Formulation and Characterization of Novel Temperature Sensitive Polymer-Coated Magnetic Nanoparticles

The objective of this research was to develop novel polymer coated magnetic nanoparticles for controlled drug delivery applications. To form these novel nanoparticles, silane-coated magnetic nanoparticles (MNPs) were used as a template for a free radial polymerization of three monomers, N-isopropylacrylamide, acrylamide, and allylamine (NIPA-AAm-AH), on the surface of MNPs. Transmission electron microscope results indicated that the size of the NIPA-AAm-AH coated MNPs was approximately 100 nm. To investigate the chemical composition and chemical state of our nanoparticles, FTIR and XPS were used. Results from chemical analysis illustrated the presence of the constituent functional groups of the NIPA-AAm-AH coated MNPs. In addition, the magnetic properties of different layers on the MNPs, analyzed by SQUID, indicated a decrease in saturation magnetization after each layer of coating. The nanoparticles were successfully conjugated to fluorescent PEG to prolong their circulating half life. Furthermore, bovine serum albumin (BSA) was used in order to investigate the protein release profile of the nanoparticles as a function of the temperature. The protein release profile indicated that the NIPA-AAm-AH coated MNPs have a significantly higher percent release at 41 °C compared to those of 4 °C and 37 °C, which demonstrates their temperature sensitivity. In the future, the release profile of therapeutic drugs from nanoparticles at various temperatures and pHs as well as targeted capability of the synthesized nanoparticles for possible applications in controlled and targeted delivery will be investigated.