Papers by Keyword: Gene Delivery

Abstract: Lipid-based formulations have been used as a widespread carrier to improve gene delivery. Niosomes, one type of lipid-based vesicular systems are produced from non-ionic surfactants which are generally inexpensive and potentially more stable than phospholipids. This article was to develop PEGylated cationic niosomes for DNA delivery. Thin film hydration and sonication method were applied for cationic niosomes. The niosome formulations were composed of Span 20, cholesterol (Chol) and plier-like cationic lipid B (PCL-B) with or without cholesterol-polyethylene glycol 2000 (Chol-PEG). The physicochemical properties of cationic niosomes and nioplexes were evaluated including particle size, zeta potential, DNA condensation and serum protection. The transfection efficiency and cell viability were examined in HeLa cells. The particle size and surface charge of PEGylated cationic niosome containing Span 20: Chol: PCL-B: Chol-PEG at the molar ratio of 2.5: 2.5: 1.5: 0.14 (N-PEG2) were 129.47 ± 2.15 nm and 25.93 ± 4.18 mV, respectively. These PEGylated cationic niosomes could condense pDNA into the nanosize particles and also enhance the serum protection ability for at least 6 h. Moreover, N-PEG2 exhibited high transfection efficiency in comparison with lipofectamine^® 2000 and low cytotoxicity. Therefore, the novel PEGylated cationic niosomes have the capability to develop as a promising potential carrier for DNA delivery.

Abstract: Gene therapy has great potential in offering highly promising treatments for cancer. Polymer-metal hybrid nanoparticles (NPs) are good candidates as gene delivery vehicles due to their unique properties and facile functionalization. The polymer component in hybrid NPs can provide accurate cancer cell targeting and high DNA binding ability while the metallic component can provide imaging functions for the nanodevices. In the present study, hybrid NPs comprising an Au-Ag bimetallic core and a folic acid-chitosan shell (Au-Ag@CS-FA) were fabricated. The structure and relevant properties of Au-Ag@CS-FA NPs were subsequently studied using a variety of techniques,like scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM) and UV-visible spectra. Their DNA binding ability was also assessed. Results showed that Au-Ag@CS-FA NPs possessed properties that can make them excellent gene delivery vehicles.

Abstract: The objective of this study was to investigate the transfection efficiency of quaternized chitosan or trimethylated chitosans (TMCs) using the plasmid DNA encoding green fluorescent protein (pEGFP-C2) on human cervical carcinoma cell line (HeLa cells). The factors affecting the transfection efficiency, e.g. degree of quaternization (DQ) and polymer/DNA weight ratio were evaluated. The results revealed that the complexes of TMC30 with DNA had the highest transfection efficiency and safety followed by the complexes of TMC60 and TMC94, respectively. Increasing the DQ of chitosan not only improve the efficiency of gene delivery, but also increase cytotoxicity. In conclusion, TMC30 showed elevated potential as a gene carrier by efficient DNA condensation and mediated the highest level of gene transfection with negligible cytotoxicity in HeLa cells.

Abstract: Polyethylenimine (PEI) was modified by cholic acid at a molar ratio of 1:1. Cholic acid (CA)-modified PEI (PEI-CA) were evaluated for formation of DNA complexes. PEI-CA/pEGFP plasmid DNA complexes were characterized for their size and zeta potential. Gel electrophoresis showed total retardation for PEI-CA/pEGFP complexes formed at weight ratios above 0.25. The particle size and zeta potential of the complexes at a polymer-to-DNA ratio of 0.5 were 295.3 nm and 30.5 mV, respectively. The transfection efficiency of PEI-CA/pEGFP complexes was comparable to unmodified PEI. Cytotoxicity result showed that PEI-CA had lower cytoxicity than PEI. This study suggests that PEI-CA has potential utility as a gene delivery carrier.

Abstract: Heart development is a precisely harmonized process of cellular proliferation, migration, differentiation, and integrated morphogenetic interactions, and therefore it is extremely vulnerable to developmental defects that cause congenital heart diseases (CHD). One of the major causes of CHD has been shown to be the mutations in key cardiac channel-forming proteins namely, connexins (Cxs). Cxs are tetra-spanning transmembrane proteins that form gap junction channels and hemichannels on cellular membrane. They allow passage of small molecules or ions between adjacent cells or between cells and the extracellular environment. Studies have revealed that the spatiotemporal expression of Cxs mainly, Cx31.9, Cx40, Cx43, and Cx45 is essentially involved in early developmental events, morphogenetic transformations, maturation, and functional significance of heart. Our lab and others have shown that mutations in gap junction proteins could result in impaired trafficking, misfolding, and improper channel function of these proteins. It has also been shown that differential expressions of cardiac Cxs are associated with pathophysiological conditions of heart. Collectively, these conditions are coupled with abrogated or modified functionality of relevant channels in cardiac tissue, which are associated with many pathological situations, including CHD. Since CHD are a major cause of morbidity, therefore recovery of such kind of heart defects associated with Cxs is extremely important but remains highly challenging. In this review, we will summarize the role of Cxs in development, morphogenesis, maturation, normal function, and pathology of heart, and propose possible bioengineering techniques to recover defects in cardiac tissues related to the modified functions of Cxs.

