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Gene Delivery (gene + delivery)
Kinds of Gene Delivery Terms modified by Gene Delivery Selected AbstractsFunctionalization of Chitosan via Atom Transfer Radical Polymerization for Gene DeliveryADVANCED FUNCTIONAL MATERIALS, Issue 18 2010Yuan Ping Abstract It is of crucial importance to modify chitosan-based polysaccharides in the designing of biomedical materials. In this work, atom transfer radical polymerization (ATRP) was employed to functionalize chitosan in a well-controlled manner. A series of new degradable cationic polymers (termed as PDCS) composed of biocompatible chitosan backbones and poly((2-dimethyl amino)ethyl methacrylate) (P(DMAEMA)) side chains of different length were designed as highly efficient gene vectors via ATRP. These vectors, termed as PDCS, exhibited good ability to condense plasmid DNA (pDNA) into nanoparticles with positive charge at nitrogen/phosphorus (N/P) ratios of 4 or higher. All PDCS vectors could well protect the condensed DNA from enzymatic degradation by DNase I and they displayed high level of transfectivity in both COS7, HEK293 and HepG2 cell lines. Most importantly, in comparison with high-molecular-weight P(DMAEMA) and ,gold-standard' PEI (25 kDa), the PDCS vectors showed considerable buffering capacity in the pH range of 7.4 to 5, and were capable of mediating much more efficient gene transfection at low N/P ratios. At their own optimal N/P ratios for trasnsfection, the PDCS/pDNA complexes showed much lower cytotoxicity. All the PDCS vectors were readily to be degradable in the presence of lysozyme at physiological conditions in vitro. These well-defined PDCS polymers have great potentials as efficient gene vectors in future gene therapy. [source] PEI,PEG,Chitosan-Copolymer-Coated Iron Oxide Nanoparticles for Safe Gene Delivery: Synthesis, Complexation, and TransfectionADVANCED FUNCTIONAL MATERIALS, Issue 14 2009Forrest M. Kievit Abstract Gene therapy offers the potential of mediating disease through modification of specific cellular functions of target cells. However, effective transport of nucleic acids to target cells with minimal side effects remains a challenge despite the use of unique viral and non-viral delivery approaches. Here, a non-viral nanoparticle gene carrier that demonstrates effective gene delivery and transfection both in vitro and in vivo is presented. The nanoparticle system (NP,CP,PEI) is made of a superparamagnetic iron oxide nanoparticle (NP), which enables magnetic resonance imaging, coated with a novel copolymer (CP,PEI) comprised of short chain polyethylenimine (PEI) and poly(ethylene glycol) (PEG) grafted to the natural polysaccharide, chitosan (CP), which allows efficient loading and protection of the nucleic acids. The function of each component material in this nanoparticle system is illustrated by comparative studies of three nanoparticle systems of different surface chemistries, through material property characterization, DNA loading and transfection analyses, and toxicity assessment. Significantly, NP,CP,PEI demonstrates an innocuous toxic profile and a high level of expression of the delivered plasmid DNA in a C6 xenograft mouse model, making it a potential candidate for safe in vivo delivery of DNA for gene therapy. [source] Polymeric Materials for Gene Delivery and DNA VaccinationADVANCED MATERIALS, Issue 8 2009David N. Nguyen Abstract Gene delivery holds great potential for the treatment of many different diseases. Vaccination with DNA holds particular promise, and may provide a solution to many technical challenges that hinder traditional vaccine systems including rapid development and production and induction of robust cell-mediated immune responses. However, few candidate DNA vaccines have progressed past preclinical development and none have been approved for human use. This Review focuses on the recent progress and challenges facing materials design for nonviral DNA vaccine drug delivery systems. In particular, we highlight work on new polymeric materials and their effects on protective immune activation, gene delivery, and current efforts to optimize polymeric delivery systems for DNA vaccination. [source] Multilayer Nanocomplexes of Polymer and DNA Exhibit Enhanced Gene Delivery,ADVANCED MATERIALS, Issue 1 2008M. Saul Polymeric-DNA complexes (polyplexes) are constructed with multiple layers of counter-polyions as DNA/polyethylenimine/poly(acrylic acid)/polyethylenimine. The increased association of polyethylenimine achieved by the multilayer approach leads to substantial increases in expression of transgene for reporter plasmids without the need for excess free polymer typically required for non-viral gene delivery. This method of polyplex preparation provides the opportunity to improve transgene expression for gene therapy