Lipolysis of Poly(Hydroxybutyrate)‐Based Films for the Tailored Release of Hydrophilic Proteins

Abstract

AbstractWe report the fabrication of poly(lactic acid) mediated poly(hydroxybutyrate) (PHB) films using a solvent casting approach. The prepared films were employed to attain additional polarities for making them hydrophilic for impregnating certain model proteins. The extent of lipolysis was assessed via lipase, hydrolytic and water contact angle (WCA) assays. The films were examined for surface chemical and thermogravimetric profiles. The lipase and hydrolytic activities turned out to be 7.28 U/mL.min and 7.85 mL/g, respectively; whereas, the WCA of the test film reduced from 100.0° to 52.8° on lipolysis which on impregnating with the proteins further reduced to <30.0°. The specimens expressed surface smoothness after lipase treatment; however, roughened after the adsorption of proteins. The surface chemical analysis exhibited increased oxygen contents after lipolysis, indicating the inclusion of oxygen‐containing polar functionalities whereas amide functionality after protein adsorption. The results suggest the feasibility of protein‐adsorbed PHB films in sustained drug delivery applications.