1.Analysis of clinical characteristics and risk factors for infection in patients with multiple myeloma treated with bortezomib
Wenting JIANG ; Jie ZHOU ; Bo LYU ; Aiming SHI ; Bingzong LI ; Jie PAN
China Pharmacy 2026;37(7):942-948
OBJECTIVE To study the clinical characteristics and potential risk factors for infection in patients with multiple myeloma (MM) following treatment with bortezomib. METHODS Clinical data were retrospectively collected from MM patients who received bortezomib-based treatment regimens at the Department of Hematology, the Second Affiliated Hospital of Soochow University, from October 2021 to February 2025. The collected data primarily included demographic characteristics, disease characteristics of MM, treatment regimens, occurrence of infections and corresponding management measures, and prophylactic medication use. Univariate and multivariate Logistic regression analyses were conducted to identify potential risk factors for MM complicated with infection. RESULTS Among the 284 MM patients treated with bortezomib, 132 patients (46.5%) experienced at least one infection. The predominant types of infections were respiratory tract infections and gastrointestinal infections. Univariate analysis showed that age at initial diagnosis, pathological classification, and grade of myelosuppression were influencing factors for infection in MM patients ( P <0.05). Further analysis of influencing factors for the two main types of infections revealed that sex, age at initial diagnosis, pathological classification, treatment regimen, and smoking history were influencing factor s for respiratory tract infections in MM patients ( P <0.05); BMI, pathological classification, treatment regimen, and grade of myelosuppression were influencing factors for gastrointestinal infections in MM patients ( P <0.05). Multivariate Logistic regression analysis indicated that age≥70 years and the presence of grade Ⅳ myelosuppression before treatment were risk factors for infection in MM patients, while the IgG-λ type was a protective factor against infection ( P <0.05). CONCLUSIONS The incidence of infection is relatively high in MM patients receiving bortezomib-based treatment regimens, with respiratory and gastrointestinal infections being the most common. Age at initial diagnosis, grade of myelosuppression, and pathological classification are influencing factors for infection in MM patients.
2.Effects of LINC02086 on proliferation, migration and invasion of gastric cancer cells by regulating Wnt/β-catenin pathway mediated M2 polarization of macrophages
Jun LI ; Yafei BU ; Jie CHEN ; Bo DING ; Lei WANG
Acta Universitatis Medicinalis Anhui 2026;61(2):192-201
ObjectiveTo investigate the effect and mechanism of long intergenic non-coding RNA02086 (LINC02086) overexpression mediated macrophage polarization on the proliferation, migration and invasion of gastric cancer cells. MethodsThe expression levels of LINC02086 in the human gastric epithelial cell line GES-1 and human gastric cancer cell lines HCG-27, NCI-N87, and AGS were determined by qRT-PCR. Human acute monocytic leukemia cells (THP-1) were induced to differentiate into M0 macrophages using phorbol 12-myristate 13-acetate (PMA). HGC-27 cells were infected with either LINC02086 overexpression lentivirus (OE-LINC02086) or its negative control lentivirus (Vector), and the culture supernatants were collected as conditioned medium (CM1). M0 macrophages were co-cultured with the infected HGC-27 cells, and the resulting supernatants were designated as conditioned medium 2 (CM2). M0 macrophages were treated with CM1 alone or in combination with Wnt/β-catenin pathway inhibitor IWR-1, forming the Vector+CM1, OE-LINC02086+CM1, and OE-LINC02086+CM1+IWR-1 groups, respectively. Flow cytometry was used to detect mannose receptor C-type 1 (CD206) expression, and qRT-PCR was employed to measure mRNA levels of interleukin-10 (IL⁃10), transforming growth factor-β (TGF⁃β), vascular endothelial growth factor (VEGF), and chemokine ligand 22 (CCL22). Western blot was performed to evaluate protein expression of CD206, VEGF, and key components of the Wnt/β-catenin pathway—Wnt family member 3a (Wnt3a), glycogen synthase kinase-3β (GSK-3β), and β-catenin. HGC-27 cells were treated with CM2 alone or combined with IWR-1, establishing the Vector+CM2, OE-LINC02086+CM2, and OE-LINC02086+CM2+IWR-1 groups. CCK-8 assay was used to evaluate cell proliferation, and Transwell assays were conducted to assess migration and invasion capabilities. ResultsCompared with GES-1 cells, the expression levels of LINC02086 