ObjectiveTo observe the effect of Liuwei Dihuangwan on behavioral impairments in the rat model of autism spectrum disorder （ASD） and explore the mechanism of action. MethodsTwelve SD pregnant rats were intraperitoneally injected with valproic acid （VPA） （10 rats） or normal saline （2 rats）， and male offspring were selected to establish the model of ASD and the control rats. Rats were randomly assigned into model， low-dose （0.75 g·kg^-1） and high-dose （1.5 g·kg^-1） Liuwei Dihuangwan， vitamin D （positive drug， 3.7×10^-5 g·kg^-1）， and blank groups. Each group was administrated with the corresponding concentration of drugs or the same volume of normal saline by gavage for 2 weeks. After the intervention， the three-chamber social test was conducted to evaluate social interaction and social preference. The open field test was carried out to observe spontaneous behavior and anxiety state. Hematoxylin-eosin staining （HE） was used to observe the pathological changes of the prefrontal tissue. Transmission electron microscopy was employed to observe the ultrastructure of mitochondria in prefrontal neurons. Immunofluorescence was used to detect the expression of ionized calcium-binding adapter molecule-1 （Iba-1） in the prefrontal tissue. Enzyme-linked immunosorbent assay （ELISA） was adopted to measure the levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6）. Western blot was employed to assess the expression differences of phosphorylated adenosine monophosphate-activated protein kinase （p-AMPK）， adenosine monophosphate-activated protein kinase （AMPK）， phosphorylated Unc-51-like autophagy-activating kinase 1 （p-ULK1）， Unc-51-like autophagy-activating kinase 1 （ULK1）， and FUN14 domain-containing protein 1 （FUNDC1）. ResultsCompared with the blank group， the model group spent less time sniffing stranger 1 and stranger 2 in the three-chamber social test （P<0.01） and showed reductions in the total distance traveled， average speed， distance traveled in the central area， and time spent in the central area in the open field test （P<0.01）. In addition， the model group showed extensive apoptosis of neurons， with shrunken nuclei and red-stained cytoplasm， and extensive necrosis of neurons in the prefrontal tissue， mitochondrial swelling， decreased matrix density， disrupted cristae， and autophagic lysosomes in neurons， increases in the rate of Iba-1 positive cells in the prefrontal area （P<0.01） and the levels of TNF-α and IL-6 （P<0.01）， and down-regulation in the expression of p-AMPK/AMPK， p-ULK1/ULK1， and FUNDC1 （P<0.01）. Compared with the model group， low-dose and high-dose Liuwei Dihuangwan and the vitamin D prolonged the time spent sniffing stranger 1 and stranger 2 in the three-chamber social test （P<0.05， P<0.01）， increased the total distance traveled， average speed， distance traveled in the central area， and time spent in the central area in the open field test （P<0.05， P<0.01）， restored the morphology of neurons in the prefrontal tissue， decreased the number of apoptotic cells， alleviated the swelling of mitochondria in neurons， increased the matrix density， mitigated the fragmentation and disorder of cristae， and increased the number of autophagosomes. Moreover， the drugs decreased the rate of Iba-1 positive cells in the prefrontal area （P<0.01）， lowered the levels of TNF-α and IL-6 （P<0.01）， and up-regulated the expression of p-AMPK/AMPK， p-ULK1/ULK1， and FUNDC1 （P<0.01）. ConclusionLiuwei Dihuangwan ameliorate autism-like behaviors and reduce neuronal apoptosis and neuroinflammatory damage in the rat model of ASD by promoting mitophagy mediated by the AMPK/ULK1/FUNDC1 pathway.

