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.
Cardiovascular disease is one of the most common causes of death. Coronary artery stent implantation has been the most important method to cure coronary disease and inhibit angiostegnosis. However, restenosis and thrombus at the site of implanting cardiovascular devices remains a significant problem in the practice of interventional cardiology. Recently, lots of studies have revealed that endothelial impairment is considered as one of the most important mechanisms contributing to restenosis. As a result, the method of accelerating endothelial regeneration at the injury site could prevent restenosis and thrombus. Considering the surface modification of cardiovascular stent implantation, this paper summarizes the progress on this direction, especially for the prevention of cardiovascular restenosis. Furthermore, this paper also proposes the methods and the future developing prospects for accelerating in vivo re-endothelialization at the site of intravascular stent with different biological molecules.
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.
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.
ObjectiveThe antibacterial properties of porous medical implant materials were reviewed to provide guidance for further improvement of new medical implant materials.MethodsThe literature related to the antibacterial properties of porous medical implant materials in recent years was consulted, and the classification, characteristics and applications, and antibacterial methods of porous medical implant materials were reviewed.ResultsPorous medical implant materials can be classified according to surface pore size, preparation process, degree of degradation in vivo, and material source. It is widely used in the medical field due to its good biocompatibility and biomechanical properties. Nevertheless, the antibacterial properties of porous medical implant materials themselves are not obvious, and their antibacterial properties need to be improved through structural modification, overall modification, and coating modification.ConclusionAt present, coating modification as the mainstream modification method for improving the antibacterial properties of porous medical materials is still a research hotspot. The introduction of new antibacterial substances provides a new perspective for the development of new coated porous medical implant materials, so that the porous medical implant materials have a more reliable antibacterial effect while taking into account biocompatibility.
ObjectiveTo review antibacterial/osteogenesis dual-functional surface modification strategy of titanium-based implants, so as to provide reference for subsequent research. MethodsThe related research literature on antibacterial/osteogenesis dual-functional surface modification strategy of titanium-based implants in recent years was reviewed, and the research progress was summarized based on different kinds of antibacterial substances and osteogenic active substances. ResultsAt present, the antibacterial/osteogenesis dual-functional surface modification strategy of titanium-based implants includes: ① Combined coating strategy of antibiotics and osteogenic active substances. It is characterized in that antibiotics can be directly released around titanium-based implants, which can improve the bioavailability of drugs and reduce systemic toxicity. ② Combined coating strategy of antimicrobial peptides and osteogenic active substances. The antibacterial peptides have a wide antibacterial spectrum, and bacteria are not easy to produce drug resistance to them. ③ Combined coating strategy of inorganic antibacterial agent and osteogenic active substances. Metal ions or metal nanoparticles antibacterial agents have broad-spectrum antibacterial properties and various antibacterial mechanisms, but their high-dose application usually has cytotoxicity, so they are often combined with substances that osteogenic activity to reduce or eliminate cytotoxicity. In addition, inorganic coatings such as silicon nitride, calcium silicate, and graphene also have good antibacterial and osteogenic properties. ④ Combined coating strategy of metal organic frameworks/osteogenic active substances. The high specific surface area and porosity of metal organic frameworks can effectively package and transport antibacterial substances and bioactive molecules. ⑤ Combined coating strategy of organic substances/osteogenic active substancecs. Quaternary ammonium compounds, polyethylene glycol, N-haloamine, and other organic compounds have good antibacterial properties, and are often combined with hydroxyapatite and other substances that osteogenic activity. ConclusionThe factors that affect the antibacterial and osteogenesis properties of titanium-based implants mainly include the structure and types of antibacterial substances, the structure and types of osteogenesis substances, and the coating process. At present, there is a lack of clinical verification of various strategies for antibacterial/osteogenesis dual-functional surface modification of titanium-based implants. The optimal combination, ratio, dose-effect mechanism, and corresponding coating preparation process of antibacterial substances and bone-active substances are needed to be constantly studied and improved.
ObjectiveTo review the research status of anti-infective graft materials and analyze their application prospects, in order to provide inspiration for the development of anti-infective vascular endograft. MethodThe research on endovascular anti-infective grafts at home and abroad was reviewed. ResultsThe anti-infective capability of endovascular graft could be achieved through main approaches like modification of the bulk material, surface modification, or a combination of both. In terms of bulk material modification, this paper delved into the creation of antibacterial composite materials by incorporating other materials into primary materials like metals (such as Mg, Zn), biologically derived materials (such as chitosan, silk fibroin, bacterial cellulose), and synthetic polymers (such as graphene and its derivatives, polyurethane, polylactic acid). Examples included Mg-Nd-Zn-Zr alloy, bacterial cellulose/chitosan nanocrystal composites, and chitosan/silk fibroin composites. For surface modifications, inorganic coatings (such as silver, copper, and nitrides) and organic coatings (such as antibiotics, antimicrobial peptides, and anti-infection polymers) had shown promising antibacterial effects in experiments. ConclusionsThe future research focus is how to synthesize the composite graft material with the mechanical properties of ordinary graft and the cell, blood compatibility and antibacterial properties through nano technology. At the same time, how to synthesize coatings with stable long-term anti-infection and anti-bacterial biofilm performance is also considered to be an important direction of future research.