were upregulated in HCG-27, NCI-N87, and AGS cells (P < 0.05), with the smallest increase observed in HCG-27 cells. Compared with Vector+CM1 group, the level of CD206 and the expression levels of IL⁃10, TGF⁃β, VEGF and CCL22 mRNA in macrophages stimulated by OE-LINC02086+CM1 increased (P<0.05). Meanwhile, the expression levels of Wnt3a and β-catenin proteins in cells increased (P<0.05), and the expression level of GSK-3β protein decreased (P<0.05). However, co-treatment with IWR-1 markedly reversed the promoting effects of LINC02086 overexpression on the expression of M2 polarization markers, including CD206, IL⁃10, and TGF⁃β mRNA, in macrophages (P<0.05), as well as its activation of the Wnt/β-catenin signaling pathway (P<0.05). Compared with Vector+CM2 group, HGC-27 cells infected with OE-LINC02086+CM2 had increased proliferation activity and increased number of migration and invasion cells (P<0.05). However, the combined intervention of IWR-1 significantly reversed the promotion of LINC02086 overexpression on the proliferation, migration and invasion of HGC-27 cells (P<0.05). ConclusionLINC02086 overexpression promotes the proliferation, migration and invasion of gastric cancer cells by activating Wnt/β-catenin pathway to mediate M2 polarization of macrophages.
3.Three-dimensional Electrical Impedance Tomography for Monitoring Gastric Hemorrhage
Zi-Han ZHAO ; Bo SUN ; Jing-Shi HUANG ; Zhi-Wei LI ; Yang WU ; Nan LI ; Jia-Feng YAO ; Tong ZHAO
Progress in Biochemistry and Biophysics 2026;53(4):1062-1075
ObjectiveGastric hemorrhage is one of the most common and life-threatening emergencies of the upper digestive tract. Early identification and continuous monitoring are essential for reducing rebleeding rates and mortality, particularly within the critical early hours after onset. Although endoscopy and radiological imaging can accurately localize bleeding sites, these approaches are invasive, resource-intensive, and unsuitable for continuous bedside monitoring. Electrical impedance tomography (EIT), as a noninvasive and radiation-free functional imaging technique, offers real-time visualization of conductivity distribution and has the potential for detecting intragastric bleeding based on the electrical contrast between blood and surrounding gastric tissues. In this study, a three-dimensional gastric EIT (3D-gEIT) framework is proposed to achieve noninvasive, real-time, and dynamic monitoring of gastric hemorrhage, with emphasis on spatial localization and quantitative volume assessment. MethodsA three-dimensional upper-abdominal simulation model incorporating the stomach, gastric wall, gastric contents, and surrounding tissues was established. Three electrode configurations, namely the dual layer ring, the four layer staggered ring, and the opposed dual plane array, were designed and systematically compared to evaluate their influence on depth sensitivity and spatial resolution. Based on the Tikhonov-Noser hybrid regularization scheme, a region-clustering constraint was introduced to develop the TK-Noser-RCC algorithm. This approach aggregates spatially adjacent elements with similar conductivity variations, thereby enhancing structural continuity and suppressing isolated noise artifacts. To validate the proposed framework, an upper-abdominal physical phantom was constructed using agar to simulate background tissue conductivity. Hemispherical high-conductivity inclusions with volumes ranging from 10 ml to 50 ml were attached to the inner gastric wall to mimic localized bleeding under different gastric filling states. Boundary voltages were acquired under a 120 kHz excitation current and reconstructed using the TK-Noser-RCC algorithm. Furthermore, an in vivo animal experiment was performed using a porcine model with adult-scale abdominal dimensions. A total of 100 ml of autologous blood was injected incrementally into the stomach to simulate progressive gastric hemorrhage, and time-difference EIT reconstruction was conducted at each injection stage to assess the dynamic system response under physiological conditions. ResultsSimulation results demonstrated that the opposed dual-plane electrode array achieved superior depth sensitivity distribution and spatial resolution. For a 40 ml hemorrhage model, the average ICC and SSIM improved by 55.9% and 38.8% compared with the dual-layer ring configuration, and by 64.0% and 39.5% compared with the four-layer staggered configuration. The proposed region-clustering constraint significantly enhanced reconstruction stability. Under added Gaussian noise of 40 dB and 30 dB, ICC values