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Journal of Polymer & Composites Original Research Special issue

Synthesis and Characterization of pH-Sensitive Poly (N-isopropylacrylamide-co-acrylic Acid) Hydrogels for Controlled Release of Doxorubicin

  1. Akshay Kumar K.S. Department of Pharmaceutics, KLE College of Pharmacy, Rajajinagar, Bengaluru 560010, KLE Academy of Higher Education and Research, Deemed-to-be-University, Belagavi, Bengaluru
  2. Suhas Narayan Sakarkar Department of Pharmaceutics, Maharashtra Institute of Pharmacy Betala Bramhapuri, Chandrapur
  3. Vijeta Bhattacharya Department of Pharmaceutics, ITM University, Gwalior
  4. Maneshwar Thippani Department of Pharmaceutical Chemistry, School Pharmacy, Anurag University, Venkatapur, Hyderabad
  5. L. Karpagavalli Department of Pharmaceutics, Meenakshi College of Pharmacy, MAHER University, Kanchipuram
  6. Deepha V. Department of Chemistry, Bannari Amman Institute of Technology, Sathyamangalam
  7. Shiny George Department of Pharmaceutical Chemistry, Hindustan College of Pharmacy, Kottayam
  8. Nitin S. Bhajipale Department of Pharmaceutical Chemistry, SGSPS, Institute of Pharmacy, Akola, Affiliated to SGBAU, Amravati
  9. Manish R. Bhise Department of Pharmaceutics, SGSPS, Institute of Pharmacy, Akola, Affiliated to SGBAU, Amravati

Abstract

pH-responsive polymeric hydrogels have attracted significant attention as intelligent biomaterials for site-specific and controlled drug delivery in cancer therapy due to their ability to respond to the acidic tumor microenvironment. In the present study, poly (N-isopropylacrylamide-co-acrylic acid) [P(NIPAM-co-AAc)] hydrogels were synthesized via free radical copolymerization and systematically characterized to evaluate their suitability for controlled delivery of doxorubicin, a widely used chemotherapeutic agent. The copolymer hydrogels were prepared using N-isopropylacrylamide and acrylic acid as monomers, N,N′-methylenebisacrylamide as a crosslinking agent, and ammonium persulfate as a thermal initiator. The formation and structural integrity of the hydrogels were confirmed by Fourier transform infrared spectroscopy, while thermal behavior was assessed using differential scanning calorimetry. Surface morphology and internal network structure were examined by scanning electron microscopy, revealing a porous architecture favorable for drug loading and diffusion. Swelling studies demonstrated pronounced pH-dependent behavior, with significantly higher swelling ratios under mildly acidic conditions compared to physiological pH, confirming the successful incorporation of pH-responsive functional groups. Doxorubicin loading efficiency was determined using equilibrium swelling methods, and in vitro release studies were conducted at pH 7.4 and 5.5 to simulate normal physiological and tumor microenvironments, respectively. The release profiles indicated sustained and controlled drug release over an extended period, with accelerated release under acidic conditions due to enhanced network expansion. The release kinetics suggested diffusion-controlled and swelling-assisted mechanisms. Overall, the findings demonstrate that P(NIPAM-co-AAc) hydrogels exhibit desirable physicochemical properties, efficient drug encapsulation, and pH-triggered release behavior, highlighting their potential as promising carriers for targeted and controlled anticancer drug delivery applications.

Keywords

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