On the morning of 11 September, at VNUHCM–University of Science (HCMUS), doctoral researcher Huỳnh Trọng Phát successfully defended his doctoral thesis in Optics, entitled ‘Synthesis of Anisotropic Gold Nanoparticles and Spectroscopic Characterisation towards Applications in Biomedical Materials’, under the supervision of Assoc. Prof. Lâm Quang Vinh.

The thesis focused on developing synthesis processes, optimising optical properties, and evaluating the biomedical potential of two types of nanomaterials: gold nanobipyramids and gold nanostars. A notable aspect of the research was the development of a ‘green’, seedless synthesis method for gold nanostars, combining the biopolymer chitosan with ultrasound assistance. The method enables precise control over particle morphology, improves synthesis efficiency, and reduces synthesis time to only a few minutes without requiring toxic surfactants.

For photothermal therapy applications, the researcher successfully conjugated the NVT1 nanobody to the surface of gold nanoparticles to target the VEGFR2 receptor on cancer cells. Experiments using near-infrared laser irradiation (808 nm, 0.5 W/cm²) on the NCI-H460 lung cancer cell line showed that the NVT1@GNS gold nanostar system selectively eliminated cancer cells with high efficacy, reducing cell viability to approximately 3%.

The research also demonstrated broad-spectrum antibacterial activity against Gram-negative and Gram-positive bacteria, as well as antibiotic-resistant strains (MRSA and MSSA). Using surface-enhanced Raman spectroscopy (SERS) combined with scanning electron microscopy (SEM), the antibacterial mechanisms were identified as involving both cell membrane disruption and intracellular oxidative stress. The thesis also successfully developed a porous polyurethane composite incorporating gold nanoparticles, with potential applications in advanced medical dressings.

The findings provide an important foundation for the development of nanomedicine therapies and next-generation medical materials. Preclinical (in vivo) studies will continue to evaluate biological safety comprehensively before potential practical applications are pursued.