Surface modification of PVA hydrogel membranes with carboxybetaine methacrylate via PET-RAFT for anti-fouling

In this study, we grafted brush-like CBMA copolymer brushes onto the surface of PVA hydrogel membrane through photo-induced electron transfer-reversible addition fragmentation chain transfer (PET-RAFT) polymerization. ATR-FTIR, XPS, AFM, UV-Vis absorption spectra and elemental analysis were adopted to characterize the hydrogels, and equilibrium swelling, water contact angle, vitro cytotoxicity assay, protein adsorption and cells adhesion experiments were used to evaluate the related property of hydrogels. The results of ATR-FTIR and XPS showed that pCBMA was successfully grafted onto the surface of PVA hydrogel membrane. The Ra roughness of hydrogel surface in AFM increased slightly from 5.44 nm to 6.12 nm. Transmittance of the PVA-g-pCBMA hydrogel in the visible range (380 nm-780 nm) was remaining at 91.2%-97.0%. The optimal reaction conditions (CPADB: 1.20 mmol/L, Eosin Y: 0.03 mmol/L and CBMA: 358 mmol/L) were confirmed through control experiments. The equilibrium swelling and water contact angle showed that the swelling ratio increased from 2.06 cm(3) g(-1) to 3.65 cm(3) g(-1), while the water contact angle decreased from 45.94 degrees to 18.06 degrees with the increase of grafting ratio (23.92%-55.18%). In vitro cytotoxicity assay by CCK-8 showed that the cells relative viability remained at least 90.55%. Anti-protein adsorption experiment illustrated approximately 57.2% improvement of anti-protein capacity at 37 degrees C, while cells adhesion experiment also showed about 64.57% improvement of anti-cells capacity. These results revealed the applicability of the oxygen tolerant PET-RAFT mechanism on the PVA modification and it was effective, feasible and non-cytotoxic method to prepare the other functional PVA hydrogel membrane.