ObjectiveThis study aims to explore the mechanism by which Yishen Huoxue Tongqiao Formula improves metabolism-neuroplasticity and treats unilateral vestibular labyrinth destruction by regulating the metabolic balance of glutamate （Glu）/γ-aminobutyric acid （GABA）. Methods48 Sprague-Dawley （SD） adult rats were randomly divided into the sham operation group， model group， Yishen Huoxue Tongqiao Formula groups with low， medium， and high doses （9.20， 18.39， 36.78 g·kg^-1）， and betahistine group （1.62 mg·kg^-1）. A unilateral vestibular labyrinth destruction （vestibular dysfunction） model was established by intratympanic injection of chloroform into the right ear， while the control group received intratympanic injection of normal saline. Drugs were administered once daily for seven consecutive days. During the period， behavioral tests were performed to evaluate the behaviors of rats after unilateral vestibular labyrinth destruction. Hematoxylin-eosin （HE） staining and Nissl staining were used to observe the neuronal morphology in the medial vestibular nucleus. Golgi staining was employed to assess the number of dendritic spines of neurons in the medial vestibular nucleus. Ultra-performance liquid chromatography-tandem mass spectrometry （LC-ESI-MS/MS） was utilized to detect Glu/GABA. Immunofluorescence and immunohistochemistry were used to detect the expressions of neuronal nuclei （NeuN）， growth-associated protein 43 （GAP-43）， and glial fibrillary acidic protein （GFAP）. Western blot and real-time fluorescent quantitative polymerase chain reaction （Real-time PCR） were applied to determine the expressions of glutamate-immunoreactive （Glu-IR）， GABA， GFAP， postsynaptic density protein 95 （PSD-95）， and GAP-43. ResultsCompared with the sham operation group， the model group presented with head deviation， balance disorder， increased tail suspension score， nuclear consolidation of medial vestibular nerve neurons， and decreased Nissl bodies （P<0.01）. The number of dendritic spines in neurons and NeuN-positive cells decreased. The content of Glu decreased. The content of GABA increased （Glu/GABA decreased）. The expression of GAP-43 was down-regulated， and GFAP was up-regulated （P<0.05， P<0.01）. The expressions of Glu-IR， PSD-95， and GAP-43 proteins， as well as Glu-IR mRNA decreased， while the expressions of GABA and GFAP proteins and mRNA increased （P<0.05， P<0.01）. Compared with those in the model group， the head deviation， imbalanced behavior， and tail suspension scores in each treatment group decreased， with alleviated neuronal injury and recovered Nissl bodies （P<0.01）. The number of dendritic spines of neurons increased， and the number of NeuN-positive cells rebounded. The content of Glu increased， and the content of GABA decreased （Glu/GABA increased）. GFAP was down-regulated， and GAP-43 was up-regulated （P<0.05， P<0.01）. The expressions of Glu-IR， PMD-95， and GAP-43 proteins， as well as Glu-IR mRNA increased， while the expressions of GABA and GFAP proteins and mRNA decreased. The effect was more significant in the high-dose group （P<0.01）. ConclusionThe Yishen Huoxue Tongqiao Formula can alleviate vestibular dysfunction， and its mechanism may be associated with regulating the metabolic balance of Glu/GABA， mitigating neural damage， improving synaptic plasticity （promoting GAP-43 expression and inhibiting GFAP expression）， and facilitating vestibular compensation.

Objective: To explore the association between takeout fast foods and sugar sweetened beverage consumption with co-occurrence of anxiety and depressive symptoms among first year junior high school students in Yunnan Province, so as to provide theoretical basis for the prevention of anxiety and depressive symptoms co-occurrence among adolescents. Methods: A random cluster sampling involving 8 500 first year junior high school students in 11 counties in Yunnan Province was conducted by a questionnaire survey from October to December 2022. The Depression Anxiety Stress Scale-21 (DASS-21) was applied to assess anxiety and depressive symptoms in first year junior high school students. Chi-square test was used to compare the anxiety-depression co-occurrence symptoms of first year junior high school students with different demographic characteristics. The association between takeout fast foods and sugar sweetened beverage consumption with co-occurrence of anxiety and depressive symptoms of adolescents was analyzed by binary Logistic regression models. Results: The detection rate of co-occurrence of anxiety and depression symptoms among first year junior high school students in Yunnan Province was 26.92%. After controlling for demographic variables and other confounders, takeout fast foods and sugar sweetened beverage consumption( OR=1.50, 95%CI =1.27-1.77) was associated with anxiety-depression co-occurrence symptoms among first year junior high school students in Yunnan Province ( P <0.01). Stratified analysis showed that both Han ( OR=1.37, 95%CI =1.07-1.77) and ethnic minorities ( OR=1.60, 95%CI =1.29-2.00) exhibited statistically significant associations between takeout fast foods and sugar sweetened beverage consumption with co-occurrence of anxiety and depressive symptoms(both P <0.05). Conclusions Takeout fast foods and sugar sweetened beverage consumption increases the risk of co-occurrence of anxiety and depressive symptoms among first year junior high school students in Yunnan Province. It is recommended to strengthen guidance on the consumption of such products among junior high school students to prevent co-occurrence of anxiety and depressive symptoms.

