Role of Unmodified Low Generation - PAMAM Dendrimers in Efficient Non-Toxic Gene Transfection

Abstract

The present study is focused on a simple execution in the applicability of non-toxic lower generation poly amidoamine (PA-MAM) dendrimers as effective nano-vectors in targeted gene delivery to the skin. So far the first three lower generation (G1, G2 and G3) PAMAM dendrimers have been overlooked as nucleic acid therapeutics. In this study, we have first carried out a systematic biophysical analysis to analyze their ability for plasmid DNA (pDNA) condensation and subsequent release by ethidium bromide assay to optimize dendrimer to DNA charge ratio for effective pDNA condensation and release. Interestingly, stopped flow fluorescence spectroscopic analysis on pDNAdendrimer binding kinetics revealed the efficiency of generations G2 and G3 in pDNA condensation in comparison with G1 through four steps. Importantly, it validates aggregation and association of the dendrimer in the vicinity of pDNA. Based on these understanding, successful in vitro cellular uptake of dendriplexes followed by their transfection into CHOÀK1 cells was demonstrated at the charge ratio Z + /-5 and 10. The interesting observations of gene transfection with CHOÀK1 cells were extended to HaCaT cell line and efficient pDNA transfections were evidenced with negligible cytotoxicity. In addition to this, the stability of the dendriplexes at the charge ratio Z + /-5 for G3 and Z + /-10 for G2 was found even upto 50 % serum concentration suggesting possible future applicability in in vivo. Overall, the current approach promises the use of lower generation dendrimers for pDNA delivery to the skin using only electrostatic nanocomplex formation without any covalent linkage.

MicroRNAs delivery into human cells grown on 3D-printed PLA scaffolds coated with a novel fluorescent PAMAM dendrimer for biomedical applications

“…The internalization of Rho-PAM, assessed by the intense red fluorescence inside the cells (Fig. 6A ), validate the use of this PAMAM derivative as a novel non-toxic delivery vector 31 , 32 .…”

Polyamidoamide Dendrimers and Cross-Linking Agents for Stabilized Bioenzymatic Resistant Metal-Free Bovine Collagen

“…Our studies focused only on the use of low-generation PAMAM dendrimers, i.e., generation 0.0 and 1.0 (having 4 and 8 free NH 2 , respectively), since it has been shown that they avoid the steric hindrance and toxicity issues which are characteristic of higher generations [28,38,39]. In particular, the non-toxicity of the auxiliary is of importance for leather processing (see below).…”

Structural Characterization of Dendriplexes In Vacuo: A Joint Ion Mobility/Molecular Dynamics Investigation

“…Characterization of dendriplexes relies on gel electrophoresis, − zeta potential determination, , atomic force microscopy (AFM), , dynamic light scattering (DLS), ,, isothermal titration calorimetry (ITC), ,, and circular dichroism (CD). ,,, Although these analytical methods are efficient to attest to the existence of the supramolecular nucleic acid/dendrimer complexes, they cannot afford a structural description of the dendriplexes at the molecular level. Molecular Dynamics (MD) investigations have recently been introduced for dendriplex structural description. ,− For instance, Maiti et al used MD simulations in explicit solvent to investigate the structures of dendriplexes associating PAMAM G2–4 to a 38-base ss-DNA and PAMAM G3–5 to a 38-base ds-DNA …”