LBL structured chitosan-layered silicate intercalated composites based fibrous mats for protein delivery

Organic rectorite (OREC) was used to prepare intercalated composites with chitosan. The negatively charged cellulose acetate (CA) fibrous mats were modified with multilayers of the positively charged chitosan or chitosan-OREC intercalated composites and the negatively charged bovine serum albumin (BSA) via electrostatic layer-by-layer (LBL) self-assembly technique. The morphology and protein delivery properties of the resultant samples were investigated by regulating the number of deposition bilayers, the outermost layer and the composition of coating bilayers. The thickness of LBL films coated CA mats increased as the number of bilayers was increased and OREC was added. X-ray photoelectron spectroscopy indicated that chitosan and OREC were deposited on CA fibers. Small angle X-ray diffraction patterns showed that OREC was intercalated by chitosan. The in vitro BSA encapsulation and release experiments demonstrated that OREC could affect the degree of protein loading capacity and release efficiency of the LBL films coating.