Protein Interactions with Polylactide-Polyglycolide Particles and Scaffolds

Abstract

Biodegradable implants of polylactide and polyglycolide are increasingly used in tissue engineering as well as alternatives to the use of metal plates and screws in the rigid fixation of fractures. Contact with proteins is the first biological event that may influence dynamic cellular interactions with these materials. In this study, the biophysical effects of protein interactions with poly (D,L-lactide)-co-glycolide (PLG) particles and scaffolds were examined using a model protein, xanthine oxidase (XO). Adsorption of XO to PLG particles or scaffolds caused a loss of activity of the XO, while preadsorbing bovine serum albumin to particles appeared to prevent loss of protein activity. Surface fluorescence of XO bound to PLG particles and scaffolds showed that XO was partially denatured. Furthermore, XO bound to PLG scaffolds was found to exist in a more native configuration than XO bound to PLG particles. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of adsorption of serum proteins to PLG demonstrated three major bands, one of which may be albumin based on isoelectric point and molecular weight. Therefore, it can be concluded from this study that certain enzymes may become irreversibly inactivated when bound to PLG particles or scaffolds.