Progress in studies on embryo toxicity of nano drug delivery system

Abstract

Nano drug delivery system (NDDS) is a kind of drug delivery system which are made up of drugs and drug carriers and their particle sizes are less than 1 000 nm. In general, polymeric micelles, liposome, nano capsule, microemulsion, and organic or inorganic nanoparticles are used as carriers in NDDS, pharmacodynamic substance and carriers are combined into new type of controlled/slow release preparations or the drugs are directly processed into nanoparticles. Embryo toxicity is an important index for non-clinic safety evaluation of NDDS. The in vitro studies showed that embryo toxicity of NDDS is related to physical and chemical properties of nanoparticles, such as size and modification materials on surface, exposure time of nanoparticles, and dosage. It has been shown that zinc oxide nanoparticles have embryo toxicity, titanium dioxide, silica, magnesium oxide, and quantum dots have different degrees of embryo toxicity, and polystyrene based nanoparticles have no embryo toxicity. The in vivo studies showed that zinc oxide nanoparticles, quantum dots containing cadmium or selenium, and high concentrations of nano silver have embryo toxicity in one or several animal models, such as rat, mouse, zebrafish, Paracentrotus lividus, Xenopus laevis, and Mytilus Galloprovincialis. Silica, titanium dioxide, chitosan nanoparticles and single-walled carbon nanotubes at different dose and size showed different effects on embryonic development of different animal models. Embryotoxic or teratogenic effects of NDDSinclude stagnation, miscarriage, and deformity, and the mechanism of toxicity is mainly related to oxidative stress and inflammation. Though embryo toxicity of NDDSin models, methods and content need further exploration and research, studies which have been carried out provide important references for further research. Key words: Nanotechnology; Embryo research; Toxicity tests