Syntheses, characterization, and antibacterial activity of chitosan grafted hydrogels and associated mica-containing nanocomposite hydrogels

Chitosan (CS) grafted poly[(acrylic acid)-co-(2-hydroxyethyl methacrylate)] (CS-g-poly(AA-co-HEMA)) at different molar ratios of AA and HEMA, and the associated nanocomposite hydrogels of CS-g-poly(AA-co-HEMA)/mica were synthesized by radical copolymerization. The grafting positions at the amino or hydroxyl groups in the CS were identified by Fourier transform infrared spectroscopy. CS-g-poly(AA-co-HEMA) hydrogels were intercalated in the mica and the amount of hydrogel insertion did not affect the spacing of the silicate layers in mica. The higher mica loadings produced a rougher surface of the nanocomposite hydrogel. The water absorbency of the CS-g-poly(AA-co-HEMA)/mica nanocomposite hydrogels decreased with increasing levels of mica loading to a lower level than those of the CS-g-poly(AA-co-HEMA) hydrogels. Both CS-g-poly(AA) and CS-g-poly(AA-co-HEMA)/mica nanocomposite hydrogels exhibited a higher antiproliferative activity against Staphylococcus aureus than did the neat CS hydrogel with CS-g-poly(AA) revealing a very pronounced minimum inhibition concentration (MIC) of 1.56 mg mL-1. The extent of mica loading in the CS-g-poly(AA-co-HEMA) nanocomposite hydrogels did not affect the MIC (12.5 mg mL-1). (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013