Routes for Drug Translocation Across the Blood-Brain Barrier: Exploiting Peptides as Delivery Vectors.

Science.gov (United States)

Kristensen, Mie; Brodin, Birger

2017-09-01

A number of potent drugs for the treatment of brain diseases are available. However, in order for them to reach their target site of action, they must pass the blood-brain barrier (BBB). The capillary endothelium comprises the major barrier of the BBB and allows only passive permeation of some small lipophilic molecules. Brain delivery of the larger biopharmaceuticals, which today includes an increasing number of novel drug entities, is therefore restricted, both due to their molecular size and their hydrophilic nature. Thus, the development of novel drug entities intended for the treatment of brain diseases such as neurodegenerative diseases or brain cancers require a delivery strategy for overcoming the BBB before reaching its final target within the brain. Peptide-based delivery vector is an emerging tool as shuttles for drug delivery across the BBB and one may explore receptor-mediated transcytosis, adsorptive-mediated transcytosis, and the paracellular route. The latter, however, being controversial due to the risk of co-delivery of blood-borne potential harmful substances. On the other hand, a number of studies report on drug delivery across the BBB exploiting receptor-mediated transcytosis and adsorptive-mediated transcytosis, indicating that peptides and peptide vectors may be of use in a central nervous system delivery context. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Pseudotyped Lentiviral Vectors for Retrograde Gene Delivery into Target Brain Regions

Directory of Open Access Journals (Sweden)

Kenta Kobayashi

2017-08-01

Full Text Available Gene transfer through retrograde axonal transport of viral vectors offers a substantial advantage for analyzing roles of specific neuronal pathways or cell types forming complex neural networks. This genetic approach may also be useful in gene therapy trials by enabling delivery of transgenes into a target brain region distant from the injection site of the vectors. Pseudotyping of a lentiviral vector based on human immunodeficiency virus type 1 (HIV-1 with various fusion envelope glycoproteins composed of different combinations of rabies virus glycoprotein (RV-G and vesicular stomatitis virus glycoprotein (VSV-G enhances the efficiency of retrograde gene transfer in both rodent and nonhuman primate brains. The most recently developed lentiviral vector is a pseudotype with fusion glycoprotein type E (FuG-E, which demonstrates highly efficient retrograde gene transfer in the brain. The FuG-E–pseudotyped vector permits powerful experimental strategies for more precisely investigating the mechanisms underlying various brain functions. It also contributes to the development of new gene therapy approaches for neurodegenerative disorders, such as Parkinson’s disease, by delivering genes required for survival and protection into specific neuronal populations. In this review article, we report the properties of the FuG-E–pseudotyped vector, and we describe the application of the vector to neural circuit analysis and the potential use of the FuG-E vector in gene therapy for Parkinson’s disease.

Efficient gene delivery to primary human retinal pigment epithelial cells: The innate and acquired properties of vectors.

Science.gov (United States)

Tasharrofi, Nooshin; Kouhkan, Fatemeh; Soleimani, Masoud; Soheili, Zahra-Soheila; Atyabi, Fatemeh; Akbari Javar, Hamid; Abedin Dorkoosh, Farid

2017-02-25

The purpose of this study is designing non-viral gene delivery vectors for transfection of the primary human retinal pigment epithelial cells (RPE). In the design process of gene delivery vectors, considering physicochemical properties of vectors alone does not seem to be enough since they interact with constituents of the surrounding environment and hence gain new characteristics. Moreover, due to these interactions, their cargo can be released untimely or undergo degradation before reaching to the target cells. Further, the characteristics of cells itself can also influence the transfection efficacy. For example, the non-dividing property of RPE cells can impede the transfection efficiency which in most studies was ignored by using immortal cell lines. In this study, vectors with different characteristics differing in mixing orders of pDNA, PEI polymer, and PLGA/PEI or PLGA nanoparticles were prepared and characterized. Then, their characteristics and efficacy in gene delivery to RPE cells in the presence of vitreous or fetal bovine serum (FBS) were evaluated. All formulations showed no cytotoxicity and were able to protect pDNA from premature release and degradation in extracellular media. Also, the adsorption of vitreous or serum proteins onto the surface of vectors changed their properties and hence cellular uptake and transfection efficacy. Copyright © 2016 Elsevier B.V. All rights reserved.

Adeno-associated viral vectors as agents for gene delivery : application in disorders and trauma of the central nervous system

NARCIS (Netherlands)

Ruitenberg, Marc J; Eggers, Ruben; Boer, Gerard J; Verhaagen, J.