remained approximately 0.85, indicating effective artifact suppression and preservation of boundary integrity. In physical phantom experiments, reconstructed hemorrhage volumes increased approximately linearly with the preset hemispherical volumes, and the reconstructed high-conductivity regions closely matched the actual bleeding locations. Both empty-stomach and full-stomach conditions were evaluated, demonstrating that the opposed dual-plane configuration maintained stable imaging performance across varying gastric contents. In the animal experiment, reconstructed low-impedance regions expanded progressively with increasing injected blood volume. The spatial localization of the hemorrhage remained stable throughout the procedure, and no significant artifacts were observed. Quantitative analysis showed that reconstructed volume and average conductivity variation exhibited an approximately linear growth trend with injected blood volume, confirming the sensitivity of the system to dynamic intragastric conductivity changes. ConclusionThe proposed 3D-gEIT framework enables quantitative reconstruction of gastric hemorrhage volume and spatial distribution with improved depth sensitivity, structural continuity, and noise robustness compared with conventional EIT approaches. By integrating optimized electrode configuration and a region-clustering-constrained reconstruction algorithm, the system provides stable dynamic monitoring under both controlled phantom conditions and in vivo physiological environments. This method offers a noninvasive, real-time, and low-cost imaging strategy for early diagnosis, postoperative monitoring, and bedside surveillance of gastric bleeding.
4.The Structure and Function of The YopJ Family Effectors in The Bacterial Type III Secretion System
Ao-Ning LI ; Wen-Bo LI ; Yu-Ying LU ; Min-Hui ZHU ; Yu-Long QIN ; Yong ZHAO ; Zhao-Huan ZHANG
Progress in Biochemistry and Biophysics 2026;53(3):516-533
The Type III Secretion System (T3SS) serves as a pivotal virulence apparatus for numerous Gram-negative bacterial pathogens, enabling them to infect both animal and plant hosts. Functioning as a molecular syringe, the T3SS directly translocates bacterial effector proteins from the bacterial cytoplasm into the interior of eukaryotic host cells. These effectors are central weapons that precisely manipulate a wide spectrum of host cellular physiological processes, ranging from cytoskeletal dynamics to immune signaling, to establish a favorable niche for bacterial survival and proliferation. Among the diverse arsenal of T3SS effectors, the YopJ family constitutes a critical group of virulence factors. Members of this family are characterized by a conserved catalytic triad structure—a hallmark of the CE clan of cysteine proteases that has been evolutionarily repurposed to confer acetyltransferase activity. A defining and intriguing feature of these enzymes is their stringent dependence on a host-derived eukaryotic cofactor, inositol hexakisphosphate (IP6), for allosteric activation. This requirement acts as a sophisticated molecular safeguard, ensuring enzymatic activity only within the appropriate host environment, thereby preventing detrimental effects on the bacterium itself. While seminal studies on individual members such as Yersinia’s YopJ and Salmonella’s AvrA have provided deep mechanistic insights, a systematic and integrative understanding of the structure-function relationships across the entire family remains fragmented. Key questions persist regarding how a conserved catalytic core has diverged to recognize distinct host substrates in different kingdoms of life. To address this gap, this article provides a systematic review of the YopJ family, focusing on three interconnected aspects: their structural features, their catalytic mechanism, and their divergent immunosuppressive strategies in animal versus plant hosts. By conducting a comparative analysis of the sequences and resolved three-dimensional structures of three representative members (e.g., HopZ1a, PopP2, AvrA), we elucidate regions of significant variation embedded within the conserved core catalytic architecture. These variable regions, often involving surface loops and substrate-binding interfaces, are crucial determinants of target specificity and functional specialization. The functional divergence of this effector family is most apparent when comparing their modes of action in different hosts. In animal hosts, YopJ-family effectors primarily sabotage innate immune signaling pathways. They achieve this by acetylating key serine and threonine