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Cationic Lipid (cationic + lipid)
Selected AbstractsSynthetic Diether-linked Cationic Lipids for Gene DeliveryCHEMICAL BIOLOGY & DRUG DESIGN, Issue 3 2006Dongliang Liu Quaternary ammonium lipids 2a,p, with diether linkages between hydrocarbon chains and their ammonium headgroups, were synthesized as potential vectors for cationic liposome-mediated gene delivery. Varying the length of carbon chains and quaternary ammonium heads as well as different anionic complexes will enable the study of the structure,function relationships of these cationic lipids in terms of gene delivery properties. [source] Maintenance of nonviral vector particle size during the freezing step of the lyophilization process is insufficient for preservation of activity: Insight from other structural indicatorsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 10 2001Marion d.C. Molina Abstract The instability of nonviral vectors as liquid formulations has stimulated considerable interest in developing dehydrated formulations that would be resistant to shipping stresses and could be stored at room temperature. Recently, we reported that high sucrose/DNA ratios are capable of maintaining particle size during the freezing step of the lyophilization process and we suggested that the separation of individual particles within sugar matrices is responsible for the reported protection of nonviral vectors during the freezing step of a typical lyophilization protocol. The purpose of this study was to extend these observations to other nonviral vectors that incorporate different cationic components. Cationic lipid-based complexes composed of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), with helper lipid cholesterol (Chol) or dioleoylphosphatidyl-ethanolamine (DOPE), showed similar protection by sucrose. Formulations of a polyethylenimine (PEI)-based vector required much higher excipient/DNA ratios for size protection compared with protamine- and lipid-based vectors. At low sucrose/DNA ratios, zeta potentials for all complexes were significantly lowered during freezing. Similar results were obtained at high sucrose/DNA ratios, except for DOTAP,DOPE-containing vectors which maintained zeta potential values comparable to unfrozen controls. The changes in zeta potential values indicate that complexes are altered during freezing despite the maintenance of particle size as determined by light scattering. Furthermore, these changes might explain the observed reduction in transfection activity and provide new information about the effects of physicochemical changes of nonviral vectors during the freezing step of lyophilization. © 2001 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 90:1445,1455, 2001 [source] Combination Nonviral Interleukin-2 Gene Immunotherapy For Head and Neck Cancer: From Bench Top to BedsideTHE LARYNGOSCOPE, Issue 3 2005Bert W. O'Malley Jr MD Abstract Objective/Hypothesis: Intralesional delivery of cytokine genes has emerged as a promising therapeutic strategy for the treatment of cancer. In addition to the therapeutic effect of the delivered cytokine gene, the components of the gene delivery system also have been shown to induce beneficial immune responses. On the basis of these principles, we hypothesized that a molecular therapy could be developed that would provide synergistic antitumor activity by way of intralesional expression of interleukin (IL)-2 from a recombinant plasmid combined with induction of endogenous interferon (IFN)-, and IL-12 cytokines by immunostimulatory DNA. Our objective in these studies was to create and optimize a novel formulation of cationic lipid and DNA that generates local production of IL-2 protein within a targeted tumor environment with concomitant induction of the antitumor cytokines IFN-, and IL-12. Study Design: Prospective laboratory drug development plan that would produce human clinical trials. Materials and Methods: Engineered bacterial plasmids containing a cytomegalovirus promoter (CMV)-IL-2 expression cassette were specifically formulated with cationic lipids and optimized for antitumor effect in a floor of mouth murine tumor model. The treated tumors were assayed for local expression of IL-2 and concurrent expression of secondary cytokines IFN-, and IL-12. Established tumors in C3H/HeJ mice were treated with various IL-2 gene formulations, and clinical and immunologic responses were evaluated. Immunologic studies were performed and included cytolytic T-cell assays and cytokine expression profiles. For human clinical trials, a phase I 10 patient formulated IL-2 gene therapy study was completed. Subsequently, two large scale, phase II multi-institutional and multi-international studies were initiated comparing non-viral IL-2 gene therapy to palliative methotrexate chemotherapy or in combination with cisplatin. Results: In the preclinical stage, maximum tumor inhibition in animal models was obtained using IL-2 plasmid formulated with 1,2-dioleyloxypropyl-3-trimethyl ammonium chloride (DOTMA):cholesterol (1:1 mol:mol) at a plasmid:lipid