Frequency-controlled magnetic release of gold-melittin conjugates from TiO₂nanocylinders for dual antimicrobial and cancer therapy

Abstract

This study presents the development of a frequency-controlled drug delivery platform employing gold (Au)-melittin (Mel) conjugates loaded onto titanium dioxide nanocylinders (TiO₂NCs) decorated with magnetic (M) nanoparticles (NPs). TiO₂NCs were synthesized via a multi-step anodization and sonication process, providing a high surface-area scaffold for drug loading, while MNPs enabled magnetically-responsive behavior. AuNPs were functionalized with Mel, a potent antimicrobial and anticancer peptide, to enhance its stability and minimize cytotoxicity. The resulting Au-Mel-loaded MNP-TiO₂NCs exhibited controlled drug release in response to alternating magnetic fields, with peak release occurring within 10 min under stimulation frequencies ranging from 10 Hz to 10 000 Hz. FTIR, TEM, EDX, and zeta potential analyses confirmed successful conjugation and integration of all components.In vitroantibacterial assays demonstrated effective inhibition ofE. coliby magnetically released Au-Mel, while cytotoxicity tests indicated selective activity against HepG2 liver cancer cells with minimal impact on HEK293 cells. This nanoplatform offers a promising solution for dual antibacterial and anticancer therapy with spatiotemporal control via external magnetic fields.