BACKGROUND:Exosomes are nanoscale extracellular vesicles secreted by various types of cells,with advantages such as high bioavailability,low toxicity,low immunogenicity,and good biocompatibility.However,natural exosomes have certain limitations in clinical therapy.By using bioengineering techniques to modify and engineer exosomes,the engineered exosomes not only improve their original therapeutic effects but also exhibit excellent biostability and targeting specificity,showing great potential for application in the field of tissue repair.OBJECTIVE:To summarize the various strategies for engineering exosomes,including functional loading and surface modification,outline the research progress of engineered exosomes in different tissue repairs,and explore the therapeutic potential of engineered exosomes in tissue repair.METHODS:PubMed database was searched for relevant literature published between 2010 and 2024 using the search terms"engineered exosomes,tissue repair,biomaterials,tissue engineering,wound healing,parenchyma,bone regeneration,cartilage,neural,myocardial,hepatic."Studies that were not closely related to the article's theme,of poor quality,repetitive,or outdated were excluded.A total of 115 articles met the inclusion criteria.RESULTS AND CONCLUSION:(1)Functional loading is used to combine therapeutic molecules with exosomes to obtain additional properties or to enhance the original physiological function of the exosome,among which ultrasonication and extrusion are simple to operate and can obtain higher drug loading capacity at the same time.(2)Surface modification can make exosomes express desired proteins or enhance their targeting,including genetic engineering and chemical modification.Genetic engineering is complicated,poorly reproducible,and the end product is poorly controllable.Chemical modification,on the other hand,is relatively simple and versatile,and is more suitable for designing highly targeted and functionally specific engineered exosomes.(3)Among the techniques for pre-treating cells to obtain engineered exosomes,hypoxic pre-treatment is more widely used because of its simplicity and clearer mechanism,which can activate glycolysis to promote cell proliferation,and regulate the vascular endothelial growth factor receptor signaling pathway through the generation of hypoxia-inducible factors to promote angiogenesis.(4)The function of exosomes is affected by various factors such as cell source,cell state,synthesis process,and extracellular environment.If the engineering strategy is complicated,it is more difficult to ensure the functional consistency of the final engineered exosomes,so the relatively simple and reliable engineering strategy is more suitable for its clinical application.(5)Engineered exosomes combined with biomaterials or scaffolds can be used to treat complex wounds of skin soft tissue,such as infected wounds and diabetic ulcers.This approach enhances exosome delivery and controls their release,promotes tissue repair,controls infection,and regulates the local microenvironment of the wound.(6)A single mechanism of engineered exosomes is often ineffective due to the specificity of the bone tissue fracture,so dual or even multi-functional engineered exosomes are needed to promote fracture repair while anti-inflammatory or remodeling the vascular system.(7)The source of exosomes has a significant impact on neural tissue repair.Exosomes derived from different neural cells promote neural repair through different effects.In addition,the combination of stents and engineered exosomes for traumatic brain injury has obvious advantages,the stent itself provides hemostasis and support,combined with the engineered exosomes itself to promote the repair effect,can obtain better therapeutic effect.(8)In cardiac and hepatic tissue repair,it is needed to develop anti-fibrotic engineered exosomes to resist the abnormal repair of cardiac and hepatic tissues themselves,which will require further research in the future.

