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that were not closely related to the article's theme,of poor quality,repetitive,or outdated were excluded.A total of 115 articles met the inclusion criteria.RESULTS AND CONCLUSION:(1)Functional loading is used to combine therapeutic molecules with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:Dental pulp stem cells,which derived from the dental pulp tissue,are one type of dental-derived mesenchymal stem cells,possess significant properties of self-renewal and multi-lineage differentiation.In recent years,series of researches focus on dental pulp stem cells and their derivatives such as extracellular vesicles,conditioned medium,and decellularized extracellular matrix,those have positive effects on the repair and regeneration of pulp tissue injury,showing an attractive clinical application.OBJECTIVE:To systematically review the researches and applications of dental pulp stem cells and their derivatives in dental pulp tissue engineering.METHODS:Literature searches were conducted in PubMed,China Biology Medicine(CBM),and China National Knowledge Infrastructure(CNKI)databases for articles published from January 2005 to June 2023.The search terms included"dental pulp stem cells,extracellular vesicles,exosomes,apoptotic bodies,conditioned medium,decellularized matrix,regeneration"in Chinese and English.After screening the titles and abstracts,duplicate and irrelevant studies were excluded.Finally,103 studies closely related to dental pulp regeneration were included for review and analysis.RESULTS AND CONCLUSION:Dental pulp stem cells and their derivatives are rich in lots of bioactive factors that can effectively promote odontogenic,angiogenic,and neurogenic differentiation,exhibiting significant potential in the formation of the pulp-dentin complex.However,the clinical translation of dental pulp stem cells and their derivatives still faces several challenges.Future researches should focus on optimizing preparation protocols,elucidating the underlying mechanisms of action,and refining safety assessments to provide novel therapeutic strategies for the repair of dental pulp injury.

Abstract The prevention and control of myopia in Chinese children and adolescents has become a major public health issue. While maintaining increased outdoor activity as a cornerstone intervention, there is an urgent need to explore new complementary approaches that can be effectively implemented in both indoor and outdoor settings. In recent years, environmental spatial frequency has gained increasing attention as one of the key environmental factors influencing the development and progression of myopia. Both animal studies and human research have confirmed that indoor environments lacking mid to high spatial frequency components, often characterized as "visually impoverished", can promote axial elongation and myopia through mechanisms such as disruption of retinal neural signaling, impaired accommodative function, and altered expression of related molecules. Based on the scientific consensus, it is recommended that "enriching of environmental spatial frequency" should be integrated into the myopia prevention and control framework. Following the principles of schoolled organization, family cooperation, community involvement, and student participation, specific measures are put forward in three areas：optimizing school visual settings, improving home spatial environments, and promoting healthy visual behavior. The aim is to create "visually friendly" indoor environments as an important supplement to outdoor activity, thereby providing a novel perspective and strategy for comprehensively advancing myopia prevention and control among children and adolescents.

Patients with Takayasu arteritis combined with aortic valve disease often have a poor prognosis following surgical valve replacement, frequently encountering complications such as perivalvular leakage, valve detachment, and anastomotic aneurysm. This article presents a high-risk case wherein severe aortic valve insufficiency associated with Takayasu arteritis was successfully managed through transcatheter aortic valve implantation via the transapical approach. The patient had satisfactory valve function with no complications observed during the six-month postoperative follow-up. This case provides a minimally invasive and feasible alternative for the clinical management of such high-risk patients.

Objective: To investigate the prevalence of undernutrition and its associated factors among left behind and non left behind primary and secondary school students in the Nutrition Improvement Program for Rural Compulsory Education Students (NIPRCES) areas of central and western China, so as to provide evidence for improving the nutritional status of children and adolescents. Methods: A survey was conducted among 123 782 students selected by random cluster sampling method in grades 3-9 from NIPRCES in central (Hebei, Shanxi, Heilongjiang, Jilin, Anhui, Jiangxi, Henan, Hunan, Hubei, and Hainan) and western (Gansu, Guangxi, Inner Mongolia, Ningxia, Tibet, Shaanxi, Guizhou, Sichuan, Xinjiang, the Xinjiang Production and Construction Corps, Yunnan, Qinghai, and Chongqing) China in 2023. Anthropometric measurements and questionnaires were used to assess nutritional and dietary status. The prevalence of undernutrition was compared between left behind and non left behind students by Chi square test, and associated factors were analyzed by three level Logistic mixed effects model. Results: The prevalence of undernutrition was 8.5% (4 326) in left behind students and 8.1% (5 905) in non left behind students. Three level Logistic mixed effect model analysis showed that whether left behind or non left behind, the undernutrition rates of primary and secondary students in western regions were higher than those of students in central regions [ OR (95% CI )=1.72(1.57-1.87),2.25(2.07- 2.43 )]; the undernutrition risk was lower for those whose fathers had a cultural level of high school or above [ OR (95% CI )=0.69(0.62-0.77),0.90(0.82-0.98)] or junior high school [ OR (95% CI )=0.72(0.66-0.79),0.92(0.85-0.99)] compared to those with primary school or below; picky eating or selective eating increased the risk of undernutrition [ OR (95% CI )=2.36(2.07-2.68),2.28(2.04-2.55)], and primary and secondary school students without nutritional content in health education classes had higher rates of undernutrition [ OR (95% CI )=1.12(1.03-1.23),1.09(1.01-1.17)](all P <0.05). Conclusion The prevalence of undernutrition is slightly higher in left behind primary and secondary students than in non left behind primary and secondary students in central and western NIPRCES areas, with variations across different characteristics.

