Designing iron oxide & silver nanocomposites with phyto- and fungo chemicals for biomedicine: lessons learned

Multifunctional nanoparticles for biomedical applications are widely researched and constantly developed because they provide wider possibilities for therapy and diagnostics. This work aims to summarise our findings towards the design of multifunctional complex iron oxide and silver nanoparticles (NPs) produced from the plants Zingiber officinale and Hypericum perforatum and mushrooms Amanita muscaria and Sparassis crispa. It was revealed that the antimicrobial and anticancer properties of the NPs were a consequence of the combination of silver and phyto- and fungo-chemicals originating from natural species. Moreover, the photoactive properties of the complex iron oxide and silver nanoparticles promoted photodynamic therapy (λ_exc = 405 nm) that significantly improved the antibacterial (E. coli, S. aureus, B. pumilus, P. fluorescence) and anticancer (HeLa, U2OS cells) effects. Notably, the gel formulations of the NPs based on hyaluronic and alginic acids had advantages over the aqueous dispersions of the NPs. For instance, being embedded into a hyaluronic acid gel, the NPs were more effective against cancer cells due to the improved uptake of hyaluronic acid by cancer cells. Another advantage of gel formulations of the NPs was connected with their microstructural properties; the nanocomposite gel adjusted its microstructure to the substrate topology, mimicking the substrate scale and pattern. Thus, complex ultrasmall iron oxide and silver nanoparticle NPs synthesized with natural extracts and their gel formulations may find diverse applications in the biomedical field, particularly for local cancer treatment and as post-operative bone or tissue scaffold after cancer or chronic osteomyelitis surgery.