1.Conduits selection for surgical repair of ventricular septal rupture combined with concurrent coronary artery bypass grafting
Jiexu MA ; Xinhe XU ; Hang XU ; Zhaoji ZHONG ; Sheng LIU
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2026;33(05):766-771
Objective To investigate the impact of graft type on perioperative outcomes and long-term prognosis in patients undergoing surgical repair of post-myocardial infarction ventricular septal rupture (VSR) with concurrent coronary artery bypass grafting (CABG). Methods A retrospective analysis was conducted on clinical data from patients who underwent VSR repair and concurrent CABG at Fuwai Hospital between 2005 and 2022. Patients were divided into an arterial graft group and a saphenous vein graft (SVG)-only group based on the type of bypass grafts used. Clinical outcomes were compared between the two groups. Results A total of 92 patients were included, comprising 56 males and 36 females, with a mean age of (62.4±7.9) years. The arterial graft group consisted of 60 patients, and the SVG-only group consisted of 32 patients. There were no statistical differences between the two groups in age, gender, body mass index, past medical history, time interval from myocardial infarction to surgery, or culprit vessel distribution (P>0.05). A higher proportion of patients in the SVG-only group received preoperative intra-aortic balloon pump (IABP) support (56.3% vs. 35.0%, P=0.049). However, cardiopulmonary bypass time, aortic cross-clamp time, and early mortality rates were similar between the two groups (P>0.05). Follow-up data revealed no statistically significant differences in cumulative 10-year survival (82.8% vs. 80.0%, P=0.940) or freedom from major adverse cardiovascular and cerebrovascular events (49.6% vs. 58.6%, P=0.491) between the SVG-only and arterial graft groups. Furthermore, graft type did not significantly affect long-term mortality in patients with a culprit vessel in the left anterior descending artery or those with multivessel disease. Conclusion In patients undergoing delayed repair of VSR with concomitant CABG, the use of arterial or saphenous vein grafts does not significantly impact perioperative outcomes or long-term prognosis. Future research should further explore the benefits of different revascularization strategies to optimize treatment for this population.
2.Association between blood pressure variability and early neurological deterioration in patients with acute mild non-disabling ischemic stroke
Journal of Apoplexy and Nervous Diseases 2026;43(3):232-237
Objective To investigate the association of blood pressure variability (BPV) with early neurological deterioration (END) and prognosis in patients with acute mild non-disabling ischemic stroke. Methods The patients with acute mild non-disabling ischemic stroke who were admitted to Stroke Center of Affiliated Hospital of Inner Mongolia University for Nationalities from January 2022 to August 2024 were enrolled, and according to the presence or absence of END, they were divided into non-END group and END group. General information, clinical data, and outcome measures were collected from all patients, and a binary logistic regression analysis was performed to determine independent risk factors for END. According to the modified Rankin Scale (mRS) score, the patients were divided into good prognosis group (mRS score ≤2 points) and poor prognosis group (mRS score >2 points), and a univariate logistic regression analysis was performed to investigate the influence of END on the 90-day neurological function prognosis of patients. Results A total of 61 patients were enrolled, with 14 patients in the END group and 47 patients in the non-END group. There was a significant difference in the coefficient of systolic pressure variation between the END group and the non-END group (P<0.05). The binary logistic regression analysis showed that systolic BPV(BPV>75%) was an independent risk factor for END (OR=14.000, 95%CI 1.471‒133.233,P=0.011).Compared with the non-END group, the END group had a significantly higher proportion of patients with a poor 90-day prognosis.Of all patients, there were 11 patients with poor prognosis and 50 patients with good prognosis on day 90. The univariate logistic regression analysis showed that END (OR=19.556,95%CI 4.038‒94.696,P<0.001) was an independent risk factor for poor prognosis. Conclusion In patients with acute mild non-disabling ischemic stroke, the increase in coefficient of systolic pressure variation is an independent risk factor for END and affects the prognosis of neurological function on day 90.
