Physicochemical Properties and Biological Performance of Polymethacrylate Based Gene Delivery Vector Systems: Influence of Amino Functionalities

Abstract

Physicochemical characteristics and biological performance of polyplexes based on two identical copolymers bearing tertiary amino or quaternary ammonium groups are evaluated and compared. Poly(2‐(dimethylamino)ethyl methacrylate)‐b‐poly(oligo(ethylene glycol) methyl ether methacrylate) block copolymer (PDMAEMA‐b‐POEGMA) is synthesized by reversible addition fragmentation chain transfer polymerization. The tertiary amines of PDMAEMA are converted to quaternary ammonium groups by quaternization with methyl iodide. The two copolymers spontaneously formed well‐defined polyplexes with DNA. The size, zeta potential, molar mass, aggregation number, and morphology of the polyplex particles are determined. The parent PDMAEMA‐b‐POEGMA exhibits larger buffering capacity, whereas the corresponding quaternized copolymer (QPDMAEMA‐b‐POEGMA) displays stronger binding affinity to DNA, yielding invariably larger in size and molar mass particles bearing greater number of DNA molecules per particle. Experiments revealed that QPDMAEMA‐b‐POEGMA is more effective in transfecting pEGFP‐N1 than the parent copolymer, attributed to the larger size, molar mass, and DNA cargo, as well as to the effective cellular traffic, which dominated over the enhanced ability for endo‐lysosomal escape of PDMAEMA‐b‐POEGMA.

RAFT Synthesis of Reactive Multifunctional Triblock‐Copolymers for Polyplex Formation

“…Such structures are often used for polyplex formation. [ 32,35,38,39,46 ] But in addition to that, it should contain an additional reactive, intermediate block for a further stimulus responsive functionalization in aqueous media (see Figure 1). This may include the addition of further bioactive compounds or a reversible stabilization of the polyplex by crosslinking (transport form).…”

Functional Polyglycidol-Based Block Copolymers for DNA Complexation

“…The cell viability was assessed using the standard MTT-dye reduction assay, as described previously [51], with some modifications [23]. The method is based on the biotransformation of the yellow tetrazolium salt MTT (3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide) to a violet formazan via the mitochondrial succinate dehydrogenase in the viable cells.…”

“…Polyplexes were prepared at different [N]/[P] ratios varying from 1:1 to 10:1. The cells used in these experiments were plated at a density of 1 × 10 5 in 24-well dishes and cultivated for 24 h prior to the incubation with corresponding pre-stained polyplexes for 2 or 24 h. Images were obtained with a Zeiss Axiovert 200 M microscope using an Objective LD Plan-Neofluar 63x/0.75 Corr (D = 0-1.5 mm), equipped with a CCD camera AxioCam MRm driven by Axiovision v4.9 software (Carl Zeiss Microscopy LLC, White Plains, NY, USA), as described previously [23]. Three independent experiments were performed.…”

“…Closely related to PEG and imparting essentially the same properties are polymers of oligo(ethylene glycol) methacrylates (OEGMAs). OEGMAs are easily polymerizable by controlled radical polymerizations allowing for a broad range of linear and non-linear random and block copolymers, including copolymers with polycationic moieties, exhibiting potential in gene delivery [23][24][25][26]. In contrast to PEG, the macromolecules of POEGMAs are considerably thicker and bulkier.…”

Direct Surface Modification of Polycaprolactone-Based Shape Memory Materials to Introduce Positive Charge Aiming to Enhance Cell Affinity

“…In biomedical field, to improve affinity with a gene or cell for a polymer system, suitable copolymerization was carried out generally [ 23 , 24 , 25 , 26 , 27 ]. Bu et al reported the surface modification of aliphatic polyesters such as PLA and PCL [ 28 ].…”