2002-01-01

The use of viral vectors as agents for gene delivery provides a direct approach to manipulate gene expression in the mammalian central nervous system (CNS). The present article describes in detail the methodology for the injection of viral vectors, in particular adeno-associated virus (AAV) vectors,

Preparation and characterization of magnetic gene vectors for targeting gene delivery

Energy Technology Data Exchange (ETDEWEB)

Zheng, S.W.; Liu, G. [College of Chemistry, Chemical Engineering and Materials Science and Key Laboratory of Organic Synthesis of Jiangsu Province, Soochow University, SIP, Suzhou 215123 (China); Hong, R.Y., E-mail: rhong@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science and Key Laboratory of Organic Synthesis of Jiangsu Province, Soochow University, SIP, Suzhou 215123 (China); State Key Laboratory of Multi-phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080 (China); Li, H.Z. [State Key Laboratory of Multi-phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080 (China); Li, Y.G., E-mail: ilguoliang@sohu.com [Department of radiology, the First Affiliated Hospital of Soochow University, Suzhou 215007 (China); Wei, D.G., E-mail: dougwei@deas.harvard.edu [Center for Nanoscale Systems, School of Engineering and Applied Science, Harvard University, 11 Oxford Street, Cambridge, MA 02139 (United States)

2012-10-15

Highlights: Black-Right-Pointing-Pointer PEI is ideal candidate polymer for the design of gene delivery systems. Black-Right-Pointing-Pointer PEI-CMD-MNPs exhibited a typical superparamagnetic behavior. Black-Right-Pointing-Pointer PEI-CMD-MNPs were well stable over the entire range of pH and NaCl concentration. Black-Right-Pointing-Pointer DNA-PEI-CMD-MNPs transfected cells by a magnet have higher transfection efficiency and gene expression efficiency. - Abstract: The PEI-CMD-MNPs were successfully prepared by the surface modification of magnetic Fe{sub 3}O{sub 4} nanoparticles with carboxymethyl dextran (CMD) and polyethyleneimine (PEI). The PEI-CMD-MNPs polyplexes exhibited a typical superparamagnetic behavior and were well stable over the entire range of pH and NaCl concentration. These PEI-CMD-MNPs were used as magnetic gene vectors for targeting gene delivery. The prepared MNPs at different surface modification stages were characterized using Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), field emissions canning electron microscopy (FE-SEM), powder X-ray diffraction (XRD) and dynamic laser light scattering (DLS) analysis. The magnetic properties were studied by vibrating sample magnetometer (VSM). To evaluate the performance of the magnetic nanoparticles as gene transfer vector, the PEI-CMD-MNPs were used to delivery green fluorescent protein (GFP) gene into BHK21 cells. The expression of GFP gene was detected by fluorescence microscope. DNA-PEI-CMD-MNPs polyplexes absorbed by the cells were also monitored by Magnetic resonance imaging (MRI). The transfection efficiency and gene expression efficiency of that transfected with a magnet were much higher than that of standard transfection.

Virus vector-mediated genetic modification of brain tumor stromal cells after intravenous delivery.

Science.gov (United States)

Volak, Adrienn; LeRoy, Stanley G; Natasan, Jeya Shree; Park, David J; Cheah, Pike See; Maus, Andreas; Fitzpatrick, Zachary; Hudry, Eloise; Pinkham, Kelsey; Gandhi, Sheetal; Hyman, Bradley T; Mu, Dakai; GuhaSarkar, Dwijit; Stemmer-Rachamimov, Anat O; Sena-Esteves, Miguel; Badr, Christian E; Maguire, Casey A

2018-05-16

The malignant primary brain tumor, glioblastoma (GBM) is generally incurable. New approaches are desperately needed. Adeno-associated virus (AAV) vector-mediated delivery of anti-tumor transgenes is a promising strategy, however direct injection leads to focal transgene spread in tumor and rapid tumor division dilutes out the extra-chromosomal AAV genome, limiting duration of transgene expression. Intravenous (IV) injection gives widespread distribution of AAV in normal brain, however poor transgene expression in tumor, and high expression in non-target cells which may lead to ineffective therapy and high toxicity, respectively. Delivery of transgenes encoding secreted, anti-tumor proteins to tumor stromal cells may provide a more stable and localized reservoir of therapy as they are more differentiated than fast-dividing tumor cells. Reactive astrocytes and tumor-associated macrophage/microglia (TAMs) are stromal cells that comprise a large portion of the tumor mass and are associated with tumorigenesis. In mouse models of GBM, we used IV delivery of exosome-associated AAV vectors driving green fluorescent protein expression by specific promoters (NF-κB-responsive promoter and a truncated glial fibrillary acidic protein promoter), to obtain targeted transduction of TAMs and reactive astrocytes, respectively, while avoiding transgene expression in the periphery. We used our approach to express the potent, yet toxic anti-tumor cytokine, interferon beta, in tumor stroma of a mouse model of GBM, and achieved a modest, yet significant enhancement in survival compared to controls. Noninvasive genetic modification of tumor microenvironment represents a promising approach for therapy against cancers. Additionally, the vectors described here may facilitate basic research in the study of tumor stromal cells in situ.

EVE: Explainable Vector Based Embedding Technique Using Wikipedia

OpenAIRE

Qureshi, M. Atif; Greene, Derek

2017-01-01

We present an unsupervised explainable word embedding technique, called EVE, which is built upon the structure of Wikipedia. The proposed model defines the dimensions of a semantic vector representing a word using human-readable labels, thereby it readily interpretable. Specifically, each vector is constructed using the Wikipedia category graph structure together with the Wikipedia article link structure. To test the effectiveness of the proposed word embedding model, we consider its usefulne...

Techniques for vector analyzing power measurements of the 2H(n vector,np)n breakup reaction at low energies

International Nuclear Information System (INIS)

Howell, C.R.; Tornow, W.; Pfuetzner, H.G.; Li Anli; Roberts, M.L.; Murphy, K.; Felsher, P.D.; Weisel, G.J.; Naqvi, A.; Walter, R.L.; Lambert, J.M.; Treado, P.A.

