Optimal Transfection Conditions Research Articles

Comparing chemical transfection, electroporation, and lentiviral vector transduction to achieve optimal transfection conditions in the Vero cell line

BackgroundTransfection is an important analytical method for studying gene expression in the cellular environment. There are some barriers to efficient DNA transfection in host cells, including circumventing the plasma membrane, escaping endosomal compartmentalization, autophagy, immune sensing pathways, and translocating the nuclear envelope. Therefore, it would be very useful to introduce an optimum transfection approach to achieve a high transfection efficiency in the Vero cell line. The aim of this study was to compare various transfection techniques and introduce a highly efficient method for gene delivery in Vero cells.MethodsIn the current study, three transfection methods were used, including chemical transfection, electroporation, and lentiviral vector transduction, to obtain the optimum transfection conditions in the Vero cell line. Vero cells were cultured and transfected with chemical transfection reagents, electroporation, or HIV-1-based lentivectors under different experimental conditions. Transfection efficiency was assessed using flow cytometry and fluorescence microscopy to detect GFP-positive cells.ResultsAmong the tested methods, TurboFect™ chemical transfection exhibited the highest efficiency. Optimal transfection conditions were achieved using 1 µg DNA and 4 µL TurboFect™ in 6 × 104 Vero cells.ConclusionTurboFect™, a cationic polymer transfection reagent, demonstrated superior transfection efficiency in Vero cells compared with electroporation and lentivirus particles, and is the optimal choice for chemical transfection in the Vero cell line.

A High-Throughput Microdroplet-Based Single Cell Transfection Method for Gene Knockout Based on the CRISPR/Cas9 System.

The efficient application of the newly developed gene-editing method CRISPR/Cas9 requires more accurate intracellular gene delivery. Traditional delivery approaches, such as lipotransfection and non-viral delivery methods, must contend with major problems to overcome the drawbacks of low efficiency, high toxicity, and cell-type dependency. The high-throughput microdroplet-based single-cell transfection method presented herein provides an alternative method for delivering genome-editing reagents into single living cells. By accurately controlling the number of exogenous plasmids in microdroplets, this method can achieve high-efficiency delivery of nucleic acids to different types of single cells. This paper presents a high-throughput quantitative DNA transfection method for single cells and explores the optimal DNA transfection conditions for specific cell lines. The transfection efficiency of cells at different concentrations of DNA in microdroplets is measured. Under the optimized transfection conditions, the method is used to construct gene-knockout cancer cell lines to determine specific gene functions through the CRISPR/Cas9 knockout system. In a case study, the migration ability of TRIM72 knockout cancer cells is inhibited, and the tumorigenicity of cells in a zebrafish tumor model is reduced. A single-cell microfluidic chip is designed to achieve CRISPR/Cas9 DNA transfection, dramatically improving the transfection efficiency of difficult-to-transfect cells. This research demonstrates that the microdroplet method developed herein has a unique advantage in CRISPR/Cas9 gene-editing applications.

