Preparation of antibacterial ZnO NP-containing schizophyllan/bacterial cellulose nanocomposite for wound dressing

Nanocomposite hydrogel is helpful to provide a moist and ideal environment for wound healing. In this research study, a nanocomposite hydrogel was prepared based on schizophyllan (SPG) and amine-functionalized bacterial cellulose (amine-functionalized BC). ZnO-nanoparticles were loaded into amine-grafted BC/SPG hydrogel to improve its antibacterial feature. The successful functionalization of bacterial cellulose by (3-aminopropyl)triethoxysilane was verified by FTIR and XRD analyses. XRD pattern of amine-grafted BC/SPG/ZnO NP showed some new peaks in comparison with XRD pattern of amine-grafted BC/SPG which verified the intercalation of ZnO into polymeric matrix. SEM images showed that the porous spaces of BC have been filled by schizophyllan as a result of the intermolecular attraction between them. Deposition of ZnO nanoparticles on the surface of amine-grafted BC/SPG has also been verified by SEM analysis. Amine-grafted BC/SPG membrane showed the higher swelling degree (850 ± 48%) in comparison with BC (512 ± 29%). The swelling ratio decreased to 725 ± 19% by addition of ZnO nanoparticles. Amine-grafted BC/SPG exhibited the higher mechanical strength (45 MPa) in comparison with pristine BC (10 MPa). The tensile strength of amine-grafted BC/SPG/ZnO NP nanocomposite reached ~ 70 MPa that might be resulted from the formation of hydrogen bonding between hydroxyl groups of polymers and oxygen atoms in the ZnO NPs. Amine-grafted BC/SPG/ZnO showed a more remarkable antibacterial efficiency against E. coli and S. aureus. As compared to BC, amine-grafted BC/SPG could stimulate the proliferation of human fibroblast cell. Cell viability showed a slight decrease after exposure to amine-grafted BC/SPG/ZnO NP nanocomposite.