In silico study of PEI-PEG-squalene-dsDNA polyplex formation: the delicate role of the PEG length in the binding of PEI to DNA

Using a two step simulation protocol the atomistic interactions between PEG and b-PEI and the effect of these interactions on DNA binding were determined

Tunable Composition of Dynamic Non-Viral Vectors over the DNA Polyplex Formation and Nucleic Acid Transfection

Polyethylene glycol (PEG) functionalization of non-viral vectors represents a powerful tool through the formation of an overall surface charge shielding ability, which is fundamental for efficient nucleic acid delivery systems. The degree of non-viral vector PEGylation and the molecular weight of utilized PEG is crucial since the excessive use of PEG units may lead to a considerable reduction of the DNA-binding capacity and, subsequently, in a reduction of in vitro transfection efficiency. Herein, we report a detailed study on a series of dynamic combinatorial frameworks (DCFs) containing PEGylated squalene, poly-(ethyleneglycol)-bis(3-aminopropyl) of different lengths, and branched low molecular weight polyethylenimine components, reversibly connected in hyperbranched structures, as efficient dynamic non-viral vectors. The obtained frameworks were capable of forming distinct supramolecular amphiphilic architectures, shown by transmission electron microscopy (TEM) and dynamic light scattering (DLS), with sizes and stability depending on the length of PEG units. The interaction of PEGylated DCFs with nucleic acids was investigated by agarose gel retardation assay and atomic force microscopy (AFM), while their transfection efficiency (using pCS2+MT-Luc DNA as a reporter gene) and cytotoxicity were evaluated in HeLa cells. In addition, the data on the influence of the poly-(ethyleneglycol)-bis(3-aminopropyl) length in composition of designed frameworks over transfection efficiency and tolerance in human cells were analyzed and compared

DyNAvectors: dynamic constitutional vectors for adaptive DNA transfection

International audienc

Optimization of Polyplex Formation between DNA Oligonucleotide and Poly(ʟ-Lysine): Experimental Study and Modeling Approach

The polyplexes formed by nucleic acids and polycations have received a great attention owing to their potential application in gene therapy. In our study, we report experimental results and modeling outcomes regarding the optimization of polyplex formation between the double-stranded DNA (dsDNA) and poly(ʟ-Lysine) (PLL). The quantification of the binding efficiency during polyplex formation was performed by processing of the images captured from the gel electrophoresis assays. The design of experiments (DoE) and response surface methodology (RSM) were employed to investigate the coupling effect of key factors (pH and N/P ratio) affecting the binding efficiency. According to the experimental observations and response surface analysis, the N/P ratio showed a major influence on binding efficiency compared to pH. Model-based optimization calculations along with the experimental confirmation runs unveiled the maximal binding efficiency (99.4%) achieved at pH 5.4 and N/P ratio 125. To support the experimental data and reveal insights of molecular mechanism responsible for the polyplex formation between dsDNA and PLL, molecular dynamics simulations were performed at pH 5.4 and 7.4

Experimental design, modeling and optimization of polyplex formation between DNA oligonucleotides and branched polyethylenimine

International audienc

Synergistic Effect of Low Molecular Weight Polyethylenimine and Polyethylene Glycol Components in Dynamic Nonviral Vector Structure, Toxicity, and Transfection Efficiency

When studying polyethylenimine derivatives as nonviral vectors for gene delivery, among the important issues to be addressed are high toxicity, low transfection efficiency, and nucleic acid polyplex condensation. The molecular weight of polyethylenimine, PEGylation, biocompatibility and, also, supramolecular structure of potential carrier can all influence the nucleic acid condensation behavior, polyplex size, and transfection efficiency. The main challenge in building an efficient carrier is to find a correlation between the constituent components, as well as the synergy between them, to transport and to release, in a specific manner, different molecules of interest. In the present study, we investigated the synergy between components in dynamic combinatorial frameworks formed by connecting PEGylated squalene, poly-(ethyleneglycol)-bis(3-aminopropyl) and low molecular weight polyethylenimine components to 1,3,5-benzenetrialdehyde, via reversible imine bond, applying a dynamic combinatorial chemistry approach. We report comparative structural and morphological data, DNA binding affinity, toxicity and transfection efficiency concerning the ratio of polyethylenimine and presence or absence of poly-(ethyleneglycol)-bis(3-aminopropyl) in composition of dynamic combinatorial frameworks. In vitro biological assessments have revealed the fact that nonviral vectors containing poly-(ethyleneglycol)-bis(3-aminopropyl) and the lowest amount of polyethylenimine have significant transfection efficiency at N/P 50 ratio and display insignificant cytotoxicity on the HeLa cell line

Chemical Attachment of 5-Nitrosalicylaldimine Motif to Silatrane Resulting in an Organic–Inorganic Structure with High Medicinal Significance

Two chemical motifs of interest for medicinal chemistry, silatrane as 1-(3-aminopropyl) silatrane (SIL M), and nitro group attached in position 5 to salicylaldehyde, are coupled in a new structure, 1-(3-{[(2-hydroxy-5-nitrophenyl)methylidene]amino}propyl)silatrane (SIL-BS), through an azomethine moiety, also known as a versatile pharmacophore. The high purity isolated compound was structurally characterized by an elemental, spectral, and single crystal X-ray diffraction analysis. Given the structural premises for being a biologically active compound, different specific techniques and protocols have been used to evaluate their in vitro hydrolytic stability in simulated physiological conditions, the cytotoxicity on two cancer cell lines (HepG2 and MCF7), and protein binding ability—with a major role in drug ADME (Absorption, Distribution, Metabolism and Excretion), in parallel with those of the SIL M. While the latter had a good biocompatibility, the nitro-silatrane derivative, SIL-BS, exhibited a higher cytotoxic activity on HepG2 and MCF7 cell lines, performance assigned, among others, to the known capacity of the nitro group to promote a specific cytotoxicity by a “activation by reduction” mechanism. Both compounds exhibited increased bio- and muco-adhesiveness, which can favor an optimized therapeutic effect by increased drug permeation and residence time in tumor location. Additional benefits of these compounds have been demonstrated by their antimicrobial activity on several fungi and bacteria species. Molecular docking computations on Human Serum Albumin (HSA) and MPRO COVID-19 protease demonstrated their potential in the development of new drugs for combined therapy