Microfluidic techniques in the development of PLGA nanoparticles: a tri-combination therapy for paraquat-induced cytotoxicity

This study investigated the preparation of PLGA nanoparticles loaded with Quercetin (Que), 4-octyl Itaconate (4-OI), and Pirfenidone (PFD) utilizing a microfluidic method. The therapeutic efficacy of a combination of these nanoparticles was evaluated to assess their potential in overcoming Paraquat (PQ)-mediated cytotoxicity in human embryonic lung fibroblasts (MRC-5) cells. The characterization of synthesized nanoparticles was conducted, foucusing on parameters such as size, zeta potential, transmission electron microscopy (TEM), encapsulation efficiency, and in vitro profiles of drug release. The cytotoxicity and protective activity of the combination therapy were evaluated through MTT tests. The characterization results revealed high Entrapment efficacy (≈ 65%), proper particle sizes (166-173 nm), narrow polydispersity index (PDI) (0.236 ± 0.06 to 0.289 ± 0.07), and significant stability over 30 days. The optimum concentrations of PQ (IC50 = 103 ± 4.54 μM) and combination therapy (Que 25 μM, 4-OI 25 μM, and PFD 400 μM) and PLGA combination therapy (PLGA-Que 2.5 μM, PLGA 4-OI 5 μM, and PLGA-PFD 50 μM) were evaluated. Oxidative damage was assessed, by measuring reactive oxygen species (ROS), lipid peroxidation (LPO), Protein carbonyl (PC), and glutathione content (GSH). Results revealed that combination therapy significantly increased cell viability compared with the single administration of PQ alone. PLGA combination therapy was more effective at low doses compared with the same free drugs in terms of cell viability. Oxidative biomarkers significantly decreased, while GSH levels significantly increased in PLGA combination therapy compared to the traditional triple combination therapy. These observations confirm that the synergistic activity of Que, 4-OI, and PFD delivered through PLGA nanoparticles exhibits substantial therapeutic potential for controlling paraquat poisoning and its pulmonary complications.