approaches to disease treatment. [source] Covalent Attachment of Low Molecular Weight Poly(ethylene imine) Improves Tat Peptide Mediated Gene Delivery,ADVANCED MATERIALS, Issue 16 2006F. Alexis A polymer-peptide hybrid biomaterial synthesized by coupling poly(ethylene imine) directly to resin-supported Tat peptide takes advantage of the unique features associated with the two original cationic materials and functions as a novel gene-delivery vector with good biocompatibility. The figure shows cells transfected with green fluorescent protein (GFP) using complexes of the polymer-peptide hybrid and GFP (scale bar: 100,,m). [source] Induction of Indoleamine 2,3-Dioxygenase by Gene Delivery in Allogeneic Islets Prolongs Allograft SurvivalAMERICAN JOURNAL OF TRANSPLANTATION, Issue 8 2010H. Dellê Indoleamine 2,3-dioxygenase (IDO), an enzyme that plays a critical role in fetomaternal tolerance, exerts immunoregulatory functions suppressing T-cell responses. The aims of this study were to promote IDO expression in rat islets using a nonviral gene transfer approach, and to analyze the effect of the in vivo induction of IDO in a model of allogeneic islet transplantation. The IDO cDNA was isolated from rat placenta, subcloned into a plasmid and transfected into rat islets using Lipofectamine. The efficiency of transfection was confirmed by qRT-PCR and functional analysis. The in vivo effect of IDO expression was analyzed in streptozotocin-induced diabetic Lewis rats transplanted with allogeneic islets under the renal capsule. Transplantation of IDO-allogeneic islets reversed diabetes and maintained metabolic control, in contrast to transplantation of allogeneic nontransfected islets, which failed shortly after transplantation in all animals. Graft survival of allograft islets transfected with IDO transplanted without any immunosuppression was superior to that observed in diabetic rats receiving nontransfected islets. These data demonstrated that IDO expression induced in islets by lipofection improved metabolic control of streptozotocin-diabetic rats and prolonged allograft survival. [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] Long Chain Pyridinium Salts with a 4-Phenyl Group as Amphiphiles for Potential Nonviral Gene Delivery.CHEMINFORM, Issue 24 2004Mariana Viorica Bogatian Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis and Evaluation of Cationic Lipids Bearing Cholesteryl Groups for Gene Delivery in vitro.CHEMINFORM, Issue 7 2003Man-Zhou Zhu Abstract For Abstract see ChemInform Abstract in Full Text. [source] Gene Delivery by Aminofullerenes: Structural Requirements for Efficient TransfectionCHEMISTRY - AN ASIAN JOURNAL, Issue 1-2 2006Hiroyuki Isobe Dr. Abstract A series of aminofullerenes that share a common structural motif have been synthesized and subjected to a systematic investigation of structure activity relationship regarding their ability for transient transfection and cytotoxicity. DNA-binding tests indicated that any water-soluble fullerene-bearing amino group would bind to double-stranded DNA. For these molecules to be effective transfection reagents, however, they require additional structural features. First, the molecule must be capable of producing submicrometer-sized fullerene/DNA aggregates that can be internalized into mammalian cells through endocytosis. Second, the molecule must be capable of releasing DNA as the aggregates are transferred into the cytoplasm. This can be achieved in at least two ways: by loss of the DNA-binding amino groups from the fullerene core, and by transformation of the amino groups to neutral groups such as amides. The screening experiments led us to identify the best reagent, a tetrapiperidinofullerene, that can be synthesized in two steps from fullerene, piperazine, and molecular oxygen, and that is more efficient at transfection than a commonly used lipid-based transfection reagent. [source] Gene delivery of Cu/Zn-superoxide dismutase improves graft function after transplantation of fatty livers in the ratHEPATOLOGY, Issue 6 2000Thorsten G. Lehmann Oxygen-derived free radicals play a central role in reperfusion injury after organ transplantation, and fatty livers are particularly susceptible. Endogenous radical scavengers such as superoxide dismutase (SOD) degrade these radicals; however, SOD is destroyed rapidly when given exogenously. Therefore, an adenoviral vector encoding the Cu/Zn-SOD gene (Ad.SOD1) was used here to test the hypothesis that organ injury would be reduced and survival increased in a rat model of transplantation of fatty livers. Donors received chow diet (untreated), high-fat diet, or ethanol-containing high-fat diet. Some of the ethanol-fed donors were infected either with the gene lacZ encoding bacterial ,-galactosidase (Ad.lacZ), or Ad.SOD1. After liver transplantation, SOD activity and protein