residues within the activation loops of critical kinases in the MAPK and NF‑κB pathways. This post-translational modification blocks the phosphorylation and subsequent activation of these kinases, leading to potent suppression of inflammatory cytokine production. Conversely, in plant hosts, the strategy broadens to dismantle the two-tiered plant immune system. YopJ homologs target a more diverse set of substrates, including immune-associated receptor-like cytoplasmic kinases (RLCKs), microtubule networks via tubulin acetylation (which disrupts cellular trafficking and signaling), and transcription factors central to defense gene regulation. This multi-target approach effectively suppresses both Pattern-Triggered Immunity (PTI) and Effector-Triggered Immunity (ETI). In conclusion, this synthesis aims to deepen the mechanistic understanding of YopJ family-mediated pathogenesis by integrating structural biology with cellular function across host kingdoms. Elucidating the precise molecular basis for substrate selection—how conserved platforms achieve target diversity—is a major frontier. Furthermore, this knowledge provides a vital theoretical foundation for developing novel anti-virulence strategies. Targeting the conserved IP6-binding pocket or the catalytic acetyltransferase activity itself represents a promising avenue for designing broad-spectrum inhibitors that could disarm this critical family of bacterial effectors, potentially offering new therapeutic approaches against a range of pathogenic bacteria.
5.Risk factors for lower extremity deep vein thrombosis in patients with acute necrotizing pancreatitis and effectiveness of risk assessment models
Liu YANG ; Gang ZHU ; Longfei ZENG ; Benjian GAO ; Bo LI
Journal of Clinical Hepatology 2026;42(3):647-654
ObjectiveTo investigate the influencing factors and independent risk factors for lower extremity deep vein thrombosis (DVT) in patients with acute necrotizing pancreatitis (ANP), to analyze the effectiveness of three commonly used risk assessment models for thrombosis (Caprini score, Padua score, and Wells score), and to provide a reference for clinical identification of high-risk individuals and optimization of prevention and treatment strategies. MethodsA retrospective analysis was performed for the clinical data of 320 patients with ANP who were admitted to Luzhou People’s Hospital and The Affiliated Hospital of Southwest Medical University from April 2013 to April 2024, and according to the presence or absence of DVT during hospitalization, the patients were divided into thrombosis group with 25 patients and control group with 295 patients. After propensity score matching, the two groups were compared in terms of past history and various examination results during hospitalization. The risk factors for lower extremity DVT in ANP patients during hospitalization were analyzed through univariate and multivariate Logistic regression, and a DVT risk prediction model was established based on independent influencing factors. The receiver operating characteristic (ROC) curve was used to assess the performance of models, and the DeLong test was used for comparison of the area under the ROC curve (AUC), sensitivity, and specificity. The independent-samples t test or the Mann-Whitney U test was used for comparison of continuous data between two groups; the chi-square test was used for comparison of categorical data between groups. ResultsAfter matching, the patients were divided into thrombosis group with 24 patients and control group with 112 patients. The clinical characteristics analysis showed that compared with the control group, the thrombosis group had significantly higher degree of pancreatic necrosis, D-dimer level, Bedside Index for Severity in Acute Pancreatitis (BISAP) score, and proportion of patients undergoing dialysis (all P<0.05). The multivariable Logistic regression analysis showed that BISAP score, degree of pancreatic necrosis, and D-dimer level were independent risk factors for lower extremity DVT in ANP patients during hospitalization (all P<0.05). The BISAP-Caprini score model had an AUC of 0.832 (95% confidence interval: 0.722 — 0.942, P<0.001) in predicting the risk of lower extremity DVT, with a Youden index of 1.661, an optimal cut-off value of 0.26, a sensitivity of 75.0%, and a specificity of 91.1%. ConclusionD-dimer, BISAP score, and the degree of pancreatic necrosis are independent risk factors for lower extremity DVT in patients with ANP during hospitalization, and the BISAP-Caprini score model can effectively predict the risk of DVT in ANP patients.
