Formulation and Characterization of Polymeric Nanoparticles for Targeted Cancer Therapy

The present study focuses on the formulation and comprehensive evaluation of polymeric nanoparticles (PNPs) encapsulating doxorubicin, aiming to enhance targeted delivery and therapeutic efficacy in breast cancer treatment. The biodegradable polymer poly(lactic-co-glycolic acid) (PLGA) was employed due to its well-documented biocompatibility and regulatory approval status for drug delivery applications. Nanoparticles were successfully synthesized using the nanoprecipitation technique, a widely used method offering advantages in terms of reproducibility and control over particle characteristics. The optimized formulation exhibited a mean particle size of 158.6 ± 3.4 nm, which falls within the ideal size range for enhanced permeability and retention (EPR) effect in tumor tissues. The negative zeta potential (-21.3 ± 1.8 mV) confirmed colloidal stability, while the encapsulation efficiency of 78.4 ± 2.1% ensured sufficient drug loading. In vitro drug release studies revealed a sustained release profile over 72 hours, critical for minimizing systemic toxicity and enhancing drug accumulation in cancer cells. The release data best fitted first-order kinetics (R² = 0.9812), indicating that the release rate is concentration-dependent, a desirable feature for maintaining therapeutic levels of drug at the target site over time. To assess cytotoxic efficacy, MTT assay was conducted on MCF-7 breast cancer cell lines. The PLGA-loaded nanoparticles demonstrated a significantly lower IC₅₀ value (2.9 µg/mL) compared to free doxorubicin (7.4 µg/mL), with p < 0.01, signifying enhanced potency and cellular uptake, potentially due to nanoparticle-mediated endocytosis and sustained intracellular drug retention. In conclusion, the findings underscore the potential of PLGA-based PNPs as an effective and reliable platform for controlled and targeted anticancer drug delivery. The superior cytotoxic profile, sustained release following first-order kinetics, and favorable physicochemical properties collectively position this system as a promising candidate for next-generation chemotherapeutic strategies.