BACKGROUND:Exosomes are nanoscale extracellular vesicles secreted by various types of cells,with advantages such as high bioavailability,low toxicity,low immunogenicity,and good biocompatibility.However,natural exosomes have certain limitations in clinical therapy.By using bioengineering techniques to modify and engineer exosomes,the engineered exosomes not only improve their original therapeutic effects but also exhibit excellent biostability and targeting specificity,showing great potential for application in the field of tissue repair.OBJECTIVE:To summarize the various strategies for engineering exosomes,including functional loading and surface modification,outline the research progress of engineered exosomes in different tissue repairs,and explore the therapeutic potential of engineered exosomes in tissue repair.METHODS:PubMed database was searched for relevant literature published between 2010 and 2024 using the search terms"engineered exosomes,tissue repair,biomaterials,tissue engineering,wound healing,parenchyma,bone regeneration,cartilage,neural,myocardial,hepatic."Studies that were not closely related to the article's theme,of poor quality,repetitive,or outdated were excluded.A total of 115 articles met the inclusion criteria.RESULTS AND CONCLUSION:(1)Functional loading is used to combine therapeutic molecules with exosomes to obtain additional properties or to enhance the original physiological function of the exosome,among which ultrasonication and extrusion are simple to operate and can obtain higher drug loading capacity at the same time.(2)Surface modification can make exosomes express desired proteins or enhance their targeting,including genetic engineering and chemical modification.Genetic engineering is complicated,poorly reproducible,and the end product is poorly controllable.Chemical modification,on the other hand,is relatively simple and versatile,and is more suitable for designing highly targeted and functionally specific engineered exosomes.(3)Among the techniques for pre-treating cells to obtain engineered exosomes,hypoxic pre-treatment is more widely used because of its simplicity and clearer mechanism,which can activate glycolysis to promote cell proliferation,and regulate the vascular endothelial growth factor receptor signaling pathway through the generation of hypoxia-inducible factors to promote angiogenesis.(4)The function of exosomes is affected by various factors such as cell source,cell state,synthesis process,and extracellular environment.If the engineering strategy is complicated,it is more difficult to ensure the functional consistency of the final engineered exosomes,so the relatively simple and reliable engineering strategy is more suitable for its clinical application.(5)Engineered exosomes combined with biomaterials or scaffolds can be used to treat complex wounds of skin soft tissue,such as infected wounds and diabetic ulcers.This approach enhances exosome delivery and controls their release,promotes tissue repair,controls infection,and regulates the local microenvironment of the wound.(6)A single mechanism of engineered exosomes is often ineffective due to the specificity of the bone tissue fracture,so dual or even multi-functional engineered exosomes are needed to promote fracture repair while anti-inflammatory or remodeling the vascular system.(7)The source of exosomes has a significant impact on neural tissue repair.Exosomes derived from different neural cells promote neural repair through different effects.In addition,the combination of stents and engineered exosomes for traumatic brain injury has obvious advantages,the stent itself provides hemostasis and support,combined with the engineered exosomes itself to promote the repair effect,can obtain better therapeutic effect.(8)In cardiac and hepatic tissue repair,it is needed to develop anti-fibrotic engineered exosomes to resist the abnormal repair of cardiac and hepatic tissues themselves,which will require further research in the future.

Objective To construct and validate the efficacy of a risk prediction model for pneumothorax after CT-guided percutaneous pulmonary puncture biopsy(CT-PCNB)based on nomograms.Methods A total of 246 patients who underwent CT-PCNB examination in the hospital from October 2020 to October 2023 were selected and divided into training set(n=144)and validation set(n=102)using a random sampling method.In the training set,univariate and multivariate logistic regression analyses were performed to identify risk factors for pneumothorax after CT-PCNB.A nomogram model was constructed based on the identified risk factors,and its accuracy was validated using the validation set.Results Multifactorial logistic regression analysis showed that age≥60 years,concomitant underlying lung disease,lesion diameter<2 cm,distance from lesion to pleura≥10 mm,puncture through interlobular pleura,and≥2 pleural punctures were the risk factors for pneumothorax after CT-PCNB in the training set(P<0.05).A nomogram model was constructed based on these six factors.The ROC curve results for the training set showed an AUC of 0.852,sensitivity of 84.50%,and specificity of 67.50%.The nomogram model was validated using the validation set,with ROC curve results showing an AUC of 0.845,sensitivity of 83.00%,and specificity of 69.50%.There was no statistically significant difference between the predicted and actual values in both the training and validation sets(χ2=1.803,1.225;P>0.05),indicating clinical validity.Conclusion The nomogram model constructed based on the risk factors for pneumothorax after CT-PCNB has high predictive efficacy and is clinically meaningful.

