Synthesis of poly[2-(dimethylamino)ethyl methacrylate] grafting from cellulose nanocrystals for DNA complexation...

Developing effective and safe non-viral gene vectors poses a challenge in gene therapy. A promising strategy emerged addressing this challenge, involving a synergistic approach combining biopolymers and cationic synthetic polymers to enhance gene delivery systems. In this study, for the first time, poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) was grafted from cellulose nanocrystals (CNC) using metal-free organocatalyzed atom-transfer radical polymerization (O-ATRP). The synthesis was confirmed through morphological, spectroscopic, and thermal analysis. The reaction achieved a 34 % monomer conversion and 15 % grafting, resulting in a CNC-g-PDMAEMA copolymer with impressive responsiveness to pH and temperature. Furthermore, CNC-g-PDMAEMA was utilized to obtain copolymer/pDNA polyplexes using a microfluidic device, providing a practical and efficient method for producing uniform, stable, and reproducible gene delivery systems. These polyplexes had sizes around 160 nm and a low PDI (<0.250). As a proof of concept, preliminary cell viability and transfection assays were conducted to demonstrate the biomaterial's applicability. These findings suggest that polyplexes (N/P = 15) at a 10 μg/mL concentration may serve as an upper limit threshold and a starting point for further in vivo studies. In summary, this research advances the development of gene delivery platforms through innovative and straightforward synthesis methods, opening up potential applications in gene therapy.