Preparation, Characterization, and Antimicrobial Activity of Cubosome Encapsulated Metal Nanocrystals

• Published in: ACS applied materials & interfaces 2020-02, Vol.12 (6), p.6944-6954
• Main Authors: Meikle, Thomas G, Dyett, Brendan P, Strachan, Jamie B, White, Jacinta, Drummond, Calum J, Conn, Charlotte E
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Drug Compounding; Drug Delivery Systems - instrumentation; Drug Delivery Systems - methods; Gram-Negative Bacteria - drug effects; Gram-Positive Bacteria - drug effects; Lipids - chemistry; Metal Nanoparticles - chemistry; Microbial Sensitivity Tests; Particle Size; Scattering, Small Angle
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.9b21783

Herein, we demonstrate a method for the functionalization of cubic phase lipid nanoparticles (cubosomes) with a series of magnetite (Fe3O4), copper oxide (Cu2O), and silver (Ag) nanocrystals, with prospective applications across a wide range of fields, including antimicrobial treatments. The resulting cubosomes are characterized using small-angle X-ray scattering and dynamic light scattering, demonstrating the retention of a typical cubic phase structure and particle size following nanocrystal encapsulation at concentrations up to 20% w/w. Cryogenic transmission electron microscopy reveals significant loading and association of each nanocrystal type with both monoolein- and phytantriol-based cubosomes. The antibiotic potential of these hybrid nanoparticles is demonstrated for the first time; cubosomes with embedded silver nanocrystals display a high level of antimicrobial activity against both Gram-positive and Gram-negative bacteria, with observed minimum inhibitory concentration values ranging from 15.6–250 μg/mL. Lastly, total internal reflection fluorescence microscopy is used to visualize cubosome–bacteria interactions, suggesting the involvement of particle interactions as a delivery mechanism.