BACKGROUND:Magnetic nanomaterials,as a hot topic in the biomedical field in recent years,are often used to enhance the targeted delivery of drugs to the affected area.OBJECTIVE:To investigate the effects of magnetic nano drug carriers on skeletal muscle injury markers and inflammatory responses in rats with sports injuries.METHODS:Magnetic nanoparticles were prepared.A total of 88 male SD rats were randomly divided into a blank group(n=8),an injury control group(n=32),a Yunnan Baiyao group(n=24),and a magnetic nano-drug carrier group(n=24)by using a random number table method.The latter three groups were modeled with exercise-induced muscle injury(treadmill slope of-16°,running speed of 16 m/min,and training time of 120 min).Immediately after exercise,after verifying the success of the model,Yunnan Baiyao patch was applied to the gastrocnemius muscle of the rats in the Yunnan Baiyao group.Yunnan Baiyao patch loaded with magnetic nanoparticles was applied to the gastrocnemius muscle of the rats in the magnetic nano-drug carrier group.At 24,48,and 120 hours after exercise,blood was drawn from the abdominal aorta of rats to detect the activities of creatine kinase and lactate dehydrogenase,as well as the levels of myoglobin,interleukin-6,and tumor necrosis factor-α.Hematoxylin-eosin staining was used to observe the infiltration of inflammatory cells in the gastrocnemius muscle.RESULTS AND CONCLUSION:(1)Compared with the blank group,the levels of myoglobin,creatine kinase,lactate dehydrogenase and tumor necrosis factorα in the injury control group at 24,48 and 120 hours after exercise were increased(P＜0.05),and the level of interleukin 6 at 24 and 120 hours after exercise was increased(P＜0.05).Compared with the injury control group,the level of myoglobin in the Yunnan Baiyao group at 24 and 48 hours after exercise was decreased(P＜0.05),the activities of creatine kinase and lactate dehydrogenase at 24,48 and 120 hours were decreased(P＜0.05),and the levels of interleukin 6 and tumor necrosis factor α at 120 hours after exercise were decreased(P＜0.05).Compared with the Yunnan Baiyao group,the level of myoglobin in the magnetic nano-drug carrier group at 24 and 48 hours after exercise was decreased(P＜0.05),the activities of creatine kinase and tumor necrosis factor α at 48 and 120 hours after exercise were decreased(P＜0.05),and the lactate dehydrogenase activity was reduced(P＜0.05).(2)Hematoxylin-eosin staining showed that a large number of inflammatory cells infiltrated in the muscle fibers of the injury control group 24 hours after exercise,and then the inflammatory cell infiltration gradually decreased,and the local damaged muscle fibers began to regenerate 120 hours after exercise.A large number of inflammatory cells infiltrated in the muscle fibers of the Yunnan Baiyao group and the magnetic nano-drug carrier group 24 hours after exercise,and then the inflammatory cell infiltration gradually decreased,and the damaged muscle fibers were regenerating 120 hours after exercise,and there was no significant difference from the blank group.(3)The results show that Yunnan Baiyao patch combined with magnetic nanoparticles can accelerate the recovery of exercise-induced muscle injury in rats,and the effect is better than that of Yunnan Baiyao alone.

BACKGROUND:A large number of studies have demonstrated that stem cell exosomes play an important role in the repair of bone defects,either directly as carriers for loading other small molecules or surface modifications,or by binding to biomaterials to promote the repair and regeneration of bone tissue.OBJECTIVE:To summarize the osteogenic mechanisms of stem cell exosomes from different sources and their research progress in bone defect repair.METHODS:Chinese search terms"stem cell,exosome,bone,biomaterial,carrier,bioceramic,polymer,metal,hydrogel,engineered exosome"were used to search CNKI.English search terms"stem cell,exosome,bone defect,biomaterial,carrier,bioceramic,ploymer,metal material,hydrogel,engineering exosome"were used to search PubMed database.According to the inclusion and exclusion criteria,77 relevant articles were finally included for summary.RESULTS AND CONCLUSION:Exosomes from stem cells of different origins can promote osteoblast proliferation and differentiation,promote angiogenesis,and regulate osteoclast activity and macrophage phenotype to promote bone formation and bone mineralization.In addition,many achievements of exosomes in the field of bone defect repair were described from two aspects:biomaterial-assisted exosomes and engineered exosomes.However,the current research on stem cell exosomes in bone tissue engineering is still insufficient,and most of these studies are limited to small animal models,while the treatment of bone defects in large animals,including humans,will be more complex,which will also become a major challenge for the treatment of bone defects.This will also be a great challenge in the dissemination of exosome therapy.

