BACKGROUND:Gradient artificial bone repair scaffolds can mimic unique anatomical features in musculoskeletal tissues,showing great potential for repairing injured musculoskeletal tissues. OBJECTIVE:To review the latest research advances in gradient artificial bone repair scaffolds for tissue engineering in the musculoskeletal system and describe their advantages and fabrication strategies. METHODS:The first author of the article searched the Web of Science and PubMed databases for articles published from 2000 to 2023 with search terms"gradient,bone regeneration,scaffold".Finally,76 papers were analyzed and summarized after the screening. RESULTS AND CONCLUSION:(1)As an important means of efficient and high-quality repair of skeletal system tissues,gradient artificial bone repair scaffolds are currently designed bionically for the natural gradient characteristics of bone tissue,bone-cartilage,and tendon-bone tissue.These scaffolds can mimic the extracellular matrix of native tissues to a certain extent in terms of structure and composition,thus promoting cell adhesion,migration,proliferation,differentiation,and regenerative recovery of damaged tissues to their native state.(2)Advanced manufacturing technology provides more possibilities for gradient artificial bone repair scaffold preparation:Gradient electrospun fiber scaffolds constructed by spatially differentiated fiber arrangement and loading of biologically active substances have been developed;gradient 3D printed scaffolds fabricated by layered stacking,graded porosity,and bio-3D printing technology;gradient hydrogel scaffolds fabricated by in-situ layered injections,simple layer-by-layer stacking,and freeze-drying method;and in addition,there are also scaffolds made by other modalities or multi-method coupling.These scaffolds have demonstrated good biocompatibility in vitro experiments,were able to accelerate tissue regeneration in small animal tests,and were observed to have significantly improved histological structure.(3)The currently developed gradient artificial bone repair scaffolds have problems such as mismatch of gradient scales,unclear material-tissue interactions,and side effects caused by degradation products,which need to be further optimized by combining the strengths of related disciplines and clinical needs in the future.

BACKGROUND:Primary osteoporosis has a high incidence,but the pathogenesis is not fully understood.Currently,there is a lack of effective early screening indicators and treatment programs. OBJECTIVE:To further explore the mechanism of primary osteoporosis through comprehensive bioinformatics analysis. METHODS:The primary osteoporosis data were obtained from the gene expression omnibus(GEO)database,and the differentially expressed genes were screened for Gene Ontology(GO)function and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis.In addition,the differentially expressed genes were subjected to protein-protein interaction network to determine the core genes related to primary osteoporosis,and the least absolute shrinkage and selection operator algorithm was used to identify and verify the primary osteoporosis-related biomarkers.Immune cell correlation analysis,gene enrichment analysis and drug target network analysis were performed.Finally,the biomarkers were validated using qPCR assay. RESULTS AND CONCLUSION:A total of 126 differentially expressed genes and 5 biomarkers including prostaglandins,epidermal growth factor receptor,mitogen-activated protein kinase 3,transforming growth factor B1,and retinoblastoma gene 1 were obtained in this study.GO analysis showed that differentially expressed genes were mainly concentrated in the cellular response to oxidative stress and the regulation of autophagy.KEGG analysis showed that autophagy and senescence pathways were mainly involved.Immunoassay of biomarkers showed that prostaglandins,retinoblastoma gene 1,and mitogen-activated protein kinase 3 were closely related to immune cells.Gene enrichment analysis showed that biomarkers were associated with immune-related pathways.Drug target network analysis showed that the five biomarkers were associated with primary osteoporosis drugs.The results of qPCR showed that the expression of prostaglandins,epidermal growth factor receptor,mitogen-activated protein kinase 3,and transforming growth factor B1 in the primary osteoporosis sample was significantly increased compared with the control sample(P<0.001),while the expression of retinoblastoma gene 1 in the primary osteoporosis sample was significantly decreased compared with the control sample(P<0.001).Overall,the study screened and validated five potential biomarkers of primary osteoporosis,providing a reference basis for further in-depth investigation of the pathogenesis,early screening and diagnosis,and targeted treatment of primary osteoporosis.