Objective: To analyze the trends of the frequency of meat, egg, and milk consumption among rural primary and junior high school students in central and western China covered by the Nutrition Improvement Program for Rural Compulsory Education Students (NIPRCES) from 2015 to 2023, so as to provide basis for formulating more targeted nutrition intervention policies and health education strategies. Methods: Using data from six rounds of monitoring and evaluation (2015-2021 and 2023), the study included 323 870 students from grade 3 to 9 across 22 provinces (autonomous regions and municipalities) in central and western China. The consumption frequencies of meat, egg, and milk over the past week were collected via questionnaires. The Cochran-Armitage trend test was used to analyze temporal trends, and multivariable Logistic regression models were employed to analyze factors associated with the frequency of meat, egg and milk consumption and to test for interaction effects between the year and gender, region, and grade level. Results: From 2015 to 2023, the proportion of students consuming meat, egg, and milk ≥1 time/day increased from 23.20 %, 10.71%, and 0.74% to 35.53%, 22.09%, and 26.63%, respectively. Trend tests indicated a significant upward trend for the daily intake of all three food categories for meat, egg and milk over the years ( Z =67.18, 64.90, 93.14, all P <0.01). Multivariable Logistic regression analysis showed that the daily meat intake was lower in the central region than in the western region ( OR=0.77, 95%CI =0.76-0.78), whereas the daily intake of eggs ( OR=1.19, 95%CI =1.17-1.22) and milk ( OR= 1.27 , 95%CI =1.24-1.29) was higher in the central region (all P <0.05). Compared with grade 3-4 students, junior high school students had lower daily intake of meat, eggs, and milk≥1 time/day ( OR =0.95, 0.77, 0.77, all P <0.05), with a declining trend as grade increased. Girls also had lower daily intake of meat, eggs, and milk ≥1 time/day than boys ( OR =0.95，0.93，0.91, all P < 0.05). Significant interactions were observed between year and region, as well as between year and grade (all P <0.05). Conclusion From 2015 to 2023, the NIPRCES improved the intake level of among rural students, but the situation of relatively insufficient intake of egg and milk among females, junior high school students and those in the western region still exists.

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:Dental pulp stem cells,which derived from the dental pulp tissue,are one type of dental-derived mesenchymal stem cells,possess significant properties of self-renewal and multi-lineage differentiation.In recent years,series of researches focus on dental pulp stem cells and their derivatives such as extracellular vesicles,conditioned medium,and decellularized extracellular matrix,those have positive effects on the repair and regeneration of pulp tissue injury,showing an attractive clinical application.OBJECTIVE:To systematically review the researches and applications of dental pulp stem cells and their derivatives in dental pulp tissue engineering.METHODS:Literature searches were conducted in PubMed,China Biology Medicine(CBM),and China National Knowledge Infrastructure(CNKI)databases for articles published from January 2005 to June 2023.The search terms included"dental pulp stem cells,extracellular vesicles,exosomes,apoptotic bodies,conditioned medium,decellularized matrix,regeneration"in Chinese and English.After screening the titles and abstracts,duplicate and irrelevant studies were excluded.Finally,103 studies closely related to dental pulp regeneration were included for review and analysis.RESULTS AND CONCLUSION:Dental pulp stem cells and their derivatives are rich in lots of bioactive factors that can effectively promote odontogenic,angiogenic,and neurogenic differentiation,exhibiting significant potential in the formation of the pulp-dentin complex.However,the clinical translation of dental pulp stem cells and their derivatives still faces several challenges.Future researches should focus on optimizing preparation protocols,elucidating the underlying mechanisms of action,and refining safety assessments to provide novel therapeutic strategies for the repair of dental pulp injury.

