Objective To propose an in vitro cytotoxicity evaluation method for novel iron-based biodegradable mateirals focusing on their degrading characteristics.Methods Half-finished scaffolds of nitrided iron tubes with a higher iron content of over 99％and a nitrogen content of 0.03％to 0.20％were selected as test samples,and based on the treatment mode were divided into an anaerobic treatment group,a non-anaerobic treatment group,a non-anaerobic treatment with removed iron particle group and a non-anaerobic treatment with plate-washing group.The anaerobic treatment group was processed in an anaerobic workstation;the conventional treatment group underwent standard handling in a biosafety cabinet;the conventional treatment with removed iron particle group was subjected to iron particle elimination using a Midimacs Starting Kit manual sorter after conventional treatment;and the conventional treatment with plate-washing group was rinsed with 0.9％sodium chloride injection before tetrazolium salt reagent treatment.Different extraction media(simulated body fluid,cell culture medium,phosphate buffer and 0.9％sodium chloride injection)were used for the immersion treatment of the test samples in each group to compare the effects of the degradation products on the survival rate of L929 cells.Results The anaerobic treatment group and the conventional treatment with removed iron particle group exhibited no detectable cytotoxicity.Trypan blue staining revealed significant cytotoxicity in the conventional treatment group,while false-negative results emerged due to interactions between the tetrazolium salt reagent and degradation products.In the non-anaerobic treatment with washing plate group,the false negative from iron particles was eliminated while potential cytotoxicity was showen,and the result accuracy was affected because some cells were washed out.Conclusion The proposed method can be used for the in vitro cytotoxicity evaluation,and facilitates the safety evaluation of the application of such materials.[Chinese Medical Equipment Journal,2025,46(3):35-41]

Transfer RNA-derived small RNAs(tsRNAs)are a novel class of non-coding small RNAs,which have various biological functions such as regulating gene expression,protein translation,epigenetic inheritance,cell proliferation and apoptosis,and communication.tsRNA is abnormally expressed in respiratory system cancers,lung injury,pulmonary hypertension,childhood obstructive sleep apnea-hypopnea syndrome and respiratory virus infections,affecting the occurrence and development of these diseases.However,the regulatory mechanism of tsRNAs in respiratory diseases has not been fully elucidated yet.Therefore,this review introduces the sources,classification and detection methods of tsRNA,summarizes the biological functions of tsRNA in respiratory diseases,related regulatory mechanisms,and its application prospects as biomarker in clinical diagnosis and prognosis evaluation,aiming to provide new ideas for the diagnosis and treatment of respiratory diseases,and to provide reference for in-depth research on tsRNA regulation of respiratory diseases.

Objective:An in vivo mammalian hepatocyte Unscheduled DNA Synthesis(UDS)test was used to evaluate the genotoxicity of Cross-linked Sodium Hyaluronate Gel and Bone Repair Materials,providing experimental evidence for establishing a UDS testing method for medical devices and materials.Methods:0.9％sodium chloride injection and cottonseed oil were used as the solvent for test materials and negative control,respectively.N-dimethylnitrosamine(NDMA)was used as the positive control for the early sampling times,and 2-acetylaminofluorene(2-AAF)was used as the positive control for the late sampling times.SD rats were administered a single dose for toxic exposure,and liver tissues were collected at 4 h and 16 h,respectively.Hepatocytes were isolated using collagenase perfusion.After labeling with 5-ethynyl-2'-deoxyuridine(EdU),and the net average fluorescence intensity(NAFI)of cell nuclei and nucleoplasm was measured by fluorescence microscope.Data from 50 cells were used to analyze the DNA repair level.Results:Compared with the negative control groups,the positive control groups(NDMA and 2-AAF)showed highly statistically significant differences in NAFI(P＜0.01),indicating successful induction of DNA damage.There was no statistically significant differences between the cross-linked sodium hyaluronate gel groups,bone repair material groups and the negative control group(P＞0.05),suggesting that these materials did not significantly induce DNA damage under the experimental conditions.Conclusion:This study first applied EdU labeling technology to the in vivo hepatic UDS assay,achieving non-radioactive labeling through click chemistry reactions.Under the conditions of this study,cross-linked sodium hyaluronate gel and bone repair materials did not exhibit genotoxicity.In the follow-up,the sample range can be expanded and the observation period can be prolonged to further improve the genotoxicity evaluation system of medical devices.

