Síntese e caracterização de materiais à base de quitosana - aplicação em adsorção de BSA

Abstract

Chitosans have interesting features, such as biocompatibility, biodegrability, good adherence and cellular affinity. The presence of amine (-NH2) and hydroxyl groups (- OH) on chitosan structure enables their chemical modification using citrates, polyphosphates, organosilanes, among others. In this work, membrane chitosans were chemically crosslinked with citrate (CIT), tripolyphosphate (TPP) and 3-aminopropiltrimetoxisilano (APTES) were synthesized for application in sorption of proteins. The characterization of the materials was made by FTIR, MEV, TG/DTG and XRD. It was found that the membranes were successful synthesized and remained stable during the sorption tests. Sorption isotherms of bovine serum albumin (BSA) in relation to solution pH and temperature were obtained and evaluated. Some mathematical models were used to evaluate the kinetic features of sorption of BSA onto the materials. From a statistical analysis using standard deviation and chi-square methodologies, the so-called kinetic order-variable model has presented the best fittings in relation to comparisons between the experimental and theoretical values of BSA sorption. The values of the variable order sorption constants (kn) were between 0.0002 and 264.91 min-1 and the values of the n constants were between 0.142 and 1.492 min -1. The Morris-Weber kinetic model has also suggested that intraparticle diffusion is an important mechanistic feature of BSA-membranes interactions. It has found that the membranous chitosan-modified materials are promising for using in processes, which demand interaction of proteins in aqueous media.