Spermine Modified PNIPAAm Nano-Hydrogel Serving as Thermo-Responsive System for Delivery of Cisplatin

Poly( N -isopropylacrylamide) (PNIPAAm) hydrogel as a temperature-responsive polymer was prepared through controlled process using reversible addition fragmentation chain transfer (RAFT) polymerization. The hydrogel was then amino modified using a biocompatible polyamine i.e. spermine and next the antitumor cisplatin drug was conjugated to the modified hydrogel via pH-sensitive spermine linkage. This system had a pH dependency and temperature sensitivity at lower critical solution temperature (LCST). Cisplatin potentially is liberated from the carrier in the acidic environment. However, the release of cisplatin from this polymeric system is increased considerably around the transition temperature of the polymer. The drug release manner of the prepared hydrogel was determined at two pH values (5.5 and 7.4) and three temperatures (37, 40 and 42 °C) at different time intervals. The in vitro toxicity assessment was conducted on MCF-7 cell line which showed the system efficiency in killing breast cancer cells.