Novel biosynthesis of manganese dioxide nanoparticles using watermelon peel extract and their biological applications

This work was the first to apply a green and environmentally acceptable technique to produce manganese dioxide nanoparticles (MnO2NPs) using watermelon peel extract (WPE). FTIR, XRD, UV-visible, and TEM were all used to completely characterize the biosynthesized MnO2NPs. MnO2NPs were produced and found to have a polycrystalline crystal structure with a mean particle size of 8 nm, according to their characterization. With MICs, or minimum inhibitory concentrations, of 400, 100, 100, and 200 µg/mL against S. aureus, B. subtilis, E. coli, and P. aeruginosa, MnO2NPs have demonstrated intriguing antibacterial effectiveness, correlating with the antimicrobial results. MnO2NPs also show excellent antibiofilm action against MRSA in a dose-dependent manner. Furthermore, MnO2NPs have high antioxidant activity; the DPPH technique yielded an IC50 of 218 µg/mL. MnO2NPs may also have anticancer properties against the MCF7 malignant cell IC50 was 366 µg/mL and 74% and 93% suppression percentages at 1000 and 500 µg/mL, respectively. In conclusion, watermelon peel material was used to biosynthesize MnO2NPs, which exhibit strong antibacterial, antibiofilm, anticancer, and antioxidant properties.