expression in liver, survival, histopathology, release of transaminases, free radical adducts in bile, and activation of NF-,B, I,B kinase (IKK), Jun-N-terminal kinase (JNK), and TNF, were evaluated. Ad.SOD1 treatment increased survival dramatically, blunted transaminase release, and reduced necrosis and apoptosis significantly. Free radical adducts were increased two-fold in the ethanol group compared with untreated controls. Ad.SOD1 blunted this increase and reduced the activation of NF-,B. However, release of TNF, was not affected. Ad.SOD1 also blunted JNK activity after transplantation. This study shows that gene therapy with Ad.SOD1 protects marginal livers from failure after transplantation because of decreased oxygen radical production. Genetic modification of fatty livers using viral vectors represents a new approach to protect marginal grafts against primary nonfunction. [source] Polymeric Materials for Gene Delivery and DNA VaccinationADVANCED MATERIALS, Issue 8 2009David N. Nguyen Abstract Gene delivery holds great potential for the treatment of many different diseases. Vaccination with DNA holds particular promise, and may provide a solution to many technical challenges that hinder traditional vaccine systems including rapid development and production and induction of robust cell-mediated immune responses. However, few candidate DNA vaccines have progressed past preclinical development and none have been approved for human use. This Review focuses on the recent progress and challenges facing materials design for nonviral DNA vaccine drug delivery systems. In particular, we highlight work on new polymeric materials and their effects on protective immune activation, gene delivery, and current efforts to optimize polymeric delivery systems for DNA vaccination. [source] Recombinant mussel adhesive protein as a gene delivery materialBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2009Dong Soo Hwang Abstract Efficient target gene delivery into eukaryotic cells is important for biotechnological research and gene therapy. Gene delivery based on proteins, including histones, has recently emerged as a powerful non-viral DNA transfer technique. Here, we investigated the potential use of a recombinant mussel adhesive protein, hybrid fp-151, as a gene delivery material, in view of its similar basic amino acid composition to histone proteins, and cost-effective and high-level production in Escherichia coli. After confirming DNA binding affinity, we transfected mammalian cells (human 293T and mouse NIH/3T3) with foreign genes using hybrid fp-151 as the gene delivery carrier. Hybrid fp-151 displayed comparable transfection efficiency in both mammalian cell lines, compared to the widely used transfection agent, LipofectamineÔ 2000. Our results indicate that this mussel adhesive protein may be used as a potential protein-based gene-transfer mediator. Biotechnol. Bioeng. 2009;102: 616,623. © 2008 Wiley Periodicals, Inc. [source] Recent developments in carbohydrate-decorated targeted drug/gene deliveryMEDICINAL RESEARCH REVIEWS, Issue 2 2010Hailong Zhang Abstract Targeted delivery of a drug or gene to its site of action has clear therapeutic advantages by maximizing its therapeutic efficiency and minimizing its systemic toxicity. Generally, targeted drug or gene delivery is performed by loading a macromolecular carrier with an appropriate drug or gene, and by targeting the drug/gene carrier to specific cell or tissue with the help of specific targeting ligand. The emergence of glycobiology, glycotechnology, and glycomics and their continual adaptation by pharmaceutical scientists have opened exciting avenue of medicinal applications of carbohydrates. Among them, the biocompatibility and specific receptor recognition ability confer the ability of carbohydrates as potential targeting ligands for targeted drug and gene delivery applications. This review summarizes recent progress of carbohydrate-decorated targeted drug/gene delivery applications. © 2009 Wiley Periodicals, Inc. Med Res Rev, 30, No. 2, 270,289, 2010 [source] Genetic manipulation, whole-cell recordings and functional imaging of the sensorimotor cortex of behaving miceACTA PHYSIOLOGICA, Issue 1 2009C. C. H. Petersen Abstract Sensory processing, sensorimotor integration and motor control are amongst the most basic functions of the brain and yet our understanding of how the underlying neuronal networks operate and contribute to behaviour is very limited. The relative simplicity of the mouse whisker sensorimotor system is helpful for detailed quantitative analyses of motor control and perception during active sensory processing. Recent technical advances now allow the measurement of membrane potential in awake-behaving mice, using whole-cell recordings and voltage-sensitive dye imaging. With these recording