scholarly journals Combinatorial library of biodegradable polyesters enables delivery of plasmid DNA to polarized human RPE monolayers for retinal gene therapy

2018 ◽  
Author(s):  
Bibhudatta Mishra ◽  
David R. Wilson ◽  
Srinivas R. Sripathi ◽  
Mark P. Suprenant ◽  
Yuan Rui ◽  
...  
Keyword(s):  
Gene Delivery ◽  
Plasmid Dna ◽  
High Throughput Screening ◽  
High Efficiency ◽  
Polymeric Nanoparticles ◽  
Retinal Pigment ◽  
Weight Ratio ◽  
Retinal Cell ◽  
Viral Gene ◽  
Rpe Cells

Abstract:Efficient gene delivery into hard-to-transfect cells is still a challenge despite significant progress in the development of various gene delivery tools. Non-viral and synthetic polymeric nanoparticles offer an array of advantages for gene delivery over the viral vectors and high in demand as they are safe to use, easy to synthesize and highly cell-type specific. Here we demonstrate the use of a high-throughput screening (HTS) platform to screen for biodegradable polymeric nanoparticles (NPs) that can transfect human retinal pigment epithelial (RPE) cells with high efficiency and low toxicity. These NPs can deliver plasmid DNA (pDNA) to RPE monolayers more efficiently compared to the commercially available transfection reagents without interfering the global gene expression profile of RPE cells. In this work, we have established an HTS platform and identified synthetic polymers that can be used for high efficacy non-viral gene delivery to human RPE monolayers, enabling gene loss- and gain-of-function studies of cell signaling and developmental pathways. This platform can be used to identify the optimum polymer, weight-to-weight ratio of polymer to DNA, and the dose of NP for various retinal cell types.

Recent advances in the analysis full/empty capsid ratio and genome integrity of adeno-associated virus (AAV) gene delivery vectors

2020 ◽  
Vol 20 ◽  
Author(s):  
L. Hajba ◽  
A. Guttman
Keyword(s):  
Gene Delivery ◽  
High Efficiency ◽  
Analytical Techniques ◽  
Viral Gene ◽  
Adeno Associated Virus ◽  
Gene Delivery Vectors ◽  
Empty Capsid ◽  
Purification Methods ◽  
Viral Gene Delivery

: Adeno-associated virus (AAV) is one of the most promising viral gene delivery vectors with long-term gene expression and disease correction featuring high efficiency and excellent safety in human clinical trials. During the production of AAV vectors,there are several quality control (QC)parameters that should be rigorously monitored to comply with clini-cal safety and efficacy. This review gives a short summary of the most frequently used AVV production and purification methods,focusing on the analytical techniques applied to determine the full/empty capsid ratio and the integrity of the encapsidated therapeutic DNA of the products.

Di-Sulfide Linked Polyethylenimine Coated Gold Nanoparticles as a Non-Viral Gene Delivery Agent in NIH-3T3 Mouse Embryonic Fibroblast

2015 ◽  
Vol 15 (10) ◽  
pp. 7895-7899 ◽  
Author(s):  
Saji Uthaman ◽  
Myeong Ju Moon ◽  
Duhwan Lee ◽  
Won Jong Kim ◽  
In-Kyu Park
Keyword(s):  
Gold Nanoparticles ◽  
Gene Delivery ◽  
Fluorescent Microscopy ◽  
Weight Ratio ◽  
Mouse Embryonic Fibroblast ◽  
Luciferase Assay ◽  
Viral Gene ◽  
Hydrodynamic Diameter ◽  
Tem Analysis ◽  
Average Size

Di-sulfide linked polyethylenimine coated gold nanoparticles (ssPEI-GNPs) of 20 nm size was prepared in order to deliver the genes to target site. DLS and TEM analysis demonstrated that the GNPs have average size of 13 nm in diameter. Upon coating the GNPs with ssPEI in the weight ratio of 1:3, the average hydrodynamic diameter of the ssPEI-GNPs was found to 19 ± 1.14 nm and a zeta potential value 41 ± 1.23 mV was observed. TEM analysis of ssPEI-GNPs demonstrated that the nanoparticles have spherical morphology. Thermogravemetric analysis of the prepared ssPEI-GNPs showed that the estimated composition of the ssPEI coated over the GNPs was approximately 5% (w/w). Gene expression capabilities of the nanoparticles were confirmed by fluorescent microscopy and luciferase assay, which demonstrated the transgene delivery capability of the ssPEI-GNPs. These results demonstrate that ssPEI-GNPs could be used as gene delivery agent.