Objective To investigate the radon activity concentrations in subways of Nanning City and assess the average annual effective doses for subway staff and passengers due to radon exposure. Methods Sixty-three stations across the subway lines 2, 3, and 5 were selected as study sites. Radon activity concentrations were measured using the scintillation counting method with scintillation vials. Results The radon activity concentrations in subway lines 2, 3, and 5 were 7.9-24.4, 12.0-26.2, and 12.6-18.2 Bq/m³, respectively. The average radon activity concentrations for these three lines were (17.4 ± 4.6), (19.1 ± 4.1), and (14.6 ± 1.7) Bq/m³, respectively. Statistical analysis using SPSS 26.0 software revealed a significant difference in radon activity concentrations among these stations (P<0.01). Considering the data in previous research, the average radon activity concentration across all stations in the subway lines of Nanning City was determined to be 17.4 Bq/m³. The estimated average annual effective dose due to radon exposure was 0.131 mSv for subway staff and 0.033 mSv for passengers. Conclusion The radon activity concentrations in the subway lines of Nanning City were significantly lower than the national standard limit (400 Bq/m³). The annual effective doses from radon exposure for both subway staff and passengers were below the limits specified in the Basic Standards for Protection Against Ionizing Radiation and for the Safety of Radiation Sources (GB18871—2002). The health impact of radon and its progeny on subway staff and passengers in the subway lines of Nanning City was extremely low and can be considered negligible.

ObjectiveTo investigate the effect of Tougu Xiaotong capsules （TGXTC） on the regulation of chondrocyte PANoptosis， delay of chondrocyte degeneration， and improvement of the symptoms in knee osteoarthritis （KOA）. MethodsIn vivo experiments： 50 male C57BL/6 mice were randomly assigned into five groups （n=10 per group）： sham operation group， model group， low-dose TGXTC group （7.2 g·kg^-1）， high-dose TGXTC group （14.4 g·kg^-1）， and diclofenac sodium group （0.05 g·kg^-1）. Except for the sham group， KOA models were established in all other groups using the modified Hulth method. Following successful model induction， the TGXTC groups received daily oral gavage of 7.2 or 14.4 g·kg^-1 for 6 weeks， while the diclofenac sodium group received 0.05 g·kg^-1 solution daily over the same duration. Model evaluation was performed using Lequesne MG score； micro-computed tomography （micro-CT） was used to scan the knee， hematoxylin-eosin （HE） staining and safranin O-fast green staining were used to observe the morphology of cartilage， transmission electron microscopy （TEM） was used to determine ultrastructural changes of PANoptosis. Multiple immunofluorescence （IF） co-localization assays was performed to detect the co-localization of cleaved Caspase-3， receptor-interacting protein 3 （RlPK3）， and the N-terminal domain of gasdermin D （GSDMD-N） in cartilage tissue， while western blot was employed to detect the expression levels of cleaved Caspase-3， RIPK3， and GSDMD-N. In vitro experiments： The knee