Prognosis
3.Effects of SPBC1604.04 Gene Deletion on Mitotic Cell Dynamics in Schizosaccharomyces pombe
Jia-Ni XU ; Jia-Yi HE ; Lang-Lin ZHENG ; Shu-Rong HE ; Shuai MA ; Xiang DING ; Yi-Ling HOU
Progress in Biochemistry and Biophysics 2026;53(5):1471-1484
ObjectiveMitochondria are not only the central organelles responsible for cellular energy metabolism but also play essential roles in regulating cell cycle progression and cytoskeletal dynamics. In recent years, accumulating evidence has demonstrated that mitochondrial homeostasis is closely associated with mitotic progression and cytokinesis. Schizosaccharomyces pombe serves as a classical and well-established model organism. Because its cell cycle regulatory mechanisms are highly conserved throughout evolution, its genetic background is clearly defined, and experimental manipulation is efficient and convenient, it has been extensively applied in studies of cell growth, division, and reproductive mechanisms. The SPBC1604.04 gene encodes a previously uncharacterized mitochondrial carrier protein in Schizosaccharomyces pombe. This gene is located on chromosome II and spans 1 018 base pairs in length. It encodes a protein consisting of 238 amino acids with a predicted molecular mass of approximately 31.03 ku. Bioinformatic analysis predicts that this protein is responsible for the transport of thiamine pyrophosphate (TPP) into mitochondria. However, the effects of SPBC1604.04 gene deletion on mitotic cell dynamics under different temperature conditions have not been fully elucidated. MethodsThe SPBC1604.04 deletion strain of Schizosaccharomyces pombe was used as the experimental model. Fluorescent protein markers were constructed in the deletion background to label mitochondria, microtubules, actin, myosin, the nuclear envelope, and chromosomes. Live-cell imaging was performed using a TCS-SP8 laser scanning confocal microscope under normal temperature conditions (25℃) and heat stress conditions (37℃). Time-lapse microscopy was applied to dynamically monitor mitochondrial morphology and distribution, spindle assembly and elongation, chromosome segregation, as well as the formation and constriction of the actomyosin ring during cytokinesis. ImageJ software was used for quantitative measurements, including microtubule length during mitosis, spindle length at different mitotic stages, mitochondrial fluorescence intensity as an indicator of mitochondrial content, actomyosin ring length, nuclear envelope area, and chromosome segregation timing. Statistical analyses were conducted to compare phenotypic differences between the wild-type and SPBC1604.04 deletion strains at both temperature conditions. Through these analyses, we systematically investigated the impact of SPBC1604.04 deletion on mitotic cell dynamics in fission yeast under both normal physiological conditions and temperature stress. ResultsAt 25℃, compared with wild-type cells, the SPBC1604.04Δ strain exhibited a pronounced tendency toward mitochondrial fragmentation, accompanied by abnormal mitochondrial content and a significant reduction in mitochondrial fluorescence intensity. These observations suggest impaired mitochondrial homeostasis under normal growth conditions. In addition, the constriction time of actomyosin ring during cytokinesis was markedly prolonged, indicating that deletion of SPBC1604.04 affects the dynamics of the contractile machinery. However, no obvious defects were observed in spindle assembly, spindle elongation, or chromosome segregation. Under heat stress at 37℃, mitochondrial morphology in the SPBC1604.04Δ strain showed a tendency to recover toward a continuous tubular network structure. Mitochondrial content was restored, fluorescence intensity increased, and the constriction time of the actomyosin ring returned to levels comparable to those of wild-type cells. These results indicate that the mitotic defects observed at normal temperature are partially or fully alleviated under heat stress conditions. ConclusionThis study demonstrates that deletion of the SPBC1604.04 gene leads to abnormal mitochondrial content in Schizosaccharomyces pombe. The mitochondrial carrier protein SPBC1604.04 participates in regulating actomyosin ring constriction during mitosis but does not appear to be directly involved in the regulation of spindle dynamics or chromosome segregation. Our findings provide key experimental evidence for understanding the functional link between the SPBC1604.04 gene, mitochondrial homeostasis, and mitotic regulation.