BACKGROUND:Periprosthetic fracture of the femoral of the knee after total knee arthroplasty is one of the common complications,and there is a lack of biomechanical research on the periprosthetic fractures of the femoral of the knee under different bone strength conditions.The three-dimensional finite element analysis can provide a biomechanical basis for clinical practice. OBJECTIVE:To investigate the biomechanical changes of anterior femoral notching after total knee arthroplasty under different bone strengths,and to provide a mechanical basis for the clinical prevention of supracondylar femoral periprosthetic fractures after knee arthroplasty. METHODS:The femoral CT data of healthy adults were obtained,and the three-dimensional model of femoral lateral replacement of the knee joint was established by Mimics,Geomagic studio,and Solidworks software.Anterior femoral notching models of different depths were constructed,and the models were imported into ANSYS software to analyze the changes of biological stress on the femoral condyle with different bone strengths and different anterior femoral notching depths.The stress changes of the femoral anterior condyle section after and before the filling of anterior femoral notching with bone cement were analyzed. RESULTS AND CONCLUSION:(1)Under any bone strength,the supracondylar stress increased with the depth of anterior femoral notching.In normal bone conditions,there was a stress abrupt change point when the anterior femoral notching depth was between 3 mm and 4 mm.In the case of osteoporosis,there was a stress abrupt point when the anterior femoral notching depth was between 2 mm and 3 mm.(2)When anterior femoral notching occurred during knee arthroplasty and the depth exceeded the thickness of the bone cortex,the supracondylar stress of the femoral gradually increased as the bone strength decreased.(3)The stress of the anterior femoral condyle section decreased when the model with an anterior femoral notching depth of 3 mm was filled with bone cement.(4)The results show that anterior femoral notching should be avoided during knee arthroplasty,especially in patients with osteoporosis.If anterior femoral notching occurs during surgery,bone cement can be used to evenly fill the anterior femoral notching to reduce the supracondylar stress of the femur and reduce the incidence of periprosthetic fractures of the femoral joint

BACKGROUND:Wogonin is a flavonoid extracted from the root of Scutellaria baicalensis.Previous studies have shown that baicalein has protective effects against cerebral ischemia-reperfusion injury,and can also reduce blood sugar and complications in diabetic mice,but its role and mechanism in diabetic cerebral infarction remain unclear. OBJECTIVE:To explore the effect of wogonin on nerve injury in rats with diabetic cerebral infarction and its mechanism. METHODS:Sprague-Dawley rats were randomly divided into six groups:control group,model group,low-dose wogonin group,medium-dose wogonin group,high-dose wogonin group,and high-dose wogonin+Ras homolog gene family member A(RhoA)activator group.Except for the control group,the other rats were established with diabetes and cerebral ischemia models using intraperitoneal injection of streptozotocin and middle cerebral artery occlusion.Low,medium-and high-dose wogonin groups were intragastrically given 10,20,40 mg/kg wogonin,respectively;high-dose wogonin+RhoA activator group was intragastrically given 40 mg/kg wogonin and intraperitoneally injected 10 mg/kg lysophosphatidic acid;control group and model group were given the same amount of normal saline once a day for 7 consecutive days.Rats in each group were evaluated for neurological deficits and their blood glucose levels were measured after the last dose.TTC staining was applied to detect the volume of cerebral infarction.Hematoxylin-eosin staining was applied to observe pathological changes in brain tissue.ELISA kit was applied to detect tumor necrosis factor-α,interleukin-6,malondialdehyde,and superoxide dismutase levels in brain tissue.Western blot was applied to detect the protein expression of RhoA and Rho-associated protein kinase(ROCK)2 in brain tissue. RESULTS AND CONCLUSION:Compared with the control group,the neuronal structure of rats in the model group was severely damaged,with cell necrosis and degeneration,the neurological deficit score,blood glucose level,and infarct volume were significantly elevated(P<0.05),the levels of tumor necrosis factor-α,interleukin-6,and malondialdehyde,and the protein expression of RhoA and ROCK2 in brain tissue were significantly increased(P<0.05),and the superoxide dismutase level was decreased(P<0.05).Compared with the model group,the low-,medium-,and high-dose wogonin groups showed improved neuronal damage,reduced cell degeneration and necrosis,a significant reduction in neurological deficit score,blood glucose level,infarct volume,and the levels of tumor necrosis factor-α,interleukin-6,and malondialdehyde,and the protein expression of RhoA and ROCK2 in brain tissue,and an increase in the superoxide dismutase level(P<0.05).Compared with the high-dose wogonin group,the high-dose wogonin+RhoA activator group significantly weakened the improvement in the above indexes of rats with diabetic cerebral infarction(P<0.05).To conclude,wogonin can improve the blood glucose level in rats with diabetic cerebral infarction,reduce cerebral infarction and nerve injury,and its mechanism may be related to the inhibition of RhoA/ROCK signaling pathway.