cartilages of 4-week-old SD rats were isolated， and a chondrocyte in vitro culture system was established through mechanical digestion with 0.2% type Ⅱ collagenase. Second-generation chondrocytes were divided into three groups： the control group， the model group （pretreated with 10 mg·L^-1 lipopolysaccharide （LPS） for 24 h followed by treatment with 1 μmol·L^-1 nigericin for 4 h）， and the TGXTC treatment group （pretreated with 10 mg·L^-1 LPS for 24 h， followed by exposure to 1 μmol·L^-1 nigericin for 4 h and subsequently treated with 100 mg·L^-1 TGXTC for an additional 24 h）. The levels of reactive oxygen species （ROS）， apoptosis， necroptosis， and pyroptosis of chondrocytes were evaluated via fluorescence microscopy following staining with ROS detection， AO/EB and YO-PRO-1/PI staining kits. Transmission electron microscopy was utilized to investigate the ultrastructural changes associated with PANoptosis in cartilage tissue of KOA mice. Inflammatory cytokine levels （IL-1β and IL-18） were measured using ELISA. Western blot was conducted to assess protein expressions related to PANoptosis， including cleaved Caspase-3， cleaved Caspase-8， RIPK3， ZBP1， GSDMD-N， and NLRP3. ResultsCompared with the sham group， the Lequesne MG scores were significantly up-regulated（P<0.01） in the model group， and the pathological changes of cartilage were significantly， with joint spaces narrower， osteophyte formation increased， secere abrasion of cartilage surface. Ultrastructural analysis revealed pronounced chondrocyte apoptosis， necroptosis， and pyroptosis， along with markedly elevated expression of cleaved Caspase-3， RlPK3， and GSDMD-N in cartilage tissue （P<0.01）. In addition， The mean fluorescence intensities of ROS， orange-red fluorescence in AO/EB staining， green fluorescence and red fluorescence in YO-PRO-1/PI staining were increased of chondrocyte in the model group （P<0.01） . The levels of inflammatory factors IL-1β and IL-18 in the supernatant were increased （P<0.01）. The expression of PANoptosis related proteins （cleaved Caspase-3， cleaved Caspase-8， RIPK3， ZBP1， GSDMD-N， and NLRP3） were also significantly upregulated（P<0.05）. Compared to the model group， the TGXTC group demonstrated a significant improvement in various parameters of mice. These included a reduction in the Lequesne MG score， an increase in joint space， a decrease in osteophyte formation， diminished cartilage damage， reduced release of ROS， and alleviation of apoptotic， necroptotic， and pyroptotic processes in chondrocytes. Additionally， mitochondrial swelling and endoplasmic reticulum dilation were also mitigated. The levels of ROS as well as IL-1β and IL-18 were significantly decreased （P<0.05）. Furthermore， the expression levels of proteins associated with PANoptosis in cartilage tissue showed marked reductions （P<0.05）. Similar results were observed in chondrocytes： cleaved Caspase-3， cleaved Caspase-8， RIPK3， ZBP1， GSDMD-N， and NLRP3 exhibited significant decreases as well （P<0.05）. ConclusionTGXTC may mitigate chondrocytes degeneration and alleviate KOA symptoms by reducing oxidative stress and suppressing the activation of PANoptosis pathways.

