Amphiphilic PEGylated Lanthanide-doped Upconversion Nanoparticles for Significantly Passive Accumulation in the Peritoneal Metastatic Carcinomatosis Models Following Intraperitoneal Administration

Inorganic nanoparticles have emerged as attractive materials for cancer research, because of their exceptional physical properties and multifunctional engineering. Whereas, inorganic nanoparticle accumulation in the tumours located in the abdominal cavity after intravenous (IV) administration is confined, due to the peritoneum-plasma barrier. To improve this situation, lanthanide-doped upconversion nanoparticles (UCNPs), coated by amphiphilic polyethylene glycol (P-PEG), were developed, serving as a representative of inorganic nanoparticles. Following intraperitoneal (IP) administration into the peritoneal metastatic carcinomatosis models, UCNPs coated by P-PEG (P-PEG-UCNPs) passively accumulated in the cancerous tissues at a larger amount than that in the main normal organs. Based on spatial proximity, P-PEG-UCNPs administrated via the IP route exhibited higher passive accumulation in the tumours in the abdominal cavity, compared to that via the IV route. It is suggested that IP administration could be a...