Study Of Polyurethane Modification By Click Chemistry For Cartilage Repair

Because of its special avascular nature,articular cartilage has little capacity to self-regenerate once damaged.At the same time,conventional clinical treatment for cartilage degeneration relies mostly on surgery,which often induces fibrous repair tissues and unsatisfactory function.Driven by the urgent medical needs,extensive efforts have been dedicated to promote cartilage tissue regeneration which is a most effective stratagy for cartilage repair.Scaffold is important in tissue engineer.The adhesion,proliferation and differentiation of seed cells are vital to success of tissue engineer,and cell adhension on scaffold is the primary requirement to further proliferation and differentitation of cells.Traditional articular cartilage tissue engineering materials in the presence of biological activity on the match and mechanical properties of certain problems,this study from the good properties of the polyurethane molecular design structure starting design pendant polyurethane material having certain reactive groups,and its side group modified to obtain a urethane material suitable for articular cartilage regeneration and repair.In this study,PCL-2000 as a soft segment HDI and BDO as a hard segment were used for the synthesis of biodegradable polyurethane.Various biodegradable polyurethane material having different characteristics were synthesized by adjusting the proportion of HDI.The molecular weight and mechanical properties of samples were studied.FTIR,Raman and 1H-NMR results revealed the structure of PU.Young's modulus and crystallinity decrease with the increasing content of HDI.Although biodegradable polyurethane has excellent mechanical properties,the bioactivity needs further improvement.In this study,2,2-propargyl-1,3-propanediol(DPPD),Azidobenzoic Acid,Azido-propylamine were synthesized used for getting functional polyurethane.Alkyne-polyurethane was synthesized and carboxyl-PU and amine-PU were synthesized by Click reaction(CuAAC).FTIR,Raman and 1H-NMR results revealed the structure of functionalized-PUs.The property of PUs was characterized with DSC,XRD and tensile mechanical test,experimental results show that the structure of the side chain of a large impact on performance.Finally,the TGF-?1 affinity peptide HSNGLPL was grafted onto the alkyne-polyurethane by Cu AAC reaction.FTIR,1H-NMR results revealed the successful incorporation of peptide HSNGLPL.DSC and XRD results showed crystallinity decrease with the increasing content of peptide.Cell viability experiments revealed that all PUs has no influenceon the cell viability in this study.