Alzheimer’s disease is a progressive， fatal， and neurodegenerative disease， clinically characterized by gradually developed cognitive and memory function decline， language and visuospatial disorders， and other aspects. It remains incurable and irreversible to date. In clinical settings， Alzheimer’s disease usually faces the possibility of untimely diagnosis， causing difficulties in the early intervention of the disease. Thus， it is essential to improve diagnostic efficiency and help patients diagnose Alzheimer’s disease as early as possible. With the continuous development of artificial intelligence （AI） technology， its application in Alzheimer’s disease imaging diagnosis has shown great potential. Meanwhile， it is also accompanied by many ethical issues. By exploring the ethical challenges brought by AI in the research and application of Alzheimer’s disease imaging diagnosis， such as data security， interpretability， algorithmic discrimination， and disclosure of incidental findings， the paper proposed the corresponding countermeasures， with a view to providing certain ethical guidance for the AI application in medical imaging diagnosis， protecting the rights and interests of subjects/patients， and promoting the healthy development of technology.

As one of the most delicate surgeries in the whole body, vitreoretinal surgery requires a high degree of refinement and stability of the surgeon's operation due to the limitation of the operating space, and the fact that any subtle surgical trauma can lead to serious visual function damage. Surgical robots can significantly improve the precision and safety of the vitreoretinal surgical procedures and have good application prospects. As an emerging technology, in recent years, scholars at home and abroad have carried out a lot of research on the surgical robot in the surgical treatment of vitreoretinal diseases, and have achieved certain research results. Starting from the development history of surgical robots, this review analyzes and summarizes the safety and stability of surgical robots assisted retinal endovascular surgery, subretinal injection, macular surgery and real-time manipulation of retinal laser photocoagulation, briefly generalized the challenges that surgical robots still faced, and aim to provide more research directions of surgical robots in the treatment of vitreoretinal diseases.

As one of the most delicate surgeries in the whole body, vitreoretinal surgery requires a high degree of refinement and stability of the surgeon's operation due to the limitation of the operating space, and the fact that any subtle surgical trauma can lead to serious visual function damage. Surgical robots can significantly improve the precision and safety of the vitreoretinal surgical procedures and have good application prospects. As an emerging technology, in recent years, scholars at home and abroad have carried out a lot of research on the surgical robot in the surgical treatment of vitreoretinal diseases, and have achieved certain research results. Starting from the development history of surgical robots, this review analyzes and summarizes the safety and stability of surgical robots assisted retinal endovascular surgery, subretinal injection, macular surgery and real-time manipulation of retinal laser photocoagulation, briefly generalized the challenges that surgical robots still faced, and aim to provide more research directions of surgical robots in the treatment of vitreoretinal diseases.

NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome mediates inflammation, induces pyroptosis, and regulates periodontal tissue remodeling through the maturation and secretion of its downstream cysteine protease 1 (Caspase-1)-dependent pro-inflammatory cytokines, interleukin (IL)-1β and IL-18. Orthodontic force mediates the aseptic inflammation of periodontal tissues and triggers adaptive alteration of periodontal tissues, thereby promoting the movement and stability of orthodontic teeth. NLRP3 inflammasome plays an important role in orthodontic tooth movement and causes periodontal tissue inflammation and orthodontic inflammatory root resorption in orthodontic patients. Literature review suggests that NLRP3 inflammasome is involved in the activation and differentiation of periodontal ligament fibroblasts, periodontal ligament stem cells, macrophages, osteoblasts, and osteoclasts in orthodontic tooth mobile tissue remodeling. Additionally, it targets the upstream nuclear factor kappa-B signaling pathway; downstream effectors, such as Caspase-1, IL-1β, and IL-18; and the NLRP3 inflammasome components for regulating tooth movement as well as treating and preventing orthodontics-associated periodontitis and orthodontic-induced inflammatory root resorption. Future studies can be focused on the specific mechanism of NLRP3 inflammasome tissue modification during orthodontic tooth movement. This article reviews the effects and regulatory mechanisms of the NLRP3 inflammasome signaling pathway on the corresponding tissue remodeling during orthodontic tooth movement.

