Synthesis of degradable linear cationic poly(amide triazole)s with DNA-condensation capability

Abstract In this article, we describe the synthesis of three new linear poly(amide triazole)s prepared by click polyaddition reactions of a dialkyne-amide oligoamine monomer and diazide having amide linkage monomers, some of them derived from d -glucose. Both Cu(I)-catalyzed and metal-free click polymerization methods were used to prepare the poly(amide triazole)s which present their secondary amine functions Boc-protected. After deprotection, water-soluble linear cationic polymers were obtained having weight average molecular weights in the 9500–18,500 g mol −1 range. All the polymers were characterized by nuclear magnetic resonance (NMR) and infrared spectroscopy (FTIR). Differential scanning calorimetry (DSC) revealed them to be amorphous, and in general, the polycationic polymers were less stable than the Boc-protected polymers as demonstrated by thermogravimetric analysis (TGA). Degradation studies of a water-soluble prototype polycationic polymer showed they are hydrolytically degradable. Polyplex formulations with DNA were characterized using dynamic light scattering (DLS). The polymers exhibit good ability to condense DNA into 100–200 nm size nanoparticles with positive zeta potential of about 20–50 mV at nitrogen/phosphate (N/P) ratios of 5 or higher. Transmission electron microscopy experiments revealed that polyplexes formed with nano-sized spheroidal structures.