New Biocomposite Matrices Structures Based on Collagen and Synthetic Polymers Designed for Medical Applications

摘要

Among the composition and morphologicalstructure field of biomaterials,the biodegradable biocomposites based on,synthetic and natural polymers as biocompatible spongious matrices has been studied.The biodegradable synthetic polymers haoe good mechanical properties,low toxicity and a controlled degradation kinetic.However,these polymers are hydrophobic and do not exhibit adequate surface for cells attachment and proliferation because of receptors absence for cells recognition.The natural polymers show good cellular interaction and high hydrophilicity.The advantages of biocomposites made of both synthetic and natural polymers are holding both physico-chemical properties of synthetic polymers and biocompatibility,cellular adhesion properties and variety ofbiological interactions induced by the contact between cells and natural polymeric support.The aim of this study was the synthesis of biocompatible porous structures by compounding synthetic polymers-(poly(L-lactic acid)(PLLA),poly(D,L-lqctic-co-glycoIic acid)(PLGA)which are biocompatible,biodegradable but hydrophobic,with natural polymer-collagen,the main protein of extracelullar matrix.The biocomposites were prepared in a polymer:collagen ratio of 2:1 by adding synthetic polymer solution,solued in chloroform,to aqueous collagen gel.The synthesis of biocomposite matrices was achieved by lyophilizing of synthetic polymer/collagen blends after dialyse against 1M KCl.Both uncrosslinked and crosslinked samples were prepared.As standard sample the uncrosslinked and crosslinked collagen matrices were chosen.The morphology of biocomposite matrices PLLA/collagen,PLGA/collagen was characterized by SEM in order to investigate the macro-,micro and nanoporosity.Physico-chemical characterization was focused on thermal stability(DSC and TGA)and surface hydrophilic character by water vapours absorption,water vapours permeability and water absorption.