ObjectiveTo investigate the mechanism by which Jianpi Xiao'ai prescription （JPXAP） inhibits colorectal cancer progression by regulating the inducible nitric oxide synthase-arginase 1 （iNOS-ARG1） metabolic axis and inducing mitochondrial reactive oxygen species （mito-ROS）-mediated mitochondrial structural and functional impairment. MethodsAn arginine metabolism disorder model of human colorectal cancer HCT116 cells was established by combined treatment with recombinant human interferon-γ （IFN-γ， 10 μg·L^-1） and N（ω）-hydroxy-L-arginine （Nor-NOHA， 200 μmol·L^-1） for 24 h， followed by intervention with 5%， 10%， or 20% JPXAP-containing serum. Cell proliferation was assessed using cell counting kit-8 （CCK-8）， 5-ethynyl-2′-deoxyuridine （EdU） staining， and colony formation assays. Cell invasion and migration were evaluated using Transwell chamber and wound healing assays. Mitochondrial membrane potential （MMP） and ROS levels were assessed by JC-1 and MitoSOX staining， respectively. Mitochondrial ultrastructure was observed by transmission electron microscopy （TEM）. The expression of iNOS， ARG1， and mitochondrial dynamics-related proteins， including mitofusin 2 （MFN2） and dynamin-related protein 1 （DRP1）， was analyzed by Western blot and immunofluorescence. The levels of L-arginine， citrulline， and urea were determined by colorimetric methods and enzyme-linked immunosorbent assay （ELISA）. ResultsCompared with the blank group， the model group exhibited significantly upregulated iNOS expression， downregulated ARG1 expression， a decreased ARG1/iNOS ratio， reduced L-arginine and urea levels， and increased citrulline levels （P<0.05）. Meanwhile， mito-ROS accumulation was significantly increased， the JC-1 red/green fluorescence ratio was decreased， and mitochondria showed swelling and cristae disruption， indicating that metabolic disorder induced mitochondrial injury. Compared with the model group， all JPXAP-treated groups further decreased the ARG1/iNOS ratio， enhanced nitric oxide （NO） and reactive nitrogen species accumulation， further reduced L-arginine and urea levels， and increased citrulline levels （P<0.01）. EdU-positive rate， colony formation rate， wound healing rate， and Transwell invasion number all decreased significantly with increasing serum concentration （P<0.01）. Mito-ROS levels were further elevated， and the JC-1 red/green ratio further decreased. TEM revealed aggravated mitochondrial swelling and vacuolization. MFN2 expression was downregulated and DRP1 expression was upregulated （P<0.01），in a dose-dependent manner. ConclusionJPXAP further activates NO-mediated oxidative/nitrosative stress under arginine metabolism imbalance， inducing mito-ROS accumulation， MMP collapse， and mitochondrial dynamics imbalance， thereby inhibiting colorectal cancer cell proliferation and migration. These findings reveal an antitumor mechanism of JPXAP based on coordinated targeting of the "metabolism-mitochondria" axis.

Objective: To analyze the features of unhealthy lifestyle patterns among primary and secondary school students in the nutrition improvement program for rural compulsory education students (NIPRCES) areas in China in 2021 and 2023, so as to provide data support for lifestyle promotion and healthy development among primary and secondary school students. Methods: Adopting a cluster random sampling method, data on primary and secondary students aged 7-15 years from nutrition and health surveillance of China NIPRCES in 2021 and 2023 were collected. The prevalence of unhealthy lifestyles among primary and secondary students such as physical inactivity, outdoor inactivity, excessive screen time, and sleep deprivation by gender, school section, urban/rural, and region were analyzed. The reporting rates of the above indicators among primary and secondary students were compared by Chi-square test. Results: In 2021 and 2023, the rates of moderate to vigorous physical inactivity among primary and secondary school students were 79.2% and 80.4%, the rates of outdoor inactivity were 42.8% and 49.3%, the rates of excessive video time were 2.6% and 2.9%, the rates of sleep deprivation were 32.9% and 22.6%, and the differences were statistically significant( χ 2=51.86,1 071.48,18.36,3 296.99, P <0.05). In 2023, the rate of outdoor inactivity for primary and secondary students increased by 6.5 percentage points compared with 2021, and the rate of sleep deprivation decreased by 10.3 percentage points compared with that in 2021. In 2021 and 2023, the reporting rates of moderate to vigorous physical inactivity, outdoor inactivity, and sleep deprivation among girls and junior high school students were higher than those among boys ( χ 2=174.41,180.11; 175.75, 85.46 ;92.22,151.35) and elementary school students ( χ 2=136.64,5.75; 40.55,4.71;162.80,3 291.61); the reporting rates of moderate to vigorous physical inactivity( χ 2=194.43,118.60) and sleep deprivation ( χ 2=969.66,983.72) among urban students were higher than those among rural students; the reporting rates of excessive video time for boys and junior high school students were higher than those for girls ( χ 2=103.62,84.85) and elementary school students ( χ 2=810.09,626.51)( P <0.05). From a regional distribution perspective, the reporting rates of moderato to vigorous physical inactivity, outdoor inactivity, and excessive video time among primary and seconday school students in the central and western regions were lower than those in the eastern region ( χ 2= 663.44,302.78; 356.97,82.10;50.89,81.83) ( P <0.05). Conclusions Unhealthy lifestyles remain prevalent among primary and secondary students in NIPRCES areas of China. These findings underscore the need to strengthen policy implementation for promoting healthy lifestyles among primary and secondary school students.