disadvantages of electroporation
Systemically injected siRNA could also be delivered into tumors by this method [Valero et al., 2008]. Replicon-immunized mice showed a strong cellular and humoral response, compared to mice immunized with regular mRNA. Langerhans cells (LC) due to their long dendritics and their horizontal orientation, create an almost continuous network that enables them to capture most antigens that enter through the skin. This is an important consideration for ex vivo gene delivery especially to hematopoietic cells. The transport of calcium-regulating hormones was found to be increased by applying electroporation and iontophoresis. A variety of different electrodes could be used depending on the cells to be treated. Keywords: Chemical delivery, gene therapy, non viral . The development of theoretical models has developed our understanding of electroporation mechanism. Intended use of the products mentioned on this page varies. Histochemical analysis of b-galactosidase plasmid electroporated muscle showed a larger transfection area per muscle and a higher plasmid copy number per muscle cell when compared with non-electroporated muscle. The initial study of in vivo EP was the delivery of chemotherapeutic agents to solid tumors. Regarding to in vivo EP is predominantly carried out intramuscularly (i.m. Several formulation strategies have been designed to enhance electroporation efficiency and minimize toxicity. As described above, the bleomycin is used with electroporation (electrochemotherapy) for treatment of tumors in the clinical setting. In addition, DNA complexes of cationic liposomes were electroporated into several histologically distinct mouse subcutaneous tumors, and the efficiency of gene transfer was compared with that of naked DNA electroporation [Anwer, 2008, Lai et al., 2008]. However, further optimization of DNA vaccine delivery is needed for this vaccine modality to ultimately be efficacious in humans [Hallengrd et al., 2012]. Figure 1. Hence, this method is amenable to a broader range of DNA amounts (from low to saturating concentrations), fragment sizes, and complexities. Although the principle of electroporation is applicable to all cell types, its efficiency depends on the electrical properties of the cells. a large electric pulse temporarily disturbs the phospholipid bilayer, allowing molecules like DNA to pass into the cell (Purves et. Advantages and Disadvantages of Power Electronic Converters Recently, peptides and mini-gene vaccines are of particular interest since several epitopes of tumor-associated antigens have been employed as therapeutic and prophylactic cancer vaccines. Electroporation offers many advantages in comparison to other transfection methods, with the main benefits being its applicability for transient and stable transfection of all cell types and its ability to transfect a large number of cells in a short amount of time once optimum electroporation conditions are determined. Recent patents have been focused on the use of genetic immunomodulators, such as universal T helper epitopes derived from tetanus toxin, E. coli heat labile enterotoxin and vegetable proteins, as well as cytokines, chemokines or co-stimulatory molecules such as IL-6, IL-15, IL-21 to amplify immunity against cancer. Advantages and disadvantages of electroporation The data clearly demonstrated that Mo-DCs electroporated with mRNA efficiently present functional antigenic peptides to cytotoxic T cells. Learn more about the Xenon Electroporation System. Licensee IntechOpen. Electrochemotherapy, via cell membrane permeabilizing electric pulses, potentiates the cytotoxicity of non-permeant or poorly permeant anticancer drugs with high intrinsic cytotoxicity, such as bleomycin or cisplatin, at the site of electric pulse. One approach to enhance protein-based vaccine potency is the use of toll-like receptor ligands, such as CpG oligonucleotides, to activate the antigen-specific T cell immune responses [Kang et al., 2011]. However, optimization of pulse and field strength parameters is still required to balance electroporation efficiency and cell viability. Application of Nanotechnology in Drug D van Drunen Littel-van den Hurk and Hannaman, 2010, History and definition of electroporation, Efficient agents involved in electroporation, Prodrugs for Masking the Bitter Taste of Drugs. During electroporation, an electrical pulse is used to create temporary pores in cell membranes through which substances like nucleic acids can pass. However, despite their potential NK cells have proven to be difficult to engineer, with high sensitivity to apoptosis and low levels of gene expression. Table 1. Non-viral vectors are attractive tools in gene therapy and vaccine delivery [Draghia-Akli et al., 2005]. For instance, electroporation has been successfully used to administer several HPV DNA vaccines to mice as well as rhesus macaques, which has prompted its use in an ongoing Phase I clinical trial of VGX-3100, a vaccine that includes plasmids targeting E6 and E7 proteins of both HPV subtypes 16 and 18, for treatment of patients with CIN 2 or 3 [Monie et al., 2010]. Therefore, the electroporation conditions for significant efficacy vary with the molecule to be delivered [Takei et al., 2008]. Up to now, several clinical