Evaluation of theranostic perspective of gold-silica nanoshell for cancer nano-medicine: a numerical parametric study.

Using gold-silica nanoshell as a reference nano-agent, this work has performed preliminary numerical parametric study to investigate the feasibility and if feasible the efficiency of using a single nano-agent to achieve theranostic goals. In total, seven generics of gold-silica nanoshells have been tested including the R[50,10] (radius of the silica core is 50 nm and thickness of the gold shell is 10 nm), R[40,15], R[55,25], R[40,40], R[75,40], R[104,23], and R[154,24] nanoshells. A planar tissue model has been constructed as the platform for parametric study. For mathematical modeling, radiant transport equation (RTE) has been applied to describe the interactions among laser lights, the hosting tissue, and the hosted nanoshells and Penne's bio-heat equation has been applied to describe the hyperthermia induced by such interactions. Effects of different nanoshell generics on the diffuse reflectance signal and hyperthermia temperature transition have been simulated, basing on which the potential of a certain nanoshell generic as theranostic nano-agent has been evaluated. It has been found that it is highly feasible for gold-silica nanoshells to be engineered for theranostic purpose and nanoshell generics that are preferentially scattering should be explored for good theranostic candidates. On the condition that nanoshell generic with the right optical properties has been located, a moderate nanoshell retention in the target tissue site is already sufficient to induce effective theranostic effects, which indicates that theranostic nano-medicine might not have a stringent requirement for the delivery technique. Among nanoshells that have been tested, the R[55,25] nanoshell seems to be a promising candidate as theranostic nano-agent. Further testing on it is highly recommended. Nanoshells that are preferentially absorbing such as the R[50,10] and R[40,15] nanoshells are efficient photothermal agent and could be used for therapeutic purpose only. However, it is not recommended that preferentially absorbing nanoshells being used for theranostic purpose due to possible negative effects such nanoshells might bring to the diffuse reflectance signal. [ABSTRACT FROM AUTHOR]