STAT6 siRNA Matrix-Loaded Gelatin Nanocarriers: Formulation, Characterization, and Ex Vivo Proof of Concept Using Adenocarcinoma Cells

The clinical utility of siRNA therapy has been hampered due to poor cell penetration, nonspecific effects, rapid degradation, and short half-life. We herewith proposed the formulation development of STAT6 siRNA (S6S) nanotherapeutic agent by encapsulating them within gelatin nanocarriers (GNC). The prepared nanoformulation was characterized for size, charge, loading efficiency, release kinetics, stability, cytotoxicity, and gene silencing assay. The stability of S6S-GNC was also assessed under conditions of varying pH, serum level, and using electrophoretic assays. In vitro cytotoxicity performance was evaluated in human adenocarcinoma A549 cells following MTT assay. The developed formulation resulted in an average particle size, surface charge, and encapsulation efficiency as 70 ± 6.5 nm, +10 ± 1.5 mV, and 85 ± 4.0%, respectively. S6S-GNC showed an insignificant (P < 0.05) change in the size and charge in the presence of buffer solutions (pH 6.4 to 8.4) and FBS (10% v/v). A549 cells were treated with native S6S, S6S-lipofectamine, placebo-GNC, and S6S-GNC using untreated cells as a control. It was observed that cell viability was decreased significantly with S6S-GNC by 55 ± 4.1% (P < 0.001) compared to native S6S (2.0 ± 0.55%) and S6S-lipofectamine complex (40 ± 3.1%). This investigation infers that gelatin polymer-based nanocarriers are a robust, stable, and biocompatible strategy for the delivery of siRNA.