GOLD NANOPARTICLE–MEDIATED PLASMONIC BLOCK COPOLYMERS: DESIGN, SYNTHESIS, AND APPLICATIONS IN SMART DRUG DELIVERY

Abstract

The development of advanced drug delivery systems has become a central focus in biomedical engineering and pharmaceutical sciences, particularly with the integration of nanotechnology into polymeric platforms. In this study, we present the design, synthesis, and application of an asymmetric diblock copolymer mediated by plasmonic gold nanoparticles for controlled and stimuli-responsive drug delivery. The system leverages the unique physicochemical properties of gold nanoparticles, including surface plasmon resonance, biocompatibility, and tunable optical activity, in conjunction with the self-assembly behavior of amphiphilic block copolymers. The copolymer is composed of hydrophilic and hydrophobic segments, strategically engineered to facilitate micelle formation in aqueous environments, where the hydrophobic core serves as a reservoir for poorly soluble therapeutic molecules. The incorporation of plasmonic gold nanoparticles into the polymer backbone introduces multifunctional responsiveness to external stimuli. Specifically, near-infrared (NIR) light irradiation induces localized heating via plasmonic resonance, resulting in the destabilization and disruption of the micellar architecture. This process enables the controlled release of hydrophobic drugs encapsulated in the micelle interior. The synthetic design of the diblock copolymer was optimized to balance stability in circulation with responsiveness upon exposure to external triggers. Structural characterization confirmed successful conjugation of the polymeric segments with gold nanoparticles, while self-assembly studies revealed stable micelle formation under physiological conditions. Drug encapsulation efficiency was evaluated using hydrophobic model compounds, and release kinetics demonstrated significant responsiveness to NIR irradiation, confirming the role of plasmonic resonance in micelle destabilization. Preliminary cytocompatibility studies suggest that the hybrid system maintains biocompatibility, underscoring its potential in translational applications. The findings lay the groundwork for further exploration of plasmonic block copolymers in areas such as targeted cancer therapy, photothermal treatment, and multimodal therapeutic strategies. Future investigations may focus on in vivo pharmacokinetics, biodistribution, and therapeutic efficacy to validate the clinical potential of this system.