6.Expert Consensus on Blood Flow and Oxygen Delivery Phenotyping and Clinical Management of Septic Shock(2025)
Wei HUANG ; Xinchen WANG ; Wenzhao CHAI ; Keliang CUI ; Bo YAO ; Zhiqun XING ; Cui WANG ; Jingjing LIU ; Shiyi GONG ; Dongkai LI ; Wanhong YIN ; Xiaoting WANG ; Wei DU
Medical Journal of Peking Union Medical College Hospital 2026;17(1):40-58
Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Septic shock is the primary cause of mortality in sepsis, with its core pathophysiological mechanism being severe ischemia and hypoxia in critical units—composed of microcirculation and the mitochondria of functional cells—resulting from disruptions in blood flow and oxygen flow following a dysregulated host response. Due to the systemically convergent yet clinically heterogeneous nature of the host response, current understanding and management strategies for hemodynamics remain inconsistent, often leading to inadequate resuscitation or overtreatment. To improve the quality of care, based on a systematic review of the "blood flow-oxygen flow" theory, an expert panel emphasizes reevaluating septic shock from an integrated perspective of blood flow and oxygen flow, and has formulated the
7.Expert Consensus on Neurocritical Care Monitoring and Management in Beijing and Tibet(2025)
Drolma PHURBU ; Wenjin CHEN ; Heng ZHANG ; Jian ZHANG ; Xiaomeng WANG ; Guoying LIN ; Wenjun PAN ; Xiying GUI ; Xin CAI ; Chodron TENZIN ; Jianlei FU ; Qianwei LI ; TSEYANG ; Yijun LIU ; Bo LIU ; Tsering DROLMA ; Yudron SONAM ; KYILV ; Samdrup TSERING ; Wa DA ; Juan GUO ; Cheng QIU ; Huan CHEN ; Xiaoting WANG ; Yangong CHAO ; Dawei LIU ; Wenzhao CHAI ; Chenggong HU ; Wanhong YIN ; Shihong ZHU
Medical Journal of Peking Union Medical College Hospital 2026;17(1):59-72
Neurocritical care involves complex pathophysiological mechanisms, and its incidence is higher, injuries are more severe, and treatment is more challenging in high-altitude environments. This consensus, based on the latest domestic and international evidence-based medical data, establishes a standardized, goal-oriented framework for neurocritical care management applicable in high-altitude regions and nationwide. The consensus was developed following international standards for evidence quality assessment and underwent two rounds of Delphi expert consultation, resulting in 32 recommendation statements covering three parts: management systems, monitoring and assessment, and core strategies. Key updates include: advocating for the establishment of independent neurocritical care units and implementing precise tiered diagnosis and treatment based on the "Five Differences in Critical Care" concept; constructing a "trinity" multimodal brain monitoring system centered on cerebral blood flow, cerebral oxygenation, and brain function, emphasizing routine bedside transcranial Doppler ultrasound, cerebral oximetry, and continuous electroencephalography monitoring; shifting management strategies from mild hypothermia therapy to targeted temperature management, and defining the "446" target management pathway for the supercritical stage; emphasizing the assessment of static and dynamic cerebrovascular autoregulation functions through multimodal methods to achieve individualized optimal mean arterial pressure management; elevating cerebrospinal fluid management goals to the level of "glymphatic system" function maintenance; implementing a multidisciplinary collaborative, whole-process management model focusing on patients' long-term neurological functional outcomes; de-escalation criteria include multidimensional indicators such as recovery of brain structure, restoration of cerebrovascular autoregulation, improvement in cerebrospinal fluid dynamics, and reduction in biomarker levels; and integrating cutting-edge technologies like artificial intelligence into post-critical care management and rehabilitation planning. This consensus systematically integrates the entire process of neurocritical care management, reflecting the modern connotation of goal-oriented, dynamic, and multimodal integration in neurocritical care medicine. It aims to adapt to new trends such as deepening understanding of pathophysiological mechanisms, the integration of medicine and engineering, and the empowerment of artificial intelligence, thereby further advancing the discipline of critical care medicine.
