Comparative toxicity of PEG and folate-derived blue-emitting silicon nanoparticles: in vitro and in vivo studies

Amino functionalization is a first step modification aiming to achieve biomedical applications of silicon nanoparticles, for example, for photodynamic therapy or radiotherapy. Nevertheless, toxicity and low quantum yields due to the positive charge of amino groups emerge as a problem that could be solved with subsequent derivatizations.

Folic and PEG-conjugated nanoparticles were obtained from amino-functionalized silicon nanoparticle (NH₂SiNP). Cytotoxicity was determined on a tumor cell line at low and high concentrations. Four end points of in vivo toxicity were evaluated on zebrafish (Danio rerio).

Folic acid functionalization reduced the cytotoxicity in comparison to amino and PEG-functionalized nanoparticles. In zebrafish, folic functionalization lowered toxicity in general while PEG increased it.

Functionalization of NH₂SiNP with folic acid reduced the toxic effects in vitro and in vivo. This could be useful for therapeutic applications. PEG functionalization did not lower the toxicity.