Cryostructuring of polymer systems. 44. Freeze-dried and then chemically cross-linked wide porous cryostructurates based on serum albumin

Abstract

AbstractSpongy cryostructurates based on bovine serum albumin (BSA) have been prepared via freezing the aqueous solutions of the protein followed by freeze-drying and subsequent cross-linking BSA macromolecules each together within the macropore walls using N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) dissolved in ethanol. The gel-fraction yield values testifies high efficiency (>93%) of the protein building-up into the 3D polymeric network. Poor swelling of the pore walls of BSA-based sponges in water (1–2 g H2O per 1 g of dry polymer) and even in the powerful protein-solubilizing media (8 m urea, 5 m guanidine hydrochloride, 1% SDS) indicates the multipoint character of albumin cross-linking via the pendant peptide bonds. As a result, strong cross-linking is able (as revealed by HS-DSC) to inhibit BSA thermal denaturation. The size of wide pores in the obtained cryostructures ranges from 40 to 250 μm and mainly depends on the freezing temperature.