ObjectiveTo investigate the effect of Tougu Xiaotong capsules （TGXTC） on the regulation of chondrocyte PANoptosis， delay of chondrocyte degeneration， and improvement of the symptoms in knee osteoarthritis （KOA）. MethodsIn vivo experiments： 50 male C57BL/6 mice were randomly assigned into five groups （n=10 per group）： sham operation group， model group， low-dose TGXTC group （7.2 g·kg^-1）， high-dose TGXTC group （14.4 g·kg^-1）， and diclofenac sodium group （0.05 g·kg^-1）. Except for the sham group， KOA models were established in all other groups using the modified Hulth method. Following successful model induction， the TGXTC groups received daily oral gavage of 7.2 or 14.4 g·kg^-1 for 6 weeks， while the diclofenac sodium group received 0.05 g·kg^-1 solution daily over the same duration. Model evaluation was performed using Lequesne MG score； micro-computed tomography （micro-CT） was used to scan the knee， hematoxylin-eosin （HE） staining and safranin O-fast green staining were used to observe the morphology of cartilage， transmission electron microscopy （TEM） was used to determine ultrastructural changes of PANoptosis. Multiple immunofluorescence （IF） co-localization assays was performed to detect the co-localization of cleaved Caspase-3， receptor-interacting protein 3 （RlPK3）， and the N-terminal domain of gasdermin D （GSDMD-N） in cartilage tissue， while western blot was employed to detect the expression levels of cleaved Caspase-3， RIPK3， and GSDMD-N. In vitro experiments： The knee cartilages of 4-week-old SD rats were isolated， and a chondrocyte in vitro culture system was established through mechanical digestion with 0.2% type Ⅱ collagenase. Second-generation chondrocytes were divided into three groups： the control group， the model group （pretreated with 10 mg·L^-1 lipopolysaccharide （LPS） for 24 h followed by treatment with 1 μmol·L^-1 nigericin for 4 h）， and the TGXTC treatment group （pretreated with 10 mg·L^-1 LPS for 24 h， followed by exposure to 1 μmol·L^-1 nigericin for 4 h and subsequently treated with 100 mg·L^-1 TGXTC for an additional 24 h）. The levels of reactive oxygen species （ROS）， apoptosis， necroptosis， and pyroptosis of chondrocytes were evaluated via fluorescence microscopy following staining with ROS detection， AO/EB and YO-PRO-1/PI staining kits. Transmission electron microscopy was utilized to investigate the ultrastructural changes associated with PANoptosis in cartilage tissue of KOA mice. Inflammatory cytokine levels （IL-1β and IL-18） were measured using ELISA. Western blot was conducted to assess protein expressions related to PANoptosis， including cleaved Caspase-3， cleaved Caspase-8， RIPK3， ZBP1， GSDMD-N， and NLRP3. ResultsCompared with the sham group， the Lequesne MG scores were significantly up-regulated（P<0.01） in the model group， and the pathological changes of cartilage were significantly， with joint spaces narrower， osteophyte formation increased， secere abrasion of cartilage surface. Ultrastructural analysis revealed pronounced chondrocyte apoptosis， necroptosis， and pyroptosis， along with markedly elevated expression of cleaved Caspase-3， RlPK3， and GSDMD-N in cartilage tissue （P<0.01）. In addition， The mean fluorescence intensities of ROS， orange-red fluorescence in AO/EB staining， green fluorescence and red fluorescence in YO-PRO-1/PI staining were increased of chondrocyte in the model group （P<0.01） . The levels of inflammatory factors IL-1β and IL-18 in the supernatant were increased （P<0.01）. The expression of PANoptosis related proteins （cleaved Caspase-3， cleaved Caspase-8， RIPK3， ZBP1， GSDMD-N， and NLRP3） were also significantly upregulated（P<0.05）. Compared to the model group， the TGXTC group demonstrated a significant improvement in various parameters of mice. These included a reduction in the Lequesne MG score， an increase in joint space， a decrease in osteophyte formation， diminished cartilage damage， reduced release of ROS， and alleviation of apoptotic， necroptotic， and pyroptotic processes in chondrocytes. Additionally， mitochondrial swelling and endoplasmic reticulum dilation were also mitigated. The levels of ROS as well as IL-1β and IL-18 were significantly decreased （P<0.05）. Furthermore， the expression levels of proteins associated with PANoptosis in cartilage tissue showed marked reductions （P<0.05）. Similar results were observed in chondrocytes： cleaved Caspase-3， cleaved Caspase-8， RIPK3， ZBP1， GSDMD-N， and NLRP3 exhibited significant decreases as well （P<0.05）. ConclusionTGXTC may mitigate chondrocytes degeneration and alleviate KOA symptoms by reducing oxidative stress and suppressing the activation of PANoptosis pathways.

