Protein adsorption behaviors of carboxymethylated bacterial cellulose membranes

Carboxymethylated bacterial cellulose (CBC) membranes with different degrees of substitution (DS) were prepared by surface carboxymethylation of bacterial cellulose, which were characterized by FTIR, contact angles and zeta potential. Both the contact angels and zeta potentials increased with the increase of degrees of carboxymethylation. Protein adsorption behaviors of CBC membranes were investigated with bovine serum albumin (BSA) as model protein and the adsorption quantity increased gradually with the increase of the DS. The protein adsorption was not only governed by the chemical structure of CBC, but also by the electrostatic interaction between CBC and BSA. The protein was found to be adsorbed on CBC membrane at pH lower its isoelectric point (pI) while no protein was adsorbed at pH above its pI. The protein adsorption on the CBC membranes was also characterized by scanning electron microscopy (SEM).