scholarly journals Long-Circulating Polymeric Nanovectors for Tumor-Selective Gene Delivery

2005 ◽  
Vol 4 (6) ◽  
pp. 615-625 ◽  
Author(s):  
Sushma Kommareddy ◽  
Sandip B. Tiwari ◽  
Mansoor M. Amiji
Keyword(s):  
Gene Therapy ◽  
Gene Delivery ◽  
Viral Vectors ◽  
High Efficiency ◽  
Transfection Efficiency ◽  
The United States ◽  
Medical Intervention ◽  
Hydrophilic Polymers ◽  
Circulation Time ◽  
Viral Gene

Significant advances in the understanding of the genetic abnormalities that lead to the development, progression, and metastasis of neoplastic diseases has raised the promise of gene therapy as an approach to medical intervention. Most of the clinical protocols that have been approved in the United States for gene therapy have used the viral vectors because of the high efficiency of gene transfer. Conventional means of gene delivery using viral vectors, however, has undesirable side effects such as insertion of mutational viral gene into the host genome and development of replication competent viruses. Among non-viral gene delivery methods, polymeric nanoparticles are increasingly becoming popular as vectors of choice. The major limitation of these nanoparticles is poor transfection efficiency at the target site after systemic administration due to uptake by the cells of reticuloendothelial system (RES). In order to reduce the uptake by the cells of the RES and improve blood circulation time, these nanoparticles are coated with hydrophilic polymers such as poly(ethylene glycol) (PEG). This article reviews the use of such hydrophilic polymers employed for improving the circulation time of the nanocarriers. The mechanism of polymer coating and factors affecting the circulation time of these nanocarriers will be discussed. In addition to the long circulating property, modifications to improve the target specificity of the particles and the limitations of steric protection will be analyzed.

scholarly journals Human Retinal Pigment Epithelial Cells Overexpressing the Neuroprotective Proteins PEDF and GM-CSF to Treat Degeneration of the Neural Retina

2021 ◽  
Vol 21 ◽  
Author(s):  
Thais Bascuas ◽  
Hajer Zedira ◽  
Martina Kropp ◽  
Nina Harmening ◽  
Mohamed Asrih ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Delivery ◽  
Retinal Pigment Epithelial ◽  
Retinal Pigment ◽  
Sleeping Beauty ◽  
Rpe Cells ◽  
Gm Csf ◽  
Sleeping Beauty Transposon ◽  
Stress Damage ◽  
Human Rpe Cells

Background: Non-viral transposon-mediated gene delivery can overcome viral vectors’ limitations. Transposon gene delivery offers the safe and life-long expression of genes such as pigment epithelium-derived factor (PEDF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) to counteract retinal degeneration by reducing oxidative stress damage. Objective: Use Sleeping Beauty transposon to transfect human retinal pigment epithelial (RPE) cells with the neuroprotective factors PEDF and GM-CSF to investigate the effect of these factors on oxidative stress damage. Methods: Human RPE cells were transfected with PEDF and GM-CSF by electroporation, using the hyperactive Sleeping Beauty transposon gene delivery system (SB100X). Gene expression was determined by RT-qPCR and protein level by Western Blot as well as ELISA. The cellular stress level and the neuroprotective effect of the proteins were determined by measuring the concentrations of the antioxidant glutathione in human RPE cells and immunohistochemical examination of retinal integrity, inflammation, and apoptosis of rat retina-organotypic cultures (ROC) exposed to H2O2. Results: Human RPE cells were efficiently transfected, showing a significantly augmented gene expression and protein secretion. Human RPE cells overexpressing PEDF and/or GM-CSF or pre-treated with recombinant proteins presented significantly increased glutathione levels post-H2O2 incubation than non-transfected/untreated controls. rPEDF and/or rGM-CSF-treated ROC exhibited decreased inflammatory reactions and cell degeneration. Conclusion: GM-CSF and/or PEDF could be delivered successfully to RPE cells by combining the use of SB100X and electroporation. PEDF and/or GM-CSF reduced H2O2-mediated oxidative stress damage in RPE cells and ROC offering an encouraging technique to re-establish a cell-protective environment to halt age-related retinal degeneration.