Objective: To analyze the association between drinking behaviors and anxiety symptoms, with the mediating role of insomnia symptoms among college freshmen, so as to provide a reference basis for reducing the occurrence of anxiety symptoms in college freshmen. Methods: From October to December 2021, 31 856 freshmen were selected by the purposive sampling method in 22 colleges across 11 provinces (Fujian, Jiangsu, Guangdong, Henan, Anhui, Hubei, Shanxi, Jiangxi, Shaanxi, Yunnan, Chongqing) in China. The Semi quantitative Food Frequency Questionnaire was used to investigate college freshmen drinking behaviors. The Depression Anxiety Stress Scale 21 and the Insomnia Severity Index were used to assess anxiety symptoms and insomnia symptoms in college freshmen. The generalized linear model was employed to analyze the association between drinking behaviors and anxiety symptoms in college freshmen, and the structural equation modeling was used to assess the mediating effect of insomnia symptoms on the association. Results: The detection rate of anxiety symptoms among college freshmen was 28.2%, the detection rates of the mild, moderate, severe and extremely severe were 6.6%, 15.9%, 3.2% and 2.6%, respectively. While 23.6% of college freshmen reported drinking in the past month, the rates were 39.8% among boys and 15.9% among girls. After adjusting for demographic variables (ethnicity, education, major, etc.) and confounding variables (self evaluation of learning burden, number of close friends, screen time, etc.), the results of generalized linear model analysis showed that beer consumption was associated with anxiety symptoms in college freshmen( β =0.09, 95% CI =0.04-0.14), girls( β =0.14, 95% CI =0.07-0.21) and those aged 19-20 years ( β =0.12, 95% CI =0.05-0.19)(all P <0.05). Red wine consumption was associated with anxiety symptoms in male students ( β =0.13, 95% CI =0.02-0.24, P <0.05). Alcohol and beer consumption were associated with insomnia in college freshmen[ β (95% CI ) =0.22(0.08-0.36),0.31(0.23-0.39),both P <0.01]. Insomnia symptoms partially mediated the association between drinking behaviors and anxiety symptoms among college freshmen with a mediating effect value of 0.05, accounting for 50.49% of the total effect. Conclusions Insomnia symptoms partially mediates the association between drinking behaviors and anxiety symptoms in college freshmen. Measures should be taken to simultaneously intervene in the drinking behaviors and insomnia symptoms of college freshmen to prevent the occurrence of their anxiety symptoms.

BACKGROUND:Research on carbon nanomaterials in the biomedical field is booming,and related scientific research results are increasing year by year.However,visualization analysis of the annual number of publications,the research status of countries,institutions,authors,and research hotspots and trends in this field is relatively scarce. OBJECTIVE:To present the research status of carbon nanomaterials in biomedical field,reveal the main research subjects,explore the research hotspots and development trends,and provide a reference for the future development of this field. METHODS:The core data set of Web of Science was used as the literature source to search the relevant researches on carbon nanomaterials in the biomedical field from 2012 to 2023.The knowledge map was generated by using Citespace software with countries,institutions,authors,keywords,and co-citations as nodes and for visualization analysis. RESULTS AND CONCLUSION:(1)A total of 2 932 papers were included in this study.In the medical field,carbon nanomaterials had a large number of papers and a fast growth rate.The United States has a large number of papers;China is an emerging force in this field,although the number of papers is the largest,but the level of research and influence need to be improved.The Chinese Academy of Sciences is the largest cooperative network institution,which mainly targets domestic institutions and lacks cooperation with well-known foreign institutions.(2)Keyword analysis displays that the green synthesis method and application of displaying carbon points have been the focus of research,followed by the new method of combining carbon nanomaterials with cancer phototherapy and immunotherapy,the key direction of future research.(3)The dynamic development trend of co-citations suggests that tissue engineering is a hot research topic of carbon nanomaterials in the field of biomedicine,mainly including the research of carbon nanomaterials for the repair and regeneration of heart and nerve tissue and as a bio-ink additive for 3D and 4D bioprinting.(4)In the future,with the development of the biomedical field in the direction of precision and treatment,researchers should speed up the creation of carbon-based systems formed by the combination of scientific and effective carbon nanomaterials with science and technology,new polymers or organic molecules,and new therapeutic methods,so as to give full play to the maximum effect of carbon nanomaterials.