4.Epidemiological investigation and analysis of a local dengue fever cluster outbreak in Qingpu District of Shanghai
Changpo LIN ; Wei WANG ; Zhangrui XU ; Yadong MA ; Zhicheng ZHANG ; Xueqin YU ; Chengcheng WANG ; Haoxuan WANG ; Yanli DAI ; Huanyu WU
Shanghai Journal of Preventive Medicine 2026;38(3):206-209
ObjectiveTo analyze the epidemiological characteristics of a local dengue fever cluster outbreak in Qingpu District of Shanghai in 2024, and to provide a reference for subsequent dengue fever prevention and control. MethodsSeven confirmed local dengue fever cases reported through the National Notifiable Infectious Diseases Surveillance System in Qingpu District of Shanghai in 2024 were selected as the research subjects. Descriptive epidemiological methods were used to conduct investigation and analysis from the aspects of onset, medical treatment and reporting, clinical symptoms, travel and contact history within 15 days before onset, and activity trajectories. ResultsA total of 7 cases were identified in this outbreak. None of the cases had a travel history to dengue-endemic areas within 15 days prior to onset, while all had shared exposure environments and mosquito bite histories, indicating a local clustered transmission pattern. The main clinical manifestations included fever (100.00%) and myalgia (42.86%). All 7 cases were positive for dengue virus serotype 2 (DENV-2) by nucleic acid testing. Genetic sequencing showed that the virus strains belonged to the Cosmopolitan genotype and were most closely related to the epidemic DENV strains circulating in southern China in recent years. ConclusionThis outbreak might be a local secondary infection caused by the short-term stay of dengue fever-infected individuals, and the possible source of importation was dengue fever endemic areas in southern China.
5.Effects of SPBC1604.04 Gene Deletion on Mitotic Cell Dynamics in Schizosaccharomyces pombe
Jia-Ni XU ; Jia-Yi HE ; Lang-Lin ZHENG ; Shu-Rong HE ; Shuai MA ; Xiang DING ; Yi-Ling HOU
Progress in Biochemistry and Biophysics 2026;53(5):1471-1484
ObjectiveMitochondria are not only the central organelles responsible for cellular energy metabolism but also play essential roles in regulating cell cycle progression and cytoskeletal dynamics. In recent years, accumulating evidence has demonstrated that mitochondrial homeostasis is closely associated with mitotic progression and cytokinesis. Schizosaccharomyces pombe serves as a classical and well-established model organism. Because its cell cycle regulatory mechanisms are highly conserved throughout evolution, its genetic background is clearly defined, and experimental manipulation is efficient and convenient, it has been extensively applied in studies of cell growth, division, and reproductive mechanisms. The SPBC1604.04 gene encodes a previously uncharacterized mitochondrial carrier protein in Schizosaccharomyces pombe. This gene is located on chromosome II and spans 1 018 base pairs in length. It encodes a protein consisting of 238 amino acids with a predicted molecular mass of approximately 31.03 ku. Bioinformatic analysis predicts that this protein is responsible for the transport of thiamine pyrophosphate (TPP) into mitochondria. However, the effects of SPBC1604.04 gene deletion on mitotic cell dynamics under different temperature conditions have not been fully elucidated. MethodsThe SPBC1604.04 deletion strain of Schizosaccharomyces pombe was used as the experimental model. Fluorescent protein markers were constructed in the deletion background to label mitochondria, microtubules, actin, myosin, the nuclear envelope, and chromosomes. Live-cell imaging was performed using a TCS-SP8 laser scanning confocal microscope under normal temperature conditions (25℃) and heat stress conditions (37℃). Time-lapse microscopy was applied to dynamically monitor mitochondrial morphology and distribution, spindle assembly and elongation, chromosome segregation, as well as the formation and constriction of the actomyosin ring during cytokinesis. ImageJ software was used for quantitative measurements, including microtubule length during mitosis, spindle length at different mitotic stages, mitochondrial fluorescence intensity as an indicator of mitochondrial content, actomyosin ring length, nuclear envelope area, and chromosome segregation timing. Statistical analyses were conducted to