trials have been planned using the electroporation with DNA vaccines for cancer therapy such as: a) Intra-tumoral IL-12 DNA plasmid (pDNA) [ID: NCT00323206, phase I clinical trials in patients with malignant melanoma, Heller and Heller, 2006; Daud et al., 2008]; 2) Intratumoral VCL-IM01 (encoding IL-2) [ID: NCT00223899; phase I clinical trials in patients with metastatic melanoma]; 3) Xenogeneic tyrosinase DNA vaccine [ID: NCT00471133, phase I clinical trials in patients with melanoma]; 4) VGX-3100 [ID: NCT00685412, phase I clinical trials for HPV infections], and 5) IM injection prostate-specific membrane antigen (PSMA)/ pDOM fusion gene [ID: UK-112, phase I/II clinical trials for prostate cancer, Low et al., 2009; Fioretti et al., 2010] [Saade and Petrovsky, 2012; Bolhassani and Rafati, 2011]. Electroporation | Thermo Fisher Scientific - FR Experimentally measured quantities consist of the membrane lifetimes, the current, the membrane conductance and transmembrane voltage. The plate and fork electrodes were used for the transfer of a plasmid vector for erythropoietin expression into rat skin and were compared with needle-type and disc-type electrodes. Cells with less conductive contents (such as adipocytes) are less susceptible. The main disadvantage of plasmid DNA vaccines is their poor immunogenicity when administered as an unformulated intramuscular injection [Anderson and Schneider, 2007]. Thermo Fisher Scientific offers the Neon NxT Electroporation System for convenient benchtop electroporation as well as the CTS Xenon Electroporation System for GMP-compliant cell therapy applications. All of these methods have a number of specific limitations, such as limited control over the amount of DNA uptake, the intracellular half-life and fate of the introduced DNA, and site of genomic integration [Valero et al., 2008]. The further improvements of electrodes including shape or arrangement of electrodes and electric conditions, by which more efficient and reliable gene transfer is achieved, are important especially in clinical trials. The investigators have shown that low-voltage electroporation can induce immunity and protect mice effectively [Daemi et al., 2012; Zhou et al., 2008]. Gold nanoparticles devoid of DNA coating were not taken up by cells during electroporation. 2000). Gene transfer to plants by electroporation: methods and - PubMed A number of studies have demonstrated the feasibility of targeted delivery of oligonucleotides, small interfering RNA (siRNA), plasmid DNA, and viral vectors to the corneal cells in vivo, specifically stromal keratocytes and corneal epithelial cells, via intrastromal injection, iontophoresis, electroporation, and gene gun. It is a relatively modern method (first described by Felgner et al., 1987), which has in this short time experienced substantial changes.The first-generation lipofection was a single-component system, in which only the lipid N-[l . Strikingly, a non-specific stimulation of CTL was observed when DCs were transfected with plasmid DNA. Its based on principles of collaboration, unobstructed discovery, and, most importantly, scientific progression. 2014 The Author(s). The thresholds for different cells in a heterogeneous tissue would thus vary [Hui, 2008]. Uses, benefits and effects of electroporation | Sisneo Bioscience Disadvantages of IRE. The magnitude of liposome enhancement was dependent on the degree of lipid saturation but independent of polar head group [Anwer, 2008]. Electroporation is a technique that increases the permeability of cell membranes by changing the transmembrane potential and subsequently disrupting the lipid bilayer integrity to allow transportation of molecules across the cell membrane via nano-size pores. Some groups have used intratumoral injection with relatively high doses, while others have applied its lower doses. This tissue-protective effect of hyaluronidase has been observed in ischemic myocardium and tissue edema. For example, dextran uptake during electroporation was enhanced by 80-fold with the addition of phosphatidylglycerol and phosphatidylcholine into the transfection medium. Anionic lipid formulation has shown significant synergistic effect with electroporation on delivering insulin in vitro and in vivo and has the potential to lower the voltage threshold to a small level [Hui, 2008]. However, transfection efficiency in primary cells is low, mostly due to the high mortality rates caused by the electric pulses. This failure of tumor targeting in vivo could be attributed to poor stability of the targeted complexes in extracellular milieu, altered integrin receptor affinity for integrin ligand or suboptimal transfection conditions. Physical delivery systems are one of the efficient non-viral methods including electroporation, micro-injection, gene gun, tattooing, laser and ultrasound [Bolhassani and Rafati, 2011]. Tumor electroporation significantly enhanced DNA delivery into solid tumors. The results indicated that both delivery methods are effective at promoting potent antibodies specific for A [Davtyan et al., 2012]. In bleomycin chemotherapy, treatment was more than 1000 times more effective with electroporation than without electroporation. Different non-viral approaches have been proposed for drug and gene delivery such as physical