techniques, it is possible to directly correlate neuronal activity with behaviour. However, in order to obtain causal evidence for the specific contributions of different neuronal networks to behaviour, it is critical to manipulate the system in a highly controlled manner. Advances in molecular neurobiology, gene delivery and mouse genetics provide techniques capable of layer, column and cell-type specific control of gene expression in the mouse neocortex. Over the next years, we anticipate considerable advances in our understanding of brain function through measuring and manipulating neuronal activity with unprecedented precision to probe the molecular and synaptic mechanisms underlying simple forms of active sensory perception and associative learning. [source] Local gene delivery to the vessel wallACTA PHYSIOLOGICA, Issue 1 2001R. C. Smith This review will provide an overview of delivery strategies that are being evaluated for vascular gene therapy. We will limit our discussion to those studies that have been demonstrated, utilizing in vivo model systems, to limit post-interventional restenosis. We also discuss the efficacy of the vectors and methods currently being used to transfer genetic material to the vessel wall. The efficiency of these techniques is a critical issue for the successful application of gene therapy. [source] Gene therapy in epilepsyEPILEPSIA, Issue 1 2009Véronique Riban Summary Results from animal models suggest gene therapy is a promising new approach for the treatment of epilepsy. Several candidate genes such as neuropeptide Y and galanin have been demonstrated in preclinical studies to have a positive effect on seizure activity. For a successful gene therapy-based treatment, efficient delivery of a transgene to target neurons is also essential. To this end, advances have been made in the areas of cell transplantation and in the development of recombinant viral vectors for gene delivery. Recombinant adeno-associated viral (rAAV) vectors in particular show promise for gene therapy of neurological disorders due to their neuronal tropism, lack of toxicity, and stable persistence in neurons, which results in robust, long-term expression of the transgene. rAAV vectors have been recently used in phase I clinical trials of Parkinson's disease with an excellent safety profile. Prior to commencement of phase I trials for gene therapy of epilepsy, further preclinical studies are ongoing including evaluation of the therapeutic benefit in chronic models of epileptogenesis, as well as assessment of safety in toxicological studies. [source] Construction of Polyethyleneimine-,-cyclodextrin/pDNA Multilayer Structure for Improved In Situ Gene Transfection,ADVANCED ENGINEERING MATERIALS, Issue 1-2 2010Yan Hu This study reports in situ gene delivery from gene-functionalized poly(D,L -lactic acid) (PDLLA, Mw of around 2.0,×,105,g,mol,1) films, which were constructed via layer-by-layer (LbL) assembly technique with low molecular weight polyethylenimine-,-cyclodextrin (PEI-CD) conjugate and plasmid DNA (pDNA). PEI-CD was characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR), respectively. The buildup of multilayered PEI-CD/pDNA pairs onto PDLLA films was monitored with contact angle measurements and UV,Vis spectrometer, respectively. A sustained release of pDNA from multilayered films was observed for 28,h. The mechanism of in situ gene delivery on PDLLA film was investigated in this study as well. Spherical PEI-CD/pDNA complexes were formed and released following the deconstruction of multilayered films, which was confirmed by transmission electron microscopy (TEM) and gel electrophoresis, respectively. Surface mediated in situ gene transfection was achieved when culturing hepatoma G2 (HepG2) and human embryonic kidney 293 (HEK293) onto PEI-CD/pDNA multilayered films. Furthermore, PEI-CD improved the gene transfection efficiency when compared with that of PEI. Such gene-functionalized biomaterial reported here has potential application in tissue engineering and implant technology. [source] Fabrication of Galactosylated Polyethylenimine and Plasmid DNA Multilayers on poly (D,L -lactic acid) Films for in situ Targeted Gene Transfection,ADVANCED ENGINEERING MATERIALS, Issue 5 2009Yan Hu This study presents surface-mediated targeted in situ gene delivery from gene-tagged poly(D,L -lactic acid) (PDLLA) films, which were fabricated via a layer-by-layer (LbL) assembly technique with galactosylated polyethylenimine (GP) and plasmid DNA (pDNA, pSV-,-galactosidase). A linear growth of GP/pDNA multilayered films was observed. The pDNA was continuously released from multilayered films for over 32,h. The multilayered structure degraded and simultaneously formed GP/pDNA complexes in situ when exposing to a physiological environment. The pDNA was well protected by GP against