Gold nanoparticles: Promising agent to improve the diagnosis and therapy of cancer

Background: Gold nanoparticles have been exploited for nanobiotechnology applications for the last two decades. New insights of the nanomaterials as promising agent for cancer diagnosis and therapy have just started to emerge. Due to the size-and shape-dependent optical, electrical and thermal properties, gold nanoparticles are being developed as diagnostic reagents, drug carriers, contrast agents, photothermal agents and radiosensitisers. This review aims to summarize the latest advances of gold nanoparticles in cancer treatment. Methods: We undertook a systematical search for research literatures using a well-framed review question and presented the applications in different fields, including early cancer diagnosis, imaging, radiotherapy, chemotherapy, gene therapy and photothermal therapy, which were fully described, filtered, combined and analyzed in order to provide documented proofs on the applications of gold nanoparticles in current cancer treatments. Results: One hundred and sixty papers were included in the review, the majority of which represent latest researches in the field of gold nanoparticle-based diagnosis and therapy for cancer. Conventional treatment strategies for cancer cannot identify normal and cancer cells. While due to the high surface area to volume ratio and rich surface func-tionalization chemistry, gold nanoparticle can greatly enhance the targeting with adverse side effects of traditional treatment on normal tissues being avoided. Conclusion: Gold nanoparticles have greatly improved the traditional treatment due to their unique properties. However, their size-dependent toxicity, distribution and clearance need further studies to make them a clinical reality.