A system that permits the delivery of cargoes to the lung endothelium would be extraordinarily useful in terms of curing a wide variety of lung-related diseases. This study describes the development of a multifunctional envelope-type nanodevice (MEND) that targets the lung endothelium, delivers its encapsulated siRNA to the cytoplasm, and eradicates lung metastasis. The key to the success can be attributed to the presence of a surface-modified GALA peptide that has dual functions: targeting the sialic acid-terminated sugar chains on the pulmonary endothelium and subsequently delivering the encapsulated cargoes to the cytosol via endosomal membrane fusion, analogous to the influenza virus. The active targeting of MENDs without the formation of large aggregates was verified by intravital real-time confocal laser scanning microscopy in living lung tissue. The GALA-modified MEND is a promising carrier that opens a new generation of therapeutic approaches for satisfying unmet medical needs in curing lung diseases.
The development of efficient gene delivery systems targeting the lung endothelium remains a serious challenge. This study reports on the design and optimization of a multifunctional envelope‐type nanodevice (MEND) for an efficient siRNA delivery to the lung endothelium based on GALA‐peptide targeting ability. The incorporation of a pH‐sensitive lipid (YSK05) results in a dramatic improvement in silencing efficiency by enhancing endosomal escape, but this also causes a reduction in the lung selectivity. Contrary to the assumption that active targeting is largely dependent on the presence of a targeting ligand, the findings of the present study indicate that nanocarrier composition is critical for achieving the organ selectivity. Interestingly, helper lipids substantially mask the liver delivery resulting in optimum lung targeting. The optimized YSK05‐MEND is 40‐fold more efficient than a previously developed MEND, with a robust lung endothelium gene knockdown at small doses. The YSK05‐MEND strongly inhibits a metastatic lung cancer model and exerts superior control over lung metastasis compared to chemotherapy or the previously developed MEND. The YSK05‐MEND is well‐tolerated in mice after acute or chronic administration. As far as it is known, YSK05‐MEND achieves the most efficient lung endothelium gene silencing reported thus far with a median effective dose of 0.01 mg siRNA kg−1 while minimally affecting the endothelium of other organs.
A α-helical GALA peptide (WEAALAEALAEALAEHLAEALAEALEALAA) has been found to possess dual functions: a pH-dependent inducer of endosomal escape, and a ligand that targets lung endothelium. In the present study, the flexibility of GALA was improved by modifying the edge with polyethylene glycol linker, to increase lung-targeting activity. We first investigated the uptake of the GALA-modified liposomes in which GALA was directly conjugated to the lipid (Cholesterol: GALA/Chol) or the phospholipid-PEG (GALA/PEG). The liposomes that were modified with GALA/PEG (GALA/PEG-LPs) were taken up at a higher level by human lung endothelial cells (HMVEC-L), in comparison with particles that were modified with GALA/Chol (GALA/Chol-LPs). Small-interfering RNA-encapsulating liposomal-based nanocarriers (multifunctional envelope-type nano device: MEND) that were formulated with a vitamin E-scaffold SS-cleavable pH-activated lipid-like material, namely GALA/PEG-MEND were also modified with GALA/PEG. Gene silencing activity in the lung endothelium was then evaluated against an endothelial marker; CD31. In comparison with the unmodified MEND, GALA/PEG-MEND exhibited a higher silencing activity in the lung. Optimization of GALA/PEG-MEND resulted in silencing activity in the lung with an ED value of 0.21 mg/kg, while non-specific gene silencing in liver was marginal. Collectively, PEGylated GALA is a promising device for use in targeting the lung endothelium.
This study describes the development of lipid nanoparticles (LNPs) for the efficient and selective delivery of plasmid DNA (pDNA) to the lungs. The GALA peptide was used as a ligand to target the lung endothelium and as an endosomal escape device. Transfection activity in the lungs was significantly improved when pDNA was encapsulated in double-coated LNPs. The inner coat was composed of dioleoylphsophoethanolamine and a stearylated octaarginine (STR-R8) peptide, while the outer coat was largely a cationic lipid, di-octadecenyl-trimethylammonium propane, mixed with YSK05, a pH-sensitive lipid, and cholesterol. Optimized amounts of YSK05 and GALA were used to achieve an efficient and lung-selective system. The optimized system produced a high gene expression level in the lungs (>10 7 RLU/mg protein) with high lung/liver and lung/spleen ratios. GALA/R8 modification and the double-coating design were indispensable for efficient gene expression in the lungs. Despite the fact that NPs prepared with 1-step or 2-step coating have the same lipid amount and composition and the same pDNA dose, the transfection activity was dramatically higher in the lungs in the case of 2-step coating. Surprisingly, 1-step or 2-step coatings had no effect on the amount of nanoparticles that were delivered to the lungs, suggesting that the double-coating strategy substantially improved the efficiency of gene expression at the intracellular level.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.