1990-01-01

Experimental methods to measure the vector analyzing powers over a broad range of kinematic configurations in the n-d breakup reaction have been developed at TUNL. These techniques employ the polarized beam facilities at TUNL and use the 2 H(d vector, n vector) 3 He reaction as a source of low-energy polarized neutrons. Our methods permit measurements to a high statistical accuracy over a large fraction of three-nucleon phase space. The techniques are described and experimental spectra along with kinematic calculations are presented. (orig.)

Porous silicon advances in drug delivery and immunotherapy.

Science.gov (United States)

Savage, David J; Liu, Xuewu; Curley, Steven A; Ferrari, Mauro; Serda, Rita E

2013-10-01

Biomedical applications of porous silicon include drug delivery, imaging, diagnostics and immunotherapy. This review summarizes new silicon particle fabrication techniques, dynamics of cellular transport, advances in the multistage vector approach to drug delivery, and the use of porous silicon as immune adjuvants. Recent findings support superior therapeutic efficacy of the multistage vector approach over single particle drug delivery systems in mouse models of ovarian and breast cancer. With respect to vaccine development, multivalent presentation of pathogen-associated molecular patterns on the particle surface creates powerful platforms for immunotherapy, with the porous matrix able to carry both antigens and immune modulators. Copyright © 2013 Elsevier Ltd. All rights reserved.

Surveillance of arthropod vector-borne infectious diseases using remote sensing techniques: a review.

Directory of Open Access Journals (Sweden)

Satya Kalluri

2007-10-01

Full Text Available Epidemiologists are adopting new remote sensing techniques to study a variety of vector-borne diseases. Associations between satellite-derived environmental variables such as temperature, humidity, and land cover type and vector density are used to identify and characterize vector habitats. The convergence of factors such as the availability of multi-temporal satellite data and georeferenced epidemiological data, collaboration between remote sensing scientists and biologists, and the availability of sophisticated, statistical geographic information system and image processing algorithms in a desktop environment creates a fertile research environment. The use of remote sensing techniques to map vector-borne diseases has evolved significantly over the past 25 years. In this paper, we review the status of remote sensing studies of arthropod vector-borne diseases due to mosquitoes, ticks, blackflies, tsetse flies, and sandflies, which are responsible for the majority of vector-borne diseases in the world. Examples of simple image classification techniques that associate land use and land cover types with vector habitats, as well as complex statistical models that link satellite-derived multi-temporal meteorological observations with vector biology and abundance, are discussed here. Future improvements in remote sensing applications in epidemiology are also discussed.

Techniques for vector analyzing power measurements of the sup 2 H(n vector,np)n breakup reaction at low energies

Energy Technology Data Exchange (ETDEWEB)

Howell, C.R.; Tornow, W.; Pfuetzner, H.G.; Li Anli; Roberts, M.L.; Murphy, K.; Felsher, P.D.; Weisel, G.J.; Naqvi, A.; Walter, R.L. (Duke Univ., Durham, NC (USA) Triangle Universities Nuclear Lab., Durham, NC (USA)); Lambert, J.M.; Treado, P.A. (Georgetown Univ., Washington, DC (USA). Dept. of Physics); Slaus, I. (Institut Rudjer Boskovic, Zagreb (Yugoslavia))

1990-05-10

Experimental methods to measure the vector analyzing powers over a broad range of kinematic configurations in the n-d breakup reaction have been developed at TUNL. These techniques employ the polarized beam facilities at TUNL and use the {sup 2}H(d vector, n vector){sup 3}He reaction as a source of low-energy polarized neutrons. Our methods permit measurements to a high statistical accuracy over a large fraction of three-nucleon phase space. The techniques are described and experimental spectra along with kinematic calculations are presented. (orig.).

Pharmacologic Effects in vivo in Brain by Vector-Mediated Peptide Drug Delivery

Science.gov (United States)

Bickel, Ulrich; Yoshikawa, Takayoshi; Landaw, Elliot M.; Faull, Kym F.; Pardridge, William M.

1993-04-01

Pharmacologic effects in brain caused by systemic administration of neuropeptides are prevented by poor transport of the peptide through the brain vascular endothelium, which comprises the blood-brain barrier in vivo. In the present study, successful application of a chimeric peptide approach to enhance drug delivery through the blood-brain barrier for the purpose of achieving a central nervous system pharmacologic effect is described. The chimeric peptide was formed by linkage of a potent vasoactive intestinal peptide (VIP) analogue, which had been monobiotinylated, to a drug transport vector. The vector consisted of a covalent conjugate of avidin and the OX26 monoclonal antibody to the transferrin receptor. Owing to the high concentration of transferrin receptors on brain capillary endothelia, OX26 targets brain and undergoes receptor-mediated transcytosis through the blood-brain barrier. Systemic infusion of low doses (12 μg/kg) of the VIP chimeric peptide in rats resulted in an in vivo central nervous system pharmacologic effect: a 65% increase in cerebral blood flow. Biotinylated VIP analogue without the brain transport vector was ineffective.

CRISPR/Cas9 delivery with one single adenoviral vector devoid of all viral genes.

