Metabolite-Based Modification of Poly(l-lysine) for Improved Gene Delivery

Abstract

Synthetic gene delivery systems employ multiple functions to enable safe and effective transport of DNA to target cells. Here, we describe metabolite-based poly(L-lysine) (PLL) modifiers that improve transfection by imparting both pH buffering and nanoparticle stabilization functions within a single molecular unit. PLL modifiers were based on morpholine (M), morpholine and niacin (MN), or thiomorpholine (TM). PLL modification with (MN) or (TM) imparted buffering function over the pH range of 5−7 both in solution and live cells and enhanced the stability of PLL DNA nanoparticles, which exhibited higher resistance to polyanion exchange and prolonged blood circulation. These properties translated into increased transfection efficiency in vitro coupled with reduced toxicity compared to unmodified PLL and PLL(M). Furthermore, PEG-PLL(MN) DNA nanoparticles transfected muscle tissue in vivo for >45 days following intramuscular injection. These polymer modifiers demonstrate the successful design of multifunctional units that improve transfection of synthetic gene delivery systems while maintaining biocompatibility.

Advances in the polymeric delivery of nucleic acid vaccines

“…Urello et al modified PEG-poly( L -lysine) (PEG-PLL) with morpholine and niacin (MN) to improve the buffering effect of the carriers, enhancing the particle's ability to resist polyanion exchange, and prolonging blood circulation. In addition, after intramuscular injection, PEG-PLL (MN) NPs were continuously transfected and expressed antigens in muscle tissue at a higher level than that of PEG-PLL for more than 45 days 179 . During intramuscular injection, nucleic acids or their nanocomplexes are primarily transfected into muscle cells or DCs present in normal skeletal muscle.…”

Nonviral nanoparticle gene delivery into the CNS for neurological disorders and brain cancer applications

“…Polymers also have advantages in being able to finely tune chemical structure to modulate function as well as facile large‐scale manufacture (Gagliardi et al, 2021). Commonly investigated synthetic polymers include poly(lactic‐co‐glycolic acid) (PLGA; Jo et al, 2020), poly( l ‐lysine) (PLL; Urello et al, 2020), poly(amidoamine) (PAMAM; Sun et al, 2019), poly(methyl methacrylate) (PMMA; Jaiswal et al, 2019), polyethyleneimine (PEI; Boussif et al, 1995; Ullah et al, 2020), poly(beta‐amino ester) (PBAE; Karlsson et al, 2020), and poly(alpha‐amino ester)/CART (Blake et al, 2020; T. J. Thomas et al, 2019; Figure 2b). Many of these polymers can be synthesized to have different polymeric architectures, including linear, branched, and dendritic structures.…”

Stimuli-Responsive Polymeric Nanosystems for Controlled Drug Delivery

“…The most extensively utilized poly (amino acids) polymers are synthesized with a single type of amino acid and poly(γ-glutamic acid) [56][57][58][59]. Capitalizing on the positive charges of lysine that can interact with nucleic acids through electrostatic interactions, the poly(L-lysine) has been widely used to design gene delivery nanosystems [60][61][62][63][64]. It can facilitate endosomal escape of DNA or RNA through the proton sponge effect.…”