scholarly journals Polymeric Nanoparticles in Gene Therapy: New Avenues of Design and Optimization for Delivery Applications

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 745 ◽  
Author(s):  
Raj Rai ◽  
Saniya Alwani ◽  
Ildiko Badea
Keyword(s):  
Gene Therapy ◽  
Gene Delivery ◽  
Targeted Delivery ◽  
Polymeric Nanoparticles ◽  
Genetic Material ◽  
Delivery Systems ◽  
Viral Gene ◽  
Cationic Polymers ◽  
Natural Polymers ◽  
Viral Gene Delivery

The field of polymeric nanoparticles is quickly expanding and playing a pivotal role in a wide spectrum of areas ranging from electronics, photonics, conducting materials, and sensors to medicine, pollution control, and environmental technology. Among the applications of polymers in medicine, gene therapy has emerged as one of the most advanced, with the capability to tackle disorders from the modern era. However, there are several barriers associated with the delivery of genes in the living system that need to be mitigated by polymer engineering. One of the most crucial challenges is the effectiveness of the delivery vehicle or vector. In last few decades, non-viral delivery systems have gained attention because of their low toxicity, potential for targeted delivery, long-term stability, lack of immunogenicity, and relatively low production cost. In 1987, Felgner et al. used the cationic lipid based non-viral gene delivery system for the very first time. This breakthrough opened the opportunity for other non-viral vectors, such as polymers. Cationic polymers have emerged as promising candidates for non-viral gene delivery systems because of their facile synthesis and flexible properties. These polymers can be conjugated with genetic material via electrostatic attraction at physiological pH, thereby facilitating gene delivery. Many factors influence the gene transfection efficiency of cationic polymers, including their structure, molecular weight, and surface charge. Outstanding representatives of polymers that have emerged over the last decade to be used in gene therapy are synthetic polymers such as poly(l-lysine), poly(l-ornithine), linear and branched polyethyleneimine, diethylaminoethyl-dextran, poly(amidoamine) dendrimers, and poly(dimethylaminoethyl methacrylate). Natural polymers, such as chitosan, dextran, gelatin, pullulan, and synthetic analogs, with sophisticated features like guanidinylated bio-reducible polymers were also explored. This review outlines the introduction of polymers in medicine, discusses the methods of polymer synthesis, addressing top down and bottom up techniques. Evaluation of functionalization strategies for therapeutic and formulation stability are also highlighted. The overview of the properties, challenges, and functionalization approaches and, finally, the applications of the polymeric delivery systems in gene therapy marks this review as a unique one-stop summary of developments in this field.

Understanding why the same gene delivery vector behaves differently in different cell types is essential for developing more adaptable transfection systems

2021 ◽  
Author(s):  
Moataz Dowaidar
Keyword(s):  
Gene Delivery ◽  
High Efficiency ◽  
Transfection Efficiency ◽  
Cell Metabolism ◽  
New Technology ◽  
Cell Types ◽  
Viral Gene ◽  
Proliferation Capacity ◽  
Delivery Vector ◽  
Different Cell Types

