Biodegradable Nanoparticles of mPEG-PLGA-PLL Triblock Copolymers as Novel Non-Viral Vectors for Improving siRNA Delivery and Gene Silencing

Abstract

Degradation of mRNA by RNA interference is one of the most powerful and specific mechanisms for gene silencing. However, insufficient cellular uptake and poor stability have limited its usefulness. Here, we report efficient delivery of siRNA via the use of biodegradable nanoparticles (NPs) made from monomethoxypoly(ethylene glycol)-poly(lactic-co-glycolic acid)-poly-l-lysine (mPEG-PLGA-PLL) triblock copolymers. Various physicochemical properties of mPEG-PLGA-PLL NPs, including morphology, size, surface charge, siRNA encapsulation efficiency, and in vitro release profile of siRNA from NPs, were characterized by scanning electron microscope, particle size and zeta potential analyzer, and high performance liquid chromatography. The levels of siRNA uptake and targeted gene inhibition were detected in human lung cancer SPC-A1-GFP cells stably expressing green fluorescent protein. Examination of the cultured SPC-A1-GFP cells with fluorescent microscope and flow cytometry showed NPs loading Cy3-labeled siRNA had much higher intracellular siRNA delivery efficiencies than siRNA alone and Lipofectamine-siRNA complexes. The gene silencing efficiency of mPEG-PLGA-PLL NPs was higher than that of commercially available transfecting agent Lipofectamine while showing no cytotoxicity. Thus, the current study demonstrates that biodegradable NPs of mPEG-PLGA-PLL triblock copolymers can be potentially applied as novel non-viral vectors for improving siRNA delivery and gene silencing.

EGF-modified mPEG-PLGA-PLL nanoparticle for delivering doxorubicin combined with Bcl-2 siRNA as a potential treatment strategy for lung cancer

“…Furthermore, we found when Bcl-2 siRNA was delivered by EGF-PEAL NPs, it exerted gene knockdown activities much more efficiently than free siRNA or PEAL NPs. This phenomenon occurs because free siRNA is unstable and carries negative charges, and thus has difficulty binding to negatively charged cellular membrane (Du et al, 2012). Therefore, apoptosis assay and xenograft tumor therapeutics results demonstrated that co-delivery of Bcl-2 siRNA and Dox via EGF-PEAL NPs hold the most potent antitumor effects.…”

Carbohydrate-Based Materials for Targeted Delivery of Drugs and Genes to the Liver

“…Monomethoxy (polyethylene glycol)-poly ( D,Llactide-co-glycolide)-poly( L -lysine) nanoparticles (mPEG-PLGA-PLL, PEAL) and galactose-modified PEAL were prepared by ROP of D -lactide and glycolide using mPEG as initiator, as shown in Figure 9 [29]. Synthesis of mPEG-PLGA-pLL was further carried out by ROP of Nɛ-CBZ-L -lysine-N-carboxyanhydrides, using amine terminated mPEG-PLGA macroinitiator.…”

Drug-loaded nano-microcapsules delivery system mediated by ultrasound-targeted microbubble destruction: A promising therapy method

“…Although the mechanism underlying its action has not been fully elucidated, UTMD has played a significant role in mediating drug and̸or gene delivery to several targets, such as eyes, tumors, skeletal muscle, heart and bone marrow stem cells (3,4,34,40,(41)(42)(43)(44)(45)(46).…”

“…By using a novel hyaluronic acid-Chitosan nanoparticle mediated by UTMD successful transfection of plasmid DNA in retinal pigment epithelium (RPE) cells in vitro and in vivo was achieved. Du et al (43) reported that UTMD is able to safely and effectively enhance siRNA-loaded nano-microcapsule delivery to RPE cells. Moreover, the most notable benefit of UTMD-mediated Cy3-siRNA loaded by nano-microcapsules was using the least amount of nano-microcapsules while maintaining a higher rate of uptake, which was achieved in rats in vivo and in vitro.…”