Efficient in vitro gene therapy with PEG siRNA lipid nanocapsules for passive targeting strategy in melanoma

Abstract

Small interfering RNA (siRNA)-mediated gene therapy is a promising strategy to temporarily inhibit the expression of proteins implicated in carcinogenesis or chemotherapy resistance. Although intra-tumoral administration can be envisaged, studies currently focus on formulating nanomedicines for intravenous injection to target tumor sites as well as metastases. The development of synthetic nanoparticles and liposomes has advanced greatly during the last decade. The objective of this work consists in formulating and optimizing the encapsulation of siRNA into lipid nanocapsules (LNCs) for efficient gene therapy to target melanoma cells. SiRNA LNCs were prepared from DOTAP/DOPE lipoplexes, and the siRNA amount and lipid/siRNA charge ratio were assayed to improve the stability and the encapsulation yield. Cryo-TEM imaging of the siRNA lipoplexes and LNC morphology revealed specific organization of the siRNA DOTAP/DOPE lipoplexes as well as specific lipid microstructures that can be eliminated by purification. No cytotoxicity of the siRNA LNCs against the melanoma SK-Mel28 cell line was observed at concentrations of up to 500 ng/mL siRNA. In vitro siRNA transfection experiments, compared to Oligofectamine™, demonstrated interesting targeted gene silencing effects. Finally, complement activation assays confirmed the feasibility of the PEGylation of siRNA LNCs as part of a passive targeting strategy for future in vivo melanoma- and metastasis-targeting experiments.

Antiviral Activity of Specific siRNA against Hemagglutinin and Neuraminidase of Influenza Virus H1N1 in MDCK Cell Culture

“…The formulations mediated highly effective in vitro delivery of antiviral siRNA into mammalian lung epithelial cells, leading to significant inhibition of viral replication when the transected cells were subsequently challenged with the H1N1 influenza virus. SD siRNA powders containing pH-responsive peptides are a promising inhalable formulation to deliver antiviral siRNA against influenza and are readily adapted for the treatment of other respiratory diseases [25,26]. Our crucial result is that the siRNA designed here is specified for the target region (HA, NA of Influenza A) with high efficiency.…”

Model Affitin and PEG modifications onto siRNA lipid nanocapsules: cell uptake and in vivo biodistribution improvements

“…[6][7][8] Among them, lipid nanocapsules (LNCs), based on emulsion phase inversion process, were adapted for siRNA encapsulation thanks to the use of DOTAP/DOPE lipids. 9,10 This LNC formulation is solventfree, low-energy consuming, easily realizable and reproducible inducing stable siRNA complexation and monodispersed formulation. Moreover, LNCs showed an efficient transfection efficacy of siRNA on U87MG glioma and SK-Mel28 melanoma cells with a signicant inhibition of two different targeted proteins.…”

“…Moreover, LNCs showed an efficient transfection efficacy of siRNA on U87MG glioma and SK-Mel28 melanoma cells with a signicant inhibition of two different targeted proteins. 9,11 With this proof of in vitro transfection, the challenge will be to preferentially accumulate the LNCs into the targeted tumor site, for an efficient in vivo siRNA delivery and a potential therapeutic application.…”

Passive and specific targeting of lymph nodes: the influence of the administration route

“…This nanocarrier was obtained using a solvent-free phase-inversion process and was composed of a lipid core and a PEGylated surfactant shell. Numerous studies have reported the use of LNCs with intravenous (IV) or local brain administration (11,12), but no data have been published using SC administration. Pharmacokinetic and biodistribution profiles were established after SC administration, using four various injection sites: behind the neck, the right and left flanks, and above the tail.…”