Development and optimization of pH-responsive quinine loaded PEGylated polymeric nanoparticles for breast cancer treatment

Abstract Breast cancer is widely recognized as the primary cause of cancer globally, necessitating innovative therapeutic strategies to improve patient outcomes. Nanotechnology has become a feasible method for treating cancer, offering targeted drug delivery and enhanced therapeutic effectiveness. In the present study, quinine-loaded pH-responsive PEGylated polymeric nanoparticles (Q-PEG-PNPs) have been synthesized using a high-pressure homogenization technique to target breast cancer. Q-PEG-PNPs were subjected to optimization, in-vitro drug release profile, antioxidant assay, anti-inflammatory assay, and brine shrimp lethality assay. The particle size and zeta potential of the optimized Q-PEG-PNPs were determined to be 112 ± 1.1 nm and −23.3 mV, respectively. The in-vitro drug release profile results demonstrated the efficacy of Q-PEG-PNPs in releasing quinine under acidic conditions. Specifically, the drug release rates were 84.35 ± 2.2 % and 32.89 ± 1.6 % at pH 5.5 and pH 7.4 after 48 h, respectively. Anti-angiogenesis effect of Q-PEG-PNPs showed thinning of the blood vessels. Brine shrimp lethality assay revealed the LC 50 concentration of Q-PEG-PNPs (60.86 μg/mL). Therefore, the pH-responsiveness and anti-angiogenic effect demonstrate the potential of Q-PEG-PNPs as a viable approach for breast cancer treatment.