Construction Of Functional Coatings On The Surface Of Titanium-based Bone Implants And Study Of Their Osteogenic Properties

Orthopedic implants are widely used in the treatment of bone defects.Titanium-based metal materials have become one of the most widely used orthopedic implants due to their excellent biocompatibility and mechanical properties.However,the biological inertia of titanium-based materials has a negative impact on their bone repair ability,so surface modification is usually needed to improve their bone integration ability or make them have anti-bacterial,anti-inflammatory and other functions.In recent years,many researchers have tended to use micro/nano hybrid topology to promote stem cell differentiation and proliferation,and achieved good results.However,the mechanism of micro-and nano-structures affecting cell behavior is still unclear.The experimental scheme of uncontrolled variables and the limitation of traditional gene analysis methods are two main constraints.In this study,micro-arc oxidation and hydrothermal method were combined to construct bionic coatings with controllable size on the surface of titanium scaffolds,and the composition and phase of micro-nano and micro-structure coatings were basically consistent.Variable control was achieved,which provided material basis for subsequent mechanism research.Then,we use high-throughput gene sequencing technology to obtain a large number of key data at the genomic level.By means of bioinformatics analysis,the effects of micron and nano-structure on cell behavior in Micro-Nanostructure were deeply analyzed.The results showed that the microstructural substrates in micro-and nano-structures had the function of promoting cell differentiation and made a major contribution in promoting cell proliferation.The nanostructure can further improve cell adhesion and binding,and then affect the subsequent osteogenic differentiation performance.Understanding the influence mechanism of Micro-Nanostructure on cell behavior is of great guiding significance to the design of micro-nano topological structure on the surface of orthopedic implants.Although orthopedic implants are mature at present,there is still a problem of premature failure,which is mainly caused by aseptic loosening and late bacterial infection.To solve these problems,different surface modification strategies were designed and developed in this study.On the one hand,we constructed aspirin sustained-release coating on the surface of titanium scaffolds to alleviate aseptic loosening of titanium-based orthopedic implants from promoting osseointegration and inhibiting immune inflammation.In addition,vancomycin is covalently bonded on the surface of titanium scaffold after micro-arc oxidation,which combines the promotion of bone integration with antibiotic bactericidal effect,and establishes a long-term anti-bacterial coating from two aspects of reducing bacterial adhesion and bactericidal effect,so as to alleviate the late infection of the scaffold.Current experimental data confirm that our coatings have practical application potential,but due to time and energy constraints,this study only carried out the preparation and characterization of materials,and subsequent biological experiments were carried out by others.In a word,the surface modification of titanium-based orthopedic implants has been studied in this paper.On the one hand,the controllable fabrication of micro-nano topology was realized,and the interaction between micro-nano structure and cells on the surface of titanium sheet and the related mechanism were deeply studied.On the other hand,we constructed a sustained-release coating of aspirin on the surface of titanium scaffolds and covalently modified vancomycin on the surface of micron-structured coatings,which tried to solve two key problems,aseptic loosening and late infection,which affect the long-term effectiveness of bone implants.