RESUMO
Currently, micro RNA (miRNA) is considered an attractive target for therapeutic intervention. A significant obstacle to the miRNA-based treatments is the efficient delivery of miRNA to the target tissue. We have developed polyethylene glycol-modified liposomes (Bubble liposomes (BLs)) that entrap ultrasound (US) contrast gas and can serve as both plasmid DNA (pDNA) or small interfering RNA (siRNA) carriers and US contrast agents. In this study, we investigated the usability of miRNA-loaded BLs (mi-BLs) using a hindlimb ischemia model and miR-126. It has been reported that miR-126 promotes angiogenesis via the inhibition of negative regulators of VEGF signaling. We demonstrated that mi-BLs could be detected using diagnostic US and that mi-BLs with therapeutic US could deliver miR-126 to an ischemic hindlimb, leading to the induction of angiogenic factors and the improvement of blood flow. These results suggest that combining mi-BLs with US may be useful for US imaging and miRNA delivery.
Assuntos
Membro Posterior/irrigação sanguínea , Isquemia/tratamento farmacológico , Lipossomos/uso terapêutico , MicroRNAs/administração & dosagem , MicroRNAs/uso terapêutico , Indutores da Angiogênese/administração & dosagem , Indutores da Angiogênese/uso terapêutico , Animais , Células Cultivadas , Portadores de Fármacos/química , Portadores de Fármacos/uso terapêutico , Eritrócitos/efeitos dos fármacos , Regulação da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Lipossomos/química , Masculino , Camundongos , Camundongos Endogâmicos ICR , Músculo Esquelético/irrigação sanguínea , Neovascularização Fisiológica/efeitos dos fármacos , Polietilenoglicóis/química , Transfecção/métodos , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidoresRESUMO
We have developed polyethyleneglycol (PEG)-modified liposomes (Bubble liposomes; BLs) that entrap ultrasound (US) contrast gas, and we have reported that the combination of BLs and US exposure was an effective tool for delivering pDNA and siRNA in vitro and in vivo. In this study, we prepared pDNA-loaded BLs using three types of cationic lipids to enhance the US imaging effect and the transfection efficiency via systemic injection. We investigated the US imaging abilities of these BLs, their protective effects on pDNA from serum component, and their transfection effects in vitro and in vivo. As a result, we demonstrated that the US imaging ability and transfection effect varied with lipid component and that p-BLs containing DSDAP could be the most stable and effective tool the among three types of p-BLs. Indeed, in ischemic muscle, p-BLs containing DSDAP could be detected using diagnostic US and could deliver bFGF-expressing pDNA using therapeutic US, leading to the induction of angiogenic factors and the improvement of blood flow. These results suggest that combining p-BLs with US exposure may be useful for stable US imaging and efficient gene delivery and may lead to the establishment of a theranostic approach, which is a combination of disease diagnosis and therapy.
