Co-Encapsulation of Violacein and Iron Oxide in Poly(lactic acid) Nanoparticles for Simultaneous Antibacterial and Anticancer Applications

To date, the possibility of drug-resistant bacterial infections in hospitals and intensive care units comprises a significant concern especially for immunocompromised cancer patients. In the current study, violacein and superparamagnetic iron oxide nanoparticles were co-encapsulated in polylactic acid nanoparticles (vio-Fe₃O₄-PLA) and tested for their antimicrobial and anticancer activity. The loaded nanoparticles presented efficient saturation magnetization that rendered this nanosystem a promising candidate for magnetic targeting. Moreover, violacein released from the nanoparticles at 500 μg/mL successfully inhibited the growth of the "superbug" methicillin-resistant Staphylococcus aureus (MRSA) with an IC50 value of 595.8 μg/mL, while it did not prove effective against multi-drug-resistant Escherichia coli at concentrations of 10-1000 μg/mL. Finally, a concentration of 500 μg/mL of drug loaded magnetic nanoparticles induced an over 80% growth inhibition of glioblastoma and melanoma cancer cell lines with IC50 values of 221.30 and 201.60 μg/mL, respectively. Since bacterial infections are a key clinical problem for cancer patients due to their compromised immune systems, the presented results suggest that our system should be further studied for its simultaneous anti-bacterial and anti-cancer properties, as it comprises a promising strategy for combating bacterial infections and providing anticancer activity through magnetic-targeted delivery.