Science.gov (United States)

Ehrke-Schulz, Eric; Schiwon, Maren; Leitner, Theo; Dávid, Stephan; Bergmann, Thorsten; Liu, Jing; Ehrhardt, Anja

2017-12-07

The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 system revolutionized the field of gene editing but viral delivery of the CRISPR/Cas9 system has not been fully explored. Here we adapted clinically relevant high-capacity adenoviral vectors (HCAdV) devoid of all viral genes for the delivery of the CRISPR/Cas9 machinery using a single viral vector. We present a platform enabling fast transfer of the Cas9 gene and gRNA expression units into the HCAdV genome including the option to choose between constitutive or inducible Cas9 expression and gRNA multiplexing. Efficacy and versatility of this pipeline was exemplified by producing different CRISPR/Cas9-HCAdV targeting the human papillomavirus (HPV) 18 oncogene E6, the dystrophin gene causing Duchenne muscular dystrophy (DMD) and the HIV co-receptor C-C chemokine receptor type 5 (CCR5). All CRISPR/Cas9-HCAdV proved to be efficient to deliver the respective CRISPR/Cas9 expression units and to introduce the desired DNA double strand breaks at their intended target sites in immortalized and primary cells.

Self-focusing therapeutic gene delivery with intelligent gene vector swarms: intra-swarm signalling through receptor transgene expression in targeted cells.

Science.gov (United States)

Tolmachov, Oleg E

2015-01-01

Gene delivery in vivo that is tightly focused on the intended target cells is essential to maximize the benefits of gene therapy and to reduce unwanted side-effects. Cell surface markers are immediately available for probing by therapeutic gene vectors and are often used to direct gene transfer with these vectors to specific target cell populations. However, it is not unusual for the choice of available extra-cellular markers to be too scarce to provide a reliable definition of the desired therapeutically relevant set of target cells. Therefore, interrogation of intra-cellular determinants of cell-specificity, such as tissue-specific transcription factors, can be vital in order to provide detailed cell-guiding information to gene vector particles. An important improvement in cell-specific gene delivery can be achieved through auto-buildup in vector homing efficiency using intelligent 'self-focusing' of swarms of vector particles on target cells. Vector self-focusing was previously suggested to rely on the release of diffusible chemo-attractants after a successful target-specific hit by 'scout' vector particles. I hypothesize that intelligent self-focusing behaviour of swarms of cell-targeted therapeutic gene vectors can be accomplished without the employment of difficult-to-use diffusible chemo-attractants, instead relying on the intra-swarm signalling through cells expressing a non-diffusible extra-cellular receptor for the gene vectors. In the proposed model, cell-guiding information is gathered by the 'scout' gene vector particles, which: (1) attach to a variety of cells via a weakly binding (low affinity) receptor; (2) successfully facilitate gene transfer into these cells; (3) query intra-cellular determinants of cell-specificity with their transgene expression control elements and (4) direct the cell-specific biosynthesis of a vector-encoded strongly binding (high affinity) cell-surface receptor. Free members of the vector swarm loaded with therapeutic cargo

New technology - demonstration of a vector velocity technique

DEFF Research Database (Denmark)

Møller Hansen, Peter; Pedersen, Mads M; Hansen, Kristoffer L

2011-01-01

With conventional Doppler ultrasound it is not possible to estimate direction and velocity of blood flow, when the angle of insonation exceeds 60-70°. Transverse oscillation is an angle independent vector velocity technique which is now implemented on a conventional ultrasound scanner. In this pa...

New techniques in 3D scalar and vector field visualization

Energy Technology Data Exchange (ETDEWEB)

Max, N.; Crawfis, R.; Becker, B.

1993-05-05

At Lawrence Livermore National Laboratory (LLNL) we have recently developed several techniques for volume visualization of scalar and vector fields, all of which use back-to-front compositing. The first renders volume density clouds by compositing polyhedral volume cells or their faces. The second is a ``splatting`` scheme which composites textures used to reconstruct the scalar or vector fields. One version calculates the necessary texture values in software, and another takes advantage of hardware texture mapping. The next technique renders contour surface polygons using semi-transparent textures, which adjust appropriately when the surfaces deform in a flow, or change topology. The final one renders the ``flow volume`` of smoke or dye tracer swept out by a fluid flowing through a small generating polygon. All of these techniques are applied to a climate model data set, to visualize cloud density and wind velocity.

New techniques in 3D scalar and vector field visualization

International Nuclear Information System (INIS)

Max, N.; Crawfis, R.; Becker, B.

1993-01-01

At Lawrence Livermore National Laboratory (LLNL) we have recently developed several techniques for volume visualization of scalar and vector fields, all of which use back-to-front compositing. The first renders volume density clouds by compositing polyhedral volume cells or their faces. The second is a ''splatting'' scheme which composites textures used to reconstruct the scalar or vector fields. One version calculates the necessary texture values in software, and another takes advantage of hardware texture mapping. The next technique renders contour surface polygons using semi-transparent textures, which adjust appropriately when the surfaces deform in a flow, or change topology. The final one renders the ''flow volume'' of smoke or dye tracer swept out by a fluid flowing through a small generating polygon. All of these techniques are applied to a climate model data set, to visualize cloud density and wind velocity

Dual AAV Vectors for Stargardt Disease.