Abstract: Gene therapy is a widespread and promising treatment of many diseases resulting from genetic disorders, infections and cancer. The feasibility of the gene therapy is mainly depends on the development of appropriate method and suitable vectors. For an efficient gene delivery, it is very important to use a carrier that is easy to produce, stable, non-oncogenic and non-immunogenic. Currently most of the vectors actually suffer from many problems. Therefore, the ideal gene therapy delivery system should be developed that can be easily used for highly efficient delivery and able to maintain long-term gene expression, and can be applicable to basic research as well as clinical settings. This article provides a brief over view on the concept and aim of gene delivery, the different gene delivery systems and use of different materials as a carrier in the area of gene therapy.

Abstract: In this work we describe the studies of preparation and stability of liposomes formed by 1,1'-[(3,5-didodeciloxycarbonyl-4-phenyl-1,4-dihydropyridine-2,6-diil) dimethylebispyridinium dibromide, novel lipid-like compound. The influence of the amount of amphiphilic compound, solvent and sonication time was studied. Liposomes were prepared by dispersing of compound in the corresponding media at a selected concentration by sonication using a probe type sonicator and characterised by atomic force microscopy (AFM) and dynamic light scattering (DLS) methods.

Abstract: We report here the intracellular trafficking characteristics of a gene delivery system composed by magnetic layered double hydroxide/DNA (MLDH/DNA) hybrids to human gastric cancer cells (SGC-7901). Perls Staining of MLDH/DNA was done to examine the intracellular iron uptake and accumulation; confocal microscopy and transmission electron microscopy were evaluated the cellular internalization feature of the MLDH/DNA system. We have indicated that the MLDH/DNA hybrids are able to enter into the nucleus within 2 h of incubation, displaying a prospect for application in targeted gene delivery.

Abstract: The present study investigated a novel surface modification on metal coronary stent for antibody immobilization. Methods: 316L stainless steel stents were surface modified with protein coatings. An Anti-DNA antibody was covalently bound to the protein surface using a bi-functional cross-linking agent SPDP. The artwork and binding stability of protein coatings were evaluated by in-vitro eluting. The feasibility and stability of anti-DNA antibody covalently bound to the stent were evaluated by means of 125I labeling. Results: We observed that pre-treating the steel surface using diluted HCL and increasing the ratio of cross-linking agent caused significantly increased binding stability of the protein coatings (p﹤0.001). The amount of chemically coupled antibody on the stents was 8 times higher than that of physically absorbed control stents. The stability of chemically coupled antibody on the stent was significantly better than physically absorbed control. Conclusion: It is concluded that we optimized the technique of protein coating on stainless steel and achieved stable anti-DNA antibody immobilization, therefore enabled efficient and highly localized non-viral gene delivery.

Abstract: Cationic carriers including polyethylenimine, liposomes, and chitosan have been used to transfer plasmid DNA in vitro by condensing anionic DNA. Here, oligochitosan (OC) was found to have capacity for in-vitro gene delivery in four cell lines. Plasmid containing green fluorescent protein (GFP) gene was used as a reporter gene. The transfection efficacy and cell viability of the transfection vehicles were analyzed by using a high-throughput image analyzer. We found that DNA polyplexes formed by high dosage of OC could be efficiently delivered into the cells. The combination of OC and polyethylenimine (PEI) were found to significantly enhance the fluorescence protein expression. The introduction of oligochitosan in PEI-mediated transfection could increase the transfection efficacy and could reduce the toxicity of PEI. Additionally, the synergistic effects of PEI and OC were confirmed in CHO, Caco2, Hep-SK, and 3T3 cell lines. The detailed mechanism of PEI and oligochitosan on transfection was investigated by using gel retardation and DNase degradation experiments. A facile and inexpensive construction of gene delivering vehicles was developed herein by using oligochitosan and PEI.