Androgenic alopecia (AGA) stands as a prevalent and challenging dermatological condition in clinical practice. Its pathogenesis is complex and the condition is prone to recurrence, which seriously affects the physical and mental health of patients. This review synthesized recent advancements in understanding the multifaceted mechanisms underlying AGA progression. It delineated the intricate interplay among genetic predispositions, hormonal influences, cytokine-mediated regulations, molecular pathway activations, and alterations in the hair follicle microenvironment. By elucidating these diverse factors and their interactions, this article aimed to provide a theoretical basis and reference for new targets of action for the clinical treatment of AGA.

Objective To investigate the impact of aortic valve calcification on ascending aortic elasticity.Methods A total of 103 patients with aortic valve calcification indicated by coronary computed tomography angiography(CCTA)(calcification group),and 101 patients without aortic valve calcification(non calcification group)were selected.The calcification group was subdivided into group A,group B,and group C based on the number of calcified leaflets.The original data was automatically reconstructed at 5％R-R intervals throughout the cardiac cycle.Cross-sectional area and diameter of the ascending aorta were measured at 45 mm above the annulus,and four ascending aortic elasticity indicators aortic(％A),aortic distensibility(AD),aortic compliance(AC)and aortic stiffness index(ASI)were calculated.Agatston method was used to calculate the aortic valve calcification score.The effect of aortic valve calcification on the elasticity of the ascending aortic and its correlation were analyzed.Results The％A,AD,and AC of the calcification group were lower than those of the non calcification group,but the ASI was higher than that of the non calcification group,the difference was statistically significant(P＜0.05).The number of calcified leaflets affected ascending aortic elasticity,with comparisons between groups A and B,the difference was no statistically significant(P＞0.05),groups A and C,and groups B and C,the difference was statistically significant(P＜0.05).Calcification score was negatively correlated with％A,AD,and AC,and positively correlated with ASI.Conclusion Aortic valve calcification can affect the elasticity of the ascending aortic,and more than two calcified leaflets have more significant effects on the elasticity of the ascending aortic.

Objective To construct and validate the efficacy of a risk prediction model for pneumothorax after CT-guided percutaneous pulmonary puncture biopsy(CT-PCNB)based on nomograms.Methods A total of 246 patients who underwent CT-PCNB examination in the hospital from October 2020 to October 2023 were selected and divided into training set(n=144)and validation set(n=102)using a random sampling method.In the training set,univariate and multivariate logistic regression analyses were performed to identify risk factors for pneumothorax after CT-PCNB.A nomogram model was constructed based on the identified risk factors,and its accuracy was validated using the validation set.Results Multifactorial logistic regression analysis showed that age≥60 years,concomitant underlying lung disease,lesion diameter<2 cm,distance from lesion to pleura≥10 mm,puncture through interlobular pleura,and≥2 pleural punctures were the risk factors for pneumothorax after CT-PCNB in the training set(P<0.05).A nomogram model was constructed based on these six factors.The ROC curve results for the training set showed an AUC of 0.852,sensitivity of 84.50%,and specificity of 67.50%.The nomogram model was validated using the validation set,with ROC curve results showing an AUC of 0.845,sensitivity of 83.00%,and specificity of 69.50%.There was no statistically significant difference between the predicted and actual values in both the training and validation sets(χ2=1.803,1.225;P>0.05),indicating clinical validity.Conclusion The nomogram model constructed based on the risk factors for pneumothorax after CT-PCNB has high predictive efficacy and is clinically meaningful.

