesicles possessed anti-inflammatory capabilities,effectively mitigating the inflammatory response in macrophages triggered by lipopolysaccharide stimulation.(2)In vivo experiment:Hematoxylin-eosin and Masson's trichrome staining revealed that in comparison to the control group,both the nanovesicle group and the nanofusion vesicle group exhibited a significant increase in granulation tissue formation and collagen fiber deposition within the wounds by day 6.Notably,the nanofusion vesicle group displayed the most pronounced effects.On day 12,the wound of nanofusion vesicle group was significantly reduced,and the healing rate was significantly faster than that of other groups(P＜0.01),and the effect of promoting wound healing was the most significant.Our findings demonstrated that nanofusion vesicles exhibited superior pro-cell proliferative,antioxidant,and anti-inflammatory properties,thereby exerting a beneficial effect on the promotion of skin wound healing in diabetic mouse models.

BACKGROUND:Bone tissue loss caused by tumors and trauma can have an adverse effect on postoperative rehabilitation.Therefore,scaffold materials are usually implanted during treatment.However,the existing implant materials are relatively simple and lack antibacterial properties.Early implantation may lead to iatrogenic autoinfection and have an adverse effect on osteogenesis.OBJECTIVE:To construct a KR-12-a5 polypeptide-nanohydroxyapatite-small intestinal submucosa composite scaffold and evaluate its feasibility as a material for promoting bone defect repair.METHODS:The small intestinal submucosa scaffold and the small intestinal submucosa scaffold containing 25,50,and 100 mg/mL nanohydroxyapatite(referred to as nHA-SIS scaffold)were prepared by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride/N-hydroxysuccinimide cross-linking method.The appropriate scaffold was screened for subsequent experiments by mechanical property testing.The antibacterial properties of KR-12-a5 polypeptide solution against Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum were detected.The nHA-SIS scaffolds were immersed in 250,500,and 1 000 μg/mL KR-12-a5 peptide solutions for 24 hours,and then freeze-dried to obtain peptide-loaded nanohydroxyapatite-porcine small intestinal submucosa composite scaffolds(denoted as P-nHA-SIS scaffolds).The sustained-release properties of the three groups of scaffolds were characterized.The nHA-SIS scaffolds and the three groups of P-nHA-SIS scaffolds were co-cultured with Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum for 24 hours or 48 hours.The scaffolds with strong antibacterial ability were screened by live and dead bacteria staining and scanning electron microscopy for subsequent experiments.The degradation properties and water absorption rates of the uncross-linked small intestinal submucosa scaffolds,cross-linked small intestinal submucosa scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were characterized.The extracts of cross-linked small intestinal submucosal scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were co-cultured with MC3T3-E1 cells.CCK-8 assay and live-dead cell staining were performed.The effects of the extracts of the three scaffolds on the migration of MC3T3-E1 cells were detected by Transwell chamber assay.RESULTS AND CONCLUSION:(1)The elastic modulus and compressive strength of 25,50,and 100 mg/mL nHA-SIS scaffolds were higher than those of small intestinal submucosal scaffolds(P＜0.05),among which the elastic modulus and compressive strength of 25 mg/mL nHA-SIS scaffolds were the highest,and this group of scaffolds were selected for subsequent experiments to load peptides.(2)KR-12-a5 peptide had strong antibacterial activity against common bacteria in bone defects(Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum).The three groups of P-nHA-SIS scaffolds all had sustained release properties.With the increase of peptide mass concentration,the antibacterial property of P-nHA-SIS scaffold was enhanced.Among them,the P-nHA-SIS scaffold loaded with 500 μg/mL peptide had achieved a satisfactory antibacterial effect,and this group of scaffolds would be selected in the future.(3)The degradation rate of the three groups of cross-linked scaffolds was lower than that of the uncross-linked scaffolds,and the water absorption rate was greater than that of the uncross-linked scaffolds.P-nHA-SIS scaffolds could promote the proliferation and migration of MC3T3-E1 cells without affecting the activity of MC3T3-E1 cells.(4)The results show that P-nHA-SIS scaffolds have strong antibacterial properties and the ability to promote the proliferation and migration of MC3T3-E1 cells,and are expected to be used in bone defect repair.