Science.gov (United States)

Trapani, Ivana

2018-01-01

Stargardt disease (STGD1), due to mutations in the large ABCA4 gene, is the most common inherited macular degeneration in humans. Attempts at developing gene therapy approaches for treatment of STGD1 are currently ongoing. Among all the vectors available for gene therapy of inherited retinal diseases, those based on adeno-associated viruses (AAV) are the most promising given the efficacy shown in various animal models and their excellent safety profile in humans, as confirmed in many ongoing clinical trials. However, one of the main obstacles for the use of AAV is their limited effective packaging capacity of about 5 kb. Taking advantage of the AAV genome's ability to concatemerize , others and we have recently developed dual AAV vectors to overcome this limit. We tested dual AAV vectors for ABCA4 delivery, and found that they transduce efficiently both mouse and pig photoreceptors , and rescue the Abca4-/- mouse retinal phenotype, indicating their potential for gene therapy of STGD1. This chapter details how we designed dual AAV vectors for the delivery of the ABCA4 gene and describes the techniques that can be explored to evaluate dual AAV transduction efficiency in vitro and in the retina, and their efficacy in the mouse model of STGD1.

The use of Listeria monocytogenes as a DNA delivery vector for cancer gene therapy.

LENUS (Irish Health Repository)

Tangney, Mark

2012-01-31

Listeria monocytogenes is an intracellular pathogen that lyses the phagosomal vacuole of infected cells, proliferates in the host cell cytoplasm and can actively enter adjacent cells. The pathogen is therefore well suited to exploitation as a vector for the delivery of DNA to target cells as the lifecycle favors cellular targeting with vector amplification and the potential for cell-to-cell spread. We have recently demonstrated DNA transfer by L. monocytogenes in growing tumors in murine models. Our approach exploited an ampicillin sensitive stain of L. monocytogenes which can be lysed through systemic administration of ampicillin to facilitate release of plasmid DNA for expression by infected mammalian cells. Here, we discuss the implications of this technology and the potential for future improvements of the system.

Physical non-viral gene delivery methods for tissue engineering.

Science.gov (United States)

Mellott, Adam J; Forrest, M Laird; Detamore, Michael S

2013-03-01

The integration of gene therapy into tissue engineering to control differentiation and direct tissue formation is not a new concept; however, successful delivery of nucleic acids into primary cells, progenitor cells, and stem cells has proven exceptionally challenging. Viral vectors are generally highly effective at delivering nucleic acids to a variety of cell populations, both dividing and non-dividing, yet these viral vectors are marred by significant safety concerns. Non-viral vectors are preferred for gene therapy, despite lower transfection efficiencies, and possess many customizable attributes that are desirable for tissue engineering applications. However, there is no single non-viral gene delivery strategy that "fits-all" cell types and tissues. Thus, there is a compelling opportunity to examine different non-viral vectors, especially physical vectors, and compare their relative degrees of success. This review examines the advantages and disadvantages of physical non-viral methods (i.e., microinjection, ballistic gene delivery, electroporation, sonoporation, laser irradiation, magnetofection, and electric field-induced molecular vibration), with particular attention given to electroporation because of its versatility, with further special emphasis on Nucleofection™. In addition, attributes of cellular character that can be used to improve differentiation strategies are examined for tissue engineering applications. Ultimately, electroporation exhibits a high transfection efficiency in many cell types, which is highly desirable for tissue engineering applications, but electroporation and other physical non-viral gene delivery methods are still limited by poor cell viability. Overcoming the challenge of poor cell viability in highly efficient physical non-viral techniques is the key to using gene delivery to enhance tissue engineering applications.

Physical non-viral gene delivery methods for tissue engineering

Science.gov (United States)

Mellott, Adam J.; Forrest, M. Laird; Detamore, Michael S.

2016-01-01

The integration of gene therapy into tissue engineering to control differentiation and direct tissue formation is not a new concept; however, successful delivery of nucleic acids into primary cells, progenitor cells, and stem cells has proven exceptionally challenging. Viral vectors are generally highly effective at delivering nucleic acids to a variety of cell populations, both dividing and non-dividing, yet these viral vectors are marred by significant safety concerns. Non-viral vectors are preferred for gene therapy, despite lower transfection efficiencies, and possess many customizable attributes that are desirable for tissue engineering applications. However, there is no single non-viral gene delivery strategy that “fits-all” cell types and tissues. Thus, there is a compelling opportunity to examine different non-viral vectors, especially physical vectors, and compare their relative degrees of success. This review examines the advantages and disadvantages of physical non-viral methods (i.e., microinjection, ballistic gene delivery, electroporation, sonoporation, laser irradiation, magnetofection, and electric field-induced molecular vibration), with particular attention given to electroporation because of its versatility, with further special emphasis on Nucleofection™. In addition, attributes of cellular character that can be used to improve differentiation strategies are examined for tissue engineering applications. Ultimately, electroporation exhibits a high transfection efficiency in many cell types, which is highly desirable for tissue engineering applications, but electroporation and other physical non-viral gene delivery methods are still limited by poor cell viability. Overcoming the challenge of poor cell viability in highly efficient physical non-viral techniques is the key to using gene delivery to enhance tissue engineering applications. PMID:23099792

Novel non-viral vectors for gene delivery: synthesis of a second-generation library of mono-functionalized poly-(guanidinium)amines and their introduction into cationic lipids.

