Analysis of model drug permeation through highly crosslinked and biodegradable polyethylene glycol membranes

Abstract

Various natural and synthetic polymers, such as hyaluronan and functionalized polyethylene glycol (PEG), have been used to fabricate biodegradable membranes. They can potentially be used for local drug release in the body because of their biodegradability. However, this biodegradability causes to difficulties in sustained drug release, and an insufficient ability to control drug permeability can lead to adverse effects. In this study, we developed biodegradable lyophilized PEG membranes from highly crosslinked PEG hydrogels to control drug permeation. Three-arm thiol-modified PEG (PEG-SH, molecular weight [ M w ] = 1300) and four-arm acrylate-modified PEG (PEG-AC, M w = 1892) were used to fabricate the PEG hydrogels, which were then lyophilized to obtain PEG membranes. The degradation time of these PEG membranes was 25 days under physiological conditions. Despite their biodegradability, the membranes allowed the permeation of model drugs constantly until complete degradation around physiological pH. The normalized diffusion coefficients (ln[ D / D 0 ]) for vitamin B 12 and lysozyme (Lys) were −2.6 and −4.8, respectively. In addition, the membranes showed biodegradability and biocompatibility in the abdominal cavity of mice. These results indicate that PEG membranes can be used for sustained drug release in the body due to their biodegradability and drug permeability. • Highly crosslinked, lyophilized polyethylene glycol (PEG) membranes were developed. • Permeability of several model drugs through the PEG membranes was analyzed. • The measured permeability of the drugs depended on their molecular weight. • PEG membranes indicated pH-dependent degradability and release kinetics. • PEG membranes showed excellent biocompatibility and biodegradability in mice.