Synthesis and characterization of ultrasmall nanoparticles for biomedical applications

The synthesis of multimodal imaging agents is indeed a growing field and a lot of research is currently being done in this area because of its wide biomedical applications. The idea behind this research is to prepare a single molecule/nanoparticle which is suitable for two or more imaging techniques and thus can act as a multimodal imaging agent, for example, the combination of optical and nuclear imaging modalities may provide complementary information for improving diagnosis as well as the treatment of diseases. These imaging agents combat the limitations of sensitivity, spatial and temporal resolution and also tissue penetrability. The high hydrophilicity of the nanoparticles and fast renal clearance of the complex from the body are the major highlights.
Amine terminated ultrasmall Silicon nanoparticles of size <4 nm were synthesized by hydrothermal method and purified by dialysis. Sulfo-Cy5 and NOTA-Bn-SCN was attached selectively to the amine terminated Si USNPs. Next step would be the radiolabeling of the particles by 64Cu and could be used for the in vitro and in vivo studies. Bispidines can also be tried as a copper chelator in the complex. Further, we could also attach single domain antibodies via PEG linkers bearing maleimide group.
The substituents after coupling with the USNPs are assumed to act as excellent multimodal imaging agent which can be used for the cancer diagnosis and therapy.