Objective To summarize the current progress in the genetic modification of vascular prostheses and to look forward to the future of genetic modification in vascular prostheses. Methods PubMed onl ine search with the key words of “vascular prostheses, gene” was undertaken to identify articles about the genetic modification of vascular prostheses. Then these articles were reviewed and summarized. Results To improve long-term patency of vascular prostheses, various genes were transfected into seeded cells. The antithrombosis activity of local vessels increased. Conclusion Progresses in tissue engineering and molecular biology make possible endothel ial ization and genetic modification of vascular prostheses. However, because most relevant researches are still basic experiments, further study is needed before cl inical appl ication.
【Abstract】 Objective To evaluate the biocompatibil ity of the sheep BMSCs cultured on the surface of photografting modified copolymers of 3-hydroxybutyrate and 3-hydroxyvalerate(PHBV). Methods BMSCs were isolated from bone marrow of the posterior il iac crest of a 6-month old sheep by whole marrow adherent culture method. The 3rd passage BMSCs were seeded onto modified PHBV and conventional PHBV films, or three-dimension scaffolds. Cell-adhesion rates were calculated by hemocytometer at 1, 2 and 6 hours after seeded. Cell morphology was examined by scanning electron microscope when the BMSCs were cultured for 3 days, 1 week and 3 weeks. Cell cycle was analyzed by flow cytometry at 5 days after seeded. The content of protein in BMSCs was determined by BCA assay and the content of DNA was quantified by Hoechst 33258 assay at 4, 8 and 12 days after seeded. Results At 1 hour after seeded, cell-adhesion rate on modified PHBV films (52.7% ± 6.0%) was significantlyhigher than that of conventional PHBV films (37.5% ± 5.3%) (P lt; 0.05); At 2 and 6 hours after seeded, cell-adhesion rate of modified PHBV films was similar to that of PHBV films (P gt; 0.05). The surface of modified PHBV film was rougher. In the early culture stage, more cells adhered to modified PHBV and the cells displayed much greater spreading morphology. Furthermore, ECM on modified PHBV were richer. There were no significant differences between the trial team and the control on the cell cycle and the content of DNA and protein of BMSCs (P gt; 0.05). Conclusion Photografting modification on PHBV can promote BMSCs’ adhesion and enhance their biocompatibil ity.
ObjectiveTo summarize the related research progress of antibacterial modification of orthopaedic implants surface in recent years. Methods The domestic and foreign related literature in recent years was extensively consulted, the research progress on antibacterial modification of orthopaedic implants surface was discussed from two aspects of characteristics of infection in orthopedic implants and surface anti-infection modification. Results The orthopaedic implants infections are mainly related to aspects of bacterial adhesion, decreased host immunity, and surface biofilm formation. At present, the main antimicrobial coating methods of orthopaedic implants are antibacterial adhesion coating, antibiotic coating, inorganic antimicrobial coating, composite antimicrobial coating, nitric oxide coating, immunomodulation, three-dimensional printing, polymer antimicrobial coating, and “smart” coating. Conclusion The above-mentioned antibacterial coating methods of orthopedic implants can not only inhibit bacterial adhesion, but also solve the problems of low immunity and biofilm formation. However, its mechanism of action and modification are still controversial and require further research.
RNA can be labeled by more than 170 chemical modifications after transcription, and these chemical modifications are collectively referred to as RNA modifications. It opened a new chapter of epigenetic research and became a major research hotspot in recent years. RNA modification regulates the expression of genes from the transcriptome level by regulating the fate of RNA, thus participating in many biological processes and disease occurrence and development. With the deepening of research, the diversity and complexity of RNA modification, as well as its physiological significance and potential as a therapeutic target, can not be ignored.
The rutile structure titanium oxide (Ti-O) film was prepared on the pure titanium material TA2 (99.999%) surface by the magnetic filter high vacuum arc deposition sputtering source. The method can not only maintain the material mechanical properties, but also improve the surface properties for better biocompatibility to accommodate the physiological environment. The preparation process of the Ti-O film was as follows. Firstly, argon ions sputtered to the TA2 substrate surface to remove the excess impurities. Secondly, a metal ion source generated Ti ions and oxygen ions by the RF discharge. Meanwhile a certain negative bias was imposed on the sample. There a certain composition of Ti-O film was obtained under a certain pressure of oxygen in the vacuum chamber. Finally, X-ray diffraction was used to research the structure and composition of the film. The results showed that the Ti-O film of the rutile crystal structure was formed under the 0.18 Pa oxygen partial pressure. A Nano scratch experiment was used to test the coating adhesion property, which demonstrated that the film was stable and durable. The contact angle experiment and the platelet clotting experiment proved that the modified surface method had improved platelet adhesion performance, and, therefore, the material possessed better biocompatibility. On the whole, the evaluations proved the modified material had excellent performance.
