Dioctadecyldimethylammonium:Monoolein Nanocarriers for Efficient in Vitro Gene Silencing

Abstract

This study describes a novel liposomal formulation for siRNA delivery, based on the mixture of the neutral lipid monoolein (MO) and cationic lipids of the dioctadecyldimethylammonium (DODA) family. The cationic lipids dioctadecyldimethylammonium bromide (DODAB) and chloride (DODAC) were compared in order to identify which one will most efficiently induce gene silencing. MO has a fluidizing effect on DODAC and DODAB liposomes, although it was more homogeneously distributed in DODAC bilayers. All MO-based liposomal formulations were able to efficiently encapsulate siRNA. Stable lipoplexes of small size (100-160 nm) with a positive surface charge (>+45 mV) were formed. A more uniform MO incorporation in DODAC:MO may explain an increase of the fusogenic potential of these liposomes. The siRNA-lipoplexes were readily internalized by human nonsmall cell lung carcinoma (H1299) cells, in an energy dependent process. DODAB:MO nanocarriers showed a higher internalization efficiency in comparison to DODAC:MO lipoplexes, and were also more efficient in promoting gene silencing. MO had a similar gene silencing ability as the commonly used helper lipid 1,2-dioleyl-3-phosphatidylethanolamine (DOPE), but with much lower cytotoxicity. Taking in consideration all the results presented, DODAB:MO liposomes are the most promising tested formulation for systemic siRNA delivery.

Stealth monoolein-based nanocarriers for delivery of siRNA to cancer cells

“…The presence of MO on the formulation was found to be advantageous due to an increased fluidification of the nanocarrier membranes and stabilization of the liposomal structures [29,32,33]. DODAB:MO liposomes were also found to be suitable for siRNA delivery, as they efficiently encapsulated siRNA, were extensively taken up by the cells and were able to silence GFP expression without inducing cytotoxicity [34]. With this work we aimed to optimize the previously developed DODAB:MO (2:1) formulation for siRNA systemic delivery, by improving the nanocarriers' performance in physiological conditions.…”

Potential antitumor activity of novel DODAC/PHO-S liposomes

“…11 Cationic lipids are amphiphilic molecules that have been used as a delivery system for nucleic acid and have several advantages, such as the fact that these liposomes are endogenous and biodegradable after administration. [12][13][14][15] This is beneficial because the presence of endogenous enzymes can break down the lipid components of the liposomes. 15 The dioctadecyldimethylammonium chloride (DODAC) is a cationic amphiphilic molecule that has been used for gene delivery.…”

Potencial antitumoral da formulação lipossomal DODAC/fosfoetanolamina sintética no modelo de hepatocarcinoma

“…Dessa forma, os lipossomas com tamanho médio entre 100 -200 nm conseguem entrar nas fenestrações mais largas dos vasos tumorais, mas não penetram nas fenestrações estreitas do endotélio dos tecidos saudáveis. O resultado deste processo é o maior acúmulo de lipossomas, preferencialmente, nos tecidos tumorais (Trédan et al, 2007;Oliveira et al, 2014;Hyodo et al, 2013;Deshpande et al, 2013;Bozzuto e Molinari, 2015).…”

“…Neste aspecto, níveis elevados de expressão dos receptores de LDL têm sido atribuídos às taxas aceleradas de mitose que são fundamentais na fisiopatologia do câncer (Contente et al, 2014). Portanto, neste trabalho, a maior sensibilidade das células de CHC Hepa1c1c7 ao tratamento com os lipossomas pode estar correlacionada à interação do DODAC com os receptores lipídicos destas células, possibilitando maior disponibilidade do DODAC carreando a FO-S. Reforçando esta hipótese, Oliveira et al (2014) verificaram que formulações lipossomais baseadas na associação da monooleína com lipídios catiônicos da família do dioctadecildimetilamônio são absorvidos, predominante, por um processo ativo, sendo a endocitose a principal via de internalização (Oliveira et al, 2014).…”