Cationic and PEGylated Amphiphilic Cyclodextrins: Co-Formulation Opportunities for Neuronal Sirna Delivery

Abstract

Optimising non-viral vectors for neuronal siRNA delivery presents a significant challenge. Here, we investigate a co-formulation, consisting of two amphiphilic cyclodextrins (CDs), one cationic and the other PEGylated, which were blended together for siRNA delivery to a neuronal cell culture model. Co-formulated CD-siRNA complexes were characterised in terms of size, charge and morphology. Stability in salt and serum was also examined. Uptake was determined by flow cytometry and toxicity was measured by MTT assay. Knockdown of a luciferase reporter gene was used as a measure of gene silencing efficiency. Incorporation of a PEGylated CD in the formulation had significant effects on the physical and biological properties of CD.siRNA complexes. Co-formulated complexes exhibited a lower surface charge and greater stability in a high salt environment. However, the inclusion of the PEGylated CD also dramatically reduced gene silencing efficiency due to its effects on neuronal uptake. The co-formulation strategy for cationic and PEGylated CDs improved the stability of the CD.siRNA delivery systems, although knockdown efficiency was impaired. Future work will focus on the addition of targeting ligands to the co-formulated complexes to restore transfection capabilities.

Early-Stage Development of Novel Cyclodextrin-siRNA Nanocomplexes Allows for Successful Postnebulization Transfection of Bronchial Epithelial Cells

“…(36) Similar results in our group have previously found that whereas SC12CDClickpropylamine nanocomplexes increase in size following 24 hr of incubation in fetal bovine serum (FBS), AU3 c particle size remains less than 250 nm up to 4 hr of incubation, which still allows for rapid internalization into cells. (37) This was also observed in this study using cell culture media containing FBS and high-throughput screening assays for cell uptake of SC12CDClickpropylamine nanocomplexes over a 24-hr period.…”

The use of collagen-based scaffolds to simulate prostate cancer bone metastases with potential for evaluating delivery of nanoparticulate gene therapeutics

“…Cell metabolic activity following transfection with the amphiphilic, cationic cyclodextrin was investigated for mitochondrial dehydrogenase activity using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay [40]. 2 Â 10 4 PC3 cells were seeded in 96-well plates 1 day prior to transfection.…”

“…In contrast to these reported studies, our aim in developing a 3D model system was to treat cells already growing in their native microenvironment. Thus, in this study the prostate cancer cells were first seeded onto scaffolds 24 h prior to the application of transfection reagents (gene delivery vectors) as is common for 2D in vitro transfection experiments [35,40,41]. For gene delivery and knockdown studies, this in vitro 3D cell culture model was considered to more accurately simulate the in vivo tumour microenvironment.…”

“…Lipofectamine 2000 ® has been widely investigated for siRNA delivery in PC3 cells [87e89]. Although the toxicity of this cyclodextrin delivery vector has been analysed and reported in other cell lines [35,40,41,85,86], the toxicity in PC3 cells has not been previously investigated and thus an MTT assay was conducted ( Fig. 7(a)).…”

Effective combination treatment of lung cancer cells by single vehicular delivery of siRNA and different kinds of anticancer drugs

“…Thus, a CD-based drug delivery system is attractive for simultaneous delivery of siRNA and anticancer drugs because it offers good biocompatibility and efficient drug delivery. [24][25][26][27] However, current reports still focus on co-delivery of siRNA and one kind of anticancer drug (eg, Carbo, Tax, or Dox). The simultaneous delivery of multiple anticancer drugs and siRNA by a single vehicle to improve therapeutic efficacy by targeting different mechanisms for the combination treatment of cancer is still lacking.…”