charge ratio of 1:0.5 (,/+). Cationic lipid formulated IL-2 plasmid significantly inhibited tumor growth compared with formulated control plasmid (P < .01) or vehicle (lactose; P < .01). Consistent with previously reported studies of the immunostimulatory activity of DNA of bacterial origin, treatment of tumors with control plasmid in cationic lipid formulation induced production of endogenous IFN-, and IL-12 but not IL-2. Treatment of tumors with formulated IL-2 plasmid produced IL-2 protein levels that were 5-fold over background and increased IFN-, by 32-fold (P < .001) and IL-12 by 5.5-fold (P < .001) compared with control plasmid formulations. The phase I human trial demonstrated dose escalation safety, which was its primary objective, and there was one anecdotal reduction in tumor size. The phase II studies have been initiated and focus on either comparing the novel nonviral IL-2 gene immunotherapy formulation alone to methotrexate or comparing IL-2 gene therapy in combination with cisplatin in recurrent or unresectable patients with head and neck squamous cell carcinoma. Conclusions: The preclinical data provided proof of principle for matching a delivered IL-2 transgene with an immunostimulatory nonviral formulation to enhance intralesional production of therapeutic cytokines for the maximization of antitumor response. Human clinical trials have demonstrated this novel therapy to be safe in the human clinical setting. Phase II trials have been initiated to assess efficacy and feasibility as a single or combination therapy for head and neck cancer. [source] Cationic and anionic lipid-based nanoparticles in CEC for protein separationELECTROPHORESIS, Issue 11 2010Christian Nilsson Abstract The development of new separation techniques is an important task in protein science. Herein, we describe how anionic and cationic lipid-based liquid crystalline nanoparticles can be used for protein separation. The potential of the suggested separation methods is demonstrated on green fluorescent protein (GFP) samples for future use on more complex samples. Three different CEC-LIF approaches for protein separation are described. (i) GFP and GFP N212Y, which are equally charged, were separated with high resolution by using anionic nanoparticles suspended in the electrolyte and adsorbed to the capillary wall. (ii) High efficiency (800,000 plates/m) and peak capacity were demonstrated separating GFP samples from Escherichia coli with cationic nanoparticles suspended in the electrolyte and adsorbed to the capillary wall. (iii) Three single amino-acid-substituted GFP variants were separated with high resolution using an approach based on a physical attached double-layer coating of cationic and anionic nanoparticles combined with anionic lipid nanoparticles suspended in the electrolyte. The soft and porous lipid-based nanoparticles were synthesized by a one-step procedure based on the self-assembly of lipids, and were biocompatible with a large surface-to-volume ratio. The methodology is still under development and the optimization of the nanoparticle chemistry and separation conditions can further improve the separation system. In contrast to conventional LC, a new interaction phase is introduced for every analysis, which minimizes carry-over and time-consuming column regeneration. [source] Effect of methylglyoxal modification and phosphorylation on the chaperone and anti-apoptotic properties of heat shock protein 27JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2006Tomoko Oya-Ito Abstract Heat shock protein 27 (Hsp27) is a stress-inducible protein in cells that functions as a molecular chaperone and also as an anti-apoptotic protein. Methylglyoxal (MGO) is a reactive dicarbonyl compound produced from cellular glycolytic intermediates that reacts non-enzymatically with proteins to form products such as argpyrimidine. We found considerable amount of Hsp27 in phosphorylated form (pHsp27) in human cataractous lenses. pHsp27 was the major argpyrimidine-modified protein in brunescent cataractous lenses. Modification by MGO enhanced the chaperone function of both pHsp27 and native Hsp27, but the effect on Hsp27 was at least three-times greater than on pHsp27. Phosphorylation of Hsp27 abolished its chaperone function. Transfer of Hsp27 using a cationic lipid inhibited staurosporine (SP)-induced apoptotic cell death by 53% in a human lens epithelial cell line (HLE B-3). MGO-modified Hsp27 had an even greater effect (62% inhibition). SP-induced reactive oxygen species in HLE-B3 cells was significantly lower in cells transferred with MGO-modified Hsp27 when compared to native Hsp27. In vitro incubation experiments showed that MGO-modified Hsp27 reduced the activity of caspase-9, and MGO-modified pHsp27 reduced activities of both caspase-9 and caspase-3. Based on these results, we propose that Hsp27 becomes a better anti-apoptotic protein after modification by MGO, which may be due to multiple mechanisms that include enhancement of chaperone function, reduction in oxidative stress, and inhibition of activity of caspases. Our