Facile Synthesis and Biophysical Characterization of Novel Zinc Oxide/Fe3O4 Hybrid Nanocomposite as a Potentially Active Agent in Sunscreens

Abstract

Zinc oxide nanoparticles (ZnO NPs) are attractive sunscreens for UV protection, but they still face some challenges due to their white color and skin whitening, and the extent of UV blocking is still limited to UV-B. Therefore, the present work aimed to develop novel sunscreen agents based on ZnO/Fe3O4 hybrid nanocomposites. ZnO/Fe3O4 hybrid nanocomposites were prepared using a facile one-step combustion method and characterized by XRD, FTIR, FESEM, and UV–Vis diffuse reflectance techniques. The in vitro sun protection factor (SPF) and antioxidant activity of the prepared samples were carried out by spectrophotometric methods. The biocompatibility potential was tested on the normal (Human lung fibroblast: WI38) and cancerous (Hepatocellular carcinoma: HEPG-2) cell lines and the antibacterial activity was tested against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Bare ZnO NPs and ZnO/Fe3O4 hybrid nanocomposites had pure structures with average particle sizes on a scale below 100 nm. The samples had antibacterial and antioxidant activity as well as the potential for biocompatibility and anticancer activity (cell viability was 80% for all nanocomposites up to 6.25 μg/mL indicating non-toxicity). The nanocomposite presented good UV absorption and SPF values (SPF = 12.2–14) not too far from those of bare ZnO (SPF = 15.4) and achieved extended protection over the UV and visible range. ZnO/Fe3O4 hybrid nanocomposites are colored compounds that can match a desired tanned skin tone and have biophysical properties that make them a promising future as a cosmetic UV protectant.