compare phenotypic differences between the wild-type and SPBC1604.04 deletion strains at both temperature conditions. Through these analyses, we systematically investigated the impact of SPBC1604.04 deletion on mitotic cell dynamics in fission yeast under both normal physiological conditions and temperature stress. ResultsAt 25℃, compared with wild-type cells, the SPBC1604.04Δ strain exhibited a pronounced tendency toward mitochondrial fragmentation, accompanied by abnormal mitochondrial content and a significant reduction in mitochondrial fluorescence intensity. These observations suggest impaired mitochondrial homeostasis under normal growth conditions. In addition, the constriction time of actomyosin ring during cytokinesis was markedly prolonged, indicating that deletion of SPBC1604.04 affects the dynamics of the contractile machinery. However, no obvious defects were observed in spindle assembly, spindle elongation, or chromosome segregation. Under heat stress at 37℃, mitochondrial morphology in the SPBC1604.04Δ strain showed a tendency to recover toward a continuous tubular network structure. Mitochondrial content was restored, fluorescence intensity increased, and the constriction time of the actomyosin ring returned to levels comparable to those of wild-type cells. These results indicate that the mitotic defects observed at normal temperature are partially or fully alleviated under heat stress conditions. ConclusionThis study demonstrates that deletion of the SPBC1604.04 gene leads to abnormal mitochondrial content in Schizosaccharomyces pombe. The mitochondrial carrier protein SPBC1604.04 participates in regulating actomyosin ring constriction during mitosis but does not appear to be directly involved in the regulation of spindle dynamics or chromosome segregation. Our findings provide key experimental evidence for understanding the functional link between the SPBC1604.04 gene, mitochondrial homeostasis, and mitotic regulation.
6.Research on the mechanism of Chaiqi yigan granules against liver cancer via the ferroptosis pathway
Bowen LIU ; Guiping MA ; Feng LI ; Xiaobin LI ; Fenping LU ; Xu PANG ; Shiping HU
China Pharmacy 2026;37(10):1272-1276
OBJECTIVE To explore the mechanism of Chaiqi yigan granules (CQYG) against liver cancer through the ferroptosis pathway. METHODS Network pharmacology combined with ferroptosis-related database was used to screen key targets and main effective components of CQYG against liver cancer via regulating ferroptosis; molecular docking technology was employed to analyze the binding ability of main active components to key targets. Human liver Huh-7 cells were divided into blank serum control (CON) group, CQYG drug-containing serum (CQYGKL) group, ferroptosis inducer (RSL3) group, mammalian target of rapamycin complex 1 (mTORC1) inhibitor (RMC-5552) group, mTORC1 agonist (CCT007093) group, and CCT007093+CQYGKL group. The levels of Fe 2+ , malondialdehyde (MDA), and glutathione (GSH) in the cells were detected in the former three groups; mRNA expressions of mammalian target of rapamycin (mTOR), sterol regulatory element-binding protein 1 (SREBP1), and stearoyl-CoA desaturase 1 (SCD1), protein expressions of SREBP1 and SCD1 as well as phosphorylation levels of mTOR and ribosomal S6 kinase (S6K) proteins were detected in all groups. RESULTS Key targets of CQYG for anti-liver cancer through the ferroptosis pathway were mTOR, SREBP1, SCD1,etc. The main active components included quercetin, tanshinone Ⅱ A , baicalein, etc. The binding energies of main active components to key targets were all less than -5 kJ/mol. Compared with CON group, the levels of Fe 2+ and MDA in the cells in CQYGKL group and RSL3 group were significantly increased, while the levels of GSH were significantly decreased ( P <0.05). mRNA expressions of mTOR, SREBP1 and SCD1, protein expressions of SREBP1 and SCD1, as well as the phosphorylation levels of mTOR and S6K proteins were significantly decreased in the CQYGKL group, RSL3 group, and RMC-5552 group, whereas all the above indicators were significantly increased in the CCT007093 group ( P <0.05). Compared with CCT007093 group, the changes in all the above indicators were significantly suppressed in the CCT007093+CQYGKL group ( P <0.05). CONCLUSIONS CQYG may induce ferroptosis by inhibiting mTORC1/SREBP1/SCD1 axis, thereby exerting anti-liver cancer effects.
