The release of bovine serum albumin from polyurethane based hydrophilic and hydrophobic disks and microbiological interactions

Abstract

Polyurethane (PU) based hydrophobic and hydrophilic disks were prepared by graft copolymerization of PU with vinyl monomers, acryl amid (AAm), itaconic acid (IA), acrylic acid (AA) and crotonic acid (CA). Grafting reactions were performed in PU–dioxane solution using benzoyl peroxide as initiator. Air–water and cyclohexan–water contact angle values of the disks (θ_air and θ_cy) were measured via “Captive Bubble Method”. Surface free energy values of the disks were determined by using θ_air and θ_cy via “Two Liquid Method” and those were compared with the swelling percentage values of the disks. The release of Bovine Serum Albumin (BSA) from protein added hydrophilic and hydrophobic PU disks were defined by spectrophotometric measurements at λ=278 nm in phosphate buffer saline (PBS). BSA releasing is completed around 48 h for all disks. The disks were also characterized by FTIR spectra and SEM micrographs. In vitro attachment of Candida albicans (C. albicans) and Lactobacillus plantarum (L. plantarum) on PU based hydrophilic and hydrophobic disks was studied at 37°C. While C. albicans attached on to all disks, L. plantarum only selectively attached. The attachment percentage values of C. albicans (25%) and L. plantarum (20%) on hydrophobic PU disk were higher than hydrophilic PU disks. The antimicrobial activity of disks was also tested against C. albicans and L. plantarum. IA and AAm grafted PU disks showed inhibitory effect for the both test bacteria.