Design of functionalizable polymer coated magnetic nanoparticles drug delivery applications

Abstract

Synthesis of monodisperse, water-dispersible and biocompatible iron oxide nanoparticles with functional groups has gained importance because of the potential applications in biomedicine such as drug delivery, MRI agent, etc. In this thesis, azide and thiol end group reactive polymers containing iron oxide nanoparticles were examined. Catechol group containing chain transfer agent was immobilized onto oleic acid coated iron oxide nanoparticle surface by means of a place exchange modification. Poly(ethylene glycol) methyl ether acrylate (PEGMEA) monomer based hydrophilic polymers were synthesized using reversible addition-fragmentation chain transfer polymerization (RAFT) with graft-from approach. Polymer coated nanoparticles were characterized by fourier transform infrared (FT-IR), thermal gravimetric analysis (TGA) and dynamic light scattering (DLS). Nanoparticles were functionalized with azido and protected maleimide groups by post-polymerization modification technique. Thiocarbonylthio end groups that originates from RAFT agent was converted into furan protected maleimide and azido groups using radical cross-coupling reaction. Removal of the furan groups after modification of end groups gives thiol reactive nanoparticles. Similarly, azido group functionalization produces alkyne reactive polymer coated nanoparticles. Thiol and acetylene containing hydrophobic dyes were conjugated with maleimide and azido end groups containing nanoparticles, respectively. Fluorescent nanoparticles easily dispersed in water after dye conjugation.