and chemical methods. Basic concepts and foreseeable future developments in electroporator design are presented in this article. The application of in vivo electroporation to the sites receiving injected plasmid DNA has allowed for dramatic increases in immune responses compared with plasmid DNA injection alone. The electroporation has been first used to enhance the delivery of chemotherapeutic drugs like cisplatin and bleomycin in cancer cells and solid tumors, respectively. The delivery of tumor necrosis factor -specific siRNA via electroporation was shown to inhibit inflammation in mice with collagen-induced arthritis. Electroporator is a generator of electric pulses that is used for permeabilization of cells. Power electronic systems suffer from some disadvantages also. Lipofection - an overview | ScienceDirect Topics Transport efficiency for small charged molecules (MW 1000, e.g., protoporphyrin IX), using the same polarity pulses, was higher than that for uncharged molecules (e.g., protoporphyrin IX methyl ester) or charged molecules with opposite polarity pulses. In skeletal muscle, electroporation enhancement of luciferase gene transfer was 10,000-fold over non-electroporated control. Return cells to growth conditions and allow them to recover. The advantage of this technique is that it is drug-free and is targeted [Heish et al., 2011]. A wide range of pulse patterns have been used both in vitro and in vivo. The enhancement of gene electroporation is associated with significant tissue damage directly related to electroporation intensity. In addition, intradermal DNA electroporation is one of the most efficient non-viral methods for the delivery of gene into the skin [Lin et al., 2012]. Intramuscular injection of erythropoietin plasmid in mouse leg produced systemic levels of erythropoietin that were 100-fold higher than those from erythropoietin plasmid alone. Search For instance, a number of studies have demonstrated long-term, complete tumor regression, using delivery of plasmids encoding IL-12 or IFN- as a single agent in melanoma and squamous cell carcinoma (SCC) [Heller and Heller, 2006]. Background Many research techniques in molecular biology require a foreign gene or protein material to be inserted into a host cell. DNA delivery by electroporation is not target-specific. A study evaluated the immunogenic potential of naked in vitro transcribed Semliki Forest virus replicon RNA (RREP) delivered intradermally in combination with electroporation [Johansson et al., 2012]. Brief introduction to this section that descibes Open Access especially from an IntechOpen perspective, Want to get in touch? Pulse magnitude and duration also has an effect on the damage caused to the cells. Increasing the number of electrodes and/or injection volume, could enhance the transfection efficiency of the conventional electroporation devices [Tjelle et al., 2006]. The efficacy of transport depends on the electrical parameters and the physicochemical properties of drugs. In the combined vaccine group, 7/9 of the volunteers receiving all three vaccinations developed neutralizing antibodies to PUUV. This vaccination was among the first infectious disease DNA vaccine to be delivered in humans using electroporation based DNA delivery [Bolhassani and Rafati, 2011]. Since the phospholipid These advancements in DNA formulation could prove to be useful in improving the safety of electroporation protocols for human applications [Anwer, 2008]. Contact our London head office or media team here. The advantages of this electroporation device are: The design of the electroporation chamber distributes the current equally among the cells and maintains a stable pH throughout the chamber; these key benefits increase cell viability dramatically. A systematic study examining the parameters influencing electroporative transdermal delivery of terazosin hydrochloride to rat skin was previously reported. Pulse protocol and electrode design need to be optimized to reduce the main side effects e.g., muscle contraction. This technique was then tested for enhanced plasmid DNA delivery and subsequently, the initiation of the first clinical trials [Heller and Heller, 2006]. The therapeutic genes delivered in those cases were diverse including cytokine genes (IL-12) and cytotoxic genes (TRAIL), making a wide range of therapeutic strategies [Tamura and Sakata, 2003]. However, due to their low immunogenicity, there is a need for novel approaches to enhance protein-based vaccine potency. These disadvantages have led to the continued development of non-viral . Skin electroporation could be particularly appropriate for topical drug delivery. When electroporation field is applied through the skin using surface plate electrodes, the major potential drop develops across the skin instead of across the targeted subcutaneous tissues. While this preclinical research is promising, further optimization of electrical conditions and electrodes would be necessary for clinical use [Fioretti et al., 2013; Heller and Lucas, 2000]. In the mid-to late 1990s, the efficacy of this approach for drug delivery was demonstrated in a variety of different animal and human tumors. In addition, lowering the electrical field will therefore be important for reducing electroporation-induced pain.