Science.gov (United States)

Byk, G; Soto, J; Mattler, C; Frederic, M; Scherman, D

1998-01-01

The development of new gene delivery technologies is a prerequisite towards gene therapy clinical trials. Because gene delivery mediated by viral vectors remains of limited scope due to immunological and propagation risks, the development of new non-viral gene delivery systems is of crucial importance. We have synthesized a secondary library of mono-functionalized poly-(guanidinium)amines generated from a library of mono-functionalized polyamines applying the concept of "libraries from libraries." The method allows a quick and easy access to mono-functionalized geometrically varied poly-(guanidinium)amines. The new building blocks were introduced into cationic lipids to obtain novel poly-(guanidinium)amine lipids, which are potential DNA vectors for gene delivery. Copyright 1998 John Wiley & Sons, Inc.

Poly-functional and long-lasting anticancer immune response elicited by a safe attenuated Pseudomonas aeruginosa vector for antigens delivery

Directory of Open Access Journals (Sweden)

Xavier Chauchet

2016-01-01

Full Text Available Live-attenuated bacterial vectors for antigens delivery have aroused growing interest in the field of cancer immunotherapy. Their potency to stimulate innate immunity and to promote intracellular antigen delivery into antigen-presenting cells could be exploited to elicit a strong and specific cellular immune response against tumor cells. We previously described genetically-modified and attenuated Pseudomonas aeruginosa vectors able to deliver in vivo protein antigens into antigen-presenting cells, through Type 3 secretion system of the bacteria. Using this approach, we managed to protect immunized mice against aggressive B16 melanoma development in both a prophylactic and therapeutic setting. In this study, we further investigated the antigen-specific CD8+ T cell response, in terms of phenotypic and functional aspects, obtained after immunizations with a killed but metabolically active P. aeruginosa attenuated vector. We demonstrated that P. aeruginosa vaccine induces a highly functional pool of antigen-specific CD8+ T cell able to infiltrate the tumor. Furthermore, multiple immunizations allowed the development of a long-lasting immune response, represented by a pool of predominantly effector memory cells which protected mice against late tumor challenge. Overall, killed but metabolically active P. aeruginosa vector is a safe and promising approach for active and specific antitumor immunotherapy.

[New strategy for RNA vectorization in mammalian cells. Use of a peptide vector].

Science.gov (United States)

Vidal, P; Morris, M C; Chaloin, L; Heitz, F; Divita, G

1997-04-01

A major barrier for gene delivery is the low permeability of nucleic acids to cellular membranes. The development of antisenses and gene therapy has focused mainly on improving methods of oligonucleotide or gene delivery to the cell. In this report we described a new strategy for RNA cell delivery, based on a short single peptide. This peptide vector is derived from both the fusion domain of the gp41 protein of HIV and the nuclear localization sequence of the SV40 large T antigen. This peptide vector localizes rapidly to the cytoplasm then to the nucleus of human fibroblasts (HS-68) within a few minutes and exhibits a high affinity for a single-stranded mRNA encoding the p66 subunit of the HIV-1 reverse transcriptase (in a 100 nM range). The peptide/RNA complex formation involves mainly electrostatic interactions between the basic residues of the peptide and the charges on the phosphate group of the RNA. In the presence of the peptide-vector fluorescently-labelled mRNA is delivered into the cytoplasm of mammalian cells (HS68 human fibroblasts) in less than 1 h with a relatively high efficiency (80%). This new concept based on a peptide-derived vector offers several advantages compared to other compounds commonly used in gene delivery. This vector is highly soluble and exhibits no cytotoxicity at the concentrations used for optimal gene delivery. This result clearly supports the fact that this peptide vector is a powerful tool and that it can be used widely, as much for laboratory research as for new applications and development in gene and/or antisense therapy.

Therapeutic Efficacy of Vectored PGT121 Gene Delivery in HIV-1-Infected Humanized Mice.

Science.gov (United States)

Badamchi-Zadeh, Alexander; Tartaglia, Lawrence J; Abbink, Peter; Bricault, Christine A; Liu, Po-Ting; Boyd, Michael; Kirilova, Marinela; Mercado, Noe B; Nanayakkara, Ovini S; Vrbanac, Vladimir D; Tager, Andrew M; Larocca, Rafael A; Seaman, Michael S; Barouch, Dan H

