Dual functionalized amino poly(glycerol methacrylate) with guanidine and Schiff-base linked imidazole for enhanced gene transfection and minimized cytotoxicity

Abstract

Efficient transfection activity and minimal toxicity are of crucial importance to the development of gene delivery systems for practical applications. In this work, guanidine and Schiff-base linked imidazole dual functionalized poly(glycerol methacrylate) (IGEP) was firstly synthesized. Subsequent investigations revealed that this new biomedical material is capable of sufficiently binding to plasmid DNA (pDNA) and formulating optimal sized 100 nm nanoparticles with positive z potentials of 10-30 mV. Biological evaluations demonstrated the strategic use of guanidine resulting in enhanced cellular uptake and nuclear localization activities by virtue of its favorable affinity to the cellular membrane, and Schiff-base linked imidazole resulting in promoted endosomal escape and DNA cargo releasing behaviors, consequently leading to better transfection efficacy compared to PEI 25K in the targeted cells. Another noteworthy fact was guanidine and imidazole minimized cytotoxicity, hence, these advantageous features provided substantial information to construct a safe and efficient gene delivery carrier towards practical development.Scheme 1 Schematic illustration of IGEP/pDNA complex formation, subsequently guanidine facilitates endocytosis and cellular uptake, imidazole mediates endosomal escape, and Schiff-base regulates DNA unpacking and release. Journal of Materials Chemistry BPaper

Increased RNAi Efficacy in Spodoptera exigua via the Formulation of dsRNA With Guanylated Polymers

“…(Co)polymers of 2-(dimethylamino)ethyl methacrylate (DMAEMA) and/or 2-(aminoethyl) methacrylate (AEMA) were synthesized by free radical polymerization to obtain polymers containing either primary (AEMA) and/or tertiary amine groups (DMAEMA). The obtained polymers were further functionalized by reacting part of the primary amines with 1H-pyrazole-1-carboxamidine hydrochloride (HPC) to yield copolymers with guanidine groups as shown in the scheme of Figure 1 using earlier described guanylation protocols (Mattheis et al, 2013 ; Guo et al, 2015 ). An overview of the synthesized polymers is given in Table 1 .…”

“…Using free radical polymerization, several (co)polymers based on AEMA and DMAEMA (pK a 9.8) were synthesized. The aim was to use the primary amino groups of AEMA for further modifications by reacting them with HPC to introduce guanidine functionalities (Guo et al, 2015 ). At the same time, the influence of DMAEMA, a well-known monomer for DNA delivery, with a higher pK a , was also analyzed (Christiaens et al, 2005 ).…”

“…Additionally, what exactly happens with the polyplex when entering the cell and the polymer after release of the dsRNA is also unclear and requires further study. In mammalian studies, guanidine containing polymers for gene delivery application have been shown to be successful not only due to their ability to bind nucleotides (Funhoff et al, 2004 ; Song and Chu, 2012 ; Choi et al, 2015 ; Guo et al, 2015 ) but also for enhancing their cell penetrating properties (Treat et al, 2011 ). Two main dsRNA cellular uptake mechanisms have been proposed in insects.…”

“…In view of this, polymers containing strong basic side groups such as guanidine (pK a 13.6) in their structure are interesting candidates. Other guanidine-containing polymers have previously been investigated in DNA delivery studies with mammalian systems and have proved to be not only able to complex the nucleotides but also to improve the transfection efficiency due to the guanidine functionalities present (Funhoff et al, 2004 ; Choi et al, 2015 ; Guo et al, 2015 ). Nevertheless, their potential as nucleotide protectors in an alkaline medium has never been analyzed.…”

Polydopamine-based nanoparticles with excellent biocompatibility for photothermally enhanced gene delivery

“…11 One of the main barriers for gene delivery is endosomal escape. 6,12 Many approaches have been studied to promote endosomal escape, such as peptide modication [13][14][15][16] and photochemical internalization (PCI). Under light irradiation, the photosensitizers used in PCI can produce reactive oxygen species (ROS), which can rupture the lysosome and endosomal membranes, thus resulting in enhanced endosomal escape.…”