Spherical nucleic acid gold nanoparticles represent a unique nanotechnology in which the spherical arrangement of oligonucleotides enables the nanoparticles to be efficiently internalized into cells expressing scavenger receptors class A (SR-A). Herein, we seek to replace the gold core with a biodegradable polymeric construct and explore their potential applications in targeted drug delivery.
Oligonucleotide-conjugated poly(ethylene glycol)-block-poly(ε-caprolactone) was synthesized and characterized by 1H NMR and gel electrophoresis. This polymer was applied to fabricate micellar nanoparticles (OLN-NPs) by an anti-solvent method. These nanoparticles have a mean particle size about 58.1 nm with a narrow size distribution (PDI <0.2) and they were also non-cytotoxic. Relative to non-targeted NPs, OLN-NPs exhibited substantially better uptake (3.94×) in a mouse endothelial cell line (C166), attributing to lipid-raft-mediated endocytosis via SR-A.
To explore the potential applications of OLN-NPs as drug carriers, paclitaxel, a poorly soluble anti-angiogenic compound, was selected as the model. OLN-NPs increased the solubility of paclitaxel by at least 300×. The boosted drug solubility in conjunction with improved cellular uptake translated into enhanced in vitro efficacy in the inhibition of angiogenesis. In conclusions, OLN-NPs show considerable promise in targeted drug delivery and their potential applications should be further investigated.