A biocompatible propolis pollen and ZnO nanorod composite with antimicrobial and antibiofilm activity

In the context of growing infections, plant-derived natural compounds play a crucial role in the search for new antimicrobial agents, as they offer a diverse array of bioactive molecules. Similarly, nanomaterials, particularly those based on zinc oxide, hold great potential for biomedical applications due to their unique properties. This study evaluates the antimicrobial efficacy of a formulation combining propolis, pollen, and ZnO nanorods (PrPoZnO). SEM and FTIR analysis confirmed ZnO nanorod integration within the propolis-pollen matrix. Antimicrobial testing revealed significant inhibitory effects on Staphylococcus aureus and Pseudomonas aeruginosa, with viability reduction of up to 85% and biofilm inhibition of 50% and 40%, respectively. The PrPoZnO mixture also reduced Candida albicans growth by 90%, inhibited biofilm formation by 60%, and suppressed the yeast-to-hyphae transition, a key virulence factor. Furthermore, the biocompatibility testing of the PrPoZnO mixture in several cell lines demonstrated no cytotoxic effects at the higher concentration, suggesting its potential for safe biomedical applications. In terms of mechanism, PrPoZnO modulated oxidative stress responses, decreasing ROS levels in bacteria while inducing ROS production in C. albicans, suggesting that ZnO nanorods are the key player to induce mechanical damage of microbes. These findings underscore the potential of PrPoZnO as an innovative and biocompatible compound, supporting its suitability for further clinical investigation.