BACKGROUND:Studies have shown that platelet-derived growth factor BB can stimulate the proliferation and osteogenic differentiation of mesenchymal stem cells and accelerate the calcification process of osteoblast-like cells.However,its clinical application has problems such as short half-life and easy decomposition.Loading the growth factor onto a suitable biomaterial scaffold can enable its slow and continuous release and maintain an effective concentration,which has become a hot topic in current research.OBJECTIVE:To observe the effect of chitosan/reduced graphene oxide scaffolds loaded with platelet-derived growth factor BB on the repair of alveolar bone defect in rats.METHODS:(1)Chitosan/reduced graphene oxide scaffolds(referred to as CS/rGO scaffolds)and chitosan/reduced graphene oxide scaffolds loaded with different mass concentrations(5,10,15,and 20 mg/L)of platelet-derived growth factor BB(referred to as CS/rGO/PDGF-BB-5,CS/rGO/PDGF-BB-10,CS/rGO/PDGF-BB-15,and CS/rGO/PDGF-BB-20 scaffolds)were prepared respectively.The five groups of scaffolds were co-cultured with rat periodontal ligament stem cells.The cell proliferation and migration were detected by CCK-8 assay and Transwell chamber assay,respectively,to screen the appropriate growth factor loading mass concentration for subsequent experiments.CS/rGO scaffolds(or extracts)and CS/rGO/PDGF-BB-15 scaffolds(or extracts)were co-cultured with rat periodontal ligament stem cells,and the osteogenic differentiation and angiogenic ability of the cells were detected.(2)The alveolar bone defect model was prepared in front of the bilateral maxillary first molars of 16 SD rats,and the rats were randomly divided into 4 intervention groups:the blank control group did not receive any intervention,the simple scaffold group was implanted with CS/rGO/PDGF-BB-15 scaffold,the control group was implanted with CS/rGO scaffold and rat periodontal ligament stem cell complex,and the experimental group was implanted with CS/rGO/PDGF-BB-15 scaffold and rat periodontal ligament stem cell complex,with 4 rats in each group.Twelve weeks after surgery,the bone repair of the alveolar bone defect was observed by Micro CT scanning and hematoxylin-eosin staining.RESULTS AND CONCLUSION:(1)CS/rGO/PDGF-BB-5,CS/rGO/PDGF-BB-10,CS/rGO/PDGF-BB-15,and CS/rGO/PDGF-BB-20 scaffolds could promote the proliferation and migration of rat periodontal ligament stem cells.Among them,the CS/rGO/PDGF-BB-15 scaffold had the most significant effect on promoting cell proliferation and migration,and this scaffold was used for subsequent experiments.Compared with the CS/rGO scaffold,the CS/rGO/PDGF-BB-15 scaffold could promote the osteogenic and angiogenic differentiation of rat periodontal ligament stem cells.(2)Micro CT scanning and hematoxylin-eosin staining results showed that the experimental group had the best alveolar bone defect repair effect,and a large amount of new bone tissue and blood vessel formation could be seen.(3)The chitosan/reduced graphene oxide scaffold loaded with platelet-derived growth factor BB can effectively promote the repair of rat alveolar bone defects by promoting the proliferation,migration,angiogenic and osteogenic differentiation of rat periodontal ligament stem cells.