BACKGROUND:Magnetic nanomaterials have biological activities such as promoting osteogenic differentiation of stem cells and inhibiting osteoclast formation,and can effectively promote the healing of injured bone tissue under the synergistic effect of magnetic fields.They have a very broad application prospect in bone injury repair. OBJECTIVE:To review the mechanism of magnetic nanomaterials and magnetic fields promoting bone repair,as well as their research progress in the field of bone injury repair. METHODS:Relevant literature search was conducted in PubMed and Web of Science databases with the search terms"magnetic nanomaterials,magnetic field,bone repair,bone tissue engineering,stem cell,osteoblast,osteoclast."The time limit of literature search was from 2003 to 2023,which was screened and analyzed.Some classic articles were manually retrieved,and 98 articles were finally included for analysis. RESULTS AND CONCLUSION:(1)Magnetic nanomaterials have biological effects such as promoting osteoblast differentiation,inhibiting osteoclast formation and regulating the immune microenvironment.In addition,magnetic nanomaterials can regulate the physicochemical properties of tissue engineering scaffolds,such as mechanical properties and surface morphology,and endowed with magnetic properties,which is conducive to the regulation of the adhesion,proliferation and osteogenic differentiation of stem cells.(2)The magnetic field has the ability to regulate multiple cell signaling pathways to promote osteoblast differentiation,inhibit osteoclast formation,stimulate angiogenesis and other biological effects,thus accelerating the healing of damaged bone tissue.(3)The joint application of magnetic nanomaterials and magnetic field accelerates the repair of bone damage by activating mechanotransduction,increasing the content of intracellular magnetic nanoparticles,and enhancing the effect of micro-magnetic field,which provides a new idea for the research of bone tissue engineering.(4)Magnetic field has demonstrated definite efficacy in the treatment of clinical fractures,osteoporosis,and osteoarthritis diseases,which is beneficial for bone tissue growth,reducing bone loss,alleviating pain,and improving the quality of life of patients.(5)Magnetic nanomaterials and magnetic fields have great potential for application in bone damage repair and regeneration,but the interaction mechanism between magnetic nanomaterials,magnetic fields,and cells has not been fully elucidated.Moreover,the key parameters of magnetic fields that regulate intracellular molecular events,including the type,intensity,frequency,duration,and mode of the magnetic field,as well as the precise biological effects of a specific magnetic field on osteoblasts and the underlying mechanisms,have yet to be defined.(6)Further attention needs to be paid to the effects on osteoclasts,nerves,blood vessels,and immune cells in the microenvironment of damaged tissues.Finally,the safety of magnetic materials for human use is yet to be systematically studied in terms of their distribution,metabolism,and acute and chronic toxicities.

BACKGROUND:In the initial stage of growth plate injury inflammation,platelet-derived growth factor BB promotes the repair of growth plate injury by promoting mesenchymal progenitor cell infiltration,chondrogenesis,osteogenic response,and regulating bone remodeling. OBJECTIVE:To elucidate the action mechanism of platelet-derived growth factor BB after growth plate injury. METHODS:PubMed,VIP,WanFang,and CNKI databases were used as the literature sources.The search terms were"growth plate injury,bone bridge,platelet-derived growth factor BB,repair"in English and Chinese.Finally,66 articles were screened for this review. RESULTS AND CONCLUSION:Growth plate injury experienced early inflammation,vascular reconstruction,fibroossification,structural remodeling and other pathological processes,accompanied by the crosstalk of chondrocytes,vascular endothelial cells,stem cells,osteoblasts,osteoclasts and other cells.Platelet-derived growth factor BB,as an important factor in the early inflammatory response of injury,regulates the injury repair process by mediating a variety of cellular inflammatory responses.Targeting the inflammatory stimulation mediated by platelet-derived growth factor BB may delay the bone bridge formation process by improving the functional activities of osteoclasts,osteoblasts,and chondrocytes,so as to achieve the injury repair of growth plate.Platelet-derived growth factor BB plays an important role in angiogenesis and bone repair tissue formation at the injured site of growth plate and intrachondral bone lengthening function of uninjured growth plate.Inhibition of the coupling effect between angiogenesis initiated by platelet-derived growth factor BB and intrachondral bone formation may achieve the repair of growth plate injury.