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.
ObjectiveTo analyze effects of histone demethylase Jumonji-domaincontaining protein 3 (JMJD3) in macrophages in order to provide a new target for treatment of macrophage-related inflammatory reactions, autoimmune diseases, and organ transplantation rejection.MethodThe related literatures of researches on the effects of JMJD3 in the macrophages in recent years were searched and reviewed.ResultsThe macrophages played the important roles in maintaining tissue homeostasis and host response, clearing pathogens and apoptotic cells, and promoting tissue repair and wound healing. The JMJD3 could regulate the balance of M1 and M2 types of macrophages through the different ways and had different effects on the polarization of M2 macrophages when it was stimulated by the different extracellular substances. In some immune diseases and wound repairing, the JMJD3 could not only promote the inflammatory responses, but also polarize the M2 macrophages so as to inhibit the inflammation and promote the tissue repair. Clinically, the JMJD3 expression might be different in the different diseases and its low or high expression both might be involved in the occurrence of diseases.ConclusionHistone demethylase enzyme JMJD3 is involved in macrophage polarization and expression of inflammatory genes, but there are still many problems that require further to be investigated.
Objective To observe the expressions of DNA methyltransferases (DNMTs) 1, 3a and 3b in retinoblastoma (RB). Methods Sixty-two RB samples and six normal retinas were studied, including 17 poorly differentiated and 45 well differentiated samples; 16 invasive and 46 non-invasive samples. The expressions of DNMT1, 3a, and 3b, and Ki-67 were detected using immunohistochemical analysis. Brown staining of nuclei was considered to represent the positive stain for DNMT1, 3a and 3b, and ki-67, blue staining as negative. The level of high expression of nuclear staining was, positive cells in DNMT1ge;65%, in DNMT3age;60% and in DNMT3bge;40%. The correlations of DNMT1, 3a and 3b expression in RB samples, and MIB-1 labeling index were analyzed. Results Viewed under the light microscope, negative expressions of DNMT1, 3a and 3b were demonstrated in normal retinas, however, positive expression was observed in RB samples, with 100% in DNMT1, 98% in DNMT3a and 92% in DNMT3b. Comparing well differentiated RB samples with poorly differentiated samples, significant differences were found in high expression of DNMT1 (chi;2=12.57,P＜0.05) and DNMT3a (chi;2=10.54,P＜0.05); also in the positive cells of DNMT1 (U=179,P＜0.05) and DNMT3a (U=198,P＜0.05). No significant difference was found comparing high expression (chi;2=1.5,P＞0.05) and positive cells (U=307,P＞0.05) of DNMT3b. When comparing invasive tumor tissues with non-invasive tumors, significant differences were shown between high expression (chi;2=4.72,P＜0.05) and positive cells comparing DNMT1 (U=236,P＜0.05). No significant difference was shown in high expression (chi;2=3.53,0.84; P＞0.05) in DNMT3a and DNMT3b, or in comparison with positive cells (U=338,257;P＞0.05). The expression of DNMTs was positively correlated with the MIB-1 labeling index in RB tissues (R2=0.554,0.376,0.219;P＜0.05). Conclusion There are high expressions of DNMT1,3a,and 3b in RB.
Traditional bone repair materials, such as titanium, polyetheretherketone, and calcium phosphate, exhibit limitations, including poor biocompatibility and incongruent mechanical properties. In contrast, ceramic-polymer composite materials combine the robust mechanical strength of ceramics with the flexibility of polymers, resulting in enhanced biocompatibility and mechanical performance. In recent years, researchers worldwide have conducted extensive studies to develop innovative composite materials and manufacturing processes, with the aim of enhancing the bone repair capabilities of implants. This article provides a comprehensive overview of the advancements in ceramic-polymer composite materials, as well as in 3D printing and surface modification techniques for composite materials, with the objective of offering valuable insights to improve and facilitate the clinical application of ceramic-polymer composite materials in the future.
