Redefining cancer photodynamic therapy with gold nanoparticles

Despite advancements made in treatment options, cancer continues to be one of the leading causes of death worldwide. Photodynamic therapy (PDT) has gained attention as a minimally invasive and highly selective treatment option for cancer. However, challenges due to the hydrophobicity of photosensitizers and their poor tumor selectivity have limited their use in cancer therapy. Recent developments in nanotechnology, particularly the use of gold nanoparticles (AuNPs), help overcome these challenges. AuNPs provide a stable and biocompatible platform to deliver photosensitizers, improving their solubility, stability, and ability to target tumors while reducing side effects. Functionalized AuNPs take advantage of mechanisms like the enhanced permeability and retention (EPR) effect and active targeting, improving reactive oxygen species (ROS) production and overall therapeutic efficacy. This review explores innovations in AuNP-based PDT systems, including ligand-functionalized nanoparticles, bioresponsive coatings, and theranostic approaches that combine imaging with therapy. By delving into important aspects of synthesis, characterization, and functionalization, we show how AuNPs improve the delivery and performance of photosensitizers. For instance, systems functionalized with prostate-specific membrane antigen (PSMA) have shown increased therapeutic precision and efficacy in vivo. These advancements are paving the way for more targeted and safer cancer treatments, establishing AuNP-based PDT as a promising approach for developing highly effective oncological therapies with greater precision and fewer side effects.