Development and characterization dual responsive magnetic nanocomposites for targeted drug delivery systems

Abstract

A drug delivery system based on dual responsive units was developed. An appealing pH- and thermo-responsive triblock terpolymer as the drug carrier was synthesized by RAFT polymerization of N-isopropyl acrylamide and methacrylic acid monomers using PEG-RAFT agent. The Fe₃O₄ magnetic nanoparticles were synthesized by co-precipitation of Fe salts. Synthesized samples were characterized by FT-IR, XRD, GPC, SEM and TEM. The dual responsive behaviour and self-assembly of the triblock terpolymers in aqueous solution were investigated using UV–vis transmittance and DLS. Based on the results of DLS and TEM, the average size of micelles was 170, 125 and 30 nm. The triblock terpolymer was used as a chemotherapy drug carrier and doxorubicin as a model drug. The release rate of the drug at two different temperatures (37 °C and 42 °C) and pHs (5.8 and 7.4) was studied. The in vitro cytotoxicity assay of free doxorubicin and drug-loaded magnetic nanoparticles was studied. The MTT assay exhibited that these polymers are biocompatible and no toxicity. As well, IC₅₀ of the DOX-loaded triblock terpolymer in MTT test demonstrated that these systems could be suitable for the treatment of cancer.

Keywords:

• Smart drug delivery system
• RAFT polymerization
• stimuli-sensitive triblock terpolymer
• magnetic iron oxide nanoparticles
• drug-loading efficiency

Acknowledgements

The authors are grateful for support from the Tabriz Payame Noor University and National Institute for Medical Research Development (NIMAD), Grant no. 958659.

Disclosure statement

No potential conflict of interest was reported by the authors.