Preparation And Biocompatibility Of HA/PDA Coating On The Surface Of 316L SS

Thrombosis formation and restenosis are still the main factors for cardiovascular stents in clinical applications. The presence of a confluent endothelium layer on stent surface have been widely considered as an ideal approach to reduce late thrombosis, restenosis and other risks. Surface modification by conjugating biomolecules has been widely proved to enhance biocompatibility of cardiovascular implanted devices. Here, the multi-coatings of hyaluronic acid (HA) and dopamine (PDA) were prepared onto 316L stainless steel (316L SS) via electrostatic interaction or hydrogen bonds in order to develop a multifunctional surface which not only provides good hemocompatibility but also functions well in inducing desirable vascular cell-material interaction. The main contents are as follows:In the present work, the multi-coatings of hyaluronic acid (HA) and dopamine (PDA) layers were characterized by atomic force microscope (AFM), fourier transform infrared spectroscopy analyzer (FTIR), the surface of hyaluronic acid quantification and water contact angle measurement (WCA). AFM, FTIR and hyaluronic acid quantitative results showed the success of hyaluronic acid is fixed on the sample surface. The results of platelet adhesion and activation, the whole blood test, proliferation of endothelial cells and smooth muscle cells, adhesion/activation of macrophages in vitro indicated the sample PDA-HA-2 (2.0mg/mL) can not only effectively inhibited platelet adhesion and activation, inhibition of smooth muscle cell proliferation and a good anti-inflammatory response, but also promoted endothelial cell proliferation and released cytokine. The PDA-HA-2 coating was proved to cause milder in vivo tissue response. An animal experiment of implantation in the femoral artery showed that PDA-HA-2 not only inhibited hyperplasia formation and inflammation, but also significantly promoted endometrial repair and regeneration.In this dissertation, the present work select functional molecules as hyaluronic acid to modificate the surface of 316L SS aim to develop a multifunctional surface which not only provides good hemocompatibility, but also functions well in inducing desirable vascular cell-material interaction.