Surface functionalization of polypropylene devices with hemocompatible DMAAm and NIPAAm grafts for norfloxacin sustained release

Abstract

To improve the hemocompatibility and elution of antimicrobial agents for medical devices, N,N′-dimethylacrylamide (DMAAm) and N-isopropylacrylamide (NIPAAm) were sequentially grafted onto polypropylene (PP) films. Various (PP-g-DMAAm)-g-NIPAAm grafts were prepared using different time periods of irradiation while keeping the radiation dose constant. The hydrogel layer that formed on the surface of the PP was temperature-responsive (shifted from 32°C for NIPAAm to 37°C for the copolymer). The (PP-g-DMAAm)-g-NIPAAm films adsorbed serum albumin but not fibrinogen and had significantly lower hemolytic and thrombogenic activity. The DMAAm promoted the loading of norfloxacin (13.3 μg cm—2) when the hydrogel layer was swollen; as the NIPAAm shrank, a sustained delivery (∼6 h) occurred at body temperature. These functionalized PP films have potential as hemo- and cyto-compatible materials for medical devices and drug delivery products.