Since their origin, non-viral gene delivery reagents have evolved into a variety of effective delivery reagents with a variety of components and designs, and are widely used in gene therapy and gene engineering. A flood of successful commercial gene delivery reagents has also developed, and PEI has emerged as the "gold standard" for the industry. On the other hand, their transfection efficiency must be enhanced and their cell toxicity must be reduced. In recent years, toxicity, efficiency and targeted investigations have progressed. In addition to creating and manufacturing reagents with reduced toxicity and higher efficiency, polypeptides that stimulate cell membrane perforation and tiny molecular compounds that can better compress pDNA, as well as various combinations with liposomes or polymer vectors, have demonstrated improved outcomes. However, most of these freshly created delivery vector reagents are still under investigation, and others require additional refinement to achieve high transfection efficiency and minimum toxicity. The processes behind the effects of various gene delivery reagents, genes, and drugs entering cells, as well as their transit, escape, and cell metabolism, are also unclear. This requires improving relevant research. Understanding why the same reagent reacts differently to different cell types is crucial to creating more adaptive transfection reagents for different cell lines. This is suggested because different cells have different growth cycles. Because of their weak proliferation capacity, primordial cells, for example, are harder to replicate.Artificial intelligence, real-world and virtual-world integration technology, big data, multiomics technology, and signal pathway research have all achieved substantial breakthroughs in recent years, and novel transfection reagents and drug delivery technologies are predicted to continue. It is worth examining how to take advantage of the scientific and high-efficiency benefits that new technology provides for research and how to solve the issues given by the in-depth examination of the selection and mechanism of action of novel composite materials in vector reagent creation.

scholarly journals Enhanced transfection of a macromolecular lignin-based DNA complex with low cellular toxicity

2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Yoon Khei Ho ◽  
Dan Kai ◽  
Geraldine Xue En Tu ◽  
G. Roshan Deen ◽  
Heng Phon Too ◽  
...  
Keyword(s):  
Gene Delivery ◽  
High Efficiency ◽  
Endosomal Escape ◽  
Viral Gene ◽  
Attractive Alternative ◽  
Cationic Polymers ◽  
Dna Amount ◽  
Cellular Toxicity ◽  
Molar Ratios ◽  
Post Transfection

Cationic polymers remain attractive tools for non-viral gene transfer. The effectiveness of these vectors rely on the ability to deliver plasmid DNA (pDNA) into the nucleus of cells. While we have previously demonstrated the potential of Lignin-PGEA-PEGMA as a non-viral gene delivery vector, alterations of cellular phenotype and cytotoxicity were observed post transfection. The present study aims to explore transfection conditions for high efficiency and low toxicity of the Lignin-PGEA-PEGMA based gene delivery system. Cellular toxicity was significantly reduced by using the centrifugation protocol, which enables rapid deposition of DNA complexes. Replacement of media post centrifugation resulted in minimal exposure of cells to excess polymers, which were toxic to cells. At an optimized DNA amount (500–750 ng) and molar ratios of nitrogen (N) in polymer to phosphate (P) in pDNA (N/P = 30–40), with the use of a novel transfection enhancer that facilitates endosomal escape and nuclear trafficking, the efficiency of gene delivery was increased significantly 24 h post transfection. The present study demonstrated an appropriately optimized protocol that enabled the utility of a novel cationic polymer blend with a mixture of fusogenic lipids and a histone deacetylate inhibitor in non-viral transfection, thereby providing an attractive alternative to costly commercial gene carriers.

scholarly journals Preparation and characterization of non-viral gene delivery systems with pEGFP-C1 Plasmid DNA

2018 ◽  
Vol 54 (1) ◽  
Author(s):  
Uğur Karagöz ◽  
Mustafa Kotmakçı ◽  
Hasan Akbaba ◽  
Vildan Bozok Çetintaş ◽  
Gülten Kantarcı
Keyword(s):  
Gene Delivery ◽  
Plasmid Dna ◽  
Delivery Systems ◽  
Viral Gene ◽  
Viral Gene Delivery

scholarly journals 661W photoreceptor cell line as a cell model for studying retinal ciliopathies

2018 ◽  
Author(s):  
Gabrielle Wheway ◽  
Liliya Nazlamova ◽  
Dann Turner ◽  
Stephen Cross
Keyword(s):  
Cell Line ◽  
Primary Cilium ◽  
High Throughput Screening ◽  
Photoreceptor Cell ◽  
Cell Model ◽  
Retinal Pigment Epithelial Cell ◽  
Retinal Pigment ◽  
Photoreceptor Cells ◽  
Retinal Cell ◽  
Epithelial Cell Line