7.Evaluation of CARIFS Score and Negative Antigen Conversion Rate of Qingxuan Daozhi Formula in Treatment of Influenza in Children (Heat Accumulation in Lung and Stomach Syndrome):A Multi-center Randomized Controlled Clinical Study
Jing WANG ; Liqun WU ; Tiegang LIU ; Yongning CAO ; Jing QIU ; Jing LI ; Huaqing TAN ; Ying ZHANG ; Xulei GOU ; Jia WANG ; Jing LI ; Haipeng CHEN ; Xueying QIN ; Yuanshuo TIAN ; Yang WANG ; Chen BAI ; Zhendong WANG ; Qianqian LI ; He YU ; Xueyan MA ; Fei DONG ; Lin JIANG ; Yingqi XU ; Jianping LIU ; Xiaohong GU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(13):188-196
ObjectiveThis paper aims to observe the syndrome improvement and negative antigen conversion rate of Qingxuan Daozhi formula in the treatment of influenza in children (heat accumulation in the lung and stomach syndrome). MethodsThrough a multi-center randomized controlled methodology design,confirmed influenza cases were collected from October 2022 to April 2023 in the pediatrics department of eight hospitals,such as Dongfang Hospital of Beijing University of Chinese Medicine. A total of 180 children with influenza and heat accumulation in the lung and stomach syndrome conforming to the standard were recruited through the clinic. The sick children meeting the inclusion criteria were randomly divided into groups by a block-randomized method. The children in the experimental group were treated with Qingxuan Daozhi formula for five days,and those in the control group were treated with Oseltamivir Phosphate Granules for five days. The primary efficacy indicator was the negative conversion rate of influenza antigen detection. Secondary efficacy indicators were the Canadian acute respiratory illness and flu scale (CARIFS) and the incidence of complications,severe cases, and critical cases. Follow-up observation was conducted on the day of enrollment,48 hours after medication,72 hours after medication, and (6+1) d after medication. ResultsOne hundred and eighty participants were randomly assigned to the experimental group (90 cases) or the control group (90 cases). All participants were followed up during the study. Comparison of influenza antigen detection results in the primary efficacy indicators showed that the average time of negative influenza antigen conversion in the experimental group was (5.29±1.25) d,and that in the control group was (5.40±1.68) d,without a statistically significant difference. After five days of intervention,52 cases in the experimental group and 51 cases in the control group converted to negative,without a statistically significant difference. CARIFS score results in the secondary efficacy indicators showed that during 72 hours after intervention,there were statistically significant differences between the experimental group and the control group in three dimensions, including headache,muscle soreness, and the need for extra care (P<0.05). On the (6+1) days after the intervention,the differences in both the experimental group and the control group were statistically significant in 10 dimensions, including sore throat,bad sleep,uncomfortable feeling,poor spirit and fatigue,crying more than usual,the need for extra care,symptom,function,influence on parents,and total score (P<0.05). The comparison results within the group in the dimensional scores of symptom, function, and influence on parents,as well as the CARIFS total score showed that with the delay of follow-up time,scores of both groups decreased significantly,with a statistically significant difference (P<0.01). Inter-group comparison results showed that the mean score of the experimental group was higher than that of the control group at the time of enrollment. With the progress of intervention,the score of the experimental group was significantly decreased compared with that of the control group. At the end of follow-up,the mean score of the experimental group was lower than that of the control group,with no statistically significant difference. In terms of the incidence of complications,severe cases, and critical cases, there were no complications,severe cases, and critical cases in the two groups,without a statistically significant difference. ConclusionThe symptom improvement effect and negative antigen conversion rate of Qingxuan Daozhi formula in the treatment of influenza in children (heat accumulation in the lung and stomach syndrome) are not inferior to Oseltamivir Phosphate granules, and children's acceptance is better. It can be more widely used in clinical treatment of influenza in children (heat accumulation in the lung and stomach syndrome).