results suggest that MGO modification and phosphorylation of Hsp27 may have important consequences for lens transparency and cataract development. J. Cell. Biochem. © 2006 Wiley-Liss, Inc. [source] Synthesis and Electro-Optical Properties of a Novel DNA,Lipid Complex Carrying Carbazole MoietiesMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 3 2010Jinqing Qu Abstract A novel DNA,lipid complex carrying carbazole (Cz) moieties was prepared by substituting the sodium counter cation with cationic lipid, namely lipid(2Cz), in which the actual mole ratio of phosphate to lipid was 1:1.05. The DNA,lipid(2Cz) complex was soluble in common organic solvents including CHCl3, CH2Cl2, methanol, and ethanol, while insoluble in THF, toluene, and water. CD spectroscopy revealed that the DNA,lipid complex took a predominantly double helical structure in methanol and that the helical structure was fairly stable against heating. A solution of the DNA,lipid(2Cz) complex emitted fluorescence in 40.0% quantum yield, which was lower than that of the corresponding lipid(2Cz) (76%). The cyclic voltammograms of the complex indicated that the oxidation potential of DNA,lipid(2Cz) was 0.65,V. The onset temperature of weight loss of the DNA,lipid complex is 230,°C according to TGA in air. [source] Modulation of adenovirus infection in vitro by antisense oligodeoxynucleotidesRESPIROLOGY, Issue 3 2003Bruce F. WHITEHEAD Objective: Antisense oligodeoxynucleotides (ODNs) may represent a novel, airway directed approach to the treatment of adenovirus infection of the lung, for which no specific therapy exists. This study assessed the efficacy of antisense ODNs in modulating adenovirus infection in vitro. Methodology: A biological assay, which quantified viral plaque formation by wild type adenovirus 5 in a lung epithelial cell line (A549), was used to evaluate the inhibitory effect of a number of antisense ODNs targeted to the early (E) 1 A and protein IX genes of adenovirus 5. Antisense ODNs (20,21mers, phosphorothioate end-protected) were designed to straddle the initiation of translation (AUG) codon of the mRNA of the targeted gene. Results: There was a consistent and significant (P < 0.005) reduction in viral plaque formation in those cells treated with an E1A antisense ODN, compared with the nonsense control ODN. Neither the addition of a cationic lipid (Lipofectamine), nor increasing the concentration of ODN from 1 µmol to 15 µmol enhanced the original inhibitory effect observed with the E1A antisense ODN. Conclusions: An antisense ODN targeted to the E1A gene can specifically inhibit adenovirus 5 infection in vitro, suggesting a potential therapeutic role for antisense ODNs in adenovirus infection of the lung. [source] Combination Nonviral Interleukin-2 Gene Immunotherapy For Head and Neck Cancer: From Bench Top to BedsideTHE LARYNGOSCOPE, Issue 3 2005Bert W. O'Malley Jr MD Abstract Objective/Hypothesis: Intralesional delivery of cytokine genes has emerged as a promising therapeutic strategy for the treatment of cancer. In addition to the therapeutic effect of the delivered cytokine gene, the components of the gene delivery system also have been shown to induce beneficial immune responses. On the basis of these principles, we hypothesized that a molecular therapy could be developed that would provide synergistic antitumor activity by way of intralesional expression of interleukin (IL)-2 from a recombinant plasmid combined with induction of endogenous interferon (IFN)-, and IL-12 cytokines by immunostimulatory DNA. Our objective in these studies was to create and optimize a novel formulation of cationic lipid and DNA that generates local production of IL-2 protein within a targeted tumor environment with concomitant induction of the antitumor cytokines IFN-, and IL-12. Study Design: Prospective laboratory drug development plan that would produce human clinical trials. Materials and Methods: Engineered bacterial plasmids containing a cytomegalovirus promoter (CMV)-IL-2 expression cassette were specifically formulated with cationic lipids and optimized for antitumor effect in a floor of mouth murine tumor model. The treated tumors were assayed for local expression of IL-2 and concurrent expression of secondary cytokines IFN-, and IL-12. Established tumors in C3H/HeJ mice were treated with various IL-2 gene formulations, and clinical and immunologic responses were evaluated. Immunologic studies were performed and included cytolytic T-cell assays and cytokine expression profiles. For human clinical trials, a phase I 10 patient formulated IL-2 gene therapy study was completed. Subsequently, two large scale, phase II multi-institutional and multi-international studies were initiated comparing non-viral IL-2 gene therapy to palliative methotrexate chemotherapy or in combination with cisplatin. Results: In the preclinical stage, maximum tumor inhibition in animal models was obtained using IL-2 plasmid formulated with 1,2-dioleyloxypropyl-3-trimethyl ammonium chloride (DOTMA):cholesterol (1:1 mol:mol) at a plasmid:lipid charge ratio of 1:0.5 (,/+). Cationic