Synthesis and Physicochemical Characterization of pH- and Thermosensitive Nanopolymers Based on N-isopropylacrylamide Containing Doxorubicin Anti-Cancer Agent

ABSTRACT

The aim of this research was to synthesize polymer-based smart nanocarriers for delivery of doxorubicin as an anti-cancer drug. For this purpose, smart polymers were prepared using N-isopropylacrylamide (NIPAAm), vinyl pyrrolidone (VP), and methacrylic acid (MAA) as monomers, which were cross-linked with N,N′-methylene bis-acrylamide (MBA) using a free radical polymerization method. Poly(N-isopropylacrylamide-co-vinylpyrrolidone-co-methacrylic acid) [P(NIPAAm-VP-MAA)] was prepared in different molar ratios and further characterized by its physicochemical properties using a particle size analyzer, Fourier transform infrared (FTIR), ¹H-NMR, and differential scanning calorimetry (DSC). Particle size analysis showed an average size of 277 nm for 50% drug entrapment. Drug release from the nanoparticles was sustained for 21 days at 37°C. The same procedure was carried out to synthesize these smart polymers without a cross-linker. Particle size analysis showed an average size of 116 nm for ∼36% drug entrapment. Drug release from the nanoparticles without a cross-linker was sustained for 18 days at 37°C. It is proposed that the P(NIPAAm-VP-MAA) nanoparticles may be considered as a pH/thermosensitive delivery nanosystem for anti-cancer drugs.

KEYWORDS:

• nanoparticle
• smart polymers
• doxorubicin
• drug delivery