Synthesis, evaluation of phospholipid biomimetic polycarbonate for potential cardiovascular stents coating

Abstract

Polycarbonate has been widely used in tissue engineering due to good biocompatibility and mechanical properties. However, there are still challenges ahead due to the poor hemocompatibility, especially in the use of Polytrimethylene carbonate (PTMC) as cardiovascular stent coating. In this study, the synthesis of a cyclic carbonate monomer containing an allyl ester moiety, 5-methyl-5-allyloxycarbonyl-1,3-dioxan-2-one (MAC), was performed for the first time. Subsequent copolymerization of the new cyclic carbonate with 1,3-trimethylene carbonate (TMC) was attempted to introduce double bonds, namely PTMAC. Finally, thiolated 2-methacryloyloxyethyl phosphorylcholine (MPC-SH) was grafted onto PTMAC via double bonds to synthesize phospholipid biomimetic polycarbonate (PTMAC-g-PC). The synthesis process was studied via Fourier transform infrared spectroscopy (FTIR), electrospray ionization mass spectrometry (ESI-MS), proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). Water contact angles (WCA) and scanning electron microscopy (SEM) were used to evaluate surface wettability and morphology of 316 L stainless steel (SS) sheets before and after modification with final polymers. Platelet adhesion and fibrinogen denaturation results all showed that phospholipid biomimetic polycarbonate has better hemocompatibility compared with phospholipid-free polycarbonate. The results of rhodamine staining and proliferation activity of different cell cultures were further revealed the anti-fouling properties of phospholipid-modified polycarbonate. Evidence is presented which shows that the successful preparation and excellent fouling resistance of the novel phospholipid biomimetic polycarbonate. This research provides a meaningful study of the novel blood contact materials and may be useful in the development of drug-stent coatings for cardiovascular stents.