DNase I digestion within formed GP/pDNA complexes. Our results demonstrated that GP contributes to receptor-mediated targeting for cell uptake and in situ gene transfection. The results reported here are potentially important for gene therapy, surface engineering of biomaterials, tissue engineering and implant technology. [source] Gene Transfer Strategies for the PhysiologistEXPERIMENTAL PHYSIOLOGY, Issue 6 2000Liang-Fong Wong Foreign genes can be introduced into whole animals using methods of germline transgenesis and somatic gene delivery. While germline transgenesis can generate useful animal models for genetic studies, it can be costly, time-consuming and requires the use of a large number of animals. An alternative means of gene transfer is to deliver genes to somatic cells using non-viral and viral technologies. Non-viral methods such as naked DNA injection, electroporation and liposome/cation lipid-mediated gene transfer are relatively inefficient. In contrast, viruses are effective vehicles that carry foreign genes into a cell rapidly and efficiently. Here we illustrate the usefulness of adenoviral vectors to express a potent and specific inhibitor of cAMP-dependent protein kinase (PKA) to study the role of cyclic 3,,5,-cyclic AMP (cAMP) in the osmotic regulation of the vasopressin gene in a transgenic rat model. The ability to modify endogenous systems within specific cells in a whole animal model allows gene effects to be studied with physiological relevance. The combination of molecular biology and integrative physiology is a powerful application that can aid in the elucidation of how gene function can translate into complex systems in an organism [source] Somatic Gene Transfer: Implications for Cardiovascular ControlEXPERIMENTAL PHYSIOLOGY, Issue 6 2000S. Kasparov There is a great need for closer integration between physiologists and molecular biologists. These two research fields might soon form a single research discipline under the umbrella of molecular physiology. One of the areas where this interaction may be particularly fruitful is with somatic gene transfer using replication-deficient viral vectors. We applied this approach to study the central control of the cardiovascular system at the level of the nucleus of the solitary tract (NTS). We assess critically this new methodology as applied to experiments in an integrative environment (such as the whole animal). The usefulness of in vivo gene transfer is illustrated by an experiment where viral gene delivery helped to circumvent the problem imposed by an absence of a specific pharmacological blocker of the enzyme, endothelial nitric oxide synthase (eNOS). The pros and cons of using adenoviral vectors as opposed to conventional pharmacological approaches are discussed. We conclude that the use of adenoviruses to manipulate genes offers a new avenue for physiologists studying neuronal mechanisms in integrative models. [source] Uptake and Release of Double-Walled Carbon Nanotubes by Mammalian CellsADVANCED FUNCTIONAL MATERIALS, Issue 19 2010Vera Neves Abstract Efforts to develop carbon nanotubes (CNTs) as nano-vehicles for precise and controlled drug and gene delivery, as well as markers for in vivo biomedical imaging, are currently hampered by uncertainties with regard to their cellular uptake, their fate in the body, and their safety. All of these processes are likely to be affected by the purity of CNT preparation, as well as the size and concentration of CNTs used, parameters that are often poorly controlled in biological experiments. It is demonstrated herein that under the experimental conditions of standard transfection methods, DWNTs are taken up by cultured cells but are then released after 24 h with no discernable stress response. The results support the potential therapeutic use of CNTs in many biomedical settings, such as cancer therapy. [source] PEI,PEG,Chitosan-Copolymer-Coated Iron Oxide Nanoparticles for Safe Gene Delivery: Synthesis, Complexation, and TransfectionADVANCED FUNCTIONAL MATERIALS, Issue 14 2009Forrest M. Kievit Abstract Gene therapy offers the potential of mediating disease through modification of specific cellular functions of target cells. However, effective transport of nucleic acids to target cells with minimal side effects remains a challenge despite the use of unique viral and non-viral delivery approaches. Here, a non-viral nanoparticle gene carrier that demonstrates effective gene delivery and transfection both in vitro and in vivo is presented. The nanoparticle system (NP,CP,PEI) is made of a superparamagnetic iron oxide nanoparticle (NP), which enables magnetic resonance imaging, coated with a novel copolymer (CP,PEI) comprised of short chain polyethylenimine (PEI) and poly(ethylene glycol) (PEG) grafted to the natural polysaccharide, chitosan (CP), which allows