The Preparation And Performance Research Of Injectable Biomimetic Cartilage By Photopolymerization

The structure of cartilage tissue is very special,which lacks of regeneration and would leave permanent lesions after injury. With the development of tissue engineering technology, repair methods for cartilage defect have become research focus in domestic and overseas. Photopolymerization hydrogels can maintain a large amount of water, which is very similar with human tissue,having advantages of minimally invasive. Its precursor solution is injectable, which can polymerize in situ after uv irradiation.The researchers have made many hydrogel system, but there are still problems about strength and biocompatibility. However, compounding synthetic polymers and natural polymer can effectively improve the mechanical strength of photopolymerization hydrogel scaffold with high biocompatibility. About the problems existing in the photopolymerization hydrogels for cartilage repair, In order to improve biocompatibility and intensity, this paper designed MPVA, MCS and MSF. Using 1 HNMR, IR, XRD, DSC test to characterize such as structure, the crystalline and thermal behavior of them. Using technology of ultraviolet light polymerization to prepare MPVA hydrogels,MCS/MPVA composited hydrogels and MCS/MSF composited hydrogels. Using photo rheological test, SEM, compression test, swelling test and MTT to study their Kinetics of Polymerization, microstructure, mechanical properties, swelling properties and biocompatibility.Results showed that the MPVA has three kinds of degree of substitution, and its aqueous solution can start gelation within 20 s. The mechanical performance of MPVA1 hydrogel is excellent, which close to the strength of natural cartilage. It can not be damaged with deformation reaching more than 80%,and compression strength being greater than 0.7 MPa.After removing force, it can still reply to its original state, showing high strength and elasticity.The mechanical properties and biocompatibility of MCS/MPVA hydrogel is good. The compression strength of MCS1/MPVA1=25/75 hydrogel is 0.41 MPa. Results of MTT show that this hydrogel is non-toxic to L-929 mouse fibroblast cells. In MCS/MSF hydrogels, MSF nanoparticles were the main junction, crosslinked with MCS.The compression strength of(6wt%)MCS+(0.01wt%)MSF hydrogel is 0.41 MPa.Results of MTT show that this hydrogel is harmfulless to Chondrocyte. Its average OD can reach more than 60% of the negative group. Those hydrogel scaffolds are injectable and bionic, with good biocompatibility and high strength. They can fill injury cartilage closely, with minimally invasive and easy shaping, which is helpful for cartilage repairing.