Targeting Macrophages Through Gold Nanoparticle-Induced Immunomodulation: A Therapeutic Approach in Inflammation and Cancer

With recent advancement in the nanosciences, diagnosis and therapeutic approach to cancer, one of the leading causes of death, has been revolutionized, due to their quantum effects and opto-electronic properties. Bionanotechnological approaches have been used in cancer therapy largely to alleviate the adverse side effects of chemotherapeutic drugs and poor clinical prognosis of the disease. In the past decade, gold nanoparticles, as an archetype material, have stirred the interest of researchers for their biomedical applications. Gold nanoparticles, due to their tunable shape and size, interact with targeted molecules present on the surface or inside a cell with high specificity. This characteristic is used to enhance the sensitivity of bioimaging, photothermal ablation of tumors, gene and drug delivery and gene silencing. Functionalization of gold nanoparticles has been shown to affect cellular uptake, cytotoxicity, and cell death. Though their safety in the biological system is recognized, their interactions with immune cells are still being explored. Herein, we first present background information on the shapes and sizes of gold nanoparticles and their modes of internalization. Then, we elucidate their immunological effect on cells like the macrophages that play a central role in inflammation in the context of cancer. Finally, we discuss the significance of tailored gold nanoparticles in targeting and re-educating M1 macrophages to assuage inflammation and cancer progression.