Recent advances in gold and silver nanoparticle based therapies for lung and breast cancers.

In recent years, gold (Au) and silver (Ag) nanoparticles (NPs) have been the centerstage of improving cancer treatments and therapies, substantially attributed to their size and shape tuneable chemical, optical and photonic properties. Owing to such specialties, diverse shapes of Au and Ag NPs have enabled an efficient cellular uptake along with remarkable improvements in early stage diagnosis of tumors. Robust synthesis methods employing several reducing agents have been the backbone of such enormous strides of Au and Ag NPs, allowing the delivery of much lower drug volumes to minimize the patient sensitization. Probes based on Au and Ag NPs functionalization with biocompatible chemical molecules have substantially improved their in vivo tracking and mediating a site-specific binding leading to improved cancer treatment with minimal risks to normal cells. With a better drug delivery potential of non-spherical shapes, the cylindrical (rod shaped) geometries have recently been investigated to possess higher cellular uptake. The rod shaped surface morphology enables a larger area for drug binding with enhanced possibility to make use of photothermal attributes. The interplay of size and shape dependent biologic activities is regulated by physicochemical changes in the tumor microenvironment, where stable drug-carrier binding is facilitated by surface modification of NPs, through moderate interactive forces ensuring minimal changes in native drug structure. The energy savvy greener methods, like microwave and microemulsions have enabled much better control on the synthesized nanoparticle shapes and geometries, through a regulation of precursor to reducing agent stoichiometries. With this viewpoint, this article focuses on most common synthesis methods of Au and Ag NPs alongside their application in more effective treatment of lung and breast cancers.