BACKGROUND:Spondylolisthesis is a common disease,and there is a lack of effective drugs to treat it.There is still a need to further define the pathogenesis and screen out more suitable therapeutic targets for spondylolisthesis.Mendelian randomization analysis can be used to explore the drugable genes associated with spondylolisthesis and provide valuable guidance for the development of more effective and targeted therapeutic drugs.OBJECTIVE:To explore potential therapeutic targets and effective drugs for spondylolisthesis by means of pharmaceutically available genome-wide Mendelian randomization analysis.METHODS:Using the Finnish database,eQTLGen consortium,drug signature database,drug-gene interaction database,protein-protein interaction database,organic small molecule biological activity database and protein structure database,which contains genome and health information of half a million Finns,data on druggable genes were subjected to two-sample Mendelian randomization analysis and co-localization analysis with data from genome-wide association studies of spondylolisthesis to identify genes highly associated with spondylolisthesis.In addition,GO and KEGG enrichment analysis,protein network construction,drug prediction and molecular docking were performed to provide valuable guidance for the development of more effective and targeted therapeutic agents.RESULTS AND CONCLUSION:In this study,we identified 34 potential drug target genes that were significantly associated with spondylolisthesis,particularly the gene APOBEC3G.This gene showed a significant association with spondylolisthesis outcomes through Mendelian analysis and co-localization analysis,suggesting that APOBEC3G may be a priority therapeutic target.As for other potential mechanisms and drugs,we still need to conduct more in-depth research to determine their roles.This study used a database from a European population,which can be used as a reference for the study of population genetics in China.

BACKGROUND:Rheumatoid arthritis is widely prevalent worldwide,with its high incidence and universality that considerably affects patients' quality of life.Previous studies have focused on a few immune cells or cytokines,whereas this study comprehensively provides a more complete view of the immune mechanisms in rheumatoid arthritis.OBJECTIVE:To explore the causal relationship between 731 immune cell phenotypes and rheumatoid arthritis using the Mendelian randomization method,thereby providing evidence of causality.METHODS:The 731 immune cell phenotypes used in this study were sourced from the GWAScatalog database,jointly developed by the National Human Genome Research Institute(NHGRI)and the European Bioinformatics Institute(EBI).The rheumatoid arthritis data were from the Finngen database,developed by the Finnish Institute for Molecular Medicine(FIMM).The inverse variance weighting method was employed as the primary analytical approach.Additionally,multiple analytical methods,including MR-Egger,weighted mode,simple mode,and weighted median,were concurrently utilized to complement the final results.Sensitivity analyses(Cochran's Q test,MR-Egger regression,and MR-presso analysis)were also conducted to verify the stability and feasibility of the data.RESULTS AND CONCLUSION:(1)After excluding results through heterogeneity testing,the inverse variance weighting analysis indicated that 10 absolute cell counts,15 median fluorescence intensities of surface antigen levels,1 morphological characteristic,and 9 relative cell counts had a causal relationship with the occurrence of rheumatoid arthritis.(2)According to cell classification,this study found that seven types of B cells,seven types of classical dendritic cells,six types of mature T cells,four types of monocytes,three types of myeloid cells,three types of TBNK cells(lymphocyte subset T cells,B cells and natural killer cells),and five types of Tregs had a causal association with the occurrence of rheumatoid arthritis.(3)Through comprehensive bidirectional two-sample MR analysis,we demonstrated the complex causal relationships between multiple immune phenotypes and rheumatoid arthritis,highlighting the intricate interaction patterns between the immune system and rheumatoid arthritis.These results provide new biomarkers for the early screening and diagnosis of rheumatoid arthritis in China,and help to improve the diagnostic accuracy and sensitivity.