efficient loading and protection of the nucleic acids. The function of each component material in this nanoparticle system is illustrated by comparative studies of three nanoparticle systems of different surface chemistries, through material property characterization, DNA loading and transfection analyses, and toxicity assessment. Significantly, NP,CP,PEI demonstrates an innocuous toxic profile and a high level of expression of the delivered plasmid DNA in a C6 xenograft mouse model, making it a potential candidate for safe in vivo delivery of DNA for gene therapy. [source] Progress toward liver-based gene therapyHEPATOLOGY RESEARCH, Issue 4 2009Takeshi Suda The liver is involved in the synthesis of serum proteins, regulation of metabolism and maintenance of homeostasis and provides a variety of opportunities for gene therapy. The enriched vasculature and blood circulation, fenestrated endothelium, abundant receptors on the plasma membranes of the liver cells, and effective transcription and translation machineries in the hepatocytes are some unique features that have been explored for delivery, and functional analysis, of genetic sequences in the liver. Both viral and non-viral methods have been developed for effective gene delivery and liver-based gene therapy. This review describes the fundamentals of gene delivery, and the preclinical and clinical progress that has been made toward gene therapy using the liver as a target. [source] Polymeric Materials for Gene Delivery and DNA VaccinationADVANCED MATERIALS, Issue 8 2009David N. Nguyen Abstract Gene delivery holds great potential for the treatment of many different diseases. Vaccination with DNA holds particular promise, and may provide a solution to many technical challenges that hinder traditional vaccine systems including rapid development and production and induction of robust cell-mediated immune responses. However, few candidate DNA vaccines have progressed past preclinical development and none have been approved for human use. This Review focuses on the recent progress and challenges facing materials design for nonviral DNA vaccine drug delivery systems. In particular, we highlight work on new polymeric materials and their effects on protective immune activation, gene delivery, and current efforts to optimize polymeric delivery systems for DNA vaccination. [source] A Class of Cationic Triblock Amphiphilic Oligopeptides as Efficient Gene-Delivery Vectors,ADVANCED MATERIALS, Issue 1 2009Wei Yang Seow A new class of triblock oligopeptides, containing arginine for DNA binding, histidine for intracellular buffering, and hydrophobic residues for enhanced cellular uptake has been designed, with each block offering unique functionalities essential for efficient gene delivery. Together, these materials demonstrate strong DNA binding ability, low cytotoxicity, and significantly higher in vivo gene-transfection efficiency compared to the PEI standard. [source] Multilayer Nanocomplexes of Polymer and DNA Exhibit Enhanced Gene Delivery,ADVANCED MATERIALS, Issue 1 2008M. Saul Polymeric-DNA complexes (polyplexes) are constructed with multiple layers of counter-polyions as DNA/polyethylenimine/poly(acrylic acid)/polyethylenimine. The increased association of polyethylenimine achieved by the multilayer approach leads to substantial increases in expression of transgene for reporter plasmids without the need for excess free polymer typically required for non-viral gene delivery. This method of polyplex preparation provides the opportunity to improve transgene expression for gene therapy approaches to disease treatment. [source] Combinatorial Modification of Degradable Polymers Enables Transfection of Human Cells Comparable to Adenovirus,ADVANCED MATERIALS, Issue 19 2007J. Green End-modified poly(,-amino ester)s, easy-to-synthesize degradable polymers, are able to deliver DNA to primary human cells at levels comparable to adenovirus and two orders of magnitude better than the commonly used non-viral vector, polyethylenimine. Small structural changes are found to affect multiple steps of gene delivery including the DNA binding affinity, nanoparticle size, intracellular DNA uptake, and final protein expression. In vivo, these polymer modifications enhance DNA delivery to ovarian tumors. [source] Genetically Manipulated Human Skeletal Myoblast Cells for Cardiac TransplantationJOURNAL OF CARDIAC SURGERY, Issue 6 2002Kh H Haider Aim: Considering the promise of skeletal myoblast cell transplantation to improve cardiac function in myocardial myopathies, we aim in the present study to investigate the potential of human skeletal myoblast cells (HSMC) as a carrier for therapeutic genes for the heart muscle. Methods: Skeletal muscle sample is obtained from rectus femoris of the donor and is processed in the tissue culture to generate HSMC