Figure 1.

Synthesis and physical characteristics of p66shc siRNA-encapsulated PLGA NPs.

Notes: (A) To prepare PLGA nanoparticles, 200 μL of 20 μM siRNA in TE7.5 buffer was added, on a drop-by-drop basis, to 800 μL of dichloromethane (DCM) containing 25 mg of PLGA (Corbion, Amsterdam, the Netherlands) and emulsified by sonication into a primary W1/O emulsion. Next, 2 mL of 2% PVA1500 (w/v) was added directly into the primary emulsion and further emulsified by sonication to form a W1/O/W2 double emulsion. The resulting product was then diluted with 6 mL of 2% PVA1500 and stirred magnetically for 3 h at room temperature to evaporate DCM. The resulting PLGA nanoparticles were collected by ultracentrifugation at 38,000 g for 10 min at 4°C, washed twice with deionized RNAase free-water, resuspended in water and finally freeze-dried. (B) Nanoparticles were assessed by the scanning electron microscope. Scale bar = 200 nm. (C, D) p66shc si_NPs were dissolved in water and measured for size and zeta potential using the Zetasizer Nano ZS90 (Size = 183.7 ± 72.21, Zeta potential = 41.1 ± 4.81). (E) siRNA release assay of nanoparticles in PBS showed the cumulative percentages of siRNA released from nanoparticles based on different matrices as a function of time.

Abbreviation: PLGA, poly(lactic-co-glycolic acid).