The Experimental Study Of Biolization Modification And The Engineering Scaffold Constructed On The Surface Of Titanium

Titanium and its alloys have been extensively used in dental and orthopedic fields for implants due to their excellent mechanical properties and biocompatibility. However, these implant materials display non-specificity and randomness after implantation into the living body and will spend a long time for clinical healing result from their bioinert properties. The strategy of titanium surface modification can effectively improve the performance of these materials involve preferably biocompatibility and bioactive. Several surface modifications, including physico-chemical and morphologic ones, have been investigated to improve the biocompatibility and bone-bonding ability of Ti implants in a certain extent. One approach, biomimetic surface engineering, develop a new strategy of the study on the surface modification and the bone-interface healing. The purpose of this study is to investigate the research strategy of the biolization modification and the scaffold constructed on the surface of titanium implants. Based on the biolization modification of the titanium surface, the polyelectrolyte complex (PEC) hydrogel composited of polycationic chitosan (CS) and polyanionic alginate(ALG) was self-organized by the Layer-by-Layer self-assemble technique on the surface of titanium, and the PEC hydrogel was used as the scaffold to encapsulate the rat bone marrow stroma cells(BMSCs) delamination for co-culture. The result of the study is the foundation of the experimental research to improve the bone-implant interface healing and the regeneration of the periodontal ligament. The research consist of three serial experiments. 1. Biomineralization and phosphorylation performed on the Ti implant surfaces. The titanium surfaces was treated in the phosphoric acid, and then the phosphorylation specimens were soaked in the simulated body fluid (SBF) to investigate the function of biomineralization. To investigate the biocompatibility of the altered biomimetic surface, the rat bone marrow stroma cells (BMSCs) were cultured on these treated sample surfaces. The results of the study showed that a layer of titanium dihydrogen orthophosphate (Ti(H2PO4)3) have been formed on the native oxide surfaces on the phosphorylation titanium, which have the ability to induce formation of bone-like apatite during immersing in SBF and thus considered bioactive. The biomineralization surfaces can induce the osteogenesis differentiation of the BMSCs. The study provide a new experimental strategy of the dental implants surface modification. The result of this study is the foundation of the experiment of the Ti surface biolization modification.2. To investigate the effects of delayed release of BMP-2 adsorbed in the biolization Ti surface, the PEC hydrogel composited of CS and ALG was self-organized on the surfaces of titanium. Subsequently, the effects of delayed release of BMP-2 encapsulated in the PEC multilayer films was evaluated by enzyme linked immunosorbent assay (ELISA). The results showed that BMP-2 can be loaded in the PEC multilayer films and controlled release in vitro. The BMP-2 encapsulated in the PEC can be kept activity and develop its osteoinduction biological effect. The study provided a new experimental strategy of constructing the PEC multilayer films on titanium surfaces. Moreover, the results also offered a foundation of the experiment of the scaffold constructed on titanium surfaces.3. Based on the above-mentioned study results, the PEC of CS and ALG was self-organized on the surface of titanium, which was used as the scaffold to encapsulate the BMSCs delamination for co-culture. The results showed that the PEC multilayer scaffolds can obviously enhance the proliferation and differentiation of rat BMSCs and can encapsulate experimental cells delamination for co-culture. The engineering scaffolds were constructed on titanium surfaces successfully in this study, which offered a new research approach and experimental foundation of the regeneration of the periodontal ligament.In this paper, based on a serial of experiments, the biolization modification on the surface of titanium implant was performed successfully and the PEC of CS and ALG was self-organized on the surface of titanium, which was used as the scaffold to encapsulate the BMSCs delamination for co-culture. The results of the study offered a new research approach and experimental foundation of the regeneration of the periodontal ligament.