Enhancement Biocompatibility of Bacterial Cellulose Membrane via Laccase/TEMPO Mediated Grafting of Silk Fibroins

Silk fibroin (SF) has the characteristic of moisture penetrability and biocompatibility. To enhance the biocompatibility of bacterial cellulose (BC), silk fibroin is grafted onto BC membrane using laccase and 2,2',6,6'-tetramethylpiperidine-N-oxyl (TEMPO). As the model compound of BC, cellobiose is incubated with laccase/TEMPO for disclosing the mechanism of enzymatic oxidation. The structure and property of the composite membranes of SF/BC are investigated by means of FTIR, XPS, DSC, and biocompatibility analysis. The results indicate that cellobiose might react with hexamethylenediamine and form Schiff bases. The concentration of amino group in SF solution noticeably decreased after laccase/TEMPO oxidation, indicating the occurrence of self-crosslinking of SF. After enzymatic grafting of SF, the content of atomic nitrogen on BC surface was increased compared to that of the control. Meanwhile, the composite membrane of SF/BC exhibits more satisfactory biocompatibility compared to BC, and it has potential applications in biomedical fields.