2018-04-01

Broadly neutralizing antibodies (bNAbs) are being explored for HIV-1 prevention and cure strategies. However, administration of purified bNAbs poses challenges in resource-poor settings, where the HIV-1 disease burden is greatest. In vivo vector-based production of bNAbs represents an alternative strategy. We investigated adenovirus serotype 5 (Ad5) and adeno-associated virus serotype 1 (AAV1) vectors to deliver the HIV-1-specific bNAb PGT121 in wild-type and immunocompromised C57BL/6 mice as well as in HIV-1-infected bone marrow-liver-thymus (BLT) humanized mice. Ad5.PGT121 and AAV1.PGT121 produced functional antibody in vivo Ad5.PGT121 produced PGT121 rapidly within 6 h, whereas AAV1.PGT121 produced detectable PGT121 in serum by 72 h. Serum PGT121 levels were rapidly reduced by the generation of anti-PGT121 antibodies in immunocompetent mice but were durably maintained in immunocompromised mice. In HIV-1-infected BLT humanized mice, Ad5.PGT121 resulted in a greater reduction of viral loads than did AAV1.PGT121. Ad5.PGT121 also led to more-sustained virologic control than purified PGT121 IgG. Ad5.PGT121 afforded more rapid, robust, and durable antiviral efficacy than AAV1.PGT121 and purified PGT121 IgG in HIV-1-infected humanized mice. Further evaluation of vector delivery of HIV-1 bNAbs is warranted, although approaches to prevent the generation of antiantibody responses may also be required. IMPORTANCE Broadly neutralizing antibodies (bNAbs) are being explored for HIV-1 prevention and cure strategies, but delivery of purified antibodies may prove challenging. We investigated adenovirus serotype 5 (Ad5) and adeno-associated virus serotype 1 (AAV1) vectors to deliver the HIV-1-specific bNAb PGT121. Ad5.PGT121 afforded more rapid, robust, and durable antiviral efficacy than AAV1.PGT121 and purified PGT121 IgG in HIV-1-infected humanized mice. Copyright © 2018 Badamchi-Zadeh et al.

Progresses towards safe and efficient gene therapy vectors.

Science.gov (United States)

Chira, Sergiu; Jackson, Carlo S; Oprea, Iulian; Ozturk, Ferhat; Pepper, Michael S; Diaconu, Iulia; Braicu, Cornelia; Raduly, Lajos-Zsolt; Calin, George A; Berindan-Neagoe, Ioana

2015-10-13

The emergence of genetic engineering at the beginning of the 1970's opened the era of biomedical technologies, which aims to improve human health using genetic manipulation techniques in a clinical context. Gene therapy represents an innovating and appealing strategy for treatment of human diseases, which utilizes vehicles or vectors for delivering therapeutic genes into the patients' body. However, a few past unsuccessful events that negatively marked the beginning of gene therapy resulted in the need for further studies regarding the design and biology of gene therapy vectors, so that this innovating treatment approach can successfully move from bench to bedside. In this paper, we review the major gene delivery vectors and recent improvements made in their design meant to overcome the issues that commonly arise with the use of gene therapy vectors. At the end of the manuscript, we summarized the main advantages and disadvantages of common gene therapy vectors and we discuss possible future directions for potential therapeutic vectors.

Beyond platinum: synthesis, characterization, and in vitro toxicity of Cu(II-releasing polymer nanoparticles for potential use as a drug delivery vector

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Harris Alesha

2011-01-01

Full Text Available Abstract The field of drug delivery focuses primarily on delivering small organic molecules or DNA/RNA as therapeutics and has largely ignored the potential for delivering catalytically active transition metal ions and complexes. The delivery of a variety of transition metals has potential for inducing apoptosis in targeted cells. The chief aims of this work were the development of a suitable delivery vector for a prototypical transition metal, Cu2+, and demonstration of the ability to impact cancer cell viability via exposure to such a Cu-loaded vector. Carboxylate-functionalized nanoparticles were synthesized by free radical polymerization and were subsequently loaded with Cu2+ via binding to particle-bound carboxylate functional groups. Cu loading and release were characterized via ICP MS, EDX, XPS, and elemental analysis. Results demonstrated that Cu could be loaded in high weight percent (up to 16 wt.% and that Cu was released from the particles in a pH-dependent manner. Metal release was a function of both pH and the presence of competing ligands. The toxicity of the particles was measured in HeLa cells where reductions in cell viability greater than 95% were observed at high Cu loading. The combined pH sensitivity and significant toxicity make this copper delivery vector an excellent candidate for the targeted killing of disease cells when combined with an effective cellular targeting strategy.

Multicompartment vectors as novel drug delivery systems: selective activation of Tγδ lymphocytes after zoledronic acid delivery.

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Agrati, Chiara; Marianecci, Carlotta; Sennato, Simona; Carafa, Maria; Bordoni, Veronica; Cimini, Eleonora; Tempestilli, Massimo; Pucillo, Leopoldo P; Turchi, Federica; Martini, Federico; Borioni, Giorgio; Bordi, Federico

2011-04-01

Multicompartment nanoscopic carriers can be easily assembled by inducing the aggregation of anionic "hybrid" niosomes by means of cationic biocompatible polyelectrolytes. The resulting vesicle clusters, whose size and overall net charge can be easily controlled by varying the polyelectrolyte-to-particle charge ratio, show an interesting potential for multidrug delivery. In this article we provide strong evidence for their effective use in vitro as multicompartment vectors selectively directed toward monocyte/macrophage cells, showing that the monocyte/macrophage-mediated activation of Tγδ lymphocytes induced by zoledronic acid is enhanced by a factor 10(3) when the zoledronic acid is intracellularly delivered through these carriers. Furthermore, the multicompartment ɛ-polylysine niosome clusters, with their intrinsic selectivity toward macrophages, appear particularly suitable for implementing therapeutic strategies against chronically infected macrophages. ɛ-polylysine niosome clusters, with their intrinsic selectivity toward macrophages, offer the potential for multidrug delivery. The effectiveness of aminobisphosphonate zoledronate is demonstrated to enhance the recruitment of Tγδ lymphocytes by macrophages by 2 orders of magnitude, suggesting a new therapeutic strategy for addressing pathologies featuring chronically infected macrophages. Copyright © 2011 Elsevier Inc. All rights reserved.

