Synthesis of Gold-Capped Mesoporous Silica Nanocarriers to Enhance Chemotherapeutic Efficacy Through Green Light Photodynamic Therapy

Porous silica nanocarriers have gained prominence for the delivery of various anticancer drugs due to their excellent surface functionalization capabilities and potential to mitigate undesirable side effects. In this study, gold nanoparticles were synthesized through a seed-mediated growth method (with diameters ranging from 7 to 10 nm) and conjugated onto mesoporous silica nanocarriers via amine-gold interactions. The large pore channels of nanocarriers were efficiently loaded with the anticancer drug doxorubicin. Physicochemical characterization was comprehensively performed using dynamic light scattering, scanning transmission electron microscopy, Fourier transform infrared spectroscopy, and an absorption spectrophotometer. The mesoporous silica nanocarriers demonstrated a rod-shaped morphology, approximately 150 nm in length and 100 nm in width. Leveraging the strong optical absorption of gold nanoparticles at 530 nm, the synergistic effect of green-light-mediated photodynamic therapy and chemotherapy was investigated on prostate cancer cells. The co-therapies successfully reduced cell viability by 54% at a concentration of 400 µg/mL nanocarriers after 10 minutes of green light exposure (540 nm, 100 mW/cm², continuous wave), demonstrating the potential of this minimally invasive treatment strategy. Our findings suggest that gold-decorated porous silica nanocarriers can effectively act as a multifunctional platform by merging chemotherapy and photodynamic therapy to enhance cancer treatment outcomes.