Mesoporous silica coated gold nanorods: a multifunctional theranostic platform for radiotherapy and X-ray imaging

The development of theranostic nanostructures is one of the most advanced branches of pharmaceutical and medical sciences in the world today. Due to the unique properties such as surface plasmon resonance, Raman signal amplification, high atomic number, gold nanostructures are of particular interest to researchers. It has been shown that the formation of mesoporous silica coating with suitable thickness and microstructural properties can increase thermal stability and increase the possibility of loading anticancer drugs in theranostic formulations. In this study, gold nanorods were synthesized by seed-mediated growth method, and then by the sol-gel technique, nanorods were used as a template to create mesoporous silica coating. In the last step, PEG silane was used to create a polyethylene glycol coating at the surface of nanostructures. Based on HRTEM micrographs, the fabricated nanostructures had an average size of approximately 80 nm, and the nanoparticles entirely separated from each other. These nanostructures were non-toxic and could be well used as X-ray contrast agents. Only at high concentrations, these nanostructures were able to have a significant effect on radiotherapy with cobalt 60 source.