Graphene Oxide-IPDI-Ag/ZnO@Hydroxypropyl Cellulose Nanocomposite Films for Biological Wound-Dressing Applications

In this work, we proposed a feasible approach to prepare multifunctional composite films by introducing a nanoscaled filler into a polymer matrix. Specifically, thanks to isophorone diisocyanate (IPDI) acting as a coupling agent, the hydroxyl groups and carboxyl groups on the surface of graphene oxide (GO) and the hydroxyl groups on the surface of silver-coated zinc oxide nanoparticles (Ag/ZnO) are covalently grafted, forming GO-IPDI-Ag/ZnO (AGO). The prepared AGO was then introduced into the hydroxypropyl cellulose (HPC) matrix to form AGO@HPC nanocomposite films by solution blending. AGO@HPC nanocomposite films exhibited improved mechanical, anti-ultraviolet, and antibacterial properties. Specifically, a tensile test showed that the tensile strength of the prepared AGO@HPC nanocomposite film with the addition of as low as 0.5 wt % AGO was increased by about 16.2% compared with that of the pure HPC film. In addition, AGO@HPC nanocomposite films showed a strong ultraviolet resistance and could effectively inactivate both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria at a low loading of AGO, and rapid sterilization plays a crucial role in wound-healing. In vivo results show that the AGO@HPC release of Ag⁺ and Zn²⁺ stimulates the immune function to produce a large number of white blood cells and neutrophils, thereby producing the synergistic antibacterial effects and accelerated wound-healing. Therefore, our results suggest that these novel AGO@HPC nanocomposite films with improved mechanical, anti-ultraviolet, and antibacterial properties could be promising candidates for antibacterial packaging, biological wound-dressing, etc. The abuse of antibiotics has brought about serious drug-resistant bacteria, and our nanofilm antibacterial does not entail such problems. In addition, local administration reduces the possibility of changing the body's immune system and organ toxicity, which greatly increases the safety.