BACKGROUND:Magnetic nanomaterials,as a hot topic in the biomedical field in recent years,are often used to enhance the targeted delivery of drugs to the affected area.OBJECTIVE:To investigate the effects of magnetic nano drug carriers on skeletal muscle injury markers and inflammatory responses in rats with sports injuries.METHODS:Magnetic nanoparticles were prepared.A total of 88 male SD rats were randomly divided into a blank group(n=8),an injury control group(n=32),a Yunnan Baiyao group(n=24),and a magnetic nano-drug carrier group(n=24)by using a random number table method.The latter three groups were modeled with exercise-induced muscle injury(treadmill slope of-16°,running speed of 16 m/min,and training time of 120 min).Immediately after exercise,after verifying the success of the model,Yunnan Baiyao patch was applied to the gastrocnemius muscle of the rats in the Yunnan Baiyao group.Yunnan Baiyao patch loaded with magnetic nanoparticles was applied to the gastrocnemius muscle of the rats in the magnetic nano-drug carrier group.At 24,48,and 120 hours after exercise,blood was drawn from the abdominal aorta of rats to detect the activities of creatine kinase and lactate dehydrogenase,as well as the levels of myoglobin,interleukin-6,and tumor necrosis factor-α.Hematoxylin-eosin staining was used to observe the infiltration of inflammatory cells in the gastrocnemius muscle.RESULTS AND CONCLUSION:(1)Compared with the blank group,the levels of myoglobin,creatine kinase,lactate dehydrogenase and tumor necrosis factorα in the injury control group at 24,48 and 120 hours after exercise were increased(P＜0.05),and the level of interleukin 6 at 24 and 120 hours after exercise was increased(P＜0.05).Compared with the injury control group,the level of myoglobin in the Yunnan Baiyao group at 24 and 48 hours after exercise was decreased(P＜0.05),the activities of creatine kinase and lactate dehydrogenase at 24,48 and 120 hours were decreased(P＜0.05),and the levels of interleukin 6 and tumor necrosis factor α at 120 hours after exercise were decreased(P＜0.05).Compared with the Yunnan Baiyao group,the level of myoglobin in the magnetic nano-drug carrier group at 24 and 48 hours after exercise was decreased(P＜0.05),the activities of creatine kinase and tumor necrosis factor α at 48 and 120 hours after exercise were decreased(P＜0.05),and the lactate dehydrogenase activity was reduced(P＜0.05).(2)Hematoxylin-eosin staining showed that a large number of inflammatory cells infiltrated in the muscle fibers of the injury control group 24 hours after exercise,and then the inflammatory cell infiltration gradually decreased,and the local damaged muscle fibers began to regenerate 120 hours after exercise.A large number of inflammatory cells infiltrated in the muscle fibers of the Yunnan Baiyao group and the magnetic nano-drug carrier group 24 hours after exercise,and then the inflammatory cell infiltration gradually decreased,and the damaged muscle fibers were regenerating 120 hours after exercise,and there was no significant difference from the blank group.(3)The results show that Yunnan Baiyao patch combined with magnetic nanoparticles can accelerate the recovery of exercise-induced muscle injury in rats,and the effect is better than that of Yunnan Baiyao alone.

