The effects of polyethylenimine/DNA nanoparticle on transcript levels of apoptosis-related genes

Immune response and protective efficacy of mannosylated polyethylenimine (PEI) as an antigen delivery vector, administered with a Streptococcus agalactiae DNA vaccine in Nile tilapia (Oreochromis niloticus)

This study examined the effectiveness of a DNA vaccine for S. agalactiae that was delivered by mannose-based polyethyleneimine (Man-PEI). The results showed that Man-PEI/pcDNA-Sip stimulated a higher serum antibody titer compared to control or other vaccine groups (p < 0.05). Additionally, it induced higher expression of immune-related genes, and increased activities of superoxide dismutase (SOD), acid phosphatase (ACP) and alkaline phosphatase (AKP). Furthermore, the Man-PEI/pcDNA-Sip group showed an improved relative percent survival (RPS) of 85.71%. These results demonstrate the potential value of Man-PEI as a vaccine delivery vehicle, and suggest that it can be effective in boosting the immune protective rate induced by pcDNA-Sip vaccines.

Nanoparticles-mediated CRISPR-Cas9 gene therapy in inherited retinal diseases: applications, challenges, and emerging opportunities

Inherited Retinal Diseases (IRDs) are considered one of the leading causes of blindness worldwide. However, the majority of them still lack a safe and effective treatment due to their complexity and genetic heterogeneity. Recently, gene therapy is gaining importance as an efficient strategy to address IRDs which were previously considered incurable. The development of the clustered regularly-interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system has strongly empowered the field of gene therapy. However, successful gene modifications rely on the efficient delivery of CRISPR-Cas9 components into the complex three-dimensional (3D) architecture of the human retinal tissue. Intriguing findings in the field of nanoparticles (NPs) meet all the criteria required for CRISPR-Cas9 delivery and have made a great contribution toward its therapeutic applications. In addition, exploiting induced pluripotent stem cell (iPSC) technology and in vitro 3D retinal organoids paved the way for prospective clinical trials of the CRISPR-Cas9 system in treating IRDs. This review highlights important advances in NP-based gene therapy, the CRISPR-Cas9 system, and iPSC-derived retinal organoids with a focus on IRDs. Collectively, these studies establish a multidisciplinary approach by integrating nanomedicine and stem cell technologies and demonstrate the utility of retina organoids in developing effective therapies for IRDs.

Cholesterol-conjugated PEGylated PAMAM as an efficient nanocarrier for plasmid encoding interleukin-12 immunogene delivery toward colon cancer cells

IL-12 is a pleiotropic cytokine, which shows an ideal applicant for tumor immunotherapy, because of its features of creating an interconnection between innate (NK cells) and adaptive (cytotoxic T lymphocyte) immunity. IL-12 gene therapy is a useful technique to deliver an immune-modulatory gene directly into tumor site thereby limiting the adverse effects of systemic administration of IL-12 proteins. One of the most largely investigated non-viral gene carriers is polyamidoamine (PAMAM). In the current research, 5 and 3% of PAMAM primary amines were substituted to transmit the plasmid encoding IL-12 gene to cells by cholesteryl chloroformate and alkyl-PEG, respectively. The features of modified PAMAMs containing size and surface charge density, cytotoxicity, and transfection efficiency were investigated in colon cancer cells. in vitro experiment showed that this modified carrier with average size of about 160 nm and zeta potential of 30 mV was able to increase the level of IL-12 production up to two folds as compared to that of the unmodified PAMAM. Improvement of the polymer hydrophobic balance along with of the modulation of the surface positive charge could provide an efficient and safe non-viral IL-12 gene for colon cancer immunogene therapy.

MicroRNA-200c Attenuates Periodontitis by Modulating Proinflammatory and Osteoclastogenic Mediators

This study tested whether microRNA (miR)-200c can attenuate the inflammation and alveolar bone resorption in periodontitis by using an in vitro and a rat model. Polyethylenimine (PEI) was used to facilitate the transfection of plasmid DNA encoding miR-200c into primary human gingival fibroblasts (HGFs) and gingival tissues of rats. We first analyzed how proinflammatory and osteoclastogenic mediators in HGFs with overexpression of miR-200c responded to Porphyromonas gingivalis lipopolysaccharide (LPS-PG) challenge in vitro. We observed that overexpression of miR-200c significantly reduced interleukin (IL)-6 and 8 and repressed interferon-related developmental regulator-1 (IFRD1) in HGFs. miR-200c also downregulated p65 and p50. In a rat model of periodontitis induced by an LPS injection at the gingival sulcus of the second maxillary molar (M2), we analyzed how the mediators in rat gingiva and alveolar bone resorption responded to miR-200c treatment by a local injection of PEI-plasmid miR-200 nanoplexes. We observed that the local injection of miR-200c significantly upregulated miR-200c expression in gingiva and reduced IL-6, IL-8, IFRD1, and the ratio of receptor activator of nuclear factor kappa-B ligand/osteoprotegerin. Using micro-computed tomography analysis and histomorphometry, we further confirmed that local treatment with miR-200c effectively protected alveolar bone resorption in the rat model of periodontitis by reducing the distance between the cemento-enamel junction and the alveolar bone crest and the inter-radicular space in the upper maxilla at M2. These findings imply that miR-200c may serve as a unique means to prevent periodontitis and associated bone loss.

