Molecular design and therapeutic applications of polymeric nanoparticles for drug delivery: A comprehensive review

Polymeric nanoparticles have emerged as versatile platforms for modern drug delivery, offering improved therapeutic outcomes through controlled release, enhanced absorption, and targeted action. Recent developments in fabrication techniques such as nanoprecipitation, emulsion polymerization, and free radical polymerization have enabled precise control over nanoparticle design, size, and functionality. Advances in stimuli-responsive systems, including pH-, temperature-, and light-sensitive polymers, as well as multifunctional nanocarriers, have further enhanced therapeutic accuracy. Applications extend to cancer therapy, where solubility and tumor targeting are improved; gene therapy, where nucleic acid delivery is optimized; and biologics delivery, where encapsulation enhances stability. Additionally, antimicrobial and antiviral uses highlight their potential against infections. Despite these achievements, challenges persist in regulating toxicity, clearance, biodistribution, and immunogenicity. This review underscores both the promise and the limitations of polymeric nanoparticles, emphasizing their transformative potential while identifying the barriers that must be addressed for successful clinical translation.