The Properties of Polyesteramide and the Effects on the Stability of Bovine Serum Albumin

ABSTRACT

The stability of a model protein, bovine serum albumin (BSA), either in solid state or entrapped in polymer matrices, was studied. A series of copolymers consisting of lactide (LA) or caprolactone (CL) with 6-methyl-2, 5-morpholinedione (MMD) were synthesized and used as the matrices. Size exclusion chromatography assay revealed that covalent aggregation of BSA occurred during the incubation of BSA or BSA–polymer matrices under certain water content. The amount of aggregate was shown to be dependent on the water content, pH value, and composition of the polymer. The content of MMD in the copolymer greatly affected properties of the material, such as hydrophilicity, water absorption, and degradation, which determined the biocompatibility of the material. In the copolymer of CL and MMD, the incorporation of glycine and lower water absorption improved the BSA stability. In the copolymer of LA and MMD, higher water absorption and glycine incorporation acted on the opposite way and the BSA stability was dependent on the overall effects of both.

KEY WORDS: :

• Polyesteramide
• Product of degradation
• Protein stability
• Water absorption