Polymer-Based Nanomaterials for Controlled Drug Delivery: Synthesis, Characterization, and Release Studies

Abstract

Polymer-based nanomaterials have become one of the most extensively investigated platforms for controlled drug delivery because of their excellent biocompatibility, biodegradability, tunable physicochemical properties, and capacity to regulate drug release with high precision. Unlike conventional drug administration, which often produces fluctuating plasma drug concentrations and systemic toxicity, polymeric nanocarriers can improve therapeutic efficacy through sustained, targeted, and stimuli-responsive drug release. Recent advances in polymer chemistry, controlled polymerization techniques, and nanofabrication technologies have enabled the development of diverse nanostructures, including polymeric nanoparticles, micelles, dendrimers, polymersomes, and nanogels for the delivery of small molecules, proteins, nucleic acids, and gene-editing therapeutics. This review critically examines the current state of polymer-based nanomaterials with particular emphasis on synthesis strategies, physicochemical characterization, drug-loading mechanisms, and controlled release behavior. Conventional fabrication techniques such as nanoprecipitation, emulsification-solvent evaporation, ionic gelation, and microfluidic synthesis are discussed alongside advanced controlled polymerization methods, including reversible addition-fragmentation chain transfer polymerization, atom transfer radical polymerization, and ring-opening polymerization. The review further summarizes modern characterization techniques, including dynamic light scattering, transmission electron microscopy, scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis, highlighting their importance in nanoparticle quality assessment. Drug release mechanisms and mathematical kinetic models are comprehensively discussed together with recent biomedical applications in cancer therapy, antimicrobial treatment, vaccine delivery, and gene therapy. Finally, the article examines current challenges related to large-scale manufacturing, regulatory approval, toxicity evaluation, and clinical translation. Collectively, polymer-based nanomaterials represent a versatile and rapidly evolving platform for next-generation precision medicine, although improvements in reproducibility, safety evaluation, and scalable manufacturing remain essential for broader clinical implementation.