Synthesis Of Enzymatic Degradable Polyurethane For Cartilage Tissue Engineering And Property Study

With the development of the tissue engineering, it has a higher requirement to the degradation rate and the tissue regeneration. Because the enzyme sensitive degradable materials can be degrade in the presence of specific enzymes. And the degradation rate of the material can be adjusted dynamically, which is widely used in drug controlled release carriers and short-term implants such as blood vessels, cartilage and so on.In order to determine the degradation sites and the rate of the polyurethane materials, the GPLGLWARK peptide was introduced into the main chain of polyurethane in this paper. This peptide can be degrade in the presence of MMP-13(matrix metalloproteinase-13) at the G-L site, which give the polyurethane enzyme sensitive property. In this paper, the influence of the ratio of soft segment, molecular weight and structure on the properties of polyurethane is investigated. The chemical structure of the polyurethane was characterized by Fourier infrared spectroscopy(ATR), nuclear magnetic resonance(HNMR), ultraviolet spectroscopy(UVS) and XPS. Proved the enzyme sensitive peptide introduced into the main chain of polyurethane successfully. The mechanical properties of the polyurethane were characterized by dynamic mechanical(DMA) and stress-strain curve. The degradation properties and degradation mechanism of the materials were studied by degradation experiments and scanning electron microscopy(SEM). cal properties of the enzyme sensitive polyurethaneThis paper selects PTMG as soft segment, 1,6-hexamethylene diisocyanate and peptide GPLGLWARK(or BDO) as hard segment. Synthesized a series of enzyme sensitive polyurethane which can be degrade in the presence of MMP-13. The effect of peptide content on the mechanical properties of polyurethane was investigated. It was found that the mechanical properties of the materials did not decrease when we increase the peptide content, but increased the toughness of the material. The higher peptide content, the better hydrophilicity, the higher degradation rate, and the surface morphology of the degradation were more rough.This paper selects PCL-PTMG-PCL triblock copolymers as soft segment, 1,6-hexamethylene diisocyanate and GPLGLWARK polypeptide as hard segment. Synthesized a series of double sensitive polyurethane with different ratio of hard and soft segments. The results showed that the hydrolyze property could be increased by increase the content of PCL, enzymatic hydrolysis properties could be improved by the increase of the peptide content.We investigated the biological properties of the enzyme sensitive polyurethane materials bycellproliferationassay.wefoundthattheintroductionofthepeptidedidnotincreasethecytotoxicity.butingeneral,polyurethanematerialhasacertaincytotoxicity,whichisalsoreportedinthepreviousstudies.