Biofunctionalized bacterial cellulose membranes by cold plasmas

Bacterial cellulose (BC) membranes were modified with oxygen (O-2), nitrogen (N-2), and tetrafluoromethane (CF4) plasmas in order to enhance cell affinity. The surface properties of the pristine and plasma-treated BCs were analyzed through water contact angles, electron spectroscopy for chemical analysis (ESCA), and scanning electron microscopy. O-2 and N-2 plasmas changed the surface of BCs to more hydrophilic while CF4 plasma altered BCs to be very hydrophobic. ESCA analyses indicated that O-2, N-2, and CF4 plasmas incorporated the functionalities of carbon-oxygen, amides and amino, and carbon-fluoride on BCs, respectively. The effects of the plasma treatments on the adhesion of L-929 fibroblast and Chinese hamster ovary cell lines showed that the cell adhesion and proliferation of both cells was significantly improved on BC-CF4, in contrast with that on the pristine BC, BC-O-2, and BC-N-2, revealing a functionality-specific effect resulted from different plasmas. Moreover, protein adsorption tests indicated that a higher quantity of proteins in cell culture medium was adsorbed on the CF4 plasma-treated BCs which presumably played the role of enhancing the subsequent cell growth. This work highlights the great potential of plasma treatments on the improvement of biocompatibility and surface property of BCs for biomedical applications.