Hydrophobicity Tuning of Cationic Polyaspartamide Derivatives for Enhanced Antisense Oligonucleotide Delivery.

Various cationic polymers are used to deliver polyplex-mediated antisense oligonucleotides (ASOs). However, few studies have investigated the structural determinants of polyplex functionalities in polymers. This study focused on the polymer hydrophobicity.

Size-tunable PEG-grafted copolymers as a polymeric nanoruler for passive targeting muscle tissues.

Muscle-targeted drug delivery is a major challenge in nanomedicine. The extravasation of nanomedicines (or nanoparticles) from the bloodstream into muscle tissues is hindered by the continuous endothelium, the so-called blood-muscle barrier. This study aimed to evaluate the optimal size of macromolecular drugs for extravasation (or passive targeting) into muscle tissues.

Fine-tuning of polyaspartamide derivatives with alicyclic moieties for systemic mRNA delivery.

Development of efficient delivery vehicles for in vitro transcribed mRNA (IVT mRNA) is currently a major challenge in nanomedicines. For systemic mRNA delivery, we developed a series of cationic amphiphilic polyaspartamide derivatives (PAsp(DET/R)s) carrying various alicyclic (R) moieties with diethylenetriamine (DET) in the side chains to form mRNA-loaded polyplexes bearing stability under physiological conditions and possessing endosomal escape functionality. While the size and ζ-potential of polyplexes were comparable among various PAsp(DET/R)s, the transfection efficiencies of polyplexes were considerably varied due to difference in the R moieties of PAsp(DET/R)s and were described by an octanol-water (or buffer at pH 7.

Installation of a Thermoswitchable Hydrophobic Domain into a Unimer Polyion Complex for Enhanced Cellular Uptake of siRNA.

Whereas small siRNA nanocarriers with a size of 10-20 nm exert high tissue-permeability, they encounter the challenge of inefficient adsorption on the cell surface, resulting in poor cellular uptake of siRNA. To solve this dilemma, this study aims to control the hydrophobicity of a small siRNA nanocarrier, unimer polyion complex (uPIC), with a size of ∼10 nm. The uPICs are fabricated to consist of a single pair between siRNA and a smart triblock copolymer comprising hydrophilic poly(2-ethyl-2-oxazoline) (PEtOx), thermoswitchable poly(2--propyl-2-oxazoline) (PnPrOx), and cationic poly(l-lysine) (PLL).