AbstractThe retina contains several ciliated cell types, including the retinal pigment epithelium (RPE) and photoreceptor cells. The photoreceptor cilium is one of the most highly modified sensory cilia in the human body. The outer segment of the photoreceptor is a highly elaborate primary cilium, containing stacks or folds of membrane where the photopigment molecules are located. Perhaps unsurprisingly, defects in cilia often lead to retinal phenotypes, either as part of syndromic conditions involving other organs, or in isolation in the so-called retinal ciliopathies.The study of retinal ciliopathies has been limited by a lack of retinal cell lines. RPE1 retinal pigment epithelial cell line is commonly used in such studies, but the existence of a photoreceptor cell line has largely been neglected in the retinal ciliopathy field. 661W cone photoreceptor cells, derived from mouse, have been widely used as a model for studying macular degeneration, but not described as a model for studying retinal ciliopathies such as retinitis pigmentosa.Here, we characterise the 661W cell line as a model for studying retinal ciliopathies. We fully characterise the expression profile of these cells over many passages, using whole transcriptome RNA sequencing, and provide this data on Gene Expression Omnibus (GEO) for the advantage of the scientific community. We show that these cells robustly express the majority of markers of cone cell origin, including short wave and medium wave opsin. Western blotting confirms expression of selected markers.Using immunostaining and confocal microscopy, alongside scanning electron microscopy, we show that these cells grow long primary cilia, reminiscent of photoreceptor outer segments, and localise many cilium proteins to the axoneme, membrane and transition zone. Immunostaining shows that opsins are localised to the base of this primary cilium. We show that siRNA knockdown of cilia genes Ift88 results in loss of cilia, and that this can be assayed by high-throughput screening. We present evidence that the 661W cell line is a useful cell model for studying retinal ciliopathies.

Progressive protein aggregation in PRPF31 patient retinal pigment epithelium cells: the mechanism and its reversal through activation of autophagy

2021 ◽  
Author(s):  
Maria Georgiou ◽  
Chunbo Yang ◽  
Robert Atkinson ◽  
Kuan-Ting Pan ◽  
Adriana Buskin ◽  
...  
Keyword(s):  
Waste Disposal ◽  
Cell Function ◽  
Core Protein ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Cell ◽  
Visual Cycle ◽  
Nuclear Speckles ◽  
Retinal Cells ◽  
Rpe Cells

Mutations in pre-mRNA processing factor 31 (PRPF31), a core protein of the spliceosomal tri-snRNP complex, cause autosomal-dominant retinitis pigmentosa (adRP). It has remained an enigma why mutations in ubiquitously expressed tri-snRNP proteins result in retina-specific disorders, and so far, the underlying mechanism of splicing factors-related RP is poorly understood. Here, we used iPSC technology to generate retinal organoids and RPE models from three patients with severe and very severe PRPF31-adRP, normal individuals and a CRISPR/Cas9-corrected isogenic control. To fully assess the impacts of PRPF31 mutations, quantitative proteomics analyses of retinal organoids and RPE cells was carried out showing RNA splicing, autophagy and lysosome, unfolded protein response (UPR) and visual cycle-related pathways to be significantly affected. Strikingly, the patient-derived RPE and retinal cells were characterised by the presence of large amounts of cytoplasmic aggregates containing the mutant PRPF31 and misfolded, ubiquitin-conjugated proteins including key visual cycle proteins, which accumulated progressively with time. Mutant PRPF31 variant was not incorporated into splicing complexes, but reduction of PRPF31 wildtype levels led to tri-snRNP assembly defects in Cajal bodies of PRPF31 patient retinal cells with reduced U4/U6 snRNPs and accumulation of U5, smaller nuclear speckles and reduced formation of active spliceosomes giving rise to global splicing dysregulation. Moreover, the impaired waste disposal mechanisms further exacerbated aggregate formation, and targeting these by activating the autophagy pathway using Rapamycin resulted in reduction of cytoplasmic aggregates and improved cell survival. Our data demonstrate that it is the progressive aggregate accumulation that overburdens the waste disposal machinery rather than direct PRPF31-initiated mis-splicing, and thus relieving the RPE cells from insoluble cytoplasmic aggregates presents a novel therapeutic strategy that can be combined with gene therapy studies to fully restore RPE and retinal cell function in PRPF31-adRP patients.

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