Rod‐Shaped Active Drug Particles Enable Efficient and Safe Gene Delivery

Abstract

Efficient microRNAs (miRNA) delivery into cells is a promising strategy for disease therapy, but is a major challenge because the available conventional nonviral vectors have significant drawbacks. In particular, after these vectors are entrapped in lysosomes, the escape efficiency of genes from lysosomes into the cytosol is less than 2%. Here, a novel approach for lethal‐7a (let‐7a) replacement therapy using rod‐shaped active pure drug nanoparticles (≈130 nm in length, PNPs) with a dramatically high drug‐loading of ≈300% as vectors is reported. Importantly, unlike other vectors, the developed PNPs/let‐7a complexes (≈178 nm, CNPs) can enter cells and bypass the lysosomal route to localize to the cytosol, achieving efficient intracellular delivery of let‐7a and a 50% reduction in expression of the target protein (KRAS). Also, CNPs prolong the t 1/2 of blood circulation by ≈threefold and increase tumor accumulation by ≈1.5–2‐fold, resulting in significantly improved antitumor efficacies. Additionally, no damage to normal organs is observed following systemic injection of CNPs. In conclusion, rod‐shaped active PNPs enable efficient and safe delivery of miRNA with synergistic treatment for disease. This nanoplatform would also offer a viable strategy for the potent delivery of proteins and peptides in vitro and in vivo.

“Locked” cancer cells are more sensitive to chemotherapy

“…Although PTX‐Ns‐induced apoptosis with higher efficacy compared with free PTX, however, this nanomedicine exhibited lower cytotoxicity at high concentrations. Our previous reports also displayed similar results . Furthermore, combined use with other drugs, such as gene and protein, made this enhancement more profound .…”

“…Our previous reports also displayed similar results . Furthermore, combined use with other drugs, such as gene and protein, made this enhancement more profound . The previous report indicated that internalized PTX‐Ns started to dissolve at 10 hr postinternalization, and therefore demonstrating sustained PTX release over time in cells .…”

“…[54][55][56] Furthermore, combined use with other drugs, such as gene and protein, made this enhancement more profound. 54,55 The previous report indicated that internalized PTX-Ns started to dissolve at 10 hr postinternalization, and therefore demonstrating sustained PTX release over time in cells. 57 Consequently, the sustained release might help the chemotherapeutic agent loaded in nanomedicines kill the cancer cells.…”

“…Transwell assays were performed in 24‐well Transwell chambers with an 8‐μm pore (Corning Life Sciences, Inc.), as described in our reports . In brief, 4T1 cells seeded at a density of 1 × 10 5 cells per well in the upper chamber for 24 hr, were incubated with 200 μl of serum‐free medium and treated with MATT formulations at a MATT concentration of 1 μg/ml for 4 hr at 37°C.…”

“…Transwell assays were performed in 24-well Transwell chambers with an 8-μm pore (Corning Life Sciences, Inc.), as described in our reports. 15,55 In brief, 4T1 cells seeded at a density of 1 × 10 5 cells per well in the upper chamber for 24 hr, were incubated with 200 μl of serum-free medium and treated with MATT formulations at a MATT concentration of 1 μg/ml for 4 hr at 37 C. MATT-LTSLs were preheated at 42 C in a water-bath for 1 hr before incubation with cells. Subsequently, the cells in the upper chamber were removed with a cotton swab and, meanwhile, the cells attached on the lower surface of the filter were fixed with 4% paraformaldehyde, stained with 0.1% crystal violet for 10 min and washed.…”