Aminolysis of poly(hydroxybutyrate)-based multicomponent films for the impregnation of bovine serum albumin

Chemical modification of native biopolymers may introduce in them some new surface functionalities for the controlled loading/release of foreign species of biomedical significance such as drugs, proteins, cellular metabolites, etc. The present study undertakes the preparation of poly(caprolactone) mediated poly(hydroxybutyrate) (PHB) multicomponent films with poly(lactic acid) as a plasticizer. The prepared films were surface chemical functionalized with amino groups using the ethylenediamine in aqueous or organic media; the process is called aminolysis. The aminolyzed multicomponent films contained active hydrophilic groups offering opportunities for the immobilization of bovine serum albumin (BSA, as a model protein). The extent of aminolysis was tracked using ninhydrin assay, and the prepared films were further characterized using contact angle measurement, Fourier transform infrared spectroscopy, scanning electron microscopy, thermal analysis, x-ray diffraction, and Raman spectroscopy. The results demonstrated the successful formation and aminolysis of PHB-based multicomponent films with desirable amino-hydrophilicity for controlled impregnation and release of BSA.