Objective To propose an in vitro cytotoxicity evaluation method for novel iron-based biodegradable mateirals focusing on their degrading characteristics.Methods Half-finished scaffolds of nitrided iron tubes with a higher iron content of over 99％and a nitrogen content of 0.03％to 0.20％were selected as test samples,and based on the treatment mode were divided into an anaerobic treatment group,a non-anaerobic treatment group,a non-anaerobic treatment with removed iron particle group and a non-anaerobic treatment with plate-washing group.The anaerobic treatment group was processed in an anaerobic workstation;the conventional treatment group underwent standard handling in a biosafety cabinet;the conventional treatment with removed iron particle group was subjected to iron particle elimination using a Midimacs Starting Kit manual sorter after conventional treatment;and the conventional treatment with plate-washing group was rinsed with 0.9％sodium chloride injection before tetrazolium salt reagent treatment.Different extraction media(simulated body fluid,cell culture medium,phosphate buffer and 0.9％sodium chloride injection)were used for the immersion treatment of the test samples in each group to compare the effects of the degradation products on the survival rate of L929 cells.Results The anaerobic treatment group and the conventional treatment with removed iron particle group exhibited no detectable cytotoxicity.Trypan blue staining revealed significant cytotoxicity in the conventional treatment group,while false-negative results emerged due to interactions between the tetrazolium salt reagent and degradation products.In the non-anaerobic treatment with washing plate group,the false negative from iron particles was eliminated while potential cytotoxicity was showen,and the result accuracy was affected because some cells were washed out.Conclusion The proposed method can be used for the in vitro cytotoxicity evaluation,and facilitates the safety evaluation of the application of such materials.[Chinese Medical Equipment Journal,2025,46(3):35-41]

Objective:An in vivo mammalian hepatocyte Unscheduled DNA Synthesis(UDS)test was used to evaluate the genotoxicity of Cross-linked Sodium Hyaluronate Gel and Bone Repair Materials,providing experimental evidence for establishing a UDS testing method for medical devices and materials.Methods:0.9％sodium chloride injection and cottonseed oil were used as the solvent for test materials and negative control,respectively.N-dimethylnitrosamine(NDMA)was used as the positive control for the early sampling times,and 2-acetylaminofluorene(2-AAF)was used as the positive control for the late sampling times.SD rats were administered a single dose for toxic exposure,and liver tissues were collected at 4 h and 16 h,respectively.Hepatocytes were isolated using collagenase perfusion.After labeling with 5-ethynyl-2'-deoxyuridine(EdU),and the net average fluorescence intensity(NAFI)of cell nuclei and nucleoplasm was measured by fluorescence microscope.Data from 50 cells were used to analyze the DNA repair level.Results:Compared with the negative control groups,the positive control groups(NDMA and 2-AAF)showed highly statistically significant differences in NAFI(P＜0.01),indicating successful induction of DNA damage.There was no statistically significant differences between the cross-linked sodium hyaluronate gel groups,bone repair material groups and the negative control group(P＞0.05),suggesting that these materials did not significantly induce DNA damage under the experimental conditions.Conclusion:This study first applied EdU labeling technology to the in vivo hepatic UDS assay,achieving non-radioactive labeling through click chemistry reactions.Under the conditions of this study,cross-linked sodium hyaluronate gel and bone repair materials did not exhibit genotoxicity.In the follow-up,the sample range can be expanded and the observation period can be prolonged to further improve the genotoxicity evaluation system of medical devices.

