Simple Modifications of Branched PEI Lead to Highly Efficient siRNA Carriers with Low Toxicity

Polymer carriers like PEI which proved their efficiency in DNA delivery were found to be far less effective for the applications with siRNA. In the current study, we generated a number of nontoxic derivates of branched PEI through modification of amines by ethyl acrylate, acetylation of primary amines, or introduction of negatively charged propionic acid or succinic acid groups to the polymer structure. The resulting products showed high efficiency in siRNA-mediated knockdown of target gene. In particular, succinylation of branched PEI resulted in up to 10-fold lower polymer toxicity in comparison to unmodified PEI. Formulations of siRNA with succinylated PEI were able to induce remarkable knockdown (80% relative to untreated cells) of target luciferase gene at the lowest tested siRNA concentration of 50 nM in Neuro2ALuc cells. The polyplex stability assay revealed that the efficiency of formulations which are stable in physiological saline is independent of the affinity of siRNA to the polymer chain. The improved properties of modified PEI as siRNA carrier are largely a consequence of the lower polymer toxicity. In order to achieve significant knockdown of target gene, the PEI-based polymer has to be applied at higher concentrations, required most probably for sufficient accumulation and proton sponge effects in endosomes. Unmodified PEI is highly toxic at such polymer concentrations. In contrast, the far less toxic modified analogues can be applied in concentrations required for the knockdown of target genes without side effects

An in-silico study to find potential effective circRNAs in the progression of Huntington’s disease

Objective(s): Huntington’s disease (HD) is identified as a progressive genetic disorder caused by a mutation in the Huntington gene. Although the pathogenesis of this disease has not been fully understood, investigations have demonstrated the role of various genes and non-coding RNAs in the disease progression. In this study, we aimed to discover the potential promising circRNAs which can bind to miRNAs of HD. Materials and Methods: We used several bioinformatics tools such as ENCORI, Cytoscape, circBase, Knime, and Enrichr to collect possible circRNAs and then evaluate their connections with target miRNAs to reach this goal. We also found the probable relationship between parental genes of these circRNAs and the disease progress. Results: According to the data collected, more than 370 thousand circRNA-miRNA interactions were found for 57 target miRNAs. Several of circRNAs were spliced out of parental genes involved in the etiology of HD. Some of them need to be further investigated to elucidate their role in this neurodegenerative disease.Conclusion: This in silico investigation highlights the potential role of circRNAs in the progression of HD and opens up new horizons for drug discovery as well as diagnostic approaches for the disease

Editing SOX Genes by CRISPR-Cas: Current Insights and Future Perspectives

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and its associated proteins (Cas) is an adaptive immune system in archaea and most bacteria. By repurposing these systems for use in eukaryote cells, a substantial revolution has arisen in the genome engineering field. In recent years, CRISPR-Cas technology was rapidly developed and different types of DNA or RNA sequence editors, gene activator or repressor, and epigenome modulators established. The versatility and feasibility of CRISPR-Cas technology has introduced this system as the most suitable tool for discovering and studying the mechanism of specific genes and also for generating appropriate cell and animal models. SOX genes play crucial roles in development processes and stemness. To elucidate the exact roles of SOX factors and their partners in tissue hemostasis and cell regeneration, generating appropriate in vitro and in vivo models is crucial. In line with these premises, CRISPR-Cas technology is a promising tool for studying different family members of SOX transcription factors. In this review, we aim to highlight the importance of CRISPR-Cas and summarize the applications of this novel, promising technology in studying and decoding the function of different members of the SOX gene family

Tetraiodothyroacetic acid-conjugated polyethylenimine for enhanced delivery of plasmid DNA via integrin receptor