Abstract 7290: Novel plasmid-based screening method for cervical cancer

Abstract Introduction: Alabama (AL) is tied for third-highest incidence rate and has second-highest death rate of cervical cancer as of 2020. Globally, cervical cancer has the fourth-highest incidence among cancers in women; 90% of deaths from cervical cancer in 2020 occurred in low- and middle-income (LMIC) countries. Inhibitor of differentiation/DNA binding 1 (Id1) expression correlates with tumorigenesis, clinical grade/stage, and aggressiveness of cervical cancer. Thus, Id1 expression could be exploited in novel screening approaches that aim to improve survival rates of cervical cancer in LMIC and clinically underserved settings. As a first step in developing an Id1-based screening approach, these preclinical studies utilized a plasmid that induces expression of a secreted reporter enzyme (secreted embryonic alkaline phosphatase, SEAP), controlled by the Id1 promoter sequence (pId1-SEAP). These studies examined relationships between Id1 expression and kinetics of reporter expression following plasmid transfection to detect human cervical cancer cells. Methods and Results: To confirm the relevance of Id1 as a target in cervical cancer, immunohistochemical staining for Id1 was performed on a human cervical cancer tissue microarray. Western blotting was performed to determine Id1 expression in human cervical cancer cell lines (HeLa, SiHa, CaSki). Optimal transfection conditions with pId1-SEAP were determined experimentally for each line, and then media was sampled through a 48-hour period post-transfection to quantify reporter SEAP expression. Immunohistochemical stain for Id1 showed that early stage and late stage human cervical cancer tissues expressed significantly (p < 0.05) higher levels of Id1 compared to normal tissues, with stain optical density values being 3e5±1e5 for early and late stage compared to 3e4±3e4 for normal tissues (early stage p=0.0001, late stage p=0.0002). Western blot for Id1 in HeLa, SiHa, and CaSki lines showed that all three positively expressed Id1, with Beta-actin-normalized expression values of 0.78±0.12, 1.12±0.05, and 0.76±0.08, respectively. The cell lines transfected with pId1-SEAP expressed SEAP at rates significantly higher than control cells, with the highest rates of production seen during the 36-48-hour post-transfection period. Rates of SEAP production (counts/hour) during this time period were 1e4±3e3 (p=0.0278), 8e2±1e2 (p=0.0834), and 3e2±5e1 (p=0.0683) for transfected HeLa, SiHa, and CaSki cells, respectively. Conclusions: The pId1-SEAP system enabled sensitive detection of cervical cancer cells. These preliminary data support future studies evaluating the in vivo performance of the system in preclinical models of early stage cervical cancer. Further development of this approach could enable sensitive and reliable detection of cervical cancer during early stages when treatment is most effective. Citation Format: Abbigael Eli, Yolanda Hartman, Benjamin B. Kasten, Rebecca Arend, Jason Warram. Novel plasmid-based screening method for cervical cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7290.

Optimizing the Delivery of mRNA to Mesenchymal Stem Cells for Tissue Engineering Applications.

Messenger RNA (mRNA) represents a promising therapeutic tool in the field of tissue engineering for the fast and transient production of growth factors to support new tissue regeneration. However, one of the main challenges to optimizing its use is achieving efficient uptake and delivery to mesenchymal stem cells (MSCs), which have been long reported as difficult-to-transfect. The aim of this study was to systematically screen a range of nonviral vectors to identify optimal transfection conditions for mRNA delivery to MSCs. Furthermore, for the first time, we wanted to directly compare the protein expression profile from three different types of mRNA, namely, unmodified mRNA (uRNA), base-modified mRNA (modRNA), and self-amplifying mRNA (saRNA) in MSCs. A range of polymer- and lipid-based vectors were used to encapsulate mRNA and directly compared in terms of physicochemical properties as well as transfection efficiency and cytotoxicity in MSCs. We found that both lipid- and polymer-based materials were able to successfully condense and encapsulate mRNA into nanosized particles (<200 nm). The overall charge and encapsulation efficiency of the nanoparticles was dependent on the vector type as well as the vector:mRNA ratio. When screened in vitro, lipid-based vectors proved to be superior in terms of mRNA delivery to MSCs cultured in a 2D monolayer and from a 3D collagen-based scaffold with minimal effects on cell viability, thus opening the potential for scaffold-based mRNA delivery. Modified mRNA consistently showed the highest levels of protein expression in MSCs, demonstrating 1.2-fold and 5.6-fold increases versus uRNA and saRNA, respectively. In summary, we have fully optimized the nonviral delivery of mRNA to MSCs, determined the importance of careful selection of the mRNA type used, and highlighted the strong potential of mRNA for tissue engineering applications.

Optimization of a lipid nanoparticle-based protocol for RNA transfection into primary mononuclear phagocytes.