Objective: To investigate the correlation between magnetic resonance imaging-based vertebral bone quality (VBQ) score and screw loosening after dynamic pedicle screw fixation with polyetheretherketone (PEEK) rods, and evaluate its predictive value. Methods: A retrospective analysis was conducted on the patients who underwent dynamic pedicle screw fixation with PEEK rods from March 2017 to June 2022. Data on age, sex, body mass index, hypertension, diabetes, hyperlipidemia history, long-term smoking, alcohol consumption, VBQ score, L1–4 average Hounsfield unit (HU) value, surgical fixation length, and the lowest instrumented vertebra were collected. Logistic regression analysis was employed to assess the relationship between VBQ score and pedicle screw loosening (PSL). Results: A total of 24 patients experienced PSL after surgery (20.5%). PSL group and non-PSL group showed statistical differences in age, number of fixed segments, fixation to the sacrum, L1–4 average HU value, and VBQ score (p < 0.05). The VBQ score in the PSL group was higher than that in the non-PSL group (3.56 ± 0.45 vs. 2.77 ± 0.31, p < 0.001). In logistic regression analysis, VBQ score (odds ratio, 3.425; 95% confidence interval, 1.552–8.279) were identified as independent risk factors for screw loosening. The area under the receiver operating characteristic curve for VBQ score predicting PSL was 0.819 (p < 0.05), with the optimal threshold of 3.15 (sensitivity, 83.1%; specificity, 80.5%). Conclusion The VBQ score can independently predict postoperative screw loosening in patients undergoing lumbar dynamic pedicle screw fixation with PEEK rods, and its predictive value is comparable to HU value.

Objective: To investigate the correlation between magnetic resonance imaging-based vertebral bone quality (VBQ) score and screw loosening after dynamic pedicle screw fixation with polyetheretherketone (PEEK) rods, and evaluate its predictive value. Methods: A retrospective analysis was conducted on the patients who underwent dynamic pedicle screw fixation with PEEK rods from March 2017 to June 2022. Data on age, sex, body mass index, hypertension, diabetes, hyperlipidemia history, long-term smoking, alcohol consumption, VBQ score, L1–4 average Hounsfield unit (HU) value, surgical fixation length, and the lowest instrumented vertebra were collected. Logistic regression analysis was employed to assess the relationship between VBQ score and pedicle screw loosening (PSL). Results: A total of 24 patients experienced PSL after surgery (20.5%). PSL group and non-PSL group showed statistical differences in age, number of fixed segments, fixation to the sacrum, L1–4 average HU value, and VBQ score (p < 0.05). The VBQ score in the PSL group was higher than that in the non-PSL group (3.56 ± 0.45 vs. 2.77 ± 0.31, p < 0.001). In logistic regression analysis, VBQ score (odds ratio, 3.425; 95% confidence interval, 1.552–8.279) were identified as independent risk factors for screw loosening. The area under the receiver operating characteristic curve for VBQ score predicting PSL was 0.819 (p < 0.05), with the optimal threshold of 3.15 (sensitivity, 83.1%; specificity, 80.5%). Conclusion The VBQ score can independently predict postoperative screw loosening in patients undergoing lumbar dynamic pedicle screw fixation with PEEK rods, and its predictive value is comparable to HU value.

Objective: To investigate the correlation between magnetic resonance imaging-based vertebral bone quality (VBQ) score and screw loosening after dynamic pedicle screw fixation with polyetheretherketone (PEEK) rods, and evaluate its predictive value. Methods: A retrospective analysis was conducted on the patients who underwent dynamic pedicle screw fixation with PEEK rods from March 2017 to June 2022. Data on age, sex, body mass index, hypertension, diabetes, hyperlipidemia history, long-term smoking, alcohol consumption, VBQ score, L1–4 average Hounsfield unit (HU) value, surgical fixation length, and the lowest instrumented vertebra were collected. Logistic regression analysis was employed to assess the relationship between VBQ score and pedicle screw loosening (PSL). Results: A total of 24 patients experienced PSL after surgery (20.5%). PSL group and non-PSL group showed statistical differences in age, number of fixed segments, fixation to the sacrum, L1–4 average HU value, and VBQ score (p < 0.05). The VBQ score in the PSL group was higher than that in the non-PSL group (3.56 ± 0.45 vs. 2.77 ± 0.31, p < 0.001). In logistic regression analysis, VBQ score (odds ratio, 3.425; 95% confidence interval, 1.552–8.279) were identified as independent risk factors for screw loosening. The area under the receiver operating characteristic curve for VBQ score predicting PSL was 0.819 (p < 0.05), with the optimal threshold of 3.15 (sensitivity, 83.1%; specificity, 80.5%). Conclusion The VBQ score can independently predict postoperative screw loosening in patients undergoing lumbar dynamic pedicle screw fixation with PEEK rods, and its predictive value is comparable to HU value.