BACKGROUND:Bone remodeling is the biological basis of orthodontic tooth movement.Type 2 diabetes mellitus leads to metabolic changes in the jaw and alveolar bone,so it is hypothesized that tooth mobility characteristics may be altered in a high-sugar environment.OBJECTIVE:To explore the impact of type 2 diabetes mellitus on orthodontic tooth movement in rats within one tooth movement cycle.METHODS:Seventy-two Sprague-Dawley rats were selected.Forty rats were randomly chosen and fed with a high-fat diet to construct a type 2 diabetes mellitus model.Thirty-two rats that were successfully modeled were randomly divided into a type 2 diabetes mellitus group(n=16)and a diabetic orthodontic group(n=16).The remaining 32 rats were randomly divided into a control group(n=16)and an orthodontic group(n=16).The rats in the orthodontic group and the diabetic orthodontic group were equipped with nickel-titanium coil spring orthodontic force application devices to move the unilateral maxillary first molars mesially with a force of 50 g.The rats were anesthetized and sacrificed on the 3rd,7th,14th,and 21st days after orthodontic treatment,and Micro-CT was used to measure the mesial displacement of the first molars and detect the changes in the bone microstructure parameters on the tension side.RESULTS AND CONCLUSION:There were significant differences in the tooth movement distances among the four groups of rats on the 3rd,7th,14th,and 21st days of orthodontic treatment(P＜0.05).There were significant differences in bone mineral density,bone volume fraction and trabecular bone separation on the tension side among the four groups on the 7th,14th,and 21st days of orthodontic treatment(P＜0.05).There were differences in the trabecular thickness among the four groups on the 3rd and 14th days of orthodontic treatment(P＜0.05).The diabetic orthodontic group had the smallest tension-side alveolar bone mineral density,bone volume fraction,and trabecular thickness,and the largest tooth movement distance and trabecular separation on the 21st day of orthodontic treatment.The above results indicate that type 2 diabetes mellitus adversely affects bone microstructural parameters on the tension side in orthodontic tooth movement in rats,suggesting the occurrence of an osteoporotic state.

BACKGROUND:Hydrogen peroxide-based bleach is widely used in clinical tooth whitening treatment,but its mechanism of action has not been uniformly determined so far.OBJECTIVE:To examine the effects of two bleaching agents,neutral 10％carbamide peroxide and neutral 40％hydrogen peroxide,on teeth and explore the mechanism of teeth whitening.METHODS:Forty-five discarded teeth extracted for orthodontic treatment were collected,and the dentin sections were made and polished.After removing the smear layer,they were randomly divided into three groups.The control group(n=15)was placed in deionized water;the carbamide peroxide group(n=15)was placed in a neutral 10％carbamide peroxide solution,and the hydrogen peroxide group(n=15)was placed in a neutral 40％hydrogen peroxide solution.The treatment was continued for 6 hours every day for 1 week.The Raman absolute intensity and Raman relative intensity of the three groups of samples were detected by Raman spectrometer every day,and the fluorescence background intensity(the difference between the Raman absolute intensity and the Raman relative intensity)was calculated.The change trend of the amide peak of the three groups of samples every day was recorded by infrared spectrometer.RESULTS AND CONCLUSION:(1)The relative Raman intensity of the three groups did not change significantly during the 1-7 days of treatment.The fluorescence background intensity of the control group did not change significantly during the 1-7 days of treatment.The fluorescence background intensity of the carbamide peroxide group showed a downward trend during the 1-7 days of treatment.The fluorescence background intensity of the hydrogen peroxide group decreased significantly during the 1-4 days of treatment and did not change significantly thereafter.(2)The peak areas of amide Ⅰ and amide Ⅲ did not change significantly during the 1-7 days of treatment in the control group.The peak areas of amide Ⅰ and amide Ⅲ showed a downward trend during the 1-7 days of treatment in the carbamide peroxide group and the hydrogen peroxide group,and the downward trend was more obvious in the hydrogen peroxide group.(3)The results show that the change in the laser-induced fluorescence background intensity of dentin Raman spectroscopy may be derived from the non-collagen components in dentin,and under the action of whitening agents,it may have a certain adverse effect on tooth tissue.

BACKGROUND:Inter-limb asymmetry is a common phenomenon observed during human growth and development.Prolonged specialized training can lead to specific adaptations in inter-limb asymmetry among athletes.OBJECTIVE:To review the formation causes,manifestations,and impacts of inter-limb asymmetry on sports performance,and provide an overview of the relevant assessment methods and intervention strategies.METHODS:A literature search was conducted in the CNKI,WanFang,PubMed,and Web of Science databases from their inception to September 2024.The search terms included"asymmetry,asymmetries,asymmetric,asymmetrical,imbalance,strength,power,force,jump,sprint,athletic performance,anthropometry,injury"in English and Chinese.After excluding duplicate publications,irrelevant content,and conference papers,a total of 131 articles were finally included for analysis.RESULTS AND CONCLUSION:(1)Inter-limb asymmetry can be influenced by various factors including genetics,task demands,training regimens,injuries,fatigue,and limb preference.These factors lead to being primarily manifested in anatomical structure,strength performance,and task-specific asymmetry.(2)An increase in inter-limb asymmetry can result in impaired performance in bilateral in-phase symmetric movements.However,the relationship between increased inter-limb asymmetry and bilateral out-of-phase symmetric movements remains unclear and requires further investigation.(3)Training interventions have been shown to effectively mitigate inter-limb asymmetry,with unilateral training demonstrating superior outcomes compared with bilateral training.The choice of training methods and content should be tailored to meet the specific demands of the sport.(4)To further clarify the relationship between inter-limb asymmetry and athletic performance,it is recommended that future research adopt the concept of"task specificity"in inter-limb asymmetry.This includes standardizing study designs,selecting sensitive testing methods and indicators,unifying calculation methods to provide more high-quality evidence,and establishing categorized warning threshold standards for inter-limb asymmetry in different sports.