Modified PAMAM vehicles for effective TRAIL gene delivery to colon adenocarcinoma: in vitro and in vivo evaluation

TRAIL (tumour necrosis factor-related apoptosis-inducing ligand) gene therapy is considered as one of the promising approaches for cancer treatment. Polyamidoamine (PAMAM) is one of the most extensively applied polymeric vector in gene delivery. In the current study, PAMAM (G4 and G5) dendrimers were modified with alkyl-carboxylate chain, PEG and cholesteryl chloroformate in order to enhance transfection efficiency through overcoming extracellular and intracellular barriers while reducing PAMAM cytotoxicity. Gene delivery efficiency of synthetized vectors was evaluated by both GFP (green fluorescent protein) reporter gene and TRAIL plasmid in colon cancer cells, in vitro and in vivo. The obtained results demonstrated that PAMAM G4-alkyl-PEG (3%)-Chol (5%)-TRAIL complexes at C/P ratio 4 could significantly increase cell death (29.45%) in comparison with unmodified PAMAM vector (15.5%). Moreover, in vivo study in C26 tumor-bearing BALB/c mice suggested that the prepared non-toxic safe vector could inhibit the tumor growth. This study represented the potent vehicle based on cholesterol-grafted PAMAM dendrimers with alkyl-PEG modification for efficient gene delivery in vitro and in vivo.

Polyethylenimine-based nanocarriers in co-delivery of drug and gene: a developing horizon

The meaning of gene therapy is the delivery of DNA or RNA to cells for the treatment or prevention of genetic disorders. The success rate of gene therapy depends on the progression and safe gene delivery system. The vectors available for gene therapy are divided into viral and non-viral systems. Viral vectors cause higher transmission efficiency and long gene expression, but they have major problems, such as immunogenicity, carcinogenicity, the inability to transfer large size genes and high costs. Non-viral gene transfer vectors have attracted more attention because they exhibit less toxicity and the ability to transfer large size genes. However, the clinical application of non-viral methods still faces some limitations, including low transmission efficiency and poor gene expression. In recent years, numerous methods and gene-carriers have been developed to improve gene transfer efficiency. The use of Polyethylenimine (PEI) based transfer of collaboration may create a new way of treating diseases and the combination of chemotherapy and gene therapy. The purpose of this paper is to introduce the PEI as an appropriate vector for the effective gene delivery.

ATRP Fabricated and Short Chain Polyethylenimine Grafted Redox Sensitive Polymeric Nanoparticles for Codelivery of Anticancer Drug and siRNA in Cancer Therapy

To overcome the limitations of conventional chemotherapy, nanoparticle-mediated combinatorial delivery of siRNA and drugs represents a new approach to overcome its associated side effects. Designing safe and efficient vehicles for their codelivery has emerged as a potential challenge in the clinical translation of these formulations. Herein, we have demonstrated a novel "two-in-one" polyplex nanosystem developed from redox sensitive, short chain polyethylenimine modified poly[(poly(ethylene)glycol methacrylate]-s-s-polycaprolactone copolymer synthesized by atom-transfer free-radical polymerization (ATRP), which can deliver doxorubicin and polo-like kinase I (plk1) siRNA, simultaneously for an enhanced chemotherapeutic effect. The nanoparticles were found to be stable at physiological buffer with and without fetal bovine serum (FBS). The developed polymeric nanosystem was found to be biocompatible and hemocompatible in vitro and in vivo at repeated dose administrations. The polymer could easily self-assemble into ∼100 nm spherical nanoparticles with enhanced doxorubicin loading (∼18%) and effective siRNA complexation at a polymer to siRNA weight ratio of 15. The doxorubicin loaded nanoparticles exhibited ∼4-fold higher drug release in endosomal pH (pH 5) containing 10 mmol of GSH compared to pH 7.4, depicting their redox-sensitive behavior. The polyplexes were capable of delivering both cargos simultaneously to cancer cells in vitro as observed by their excellent colocalization in the cytoplasm of MDA-MB-231 and HeLa cells using confocal laser microscopy. Moreover, in vitro transfection of the cells with polyplexes exhibited 50-70% knockdown of plk1-mRNA expression in both cell lines. In vivo administration of the drug loaded polyplexes to EAT tumor bearing (EAT, Ehrlich ascites tumor) Swiss albino mice showed a ∼29-fold decrease in percent tumor volume in comparison to the control group. The results highlight the therapeutic potential of the polyplexes as a combined delivery of doxorubicin and plk1-siRNA in cancer therapy.

Brain-Targeted Polymers for Gene Delivery in the Treatment of Brain Diseases

Gene therapies have become a promising strategy for treating neurological disorders, such as brain cancer and neurodegenerative diseases, with the help of molecular biology interpreting the underlying pathological mechanisms. Successful cellular manipulation against these diseases requires efficient delivery of nucleic acids into brain and further into specific neurons or cancer cells. Compared with viral vectors, non-viral polymeric carriers provide a safer and more flexible way of gene delivery, although suffering from significantly lower transfection efficiency. Researchers have been devoted to solving this defect, which is attributed to the multiple barriers existing for gene therapeutics in vivo, such as systemic degradation, blood-brain barrier, and endosome trapping. This review will be mainly focused on systemically administrated brain-targeted polymers developed so far, including PEI, dendrimers, and synthetic polymers with various functions. We will discuss in detail how they are designed to overcome these barriers and how they efficiently deliver therapeutic nucleic acids into targeted cells.