Scientists attached the natural antimicrobial peptide LL‑37 (and a synthetic version called CSA‑13) to tiny magnetic particles. This combo killed several Candida yeast strains even better than the free peptides, worked in body‑like fluids, stopped biofilm formation, and didn’t hurt bone‑cell growth, showing it’s safe in the lab.

Fungal infections caused by Candida spp. represent an emerging problem during treatment of immunocompromised patients and those hospitalized with serious principal diseases. The ever-growing number of fungal strains exhibiting drug resistance necessitates the development of novel antimicrobial therapies including those based on membrane-permeabilizing agents and nanomaterials as drug carriers. In this study, the fungicidal activities of LL-37 peptide, ceragenin CSA-13 and its magnetic derivatives (MNP@LL-37, MNP@CSA-13) against laboratory and clinical strains of C. albicans, C. glabrata and C. tropicalis were evaluated. These experiments confirm the high anti-fungal activity of these well-characterized agents mediated by their interaction with the fungal membrane and demonstrate elevated activity following immobilization of LL-37 and CSA-13 on the surface of magnetic nanoparticles (MNPs). Furthermore, MNP-based nanosystems are resistant to inhibitory factors present in body fluids and effectively inhibit formation of fungal biofilm. Simultaneously, synthesized nanostructures maintain immunomodulatory properties, described previously for free LL-37 peptide and CSA-13 substrate and they do not interfere with the proliferation and viability of osteoblasts, confirming their high biocompatibility.