BACKGROUND:A large number of studies have demonstrated that stem cell exosomes play an important role in the repair of bone defects,either directly as carriers for loading other small molecules or surface modifications,or by binding to biomaterials to promote the repair and regeneration of bone tissue.OBJECTIVE:To summarize the osteogenic mechanisms of stem cell exosomes from different sources and their research progress in bone defect repair.METHODS:Chinese search terms"stem cell,exosome,bone,biomaterial,carrier,bioceramic,polymer,metal,hydrogel,engineered exosome"were used to search CNKI.English search terms"stem cell,exosome,bone defect,biomaterial,carrier,bioceramic,ploymer,metal material,hydrogel,engineering exosome"were used to search PubMed database.According to the inclusion and exclusion criteria,77 relevant articles were finally included for summary.RESULTS AND CONCLUSION:Exosomes from stem cells of different origins can promote osteoblast proliferation and differentiation,promote angiogenesis,and regulate osteoclast activity and macrophage phenotype to promote bone formation and bone mineralization.In addition,many achievements of exosomes in the field of bone defect repair were described from two aspects:biomaterial-assisted exosomes and engineered exosomes.However,the current research on stem cell exosomes in bone tissue engineering is still insufficient,and most of these studies are limited to small animal models,while the treatment of bone defects in large animals,including humans,will be more complex,which will also become a major challenge for the treatment of bone defects.This will also be a great challenge in the dissemination of exosome therapy.

BACKGROUND:Spondylolisthesis is a common disease,and there is a lack of effective drugs to treat it.There is still a need to further define the pathogenesis and screen out more suitable therapeutic targets for spondylolisthesis.Mendelian randomization analysis can be used to explore the drugable genes associated with spondylolisthesis and provide valuable guidance for the development of more effective and targeted therapeutic drugs.OBJECTIVE:To explore potential therapeutic targets and effective drugs for spondylolisthesis by means of pharmaceutically available genome-wide Mendelian randomization analysis.METHODS:Using the Finnish database,eQTLGen consortium,drug signature database,drug-gene interaction database,protein-protein interaction database,organic small molecule biological activity database and protein structure database,which contains genome and health information of half a million Finns,data on druggable genes were subjected to two-sample Mendelian randomization analysis and co-localization analysis with data from genome-wide association studies of spondylolisthesis to identify genes highly associated with spondylolisthesis.In addition,GO and KEGG enrichment analysis,protein network construction,drug prediction and molecular docking were performed to provide valuable guidance for the development of more effective and targeted therapeutic agents.RESULTS AND CONCLUSION:In this study,we identified 34 potential drug target genes that were significantly associated with spondylolisthesis,particularly the gene APOBEC3G.This gene showed a significant association with spondylolisthesis outcomes through Mendelian analysis and co-localization analysis,suggesting that APOBEC3G may be a priority therapeutic target.As for other potential mechanisms and drugs,we still need to conduct more in-depth research to determine their roles.This study used a database from a European population,which can be used as a reference for the study of population genetics in China.

Objective To assess the echogenicity of the ultrasound-guided catheter and its associated delivery system. Methods The study consisted of in vitro characterization experiments and animal studies. In the in vitro phase, the acoustic and mechanical properties of the ultrasound-guided catheter were compared with those of the traditional MPA2 catheter, including parameters such as echo intensity, recognizability, and angle dependence. In the animal experiments, a ventricular septal defect (VSD) model was established in miniature pigs to compare the procedural performance of the ultrasound-guided delivery system versus the conventional system. Evaluation indicators included the time required for the system to cross the VSD, the detection rate of the system within the right ventricle, and the occurrence of intraoperative complications. Results The ultrasound-guided catheter demonstrated a significantly higher mean echo intensity than the MPA2 catheter [(237.3±1.8) dB vs. (190.9±13.1) dB, P<0.001] and a markedly improved recognizability rate (82.3%±5.6% vs. 26.7%±3.2%, P<0.001), along with better angle independence and image quality. In animal experiments, the ultrasound-guided delivery system significantly reduced the time required to cross the VSD [(18.5±5.7) min vs. (30.3±4.5) min, P<0.001] and substantially increased the detection rate within the right ventricle (100.0% vs. 30.0%). No severe complications occurred in any experimental animal. Conclusion The ultrasound-guided catheter and its corresponding delivery system exhibite superior ultrasound visibility and operational performance in both in vitro and animal experiments, indicating strong potential for clinical application.

