Stealth iron oxide nanoparticles for organotropic drug targeting.

The ability of peculiar iron oxide nanoparticles (IONPs) to evade the immune system was demonstrated in vivo. The nanomaterial was provided directly into the farming water of zebrafish (Danio rerio) and the distribution of IONPs and the delivery of oxytetracycline (OTC) was studied evidencing the successful overcoming of the intestinal barrier and the specific and prolonged (28 days) organotropic delivery of OTC to the fish ovary. Noteworthy, no sign of adverse effects was observed. In fish blood, IONPs were able to specifically bind apolipoprotein A1 (Apo A1) and molecular modelling showed the structural analogy between the IONP@Apo A1 nano-conjugate and high-density lipoprotein (HDL). Thus, the preservation of the biological identity of the protein explains the observed overcoming of the intestinal barrier, the great biocompatibity of the nanomaterial and the prolonged drug delivery (benefitting of the lipoprotein transport route). The present study promises novel and unexpected stealth materials in nanomedicine.