Targeted delivery of polymer-based nanoparticles has been considered as an efficient approach to transfer genetic materials such as plasmid DNA and siRNA. Given the presence of the binding site for tetraiodothyroacetic acid on integrin receptor and overexpression of integrin ?V?3receptor on tumor cells, early escape from endosomal compartment by the proton sponge effect of PEI and entry of tetraiodothyroacetic acid conjugated nanoparticles into cell nucleus by TR receptors, we hypothesized that conjugation of tetraiodothyroacetic acid with PEI may overcome three major barriers considered as the main obstacles in polycation-based gene delivery. In order to test the hypothesis, modified polymer/plasmid DNA complexes were prepared and their ability in transferring plasmid encoding Interleukin-12 was investigated. Moreover, the conjugates were characterized with respect to plasmid DNA condensation ability, particle size and zeta potential as well as cell-induced toxicity and plasmid protection against DNase degradation. The results demonstrated that tetraiodothyroacetic acid derivatives of PEI were able to condense plasmid encoding IL-12 gene at a carrier to plasmid DNA (C/P) weight ratio ? 2:1. The measured particle size was around 180 nm. The highest level of IL-12 gene expression was achieved by the nanoparticles prepared by modified PEI at carrier to plasmid ratio of 8 where they could increase the level of gene expression up to 4 times compared to that of naked plasmid. The cell viability in such C/P ratios is up to 85%. These results suggest that tetraiodothyroacetic acid conjugation of PEI is a simple modification strategy for future investigations aimed at developing a targeting gene vehicle

Preparation of Hydrocortisone Conjugated Polyethylenimine Nanocarriers and its Characterizations for Potential Application in Targeted Gene Delivery

Background & objective: nowadays, gene therapy has been considered as a novel therapeutic approach. Particularly, following the introduction of immunotherapy and gene editing using CRISPR/Cas9 platform great attention has been directed to gene therapy. However, finding an efficient carrier with low toxicity is still one of the major challenges for researchers. Among non-viral gene carriers, polyethyleneimine (PEI) could be considered as the most studied polycationic compound for gene delivery. However, toxicity, lack of targeting and non-specific interactions with serum components limit its wide application. Therefore, PEI structure must be modified through chemical conjugations. In this study, conjugation of hydrocortisone on the polymer structure was carried out in order to direct the carriers into the cell nucleus. Materials & Methods: hydrocortisone was conjugated onto polyethylenimine followed by the grafting of the targeted PEI domain onto another unmodified polymer via succinic acid linker. The conjugate w::as char::acterized in terms of buffering capacity, zeta potential, particle size, protection of DNA against enzymes and condensation ability. Results: The results demonstrated that the conjugates could condense plasmid DNA successfully and form nanoparticles with the size of around 300 nm. Meanwhile, the conjugates showed higher buffering capacity compared with the unmodified polymer. Also, the protection ability of the conjugates was significant rather than the parent polymer. Conclusion: According to the results, design and synthesis of the PEI derivative with two separated domains responsible for targeting and plasmid condensation could be considered as an efficient strategy to create nano gene delivery systems

Editorial: Integrin Ligands and Their Bioconjugate Systems: Synthesis, Conformation, and Biological Activity

De Marco R, Dehshahri A, Baiula M, Dodero VI. Editorial: Integrin Ligands and Their Bioconjugate Systems: Synthesis, Conformation, and Biological Activity. Frontiers in Chemistry. 2022;10: 954618

Green Synthesis of Selenium Nanoparticles by Cyanobacterium Spirulina platensis (abdf2224): Cultivation Condition Quality Controls

Selenium nanoparticles (SeNPs) are well-known bioactive compounds. Various chemical and biological methods have been applied to SeNP synthesis. Spirulina platensis is a widely used blue-green microalgae in various industries. In this study, the biosynthesis of SeNPs using sodium selenite and Spirulina platens has been developed. The SeNP synthesis was performed at different cultivation condition including pH and illumination schedule variation. The SeNPs were characterized by FT-IR, XRD, size, and zeta potential measurements, and the antioxidant activities of selected SeNPs were evaluated by DPPH and FRAP assays. FT-IR analysis showed the production of SeNPs. The 12 h dark/12 h light cycles and continuous light exposure at pH 5 led to the production of stable SeNPs with sizes of 145±6 and 171±13 nm, respectively. Antioxidant activity of selected SeNPs was higher than sodium selenite. It seems that green synthesis is a safe method to produce SeNPs as well as a convenient method to scale-up this production