Objective To investigate the impact of aortic valve calcification on ascending aortic elasticity.Methods A total of 103 patients with aortic valve calcification indicated by coronary computed tomography angiography(CCTA)(calcification group),and 101 patients without aortic valve calcification(non calcification group)were selected.The calcification group was subdivided into group A,group B,and group C based on the number of calcified leaflets.The original data was automatically reconstructed at 5％R-R intervals throughout the cardiac cycle.Cross-sectional area and diameter of the ascending aorta were measured at 45 mm above the annulus,and four ascending aortic elasticity indicators aortic(％A),aortic distensibility(AD),aortic compliance(AC)and aortic stiffness index(ASI)were calculated.Agatston method was used to calculate the aortic valve calcification score.The effect of aortic valve calcification on the elasticity of the ascending aortic and its correlation were analyzed.Results The％A,AD,and AC of the calcification group were lower than those of the non calcification group,but the ASI was higher than that of the non calcification group,the difference was statistically significant(P＜0.05).The number of calcified leaflets affected ascending aortic elasticity,with comparisons between groups A and B,the difference was no statistically significant(P＞0.05),groups A and C,and groups B and C,the difference was statistically significant(P＜0.05).Calcification score was negatively correlated with％A,AD,and AC,and positively correlated with ASI.Conclusion Aortic valve calcification can affect the elasticity of the ascending aortic,and more than two calcified leaflets have more significant effects on the elasticity of the ascending aortic.

Androgenic alopecia (AGA) stands as a prevalent and challenging dermatological condition in clinical practice. Its pathogenesis is complex and the condition is prone to recurrence, which seriously affects the physical and mental health of patients. This review synthesized recent advancements in understanding the multifaceted mechanisms underlying AGA progression. It delineated the intricate interplay among genetic predispositions, hormonal influences, cytokine-mediated regulations, molecular pathway activations, and alterations in the hair follicle microenvironment. By elucidating these diverse factors and their interactions, this article aimed to provide a theoretical basis and reference for new targets of action for the clinical treatment of AGA.

Objective:To explore the role of cathepsin S(CTSS) in diabetic vascular injury-induced restenosis.Methods:(1) Dendritic cells(DCs) were stimulated with different concentrations of glucose, and CTSS was either knocked down or upregulated in dendritic cells using adenovirus transfection. The mRNA and protein expression levels of CTSS were detected by RT-qPCR and Western blot, and the changes of interleukin(IL)-6 levels were assessed using RT-qPCR and ELISA in response to CTSS. (2) The extent of Th17 cell differentiation was evaluated with Flow cytometry when CTSS was downregulated or overexpressed. Levels of ROR-γt, IL-17A, IL-17F, IL-22, and IL-23 were measured. (3) Streptozomycin(STZ, 60 mg/kg) was injected into the intraperitoneal cavity of rats fasted for 12 h to obtain a diabetic rat model, and the restenosis model was obtained by balloon catheter and carotid guidewire injury, and the differentiation degree of Th17 cells in different groups of rats was compared when CTSS was up-regulated and down-regulated.Results:(1) DC viability decreased when stimulated with 35 mmol/L glucose for 48 hours. Compared to the control group, glucose treatment led to a concentration-dependent increase in CTSS and IL-6 levels in DCs( P<0.05). Inhibition of CTSS reduced IL-6 protein levels, while its overexpression increased IL-6 protein levels( P<0.05). (2) Compared with the control group, CTSS inhibition in DC decreased the percentage of Th17 cells in T cells, with decreased protein levels of ROR-γt, IL-17A, IL-17F, IL-22, and IL-23, and vice versa ( P<0.050). (3) After carotid artery injury, CTSS expression was increased in perivascular adipose tissue(PVAT) of rats, and levels of ROR-γt, IL-17A, IL-17F, IL-22, and IL-23 in PVAT were significantly elevated. Down-regulation of CTSS eliminated the glucose-induced enhancement. Conclusion:Inhibition of CTSS in DC reduces Th17 cell differentiation and thereby suppresses restenosis following diabetic vascular injury.