Objective: To investigate the correlation between magnetic resonance imaging-based vertebral bone quality (VBQ) score and screw loosening after dynamic pedicle screw fixation with polyetheretherketone (PEEK) rods, and evaluate its predictive value. Methods: A retrospective analysis was conducted on the patients who underwent dynamic pedicle screw fixation with PEEK rods from March 2017 to June 2022. Data on age, sex, body mass index, hypertension, diabetes, hyperlipidemia history, long-term smoking, alcohol consumption, VBQ score, L1–4 average Hounsfield unit (HU) value, surgical fixation length, and the lowest instrumented vertebra were collected. Logistic regression analysis was employed to assess the relationship between VBQ score and pedicle screw loosening (PSL). Results: A total of 24 patients experienced PSL after surgery (20.5%). PSL group and non-PSL group showed statistical differences in age, number of fixed segments, fixation to the sacrum, L1–4 average HU value, and VBQ score (p < 0.05). The VBQ score in the PSL group was higher than that in the non-PSL group (3.56 ± 0.45 vs. 2.77 ± 0.31, p < 0.001). In logistic regression analysis, VBQ score (odds ratio, 3.425; 95% confidence interval, 1.552–8.279) were identified as independent risk factors for screw loosening. The area under the receiver operating characteristic curve for VBQ score predicting PSL was 0.819 (p < 0.05), with the optimal threshold of 3.15 (sensitivity, 83.1%; specificity, 80.5%). Conclusion The VBQ score can independently predict postoperative screw loosening in patients undergoing lumbar dynamic pedicle screw fixation with PEEK rods, and its predictive value is comparable to HU value.

BACKGROUND:Heterotopic ossification is a dynamic growth process.Diverse heterotopic ossification subtypes have diverse etiologies or induction factors,but they exhibit a similar clinical process in the intermediate and later phases of the disease.Acquired heterotopic ossification produced by trauma and other circumstances has a high incidence. OBJECTIVE:To summarize the molecular biological mechanisms linked to the occurrence and progression of acquired heterotopic ossification in recent years. METHODS:The keywords"molecular biology,heterotopic ossification,mechanisms"were searched in CNKI,Wanfang,PubMed,Embase,Web of Science,and Google Scholar databases for articles published from January 2016 to August 2022.Supplementary searches were conducted based on the obtained articles.After the collected literature was screened,131 articles were finally included and summarized. RESULTS AND CONCLUSION:(1)The occurrence and development of acquired heterotopic ossification is a dynamic process with certain concealment,making diagnosis and treatment of the disease difficult.(2)By reviewing relevant literature,it was found that acquired heterotopic ossification involves signaling pathways such as bone morphogenetic protein,transforming growth factor-β,Hedgehog,Wnt,and mTOR,as well as core factors such as Runx-2,vascular endothelial growth factor,hypoxia-inducing factor,fibroblast growth factor,and Sox9.The core mechanism may be the interaction between different signaling pathways,affecting the body's osteoblast precursor cells,osteoblast microenvironment,and related cytokines,thereby affecting the body's bone metabolism and leading to the occurrence of acquired heterotopic ossification.(3)In the future,it is possible to take the heterotopic ossification-related single-cell osteogenic homeostasis as the research direction,take the osteoblast precursor cells-osteogenic microenvironment-signaling pathways and cytokines as the research elements,explore the characteristics of each element under different temporal and spatial conditions,compare the similarities and differences of the osteogenic homeostasis of different types and individuals,observe the regulatory mechanism of the molecular signaling network of heterotopic ossification from a holistic perspective.It is beneficial to the exploration of new methods for the future clinical prevention and treatment of heterotopic ossification.(4)Meanwhile,the treatment methods represented by traditional Chinese medicine and targeted therapy have become research hotspots in recent years.How to link traditional Chinese medicine with the osteogenic homeostasis in the body and combine it with targeted therapy is also one of the future research directions.(5)At present,the research on acquired heterotopic ossification is still limited to basic experimental research and the clinical prevention and treatment methods still have defects such as uncertain efficacy and obvious side effects.The safety and effectiveness of relevant targeted prevention and treatment drugs in clinical application still need to be verified.Future research should focus on clinical prevention and treatment based on basic experimental research combined with the mechanism of occurrence and development.