New Poly(d-glucaramidoamine)s Induce DNA Nanoparticle Formation and Efficient Gene Delivery into Mammalian Cells

Abstract

In this report, four new poly(d-glucaramidoamine)s (1-4) have been designed to lower the toxicity of conventional polymeric nucleic acid delivery vehicles by incorporating a carbohydrate comonomer within a polyethylenimine (PEI)-like backbone. Polymers 1-4 were synthesized via polycondensation of esterified d-glucaric acid and four different amine-containing comonomers [diethylenetriamine (1), triethylenetetramine (2), tetraethylenepentamine (3), and pentaethylenehexamine (4)] in methanol. Viscometry and NMR studies suggest that the polymers are mostly linear (for 1-4, the alpha value in the Mark-Houwink-Sakurada equation = 0.6-0.7), thus indicating that polymerization occurs predominantly through the primary amines with a low degree of branching off the secondary amines. Results of gel electrophoresis shift assays show that polymers 1-4 bind pDNA at N/P ratios of 5, 3, 2, and 2, respectively. Also, dynamic light scattering and TEM experiments indicate that 1-4 compact DNA into nanoparticles (polyplexes) between 140 and 440 nm at an N/P ratio of 30. Furthermore, polyplexes formed with 1-4 deliver pDNA (plasmid DNA) containing the firefly luciferase reporter gene to BHK-21 cells in a nontoxic and highly efficient manner (as determined by luciferase gene expression). In particular, polymer 4 reveals very high delivery efficiency (equivalent to linear PEI). This result may be due in part to the "proton sponge" hypothesis proposed by Behr et al. Polymers containing amines that are protonated in the endosomal pH range (between about 7.4-5.0) reveal enhanced gene delivery profiles.

Poly(ethylene glycol)-block-cationic polylactide nanocomplexes of differing charge density for gene delivery

“…A variety of biodegradable CPs such as poly(b-amino ester)s [14e17], poly[a-(4-aminobutyl)-L-glycolic acid] [18], poly(4-hydroxy-L-proline ester) [19], poly(D-glucaramidoamine) [20], cationic poly(a-hydroxy acid) [21], and cationic cyclodextrin [22] have been successfully synthesized and used in gene delivery studies. In addition to protecting therapeutic genes from nuclease degradation, synthetic design of CPs can be directed to optimize their biodegradability and improve their biocompatibility for repeated administration of gene-based therapies [23,24].…”

Biodegradable cationic polyester as an efficient carrier for gene delivery to neonatal cardiomyocytes

“…Numerous polymers including polyethyleneimine (PEI) (Boussif et al, 1995;Shuai et al, 2003), polylysine (PLL) (Kang et al, 2005), dendrimers (Bayele et al, 2005;Braun et al, 2005;Marano et al, 2005), poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) ( Van de Wetering et al, 1999), poly(ester amine)s (Zhong et al, 2005a,b), poly(D-glucaramidoamine) (Liu and Reineke, 2005;Liu and Reineke, 2006;Liu et al, 2004), and polysaccharideoligoamine based conjugates (Azzam et al, 2002;Yudovin-Farber et al, 2005) have been developed for gene delivery to other types of cells. For gene delivery to cardiomyocytes, polymer carriers must have low toxicity and be able to degrade into small molecules for exclusion from the cells.…”

Precision Polymers: Monodisperse, Monomer‐Sequence‐Defined Segments to Target Future Demands of Polymers in Medicine

“…In polymer-facilitated gene delivery, the carrier polymers have to fulfill a cascade of several complex functions throughout the process of delivery, such as i) complexation and condensation of DNA, ii) translocation via the cell membrane, iii) liberation of the cargo DNA, and iv) delivery of DNA into the cell nucleus. [1] Among several other systems, [5,6] three major polymer classes predominate the literature since the beginning of polymerfacilitated DNA transport and delivery. It remains a surprising fact that these polymeric carriers are derived from rather simple polymers based on, for example, poly(L-lysine) (PLL), poly(ethylene imine)s (PEI), or chitosan.…”