Advanced Breast Cancer Therapy: Thermosensitive Hybrid Hydrogel (PLGA-PEG-PLGA) with Metallic Nanoparticles Enhancing Withaferin-A Release

<b>Background:</b> Drug-delivering copolymers respond to temperature through sol-to-gel transitions. Lower transitions involve micellar growth, while upper transitions bring about micellar structure breakage. The fine-tuned PLGA-PEG-PLGA hydrogel, embedding silver or zinc nanoparticles, achieved a prolonged release of Withaferin-A.<br/>Aim: This study sought to develop a hybrid hydrogel with in situ gel-forming for sustained release, utilizing the PLGA-PEG-PLGA copolymer and incorporating silver and zinc nanoparticles entrapped with Withaferin-A to address breast cancer.<br/><b>Materials and Methods:</b> PLGA (75:25) to PEG copolymer (3:1 ratio) formulated as <i>in situ</i> gel-forming hybrid hydrogel. Characterization involved 1H NMR, dynamic light scattering, and rheology. Silver and zinc nanoparticles were green synthesized using Camillia sinensis extract, and the characteristics of the prepared nanoparticles were analyzed through FTIR, Zeta potential, XRD, TEM, and FE-SEM. Subsequent to the drug entrapment into a hybrid hydrogel, <i>in vitro</i> drug release studies were conducted using a trans-diffusion cell apparatus. In vitro cell line studies using MCF-7 and MDA-MB-231 were conducted.<br/><b>Results: </b>Silver and zinc nanoparticles exhibited a particle size of 255 nm and 128.5 nm, respectively, with zeta potentials of -17.5 mV and -12.9 mV. XRD analysis confirmed 2-theta (deg) values of 56.20 and 56.64 for silver and zinc nanoparticles, respectively. FE-SEM and TEM reports displayed spherical-shaped silver nanoparticles and cylindrical-shaped zinc nanoparticles. Hydrogels demonstrated controlled release of Withaferin-A over 39 to 43 days based on polymer concentration. Effective internalization and antiproliferative impact in MCF-7 and MDA-MB-231 breast malignancy cell lines with negligible hemolytic effects. Zinc Nps induce selective cytotoxicity and apoptosis. Silver NPs exhibited dose-dependent cytotoxicity, inducing cell death and cell cycle hindrance in breast carcinoma cells.<br/><b>Conclusion: </b>The temperature-responsive PLGA-PEG-PLGA copolymer-based hybrid hydrogel, developed by incorporating silver and zinc nanoparticles, facilitated the sustained and controlled release of Withaferin-A. The formulation exhibits potential for efficient drug delivery in breast cancer therapy, with promising physicochemical properties and drug release kinetics.