Background Metals and metalloids in fine particulate matter (PM_2.5) may cause damage to the respiratory and circulatory systems of the human body, and long-term exposure is prone to causing chronic poisoning, cancer, and other adverse effects. Objective To assess the distribution characteristics of metals and metalloids in outdoor PM_2.5 in a southern city of China, conduct source apportionment, and evaluate the associated health risks, thereby providing theoretical support for further pollution control measures. Methods PM_2.5 samples were collected in districts A, B, and C of a southern China city, and the concentrations of 17 metals and metalloids were detected by inductively coupled plasma-mass spectrometry (ICP-MS). Pollution sources were assessed through enrichment factor and principal components analysis, and the main pollution sources were quantified using absolute principal component scores-multivariate linear regression (APCS-MLR). Health risks were evaluated based on the Technical guide for environmental health risk assessment of chemical exposure (WS/T777—2021). Results The ambient air PM_2.5 concentrations in the city were higher in winter and spring, and lower in summer and autumn. The annual average concentrations of ambient PM_2.5 in districts A, B, and C were 36.7, 31.9, and 24.4 μg·m⁻³, respectively. The ambient PM_2.5 levels in districts B and C were below the second-grade limit set by the Ambient air quality standards (GB 3095—2012). The enrichment factors of cadmium (Cd), aluminum (Al), and antimony (Sb) were greater than 10, those of copper (Cu), lead (Pb), arsenic (As), nickel (Ni), mercury (Hg), and molybdenum (Mo) fell between 1 and 10, and those of manganese (Mn), vanadium (V), chromium (Cr), cobalt (Co), barium (Ba), beryllium (Be), and uranium (U) were below or equal to 1. The comprehensive evaluation of source analysis showed that the main pollution sources in districts A and C and the whole city were coal-burning. In district B, the main pollution source was also coal combustion, followed by industrial process sources and dust sources. The carcinogenic risks of As and Cr were between 1×10⁻⁶ and 1×10⁻⁴. However, the hazard quotients for 15 metals and metalloids in terms of non-carcinogenic risk were below 1. Conclusion Cr and As in the atmospheric PM_2.5 of the city present a certain risk of cancer and should be paid attention to. In addition, preventive control measures should be taken against relevant pollution sources such as industrial emission, dust, and coal burning.

ObjectiveTo explore the mechanism by which the ethanol extract of Epimedium brevicornu （EEBM） intervenes in mesenchymal adipose-derived stem cells （ADSCs） to delay aging in castrated rats. MethodsForty-five 3-month-old SPF female SD rats were ovariectomized and randomly divided into model group， ADSCs treatment group， and ADSCs groups treated with low， medium， and high concentrations of EEBM （1， 50， 100 μg·L^-1）， referred to as the AE low， medium， and high concentration groups， with 9 rats in each group. After tail vein injection of 200 μL of the corresponding stem cell suspension， aging-related indicators including cyclin-dependent kinase inhibitor （p21）， tumor suppressor gene （p53）， interleukin-6 （IL-6）， interleukin-8 （IL-8）， superoxide dismutase （SOD）， malondialdehyde （MDA）， B-cell lymphoma-2 （Bcl-2）， Bcl-2-associated X protein （Bax）， cysteine-aspartic acid protease-3 （Caspase-3）， and lipofuscin were measured using enzyme-linked immunosorbent assay （ELISA） and Western blot. ResultsCompared with the model group， the IL-6 content in the AE low， medium， and high concentration groups was significantly decreased （P<0.05）. Lipofuscin， MDA， and IL-8 levels in the ADSCs treatment group and AE low， medium， and high concentration groups were significantly reduced （P<0.01）， while SOD content was significantly increased （P<0.05， P<0.01）. Compared with the ADSCs treatment group， lipofuscin and IL-8 levels in the AE low， medium， and high concentration groups were significantly reduced （P<0.05， P<0.01）. The MDA content was significantly decreased in the AE medium concentration group （P<0.01）. Compared with the model group， protein levels of p21， p53， Bax， and Caspase-3 in the ADSCs treatment group and AE low， medium， and high concentration groups were significantly reduced （P<0.05， P<0.01）， while the Bcl-2 protein level was significantly increased （P<0.01）. Compared with the ADSCs treatment group， protein levels of p21， p53， Bax， and Caspase-3 in the AE low， medium， and high concentration groups were significantly reduced （P<0.05， P<0.01）， and the Bcl-2 protein level in the AE low concentration group was significantly increased （P<0.01）. ConclusionThe results of this experiment show that EEBM-treated ADSCs or ADSCs may delay aging in castrated rats by inhibiting cell apoptosis， reducing cell cycle inhibitors and pro-inflammatory factors， enhancing antioxidant capacity， and reducing oxidative reactions. Moreover， EEBM-treated ADSCs demonstrate stronger anti-aging effects than ADSCs alone. This study provides experimental evidence supporting the clinical use of EEBM to intervene in ADSCs and delay aging.