The unfolding of bovine serum albumin (BSA) was induced by heating at 80 ℃

and hydrophobic residues were exposed on the BSA surface

which caused the gelation of BSA.Influences of heating temperature and time

pH value and the ratio of BSA to chitosan on the self-assembly behavior between denatured BSA and chitosan (CS) in aqueous solutions were explored by the ultraviolet-visible spectroscopy (UV-Vis) and dynamic light scatter (DLS).The self-assembly behavior of BSA and chitosan occurred at 80 ℃ for 15-20 min.At pH 4.7(the isoelectric point of BSA

pI=4.7)

electrostatic interactions between BSA and chitosan enhanced

and as pH is increased

precipitates were formed in the mixture system.At high concentrations of BSA

aggregation of denatured BSA resulted in precipitation of the aggregates.The results indicated that chitosan hindered the gelation process of BSA and self-assembled with denatured BSA by heating at 80 ℃.BSA-CS self-assemblies were fabricated at pH 5.4 in aqueous solutions by heating at 80 ℃.The morphology of nanoparticles was observed by the transmission electron microscopy (TEM) and the size and it distribution were measured by DLS.BSA-CS self-assemblies were constituted by the core consisting of BSA aggregates and the shell consisting of chitosan chains.Self-assemblies were stored without any changes at room temperature for 40 days.