Structure Design,Preparation And Applications Of The Atelocollagen Biomaterials

Collagen is a fiber formed by three strands of helix.The amino acid sequence at the N and C ends of collagen is termed telopeptide,which determines the antigenicity of collagen.Atelocollagen means that the telopeptides were removed from the collagen helixes.Atelocollagen has excellent immunogenicity,biocompatibility and biodegradability,and can be made into different structural and functional biomaterials through delicate material designs for various medical purposes.This thesis started by studying the preparation of atelocollagen,followed by describing the designs and preparations of various biomedical materials based on the atelocollagen.Firstly,an enzymatic method to prepare the atelo type I collagen gel was developed.Various characterizations including electrophoresis,amino acid analysis and ELISA were conducted in order to evaluate the removal efficiency of the telopeptide.The results showed that the terminal peptides were effectively removed and the purity of the atelocollagen was 99.8%.Secondly,biocompatible porous material was prepared using the atelocollagen.The materials were subjected to various characterizations including the Fourier transform infrared analysis,differential scanning calorimetry,SEM,tensile strength and water absorption method.The results showed that the helix structure of the collagen was partially preserved during the heat treatment and sterilization process,and the porous structure was durable upon immersion in solution.The decomposition properties and hemostasis functions of the porous materials were evaluated both in vitro and in vivo,demonstrating their high biocompatibilities and superior hemostasis effects.The material has been commercialized and verified by clinical trials.Thirdly,an atelocollagen bilayer membrane was fabricated by the self-assembly technique.The menbrane was thoroughly characterized using SEM,tensile strength,hydroxyproline content analysis,and water absorption and swelling test etc..The results showed that after in vitro molecular self-assembly process,the tensile strength of the material was remarkably improved,which could meet the requirement of stitching during the guided tissue regeneration process.The inactivation of the virus was achieved by irradiation,and the biocompatibility of the material was verified.The material has been commercialized and was used in clinical application.Finally,a hydroxyapatite/atelocollagen composite porous material was developed as a bone repair material.The material was fully characterized by SEM,Fourier transform infrared,contact angle,and water absorption and swelling analysis etc.The porous material was able to load and release simulated drugs.Cell experiments and animal experiments showed that the hydroxyapatite/atelocollagen composite presented high biocompatibility and was able to effectively induce bone regeneration in vivo.The material has been used in animal medical treatment.