8.Genotypic diversity and antibiotic resistance of Enterococcus in dairy farming workplaces
Xiangnan WEI ; Yanggui CHEN ; Jia HUANG ; Fulong WANG ; Jiguo JIN ; Fan WU ; Xixiao MA ; Zhaojie WANG ; Xingyu WANG ; Wanting XU ; Jianyong WU ; Fuye LI
Journal of Environmental and Occupational Medicine 2026;43(5):582-590
Background Under intensive dairy farming conditions, Enterococcus spp. can be transmitted between animals, farm workers, and the environment via multiple vectors such as feces, soil, water, air, and farming equipment, posing a potential threat to public health. Objective To elucidate the prevalence, distribution, and antimicrobial resistance profiles of Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium) among farm workers, dairy cattle, and the farm environment in Xinjiang, and to assess the risk of their cross-host transmission. Methods From May 2024 to January 2025, a total of 317 samples were collected from 11 large-scale dairy farms in Xinjiang, China, including feces from farm workers (n=130) and dairy cattle (n=154), and environmental samples (n=33). E. faecalis and E. faecium were isolated and identified, followed by antimicrobial susceptibility testing and multilocus sequence typing (MLST) to analyze their molecular characteristics. Results A total of 183 Enterococcus isolates were obtained (66 E. faecalis and 117 E. faecium isolated). The isolation rates of both species showed statistically significant differences among the three sources (χ2=29.21, P=0.003). Antimicrobial resistance analysis revealed that E. faecalis generally exhibited higher resistance rates across multiple antibiotic classes than E. faecium. High resistance to rifampicin was observed across all sources (50.00%–81.25%), with statistical variation among origins (χ2=8.03, P=0.024). Multidrug-resistant strains accounted for 69.10% of the isolates. Multidrug resistance patterns in E. faecium varied significantly by source (χ2=27.19, P=0.014), and one isolate displayed resistance to eight antibiotic classes. MLST indicated high genetic diversity; E. faecalis was dominated by ST472 and ST227 of which the distrubution was significantly different among sources, while E. faecium primarily clustered into clonal complexes CC94 (centered on ST94) and CC17 (centered on ST22). Conclusion Resistant Enterococcus strains exhibit cross-transmission among farm workers, animals, and the environment. Under the "One Health" framework, standardized farming protocols and prudent antimicrobial use are essential to disrupt the transmission chain of resistant clones and mitigate the spread of antimicrobial resistance at its source.
9.Genotypic diversity and antibiotic resistance of Enterococcus in dairy farming workplaces
Xiangnan WEI ; Yanggui CHEN ; Jia HUANG ; Fulong WANG ; Jiguo JIN ; Fan WU ; Xixiao MA ; Zhaojie WANG ; Xingyu WANG ; Wanting XU ; Jianyong WU ; Fuye LI
Journal of Environmental and Occupational Medicine 2026;43(5):582-590
Background Under intensive dairy farming conditions, Enterococcus spp. can be transmitted between animals, farm workers, and the environment via multiple vectors such as feces, soil, water, air, and farming equipment, posing a potential threat to public health. Objective To elucidate the prevalence, distribution, and antimicrobial resistance profiles of Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium) among farm workers, dairy cattle, and the farm environment in Xinjiang, and to assess the risk of their cross-host transmission. Methods From May 2024 to January 2025, a total of 317 samples were collected from 11 large-scale dairy farms in Xinjiang, China, including feces from farm workers (n=130) and dairy cattle (n=154), and environmental samples (n=33). E. faecalis and E. faecium were isolated and identified, followed by antimicrobial susceptibility testing and multilocus sequence typing (MLST) to analyze their molecular characteristics. Results A total of 183 Enterococcus isolates were obtained (66 E. faecalis and 117 E. faecium isolated). The isolation rates of both species showed statistically significant differences among the three sources (χ2=29.21, P=0.003). Antimicrobial resistance analysis revealed that E. faecalis generally exhibited higher resistance rates across multiple antibiotic classes than E. faecium. High resistance to rifampicin was observed across all sources (50.00%–81.25%), with statistical variation among origins (χ2=8.03, P=0.024). Multidrug-resistant strains accounted for 69.10% of the isolates. Multidrug resistance patterns in E. faecium varied significantly by source (χ2=27.19, P=0.014), and one isolate displayed resistance to eight antibiotic classes. MLST indicated high genetic diversity; E. faecalis was dominated by ST472 and ST227 of which the distrubution was significantly different among sources, while E. faecium primarily clustered into clonal complexes CC94 (centered on ST94) and CC17 (centered on ST22). Conclusion Resistant Enterococcus strains exhibit cross-transmission among farm workers, animals, and the environment. Under the "One Health" framework, standardized farming protocols and prudent antimicrobial use are essential to disrupt the transmission chain of resistant clones and mitigate the spread of antimicrobial resistance at its source.
