Characterization of Cationic Bolaamphiphile Vesicles for siRNA Delivery into Tumors and Brain

Abstract

Small interfering RNAs (siRNAs) are potential therapeutic substances due to their gene silencing capability as exemplified by the recent approval by the US Food and Drug Administration (FDA) of the first siRNA therapeutic agent (patisiran). However, the delivery of naked siRNAs is challenging because of their short plasma half-lives and poor cell penetrability. In this study, we used vesicles made from bolaamphiphiles (bolas), GLH-19 and GLH-20, to investigate their ability to protect siRNA from degradation by nucleases while delivering it to target cells, including cells in the brain. Based on computational and experimental studies, we found that GLH-19 vesicles have better delivery characteristics than do GLH-20 vesicles in terms of stability, binding affinity, protection against nucleases, and transfection efficiency, while GLH-20 vesicles contribute to efficient release of the delivered siRNAs, which become available for silencing. Our studies with vesicles made from a mixture of the two bolas show that they were able to deliver siRNAs into cultured cancer cells, into a flank tumor and into the brain. The vesicles penetrate cell membranes and the bloodbrain barrier (BBB) by endocytosis and transcytosis, respectively, mainly through the caveolae-dependent pathway. These results suggest that GLH-19 strengthens vesicle stability, provides protection against nucleases, and enhances transfection efficiency, while GLH-20 makes the siRNA available for gene silencing.

Biomedically Relevant Applications of Bolaamphiphiles and Bolaamphiphile-Containing Materials

“…The Heldman group has been a leader in the development of BA-based targeted delivery systems featuring acetylcholine (ACh) head groups (Grinberg et al, 2008 ; Popov et al, 2010 , 2012 ; Dakwar et al, 2012 ). In a series of joint papers between the Heldman and Shapiro groups (Kim et al, 2013 , 2020 ; Gupta et al, 2015 ), the applicability of these ACh-containing BAs to siRNA delivery has been extensively explored. In 2013 (Kim et al, 2013 ), the first joint report described the in silico, in vitro , and in vivo delivery of siRNA.…”

“…Having a lower density of cationic charge on the BA's terminal groups (one ACh group vs. two) led to enhanced transfection. In their most recent publication combining both simulation and experiment (Kim et al, 2020 ), the authors probed further the relationship between BA structure and siRNA delivery. Here combinations of structurally similar BAs gave the most desirable delivery properties.…”

Elevated Stratifin promotes cisplatin-based chemotherapy failure and poor prognosis in non-small cell lung cancer

“…The lentivirus-mediated SFN shRNA were co-transfected with packaging system using Lipofectamine 3000 (Thermo Fisher Scientific) in HEK293T cells according to the manufacturer’s protocol. 30 A549 cells were infected with lentiviral particles in the presence of 8 μg/mL polybrene (Sigma-Aldrich, St. Louis, MO, USA) and selected with 1.5 μg/mL puromycin (Sigma-Aldrich). shRNA a random 122 sequence was set up as a control.…”

Exosomes as Smart Nanoplatforms for Diagnosis and Therapy of Cancer

“…However, only maintaining stability is not enough. Since naked RNAs have a poor ability of cell penetration, it is hard for RNAs to enter into the cell (98). Even after entering the cell, they run the risk of being hydrolyzed by lysosomes (89).…”