The effective delivery of synthetic RNA into mononuclear phagocytes is a prerequisite for experimental research and therapeutic development. However, traditional methods are highly ineffective and toxic for these cells. Here, we aimed to optimize a transfection protocol for primary bone marrow-derived phagocytes, specifically dendritic cells and macrophages, using lipid nanoparticles generated by microfluidics. Our results show that a lipid mixture similar to that used in Moderna's COVID-19 messenger RNA vaccine outperforms the others tested. Improved messenger RNA transfection can be achieved by replacing uridine with methylpseudouridine but not methoxyuridine, which interferes with transfection. The addition of diphenyleneiodonium or apocynin can enhance transfection in a cell type-dependent manner without adverse effects, while apolipoprotein E provides no added value. These optimized transfection conditions can also be used for microRNA agonists and antagonists. In sum, this study offers a straightforward, highly efficient, reproducible, and nontoxic protocol to deliver RNA into different primary mononuclear phagocytes in culture.

Optimization of transfection methods for human lymphoblast TK6 cell line

Transfection has recently gained attention in the field of biomedical research due to its ability to manipulate gene expression. Every mammalian cell type has a characteristic set of requirements for optimal transfection. Some cells can be difficult to transfect and require optimization for successful transfection. Human lymphoblast TK6 cell line, an important cell line for genotoxic studies, is known to be extremely hard to transfect. Thus, optimizing transfection methods for human lymphoblast TK6 are increasingly important. To accomplish this, TK6 human lymphoblasts were transfected with plasmid constructs that expressed green fluorescent protein (GFP) and NanoLuc® activity. We compared the transfection efficiency of three commercially available transfection reagents, including Amaxa 96-well Nucleofection procedure using various solutions (SF, SE, and SG), Lipofectamine LTX, and Metafectene Pro®. The transfection efficiency and toxicity of various reagents were tested by fluorescence microscopy, luciferase activity, and cell viability assays. Amaxa 96-well Nucleofection Solution SF was identified as the best transfection reagent due to its relatively high luciferase activity, acceptable cell viability (80%), and GFP transfection efficiency (80%). Optimal conditions for transfection utilized with this reagent included 0.4 μg of plasmid DNA, 1.8 × 105 cells, and using the DS 137 Nucleofector program.

In vitro investigation of HBV clinical isolates from Chinese patients reveals that genotype C isolates possess higher infectivity than genotype B isolates.

Hepatitis B virus (HBV) genotype B and C are two major genotypes that are prevalent in Asia and differ in natural history and disease progression. The impact of HBV genotypes on viral replication and protein expression has been explored by the transfection of hepatoma cells with replication-competent HBV DNA, which mimics the later stages of the viral life cycle. However, the influence of HBV genotypes on the early events of viral infection remains undetermined, mainly due to the difficulties in obtaining sufficient infectious viral particles for infection assays. Here, we report that a high-titer HBV inoculum can be generated from the transient transfection-based cell model after optimizing transfection conditions and modifying the HBV-expressing construct. By performing in vitro infection assays using transiently transfected derived viruses, we found that clinical genotype C isolates possessed higher infectivity than genotype B isolates. Moreover, we identified a naturally occurring mutation sL21S in small hepatitis B surface protein, which markedly decreased the infectivity of HBV genotype C isolates, but not that of genotype B isolates. In summary, using infectious viral particles provided by the optimized transient transfection-based cell model, we have been able to investigate a wide range of HBV variants on viral infectivity, which may contribute to our understanding of the reasons for different clinical outcomes in HBV infections and the development of therapeutic drugs targeting the early stages of HBV life cycle.

Design of transfections: Implementation of design of experiments for cell transfection fine tuning.

Transfection is the process by which nucleic acids are introduced into eukaryotic cells. This is fundamental in basic research for studying gene function and modulation of gene expression as well as for many bioprocesses in the manufacturing of clinical‐grade recombinant biologics from cells. Transfection efficiency is a critical parameter to increase biologics' productivity; the right protocol has to be identified to ensure high transfection efficiency and therefore high product yield. Design of experiments (DoE) is a mathematical method that has become a key tool in bioprocess development. Based on the DoE method, we developed an operational flow that we called “Design of Transfections” (DoT) for specific transfection modeling and identification of the optimal transfection conditions. As a proof of principle, we applied the DoT workflow to optimize a cell transfection chemical protocol for neural progenitors, using polyethyleneimine (PEI). We simultaneously varied key influencing factors, namely concentration and type of PEI, DNA concentration, and cell density. The transfection efficiency was measured by fluorescence imaging followed by automatic counting of the green fluorescent transfected cells. Taking advantage of the DoT workflow, we developed a new simple, efficient, and economically advantageous PEI transfection protocol through which we were able to obtain a transfection efficiency of 34%.