Tropism-Modification Strategies for Targeted Gene Delivery Using Adenoviral Vectors

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Andrew H. Baker

2010-10-01

Full Text Available Achieving high efficiency, targeted gene delivery with adenoviral vectors is a long-standing goal in the field of clinical gene therapy. To achieve this, platform vectors must combine efficient retargeting strategies with detargeting modifications to ablate native receptor binding (i.e. CAR/integrins/heparan sulfate proteoglycans and “bridging” interactions. “Bridging” interactions refer to coagulation factor binding, namely coagulation factor X (FX, which bridges hepatocyte transduction in vivo through engagement with surface expressed heparan sulfate proteoglycans (HSPGs. These interactions can contribute to the off-target sequestration of Ad5 in the liver and its characteristic dose-limiting hepatotoxicity, thereby significantly limiting the in vivo targeting efficiency and clinical potential of Ad5-based therapeutics. To date, various approaches to retargeting adenoviruses (Ad have been described. These include genetic modification strategies to incorporate peptide ligands (within fiber knob domain, fiber shaft, penton base, pIX or hexon, pseudotyping of capsid proteins to include whole fiber substitutions or fiber knob chimeras, pseudotyping with non-human Ad species or with capsid proteins derived from other viral families, hexon hypervariable region (HVR substitutions and adapter-based conjugation/crosslinking of scFv, growth factors or monoclonal antibodies directed against surface-expressed target antigens. In order to maximize retargeting, strategies which permit detargeting from undesirable interactions between the Ad capsid and components of the circulatory system (e.g. coagulation factors, erythrocytes, pre-existing neutralizing antibodies, can be employed simultaneously. Detargeting can be achieved by genetic ablation of native receptor-binding determinants, ablation of “bridging interactions” such as those which occur between the hexon of Ad5 and coagulation factor X (FX, or alternatively, through the use of polymer

Development and validation of brain and spinal cord vector and cell-delivery techniques in pre-clinical minipig models of neurodegenerative disorders

Czech Academy of Sciences Publication Activity Database

Juhás, Štefan; Juhásová, Jana; Klíma, Jiří; Maršala, M.; Maršala, S.; Atsushi, Y.; Johe, K.; Motlík, Jan

2015-01-01

Roč. 78, Suppl 2 (2015), s. 9-10 ISSN 1210-7859. [Conference on Animal Models for neurodegenerative Diseases /3./. 08.11.2015-10.11.2015, Liblice] R&D Projects: GA MŠk ED2.1.00/03.0124; GA MŠk(CZ) 7F14308 Institutional support: RVO:67985904 Keywords : minipig models of neurodegenerative disorders * brin and spinal cord cell delivery techniques Subject RIV: EB - Genetics ; Molecular Biology

A histogram-based technique for rapid vector extraction from PIV photographs

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Humphreys, William M., Jr.

1991-01-01

A new analysis technique, performed totally in the image plane, is proposed which rapidly extracts all available vectors from individual interrogation regions on PIV photographs. The technique avoids the need for using Fourier transforms with the associated computational burden. The data acquisition and analysis procedure is described, and results of a preliminary simulation study to evaluate the accuracy of the technique are presented. Recently obtained PIV photographs are analyzed.

Three-dimensional tumor spheroids for in vitro analysis of bacteria as gene delivery vectors in tumor therapy.

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Osswald, Annika; Sun, Zhongke; Grimm, Verena; Ampem, Grace; Riegel, Karin; Westendorf, Astrid M; Sommergruber, Wolfgang; Otte, Kerstin; Dürre, Peter; Riedel, Christian U

2015-12-12

Several studies in animal models demonstrated that obligate and facultative anaerobic bacteria of the genera Bifidobacterium, Salmonella, or Clostridium specifically colonize solid tumors. Consequently, these and other bacteria are discussed as live vectors to deliver therapeutic genes to inhibit tumor growth. Therapeutic approaches for cancer treatment using anaerobic bacteria have been investigated in different mouse models. In the present study, solid three-dimensional (3D) multicellular tumor spheroids (MCTS) of the colorectal adenocarcinoma cell line HT-29 were generated and tested for their potential to study prodrug-converting enzyme therapies using bacterial vectors in vitro. HT-29 MCTS resembled solid tumors displaying all relevant features with an outer zone of proliferating cells and hypoxic and apoptotic regions in the core. Upon incubation with HT-29 MCTS, Bifidobacterium bifidum S17 and Salmonella typhimurium YB1 selectively localized, survived and replicated in hypoxic areas inside MCTS. Furthermore, spores of the obligate anaerobe Clostridium sporogenes germinated in these hypoxic areas. To further evaluate the potential of MCTS to investigate therapeutic approaches using bacteria as gene delivery vectors, recombinant bifidobacteria expressing prodrug-converting enzymes were used. Expression of a secreