The presence of thrombus on the surface of blood-contacting biomaterials in clinical practice can significantly impact both the longevity of the biomaterials and the overall survival prognosis of patients. The administration of anticoagulant and antiplatelet medications may heighten the risk of systemic bleeding. Developing biomaterials with anti-thrombogenetic properties and enabling localized anti-thrombosis may offer a solution to these challenges. The development strategies for anti-thrombogenetic biomaterials can be categorized into three main approaches based on the mechanisms of thrombus formation on biomaterial surfaces: altering physical and chemical properties, designing coatings containing or releasing active substances, and promoting endothelialization. However, due to the intricate and interconnected nature of these mechanisms, biomaterials constructed using a single approach may not effectively prevent thrombus formation. The collaborative intervention of various mechanisms can facilitate the development of biomaterials with enhanced blood compatibility.
Objective To investigate the memory amelioration of the Alzheimer disease (AD)model rat after being transplanted the single neural stem cells(NSC) and NSC modified with human brain-derived neurotrophic factor（hBDNF） gene. Methods Forty SD rats were divided evenly into 4 groups randomly. The AD model rats were made by cutting unilaterallythe fibria fornix of male rats. Ten to twelve days after surgery, the genetically modified and unmodified NSC were implanted into the lateral cerebral ventricle of group Ⅲ and group Ⅳ respectively. Two weeks after transplantation, theamelioration of memory impairment of the rats was detected by Morris water maze. Results The average escaping latency of the group Ⅲ and group Ⅳ (41.84±21.76 s,25.23±17.06 s respectively) was shorter than that of the group Ⅱ(70.91±23.67 s) (Plt;0.01). The percentage of swimming distance inthe platform quadrant in group Ⅲ (36.9%) and in group Ⅳ(42.0%) was higherthan that in the group Ⅱ(26.0%) (Plt;0.01). More marginal and random strategies were used in group Ⅱ.The percentage of swimming distance in the platform quadrant in group Ⅳ was also greater than that in group Ⅲ(Plt;0.05). There were no significant differences in the average escaping latency, the percentage of swimming distance in the platform quadrant and the probe strategy between group Ⅳ and group Ⅰ(Pgt;0.05).More lineal and oriented strategies were used in group Ⅳ. Conclusion The behavioral amelioration of AD model rat was obtained by transplanting single NSC and hBDNF-gene-modified NSC. The effect of the NSC group modified with hBDNF gene is better than that of the groupⅢ.
Retinoblastoma (RB) is a common intraocular tumor in children, often leading to blindness or disability, and its pathogenesis involves genetic and epigenetic regulation. Epigenetics regulates gene expression through mechanisms such as DNA methylation and histone modification without altering the DNA sequence, and the imbalance of its homeostasis is considered a crucial factor in the development and progression of RB. Therapeutic strategies targeting these abnormal modifications offer new potential treatment avenues for RB. Although current research has highlighted the importance of epigenetics in RB, the specific mechanisms of action, the relationship with genetic bases, and the development of targeted drugs remain largely unknown. Therefore, further in-depth research into the epigenetic mechanisms of RB is of great significance for elucidating its carcinogenic mechanisms, identifying effective therapeutic targets, and developing new drugs.
Objective To review the current researches of scaffold materials for skeletal muscle tissue engineering, to predict the development trend of scaffold materials in skeletal muscle tissue engineering in future. Methods The related l iterature on skeletal muscle tissue engineering, involving categories and properties of scaffold materials, preparative techniqueand biocompatibil ity, was summarized and analyzed. Results Various scaffold materials were used in skeletal muscle tissue engineering, including inorganic biomaterials, biodegradable polymers, natural biomaterial, and biomedical composites. According to different needs of the research, various scaffolds were prepared due to different biomaterials, preparative techniques, and surface modifications. Conclusion The development trend and perspective of skeletal muscle tissue engineering are the use of composite materials, and the preparation of composite scaffolds and surface modification according to the specific functions of scaffolds.
Objective To summarize the research progress of biocompatibility and surface modification of nickel titanium shape memory alloys (Ni-Ti SMA). Methods The relative researches about Ni-Ti SMA at home and abroad were reviewed, collated, analyzed, and summarized. Results At present, Ni-Ti SMA as an internal fixation material has been widely used in clinic. It has the following advantages: the super elasticity, the shape memory characteristic, the good wear resistance, and the strong corrosion resistance. It also can effectively avoid the internal fixator rupture caused by stress shielding. After surface modification, the biocompatibility of Ni-Ti SMA has been improved. Conclusion The Ni-Ti SMA is the most promising alloy material for the long-term internal fixator because of its excellent material properties.
ObjectiveTo obtain rat hair follicle stem cells (rHFSCs) which can constantly and highly express vascular endothelial growth factor 165 (VEGF165), and to observe the expression of VEGF165 gene in rat HFSCs. MethodsThe cirri skin of 1-week-old Sprague Dawley rat was harvested and digested by using combination of Dispase and type IV collagenases. The bulge was isolated under microscope. The rHFSCs were cultured by tissue block method. After purified by rapid adhering on collagen type IV, the growth curve of different generations rHFSCs was drawn. The cells were identified by immunofluorescence staining and real time quantitative PCR (RT-qPCR) analysis that tested the expression level of correlated genes. Lentivirus of pLV-internal ribosome entry site (IRES)-VEGF165-enhanced green fluorescent protein (EGFP) (experimental group) and pLV-IRES-EGFP empty vector (control group) was packaged by calcium transfected method and the rHFSCs were transfected. The green fluorescent protein expression was observed by inverted fluorescence microscope, and VEGF165 mRNA and protein expressions were detected using RT-PCR and Western blot. ResultsThe rHFSCs which were isolated, cultured, and purified were like the "slabstone", and had strong adhesion ability and colony formation ability. The purified cells were in latent growth phase at 2-3 days; they were in exponential growth phase at 5-6 days. The expressions of cytokeration 15 (CK15), integrin α6, and integrin β1 (markers of HFSCs) were positive by immunocytochemistry. The RT-qPCR analysis showed that CK15, CK19, integrin α6, and integrin β1 expressed highly, but CD34 (a marker of epidermal stem cells) and CK10 (a marker of keratinocyte) expressed lowly. After 14 days, the transfection efficiency was up to 85.76%±1.91%. RT-PCR analysis and Western blot showed that VEGF165 mRNA and protein expressions were positive in experimental group, and were negative in control group. ConclusionThe rHFSCs with high purity and strong proliferation ability can be obtained by using microscope combined with tissue cultivation and rapid cell adhesion on collagen type IV. The rHFSCs with high expression of VEGF165 can be successfully obtained by lentiviral transfection. This method provides good seeding cells for tissue engineering to construct artificial hair follicles, blood vessels, and skins.
Time-to-event outcomes are a key component in survival analyses. Effect modification by time, also known as interaction between effect and time, can exist in time-to-event data and influence the analysis process. Our objective is to discuss the proper methods to conduct evidence synthesis of time-to-event data when effect modification by time exists.
OBJECTIVE: To modify the surface of poly(D,L-lactide) film by anhydrous ammonia gaseous plasma treatment. METHODS: The changes of contact angles were measured and surface energy were calculated. Mouse 3T3 fibroblast cells were cultured on plasma modified and control poly(D,L-lactide) films. RESULTS: It was found that the hydrophilicity and surface energy of the materials have been increased after plasma treatment. Cell culture results showed that ammonia plasma treatment could promote the cell attachment and cells growth. After 4 days culture, the cells on the plasma treated films were 2-folds quantitatively compared with that of the control films. CONCLUSION: Ammonia plasma treatment can improve the cell affinity to poly(D,L-lactide).
Objective To summarize the physicochemical properties, manufacturing technique, and biological characteristics of porous tantalum and its application progress and related problems in spinal surgery. Methods The domestic and foreign related literature about porous tantalum was summarized and analyzed. Results Porous tantalum is characterized by high porosity, high coefficient of friction, low elastic modulus, good biocompatibility, and superior osseointegration capability. Its manufacture methods include chemical vapor deposition and infiltration technique, foam impregnation and powder metallurgy technique, and heat treatment method. Good clinical efficacy has achieved in the application of porous tantalum interbody fusion Cage in cervical and lumbar fusion surgery, but there is controversy in spinal fusion rate, especially in cervical fusion rate. Surface modification can increase the osseointegration capability of porous tantalum and intervertebral bony fusion. Conclusion Good clinical efficacy has achieved in the application of porous tantalum interbody fusion Cage in lumbar fusion surgery, while there is a dispute in cervical fusion surgery. In order to further observation, studies with more patients and longer follow-up would be needed.
Objective To review the basical research progress of porous tantalum in bone tissue engineering. Methods The related basical research in fabrication, cytobiology, and surface modification of porous tantalum was reviewed and analyzed. Results The outstanding physiochemical properties of porous tantalum granted its excellent performance in biocompatibility and osteointegration, as well as promoting cartilage and tendon tissue restoration. However, the clinical utilization of porous tantalum is somehow greatly limited by the complex and rigid commercial fabrication methods and extraordinary high cost. Along with the publication of novel fabrication and surface modification technology, the application of porous tantalum will be more extensive, the promotion in bone tissue regeneration will be more prominent. Conclusion Porous tantalum has advantage in bone defect restoration, and significant breakthrough technology is needed in fabrication methods and surface modification.