A Background Assessable and Correctable Bimolecular Fluorescence Complementation System for Nanoscopic Single-Molecule Imaging of Intracellular Protein-Protein Interactions.

Bimolecular Fluorescence Complementation (BiFC) is a versatile approach for intracellular analysis of protein-protein interactions (PPIs), but the tendency of the split fluorescent protein (FP) fragments to self-assemble when brought into close proximity of each other by random collision can lead to generation of false-positive signals that hamper high-definition imaging of PPIs occurring on the nanoscopic level. While it is thought that expressing the fusion proteins at a low level can remove false positives without impacting specific signals, there has been no effective strategy to test this possibility. Here, we present a system capable of assessing and removing BiFC false positives, termed Background Assessable and Correctable-BiFC (BAC-BiFC), in which one of the split FP fragments is fused with an optically distinct FP that serves as a reference marker, and the single-cell fluorescence ratio of the BiFC signal to the reference signal is used to gauge an optimal transfection condition. We showed that when BAC-BiFC is designed to image PPIs regulating Human Immunodeficiency Virus type 1 (HIV-1) assembly, the fluorescence ratio could decrease with decreasing probe quantity, and ratios approaching the limit of detection could allow physiologically relevant characterization of the assembly process on the nanoscale by single-molecule localization microscopy (SMLM). With much improved clarity, previously undescribed features of HIV-1 assembly were revealed.

MRNA Transfection-Induced Activation of Primary Human Monocytes and Macrophages: Dependence on Carrier System and Nucleotide Modification

Monocytes and macrophages are key players in maintaining immune homeostasis. Identifying strategies to manipulate their functions via gene delivery is thus of great interest for immunological research and biomedical applications. We set out to establish conditions for mRNA transfection in hard-to-transfect primary human monocytes and monocyte-derived macrophages due to the great potential of gene expression from in vitro transcribed mRNA for modulating cell phenotypes. mRNA doses, nucleotide modifications, and different carriers were systematically explored in order to optimize high mRNA transfer rates while minimizing cell stress and immune activation. We selected three commercially available mRNA transfection reagents including liposome and polymer-based formulations, covering different application spectra. Our results demonstrate that liposomal reagents can particularly combine high gene transfer rates with only moderate immune cell activation. For the latter, use of specific nucleotide modifications proved essential. In addition to improving efficacy of gene transfer, our findings address discrete aspects of innate immune activation using cytokine and surface marker expression, as well as cell viability as key readouts to judge overall transfection efficiency. The impact of this study goes beyond optimizing transfection conditions for immune cells, by providing a framework for assessing new gene carrier systems for monocyte and macrophage, tailored to specific applications.

Optimized AAV package and experimental application of recombinant AAV8/hFⅧ for gene therapy on hemophilia A mice

目的评价携带人凝血因子FⅧ（hFⅧ）的重组腺相关病毒（AAV）血清型8（AAV8/hFⅧ）病毒治疗血友病A（HA）小鼠效果。方法应用pAAV-CB-EGFP，pH22（AAV2血清型）和pfΔ6（腺病毒辅助质粒）摸索在HEK-293细胞中AAV的包装条件，pH22、pfΔ6及pAAV-CB-EGFP质粒按照1∶1∶1的比例进行转染，免疫荧光显微镜观察四个条件（包括10 cm培养皿转10 µg质粒，20 cm培养皿分别转20、30和40 µg质粒）的病毒包装效果。应用最佳包装条件在HEK-293细胞中包装AAV2-EGFP，通过冻融法获得AAV2粗提液，感染HEK-293细胞和16095细胞，应用荧光显微镜观察包装效果。应用最佳转染条件将pAAV-TTR-hFⅧ、pH28、pfΔ6按1∶1∶1的比例转染HEK-293细胞获得AAV8/hFⅧ，两轮的氯化铯梯度离心法纯化病毒，以8×1012 vg/kg剂量经尾静脉注射HA小鼠进行基因治疗，活化部分凝血活酶时间（APTT）测定分析FⅧ的活性。结果20 cm培养皿转染20 µg质粒的条件能够在24、48和72 h都达到最佳的转染效果，且该条件包装的AAV2粗提液在16095细胞中具有较高的感染率。HA小鼠体内AAV8/hFⅧ能够在注射后12周仍有维持在治疗水平的FⅧ活性。结论利用优化包装条件制备的AAV8/hFⅧ能够在HA小鼠体内有效维持治疗水平的FⅧ活性达12周。