10.Preparation and antibacterial properties of porcine small intestinal submucosal composite nanohydroxyapatite bioscaffold loaded with antimicrobial peptide KR-12-a5
Qiquan YAN ; Libin YANG ; Mengjun LI ; Yazhuo NI ; Keying CHEN ; Bo XU ; Yaoyang LI ; Shiqing MA ; Rui LI ; Jianwen LI
Chinese Journal of Tissue Engineering Research 2026;30(2):384-394
BACKGROUND:Bone tissue loss caused by tumors and trauma can have an adverse effect on postoperative rehabilitation.Therefore,scaffold materials are usually implanted during treatment.However,the existing implant materials are relatively simple and lack antibacterial properties.Early implantation may lead to iatrogenic autoinfection and have an adverse effect on osteogenesis.OBJECTIVE:To construct a KR-12-a5 polypeptide-nanohydroxyapatite-small intestinal submucosa composite scaffold and evaluate its feasibility as a material for promoting bone defect repair.METHODS:The small intestinal submucosa scaffold and the small intestinal submucosa scaffold containing 25,50,and 100 mg/mL nanohydroxyapatite(referred to as nHA-SIS scaffold)were prepared by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride/N-hydroxysuccinimide cross-linking method.The appropriate scaffold was screened for subsequent experiments by mechanical property testing.The antibacterial properties of KR-12-a5 polypeptide solution against Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum were detected.The nHA-SIS scaffolds were immersed in 250,500,and 1 000 μg/mL KR-12-a5 peptide solutions for 24 hours,and then freeze-dried to obtain peptide-loaded nanohydroxyapatite-porcine small intestinal submucosa composite scaffolds(denoted as P-nHA-SIS scaffolds).The sustained-release properties of the three groups of scaffolds were characterized.The nHA-SIS scaffolds and the three groups of P-nHA-SIS scaffolds were co-cultured with Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum for 24 hours or 48 hours.The scaffolds with strong antibacterial ability were screened by live and dead bacteria staining and scanning electron microscopy for subsequent experiments.The degradation properties and water absorption rates of the uncross-linked small intestinal submucosa scaffolds,cross-linked small intestinal submucosa scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were characterized.The extracts of cross-linked small intestinal submucosal scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were co-cultured with MC3T3-E1 cells.CCK-8 assay and live-dead cell staining were performed.The effects of the extracts of the three scaffolds on the migration of MC3T3-E1 cells were detected by Transwell chamber assay.RESULTS AND CONCLUSION:(1)The elastic modulus and compressive strength of 25,50,and 100 mg/mL nHA-SIS scaffolds were higher than those of small intestinal submucosal scaffolds(P<0.05),among which the elastic modulus and compressive strength of 25 mg/mL nHA-SIS scaffolds were the highest,and this group of scaffolds were selected for subsequent experiments to load peptides.(2)KR-12-a5 peptide had strong antibacterial activity against common bacteria in bone defects(Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum).The three groups of P-nHA-SIS scaffolds all had sustained release properties.With the increase of peptide mass concentration,the antibacterial property of P-nHA-SIS scaffold was enhanced.Among them,the P-nHA-SIS scaffold loaded with 500 μg/mL peptide had achieved a satisfactory antibacterial effect,and this group of scaffolds would be selected in the future.(3)The degradation rate of the three groups of cross-linked scaffolds was lower than that of the uncross-linked scaffolds,and the water absorption rate was greater than that of the uncross-linked scaffolds.P-nHA-SIS scaffolds could promote the proliferation and migration of MC3T3-E1 cells without affecting the activity of MC3T3-E1 cells.(4)The results show that P-nHA-SIS scaffolds have strong antibacterial properties and the ability to promote the proliferation and migration of MC3T3-E1 cells,and are expected to be used in bone defect repair.

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