The prescription of Qidong Yixin oral liquid is derived from the experience of national medical master Ren Jixue in treating viral myocarditis （VMC）. It has the functions of tonifying Qi， nourishing the heart，calming the mind， and relieving palpitations. It is used to treat VMC and angina pectoris of coronary heart disease caused by deficiency of both Qi and Yin. However，the understanding of its efficacy evidence， advantageous aspects， dosage and administration， and medication safety remains insufficient in clinical practice. Therefore，the development of the Expert Consensus on the Clinical Application of Qidong Yixin Oral Liquid （hereinafter referred to as consensus） was initiated. Consensus strictly followed the process and methods of the expert consensus on the clinical application of Chinese patent medicines of the China Association of Chinese Medicine，successively completing multiple tasks such as the consensus project initiation，determination of clinical problems，evidence search and evaluation，formation of recommendation opinions and consensus suggestions，solicitation of opinions，peer review， submission for review and release， and so on. Consensus formed a total of 10 recommendation opinions and 12 consensus suggestions，clarifying the clinical positioning，efficacy advantages，syndrome differentiation，dosage and administration，combination therapy，timing of medication，adverse reactions，contraindications， and precautions of Qidong Yixin oral liquid，indicating that it has good clinical advantages and safety in the treatment of VMC and angina pectoris of coronary heart disease，providing norms and references for physicians to safely and rationally apply Qidong Yixin oral liquid. Consensus was reviewed and approved for release by the Standardization Office of the China Association of Chinese Medicine on December 23， 2024. Standard number：GSCACM-376-2024.

Breast cancer （BC）， a common malignant tumor in women， is characterized by high incidence and mortality rates， posing a serious threat to women's life and health. Currently， the commonly used treatments for BC include surgery， radiotherapy， chemotherapy， molecular targeted therapy， and endocrine therapy. Although radiotherapy and chemotherapy can effectively kill tumor cells and inhibit the proliferation and differentiation of tumor cells， they can induce adverse reactions such as hematopoietic dysfunction and impaired immune function. The other treatment methods also have problems such as drug resistance， high recurrence rates， reduced quality of life， and poor clinical efficacy. Therefore， it is urgent to explore new drugs with better efficacy and lower toxicity. Ferroptosis is a form of iron-dependent， non-apoptotic programmed cell death triggered by lipid peroxidation. In recent years， ferroptosis has become a hot topic in the field of cancer treatment and has been gradually proven to effectively inhibit the proliferation and metastasis of BC cells， reduce the drug resistance of BC to chemotherapy drugs， and enhance the sensitivity of BC to radiotherapy. Traditional Chinese medicine （TCM）， with multiple components， multiple targets， and mild side effects， is widely used in the treatment of BC. A large number of studies have shown that active ingredients of TCM， such as saponins， flavonoids， terpenoids， phenols， and polysaccharides， can inhibit the proliferation and metastasis of BC cells by modulating ferroptosis-related pathways. These include iron metabolism， lipid metabolism， cystine/glutamate antiporter system Xc^-/glutathione/glutathione peroxidase 4， Specifically， these ingredients elevate the levels of lipid peroxidation， reactive oxygen species， malondialdehyde， and Fe²⁺ in BC cells， thereby inducing ferroptosis-mediated suppression of tumor progression. This article reviews the relevant literature at home and abroad in recent years， summarizes the mechanisms of ferroptosis in regulating BC and the research progress in the active components of TCM targeting ferroptosis in the intervention of BC， aiming to provide ideas for the development of new drugs for the treatment of BC.