Self-Assembly and Cellular Uptake of Degradable and Water-Soluble Polyperoxides

Water-soluble polyperoxides (PPs) as a new type of degradable and polymeric material were synthesized by the radical alternating copolymerization of sorbic derivatives containing a tetra(ethylene oxide) unit in the ester group using molecular oxygen. The obtained PPs showed a lower critical solution temperature (LCST)-type phase separation, and the transition temperature decreased according to the content of the hydrophobic ester group in the PPs. The PPs formed nanoaggregates with a diameter of 250-370 nm in water under the LCST. These PP aggregates were revealed to include 1-anilinonaphthalene-8-sulfonic acid as the fluorescence probe and epirubicin as the anticancer drug in their hydrophobic compartment. We evaluated the cytotoxicity and cellular uptake of the PPs in order to test their ability as a carrier used for the delivery of anticancer drugs. The cell viability in the presence of the PPs was comparable to those for the other biodegradable polymers, and epirubicin was taken up into the A549 efficiently with the PPs via an endocytosis mechanism.