8.Standards for the Application of Hemodynamic Monitoring Technology in Critical Care
Hua ZHAO ; Hongmin ZHANG ; Xin DING ; Huan CHEN ; Jun DUAN ; Wei DU ; Bo TANG ; Yuankai ZHOU ; Dongkai LI ; Xinchen WANG ; Cui WANG ; Gaosheng ZHOU ; Xiaoting WANG
Medical Journal of Peking Union Medical College Hospital 2026;17(1):73-85
With the rapid advancement of hemodynamic indices and monitoring technologies, their classification methods and application processes have become increasingly complex. Currently, no unified standard hasbeen established, making it difficult to fully meet the clinical requirements for hemodynamic management. To assist in hemodynamic monitoring assessment and therapeutic decision-making in critically ill patients, the Critical Hemodynamic Therapy Collaborative Group, in conjunction with the Critical Ultrasound Study Group, has jointly developed the Standard for the Application of Hemodynamic Monitoring Techniques in Critical Care. The first part of this standard systematically categorizes hemodynamic indicators into flow indicators, pressure and its derivative indicators, and tissue perfusion indicators, while elaborating on the clinical application of each. The second part establishes a standardized clinical implementation pathway for hemodynamic monitoring. It proposes a tiered monitoring strategy-comprising basic, advanced, indication-specific, and special scenario monitoring-tailored to different clinical settings. It emphasizes the central role of critical care ultrasound across all levels of monitoring and establishes hemodynamic assessment standards for organs such as the brain, kidneys, and gastrointestinal tract. This standard aims to provide a unified framework for clinical practice, teaching, training, and research in critical care medicine, thereby promoting standardized development within the discipline.
9.Exploring on Quality Evaluation Methods of Clinical Case Reports in Traditional Chinese Medicine Based on China Clinical Cases Library of Traditional Chinese Medicine
Kaige ZHANG ; Feng ZHANG ; Bo ZHOU ; Haimin CHEN ; Yong ZHU ; Changcheng HOU ; Liangzhen YOU ; Weijun HUANG ; Jie YANG ; Guoshuang ZHU ; Shukun GONG ; Jianwen HE ; Yang YE ; Yuqiu AN ; Chunquan SUN ; Qingjie YUAN ; Buman LI ; Xingzhong FENG ; Kegang CAO ; Hongcai SHANG ; Jihua GUO ; Xiaoxiao ZHANG ; Zhining TIAN
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(1):271-276
As the core vehicle for preserving and transmitting traditional Chinese medicine(TCM) academic thought and clinical experience, the establishment of a robust quality evaluation system for TCM clinical case reports is a crucial component in the current standardization and modernization of TCM. Based on the practical experience of constructing the China Clinical Cases Library of Traditional Chinese Medicine by the China Association of Chinese Medicine, this study conducted a comprehensive analysis of critical challenges, including insufficient authenticity and unfocused evaluation criteria. It proposed a three-dimensional evaluation framework grounded in the structure-process-outcome logic, encompassing three dimensions of authenticity and standardization, characteristics and advantages, application and translational impact. This framework integrated 12 key evaluation indicators in a systematic manner. The model preserved the academic characteristics of TCM syndrome differentiation and treatment, while aligning with modern scientific research standards, achieving a balance between individualized TCM experience and standardized evaluation. Concurrently, this study provided theoretical foundations and methodological guidance for evaluating the quality of TCM clinical cases, contributing significantly to the inheritance of TCM knowledge, evidence-based practice, and the reform of talent evaluation mechanisms.
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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