lipid formulated IL-2 plasmid significantly inhibited tumor growth compared with formulated control plasmid (P < .01) or vehicle (lactose; P < .01). Consistent with previously reported studies of the immunostimulatory activity of DNA of bacterial origin, treatment of tumors with control plasmid in cationic lipid formulation induced production of endogenous IFN-, and IL-12 but not IL-2. Treatment of tumors with formulated IL-2 plasmid produced IL-2 protein levels that were 5-fold over background and increased IFN-, by 32-fold (P < .001) and IL-12 by 5.5-fold (P < .001) compared with control plasmid formulations. The phase I human trial demonstrated dose escalation safety, which was its primary objective, and there was one anecdotal reduction in tumor size. The phase II studies have been initiated and focus on either comparing the novel nonviral IL-2 gene immunotherapy formulation alone to methotrexate or comparing IL-2 gene therapy in combination with cisplatin in recurrent or unresectable patients with head and neck squamous cell carcinoma. Conclusions: The preclinical data provided proof of principle for matching a delivered IL-2 transgene with an immunostimulatory nonviral formulation to enhance intralesional production of therapeutic cytokines for the maximization of antitumor response. Human clinical trials have demonstrated this novel therapy to be safe in the human clinical setting. Phase II trials have been initiated to assess efficacy and feasibility as a single or combination therapy for head and neck cancer. [source] Highly efficient gene transfer into hepatocyte-like HepaRG cells: New means for drug metabolism and toxicity studiesBIOTECHNOLOGY JOURNAL, Issue 3 2010Veronique Laurent Abstract HepaRG progenitor cells are capable of differentiating into hepatocyte-like cells that express a large set of liver-specific functions. These cells, however, only express small amounts of an important cytochrome P450, the CYP2E1, which limits their use for toxicological studies of drugs metabolized by this pathway. Our aim was to establish an efficient transfection protocol to increase CYP2E1 expression in HepaRG cells. Transfection protocols of the green fluorescent protein (GFP) reporter gene were evaluated using electroporation and cationic lipids belonging to the lipophosphonates, lipophosphoramidates and lipids derived from glycine betaine. Following optimization of the charge ratios, plasmid DNA and formulations with neutral co-lipids, the lipophosphoramidate compounds KLN47 and BSV10, allowed expression of the GFP in ,50% of adherent progenitor HepaRG cells, while electroporation targeted GFP expression in ,85% of both progenitor and differentiated cells in suspension. Transient enforced expression of active CYP2E1 was also achieved in progenitors and/or differentiated HepaRG cells using the electroporation and the lipophosphoramidate compound BSV10. Importantly, in electroporated cells, CYP2E1 expression level was correlated with a significant increase in CYP2E1-specific enzymatic activity, which opens new perspectives for this CYP-dependent drug metabolism and toxicity studies using HepaRG cells. [source] Synthesis and Transfection Activity of New Cationic Phosphoramidate Lipids: High Efficiency of an Imidazolium DerivativeCHEMBIOCHEM, Issue 9 2008Mathieu Mével Dr. Abstract In an effort to enhance the gene-transfer efficiencies of cationic lipids and to decrease their toxicities, a series of new phosphoramidate lipids with chemical similarity to cell membrane phospholipids was synthesised. These lipids contained various cationic headgroups, such as arginine methyl ester, lysine methyl ester, homoarginine methyl ester, ethylenediamine, diaminopropane, guanidinium and imidazolium. Their transfection abilities, either alone or with the co-lipid DOPE, were evaluated in HEK293,T7 cells. We found that imidazolium lipophosphoramidate 7,a/DOPE lipoplexes gave the most efficient transfection with low toxicity (15,%). The luciferase activity was 100 times higher than that obtained with DOTAP/DOPE lipoplexes. The size, , potential, pDNA,liposome interactions and cellular uptakes of the lipoplexes were determined. No definitive correlation between the , potential values and the transfection efficiencies could be established, but the uptake of lipoplexes by the cells was correlated with their final transfection efficiencies. Our results show that imidazolium phosphoramidate lipids constitute a potential new class of cationic lipids for gene transfer. [source] Synthetic Diether-linked Cationic Lipids for Gene DeliveryCHEMICAL BIOLOGY & DRUG DESIGN, Issue 3 2006Dongliang Liu Quaternary ammonium lipids 2a,p, with diether linkages between hydrocarbon chains and their ammonium headgroups, were synthesized as potential vectors for cationic liposome-mediated gene delivery. Varying the length of carbon chains and quaternary ammonium heads as well as different anionic complexes will enable the study of the structure,function relationships of these cationic lipids in terms of gene delivery properties. [source] | ||||||||||||||||