by a patented process of Cell Therapy Inc. The HSMC are grown in large 225 mm2 tissue culture flasks coated with collagen for enhanced cell adherence, using patented Super Medium (Cell Therapy Inc., Singapore) containing 10% fetal calf serum, to 80% confluence. The HSMC are passaged at regular time intervals of 48-72 hours to prevent in vitro differentiation. The HSMC thus obtained are transduced three times with retroviral vector carrying Lac-Z reporter gene before transplantation. The Lac-Z transduced HSMC are harvested by trypsinization, washed and re-suspended in serum free Super Medium. Ischemic Porcine model is created by clamping ameroid ring around left circumflex coronary artery in Yorkshire swine, four weeks prior to cell transplantation. For cell transplantation, the animal is anaesthetized, ventilated and heart is exposed by left thoracotomy. Fifteen injections (0.25 ml each) containing 300 million cells are injected in to the left ventricle endocardially under direct vision. For control animal, only culture medium without cells is injected. The animal is euthanized at pre-determined time, heart is explanted and processed for histological examination. The cryosectioning of the tissue and subsequent staining for Lac-Z expression and Hematoxylin-Eosin staining is carried out by standard methods. Results: The skeletal muscle samples processed by the patented method of Cell Therapy yield 85-90% pure HSMC. The preliminary data shows that repeated transductions of myoblast cells with retrovirus carrying Lac-Z yield highly efficient 70-75% Lac-Z positive HSMC population (Figure 1). Dye exclusion test using Trypan blue reveals >95% cell viability at the time of injection. Gross sections of the cardiac tissue stained positive for Lac-Z expression (Figure 2). Histological examination showed the presence of grafted myoblast cells expressing Lac-Z gene in the cardiac tissue (Figure 3). Conclusion: In the light of our preliminary results, we conclude that HSMC may prove to be excellent carriers of transgene for cardiac muscle cells which otherwise are refractory to ordinary gene transfection methods. The use of HSMC mediated gene delivery to cardiac muscle is safer as compared to direct injection of viral vectors in to the heart muscle. Furthermore, the grafted myoblast cells will additionally serve to strengthen the weakened heart muscle. Figure 1.Human Skeletal myoblasts transduced with Lac-Z carrying retrovirus and stained with x-gal. Figure 2.Gross sections of heart muscle stained for Lac-Z expression. Figure 3.X-gal stained porcine heart muscle counter-stained with Eosin. The heart was explanted 6 weeks after transplantation of Lac-Z stained human myoblasts. The arrow shows Lac-Z expressing myoblast cells. [source] A novel immunotherapy for superficial bladder cancer by intravesical immobilization of GM-CSFJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 6b 2010Zhiming Hu Abstract In situ gene therapy with granulocyte-macrophage colony-stimulating factor (GM-CSF) was demonstrated to successfully inhibit tumour cell growth in a mouse orthotopic bladder cancer model, but suffered from several disadvantages, such as limited efficiency for gene delivery, low expression efficiency of the transgene and the safety concern resulting from viral vector. In order to address the limits, a novel immunotherapy was developed attentively through immobilization of streptavidin-tagged bioactive GM-CSF on the biotinylated mucosal surface of bladder wall on the basis of both the unique property of streptavidin (SA) to bind rapidly and almost irreversibly to any biotin-linked molecule and the outstanding ability of biotin to be incorporated easily into the proteins on the cell surface. The mouse orthotopic model of MB49 bladder cancer was used to evaluate the feasibility and efficacy of the novel immunotherapy performed twice a week for 3 weeks. Briefly, 1 day after intravesical implantation of 1 × 106 MB49 tumour cells in C57BL/6 mouse, 100 ,l of 1 mg/ml NHS-PEO4-biotin was instilled and allowed to incubate in the bladder for 30 min., followed by intravesical instillation of 100 ,l of 0.15 mg/ml SA-GM-CSF bifunctional fusion protein and incubation for 1 hr. SA-GM-CSF fusion protein was shown to be immobilized efficiently and durably on the biotinylated mucosal surface of bladder wall. The bladder cancer incidence was dramatically decreased from 100% in the control group to 37.5% in the SA-GM-CSF group. Importantly, 70% of the SA-GM-CSF-cured mice were protected against a second intravesical wild-type MB49 tumour challenge, indicating that an effective anti-tumour immunity was generated against MB49 bladder cancer. Thus, the novel immunotherapy may be an attractive therapeutic alternative and should be evaluated in bladder cancer patients. [source] | |||||||||||||||||||||||||||||||