Objective To study the photodynamic performance and the killing effect of photodynamic therapy on lung cancer of novel chlorin compounds 2-（4-（5,15,20-triphenyl-7H,8H-porphyrin-10-yl） phenoxy） acetic acid（D1）and 4-（4-（5,15,20-triphenyl-7H,8H-porphyrin-10-yl） phenoxy） butanoic acid （D2）. Methods The ultraviolet visible absorption spectrum and fluorescence spectrum of D1 and D2 were determined. The singlet oxygen generation capacity of D1 and D2 was measured by using DPBF as singlet oxygen capture agent. Fluorescence assay was used to detect the cellular phagocytosis rate of the compounds in A549 cells, and MTT assay was used to detect their dark toxicity and phototoxicity. A nude mouse model of lung cancer was established to investigate the antitumor activity of the compounds mediated photodynamic action in vivo, and the blood concentration of D2 in nude mice, its distribution in tumor tissue and skin tissue were further detected. Results D1 and D2 had strong absorption at 652 nm with the best excitation wavelength at 429 nm and 427 nm, and the optimal emission wavelength was at about 659 nm. They also had a higher singlet oxygen generation rate than the control drug m-THPC. D1 and D2 had no dark toxicity at concentrations below 10 μmol/L, and could be ingested by A549 cells, basically reaching saturation in 18~24 hours. After laser irradiation at 650 nm wavelength, D1 and D2 showed significant antitumor activity in vivo and in vitro （P<0.01）. However, D2 could selectively accumulate in tumor tissues after administration, and the optimal treatment time was less than 30 min after administration. Conclusion D2 had excellent photodynamic antitumor activity and could selectively aggregate in tumor tissues, which had the potential to be a candidate drug for photosensitizer and treatment of lung cancer with independent intellectual property rights, and was worth further research.

Objective To establish an epirubicin (EPI)-resistant murine triple-negative breast cancer (TNBC) (4T1/EPI) cell line and evaluate its biological characteristics and drug resistance. Methods The EPI-resistant cell line 4T1/EPI was developed through intermittent induction with gradually increasing EPI concentrations in vitro. Morphological changes were observed under an inverted microscope. Drug resistance index (MTT assay), cell doubling time (CCK-8 assay), and migration ability (wound healing assay) were evaluated. Western blot was used to detect the expression of drug resistance-related proteins. Transcriptome sequencing and KEGG pathway enrichment analysis were performed to identify the pathways and targets involved in EPI resistance, followed by experimental validation. Results The 4T1 cells eventually grew normally in a medium containing 100 ng/mL EPI, confirming the establishment of the 4T1/EPI resistant cell line. After stable resistance was acquired, morphological alterations were observed. Compared with their parental 4T1 cells, 4T1/EPI cells showed significantly prolonged doubling time (P<0.01) and enhanced migration ability (P<0.05). Expression levels of drug resistance-related proteins MDR1, MRP1 (P<0.01), and ABCG2 (P<0.05) were elevated in 4T1/EPI cells. In vivo models also demonstrated significant EPI resistance in 4T1/EPI tumors in terms of tumor weight and volume. Transcriptome sequencing highlighted the involvement of the PI3K/Akt signaling pathway and ABC transporter pathway. Validation experiments showed the upregulation of Erbb3, Egfr, PI3K, and Akt (P<0.05) and significant downregulation of Fgfr1 (P<0.01) in 4T1/EPI cells. Conclusion The EPI-resistant TNBC cell line 4T1/EPI was successfully established, exhibiting significant resistance in vitro and in vivo. The mechanism may involve the EPI-induced upregulation of Egfr and Erbb3, activating the PI3K/Akt pathway and subsequently enhancing ABC transporter expression.