Разработка костно-пластического материала, импрегнированного плазмидой с геном костного морфогенетического белка-2

The biological properties of a new gene-activated osteoplastic material based on chitosan sponges impregnated with plasmids with the gene for the bone morphogenetic protein-2 (BMP2) have been studied. The optimal conditions for transfection of multipotent mesenchymal stromal cells with TurboFect reagent were selected. The in vitro osteoinducing effect of the developed material associated with an increase in the expression of osteogenic markers in mesenchymal stromal cells was shown. The designed gene-activated material can be used to repair bone defects. gene-activated material, plasmids, BMP-2, gene therapy, bone regeneration The work was supported by the Russian Science Foundation (Grant no. 16-15-00298).

Introduction of a plasmid and a protein into bovine and swine cells by water-in-oil droplet electroporation.

Instrument cost is a major problem for the transduction of DNA fragments and proteins into cells. Water-in-oil droplet electroporation (droplet-EP) was recently invented as a low-cost and effective method for the transfection of plasmids into cultured human cells. We here applied droplet-EP to livestock animal cells. Although it is difficult to transfect plasmids into bovine fibroblasts using conventional lipofection methods, droplet-EP enabled us to introduce an enhanced green fluorescent protein (EGFP)-expressing plasmid into bovine earlobe fibroblasts. The optimal transfection condition was 3.0 kV, which allowed 19.1% of the cells to be transfected. For swine earlobe fibroblasts, the maximum transfection efficacy was 14.0% at 4.0 kV. After transfection with droplet-EP, 69.1% of bovine and 76.5% of swine cells were viable. Furthermore, droplet-EP successfully transduced Escherichia coli recombinant EGFP into frozen-thawed bovine sperm at 1.5 kV. Flow cytometry analysis revealed that 71.5% of spermatozoa exhibited green fluorescence after transfection. Overall, droplet-EP is suitable for the transfection of plasmids and proteins into cultured livestock animal cells.

Production of Lentiviral Vectors Using Suspension Cells Grown in Serum-free Media

Lentiviral vectors are increasingly utilized in cell and gene therapy applications because they efficiently transduce target cells such as hematopoietic stem cells and T cells. Large-scale production of current Good Manufacturing Practices-grade lentiviral vectors is limited because of the adherent, serum-dependent nature of HEK293T cells used in the manufacturing process. To optimize large-scale clinical-grade lentiviral vector production, we developed an improved production scheme by adapting HEK293T cells to grow in suspension using commercially available and chemically defined serum-free media. Lentiviral vectors with titers equivalent to those of HEK293T cells were produced from SJ293TS cells using optimized transfection conditions that reduced the required amount of plasmid DNA by 50%. Furthermore, purification of SJ293TS-derived lentiviral vectors at 1 L yielded a recovery of 55% ± 14% (n = 138) of transducing units in the starting material, more than a 2-fold increase over historical yields from adherent HEK293T serum-dependent lentiviral vector preparations. SJ293TS cells were stable to produce lentiviral vectors over 4 months of continuous culture. SJ293TS-derived lentiviral vectors efficiently transduced primary hematopoietic stem cells and T cells from healthy donors. Overall, our SJ293TS cell line enables high-titer vector production in serum-free conditions while reducing the amount of input DNA required, resulting in a highly efficient manufacturing option.

Inducible UCP1 silencing: A lentiviral RNA-interference approach to quantify the contribution of beige fat to energy homeostasis.

Energy consuming, heat-producing beige adipocytes, located in classic white adipose tissue (WAT), hold promise for the treatment of obesity. Few reports have quantitatively assessed the contribution of browned 'WAT' to energy expenditure. There is a need for methods to examine beige-fat thermogenesis, independently of classical brown fat. The aim of this study is to optimize an inducible lentiviral shRNA to conditionally knock-down Ucp1 and assess the effects on 'browned' WAT. Primary adipocytes from mouse inguinal WAT converted into thermogenic adipocytes when stimulated with β-adrenergic agonist and thiazolidinedione. There was increased UCP1 protein and importantly increases in various indicators of mitochondrial bioenergetics. Next, we determined optimal transfection conditions for the UCP1-shRNA lentiviral system and subsequently applied this to 'browned' WAT. UCP1 knockdown decreased the brown/beige-fat gene profile and decreased mitochondrial respiration. In summary, this study optimizes lentiviral UCP1-shRNA technology in vitro. This technique could be applied to inguinal fat depots in vivo. This would allow investigation of contribution of depots to whole-body metabolism to help elucidate the physiological relevance of beige fat.

High cell density transient transfection of CHO cells for TGF-β1 expression.

High cell densities for transient transfection with polyethyleneimine (PEI) can be used for rapid and maximal production of recombinant proteins. High cell densities can be obtained by different cultivation systems, such as batch or perfusion systems. Herein, densities up to 18 million cells/mL were obtained by centrifugation for transfection evaluation. PEI transfection efficiency was easily determined by transfected enhanced green fluorescence protein (EGFP) reporter plasmid DNA (pDNA). A linear correlation between fluorescence intensity and transfection efficiency was improved. The transfection efficiency of PEI was highly dependent on the transfection conditions and directly related to the level of recombinant protein. Several factors were required to optimize the transient transfection process; these factors included the media type (which is compatible with low or high cell density transfection), the preculture CHO-K1 suspension cell density, and the pDNA to PEI level. Based on design of experiment (DoE) analyses, the optimal transfection conditions for 10×106cells/mL in the CHOMACS CD medium achieved 73% transfection efficiency and a cell viability of over 80%. These results were confirmed for the production of transforming growth factor-beta 1 (TGF-β1) in a shake flask. The purified TGF-β1 protein concentration from 60mL supernatant was 27µg/mL, and the protein was biologically active.

Electroporation of CRISPR-Cas9 into Malignant B Cells for Loss-of-Function Studies of Target Gene Via Knockout.

CRISPR-Cas9 is a unique technology that enables geneticists and medical researchers to edit genomic DNA for studying biology, pathogenesis, and molecular basis of treatment in malignant B cells. Unfortunately, malignant B cells are extremely difficult to transfect by most traditional methods. In this chapter, we describe the use of the Nucleofector™ Technology-based electroporation system with optimized transfection conditions for generating a malignant B cell model, JEKO-1, with ROR1-gene knockout via CRISPR-Cas9 technology.

Enhanced Production of Anti-PD1 Antibody in CHO Cells through Transient Co-Transfection with Anti-Apoptotic Gene Bcl-xL Combined with Rapamycin

CHO cells are often used to produce monoclonal antibodies in mammalian cell expression systems. In the process of large-scale cell culture, apoptosis is related to cell survival and product quality. Over-expressing an anti-apoptotic gene to delay apoptosis and improve cell growth is one of the strategies for improving productivity of monoclonal antibodies. Autophagy inducer rapamycin can extend the culture duration of CHO cells and affect the yield of antibodies. A method was developed for transient co-transfection of anti-apoptotic genes and genes of interest combined with rapamycin to increase the transient expression of the anti-PD1 antibody. Under the optimal transfection conditions, the combination of Bcl-xL and rapamycin can significantly delay cell apoptosis, inhibit cell proliferation, and prolong cell life-time. As a result, anti-PD1 monoclonal antibody expression levels are increased by more than 2 times.

Cationic Derivatives of Polyisoprenoids and Commercial Lipid‐Based DNA Carriers for Transfection in vivo in Spontaneously Hypertensive Rats

Development of efficient vectors for transfection constitutes a major challenge in modern gene therapy. Viral vectors are considered more effective, but plagued by safety concerns. Research shows that derivatives of polyisoprenoid alcohols (trimethylpolyprenylammonium iodides, called PTAI), may serve as lipofectants. In previous research PTAI were proved to be effective as DNA carriers in vitro and in vivo as carriers of DNA vaccines against influenza virus.In the present study the effectiveness of two compositions (PTAI‐6–8 and PTAI‐10–14, containing a mixture of polyprenols with chain lengths from 6 to 8 subunits and from 10 to 14 subunits, respectively and helper lipids: DOPE (1,2‐dioleoyl‐sn‐glycero‐3‐phosphatidylethanolamine) and DC‐cholesterol (3β‐[N‐(N′,N′‐dimethylaminoethane)‐carbamoyl]cholesterol hydrochloride) was investigated for DNA delivery into rats' cells and compared to the commercially available reagents for transfection: in vivo‐jetPEI® (Polyplus‐transfection) and Avalanche®‐in vivo Transfection Reagent (EZ Biosystems LLC). Selected mixtures were used to enhance the expression of vascular endothelial growth factor type A (VEGF‐A) in spontaneously hypertensive rats (SHR). VEGF deficiency is considered one of the factors in the development of hypertension and related kidney diseases.In preliminary experiments, the mixtures containing lipid‐carriers and plasmid DNA (encoding reporter gene and VEGF‐A) were administered intravenously and observed for 24, 48 or 72 h, to establish the optimal conditions for transfection. Subsequently rats were anesthetized, perfused with PBS, and tissues (liver, spleen, kidney, lung) were collected for analysis. Transfection efficiency was evaluated by flow cytometry (BD FACSCanto™ II system) in single cell suspensions prepared from collected tissues.In almost all tested cell suspensions the level of fluorescence of reporter gene (eGFP or mCherry) was undetectable. Only in the liver higher expression of mCherry was observed with commercial reagents (the % of mCherry positive liver cells with Avalanche® was 42 versus 12% in control group receiving 5% glucose; p&lt;0.05). Due to low efficiency of intravenously applied carriers, we tested if selected mixtures are able to provide stable expression of VEGF‐A gene after direct administration to the kidney. SHR were implanted with osmotic pumps (model 2001, ALZET®) connected to catheters allowing the infusion into the renal medulla.The fluorescence of mCherry in the kidneys was undetectable and there were no changes in tissue, plasma and urine levels of VEGF‐A (ELISA). Unfortunately we were not able to prove the usefulness of PTAI for transfection, however all selected mixtures, including commercially available reagents failed to deliver DNA to renal cellsSupport or Funding InformationNCN 2015/17/N/NZ4/02831This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Gene delivery into Siberian sturgeon cell lines by commercial transfection reagents.

The optimal transfection conditions for efficient transgene delivery into a specific cell type should be empirically determined, particularly in cases involving unusual cell types. We compared the conditions for effective introduction of transgenes into Siberian sturgeon (Acipenser baerii) cell lines by evaluating the cytotoxicity and transfection efficiency of three commercially available transfection reagents: Lipofectamine 2000, X-tremeGENE HP DNA Transfection Reagent, and GeneJuice Transfection Reagent. Plasmid vectors containing the gene encoding enhanced green fluorescent protein were mixed with each of the transfection reagents using reagent-to-plasmid ratios of 1:1, 2:1, and 4:1. Then, the complexes were used to transfect three Siberian sturgeon cell lines derived from the heart, head kidney, and gonad. Cytotoxicity and transfection efficiency were measured via flow cytometry after propidium iodide staining. No significant cytotoxicity was observed at the optimal treatment conditions in all cases, with the exception of Lipofectamine 2000-treated gonad-derived cells. Although the transfection efficiencies in A. baerii cells were generally low, X-tremeGENE HP DNA Transfection Reagent showed the highest transfection efficiency at ratios of 2:1 or 4:1, depending on the cell type. Hence, X-tremeGENE HP DNA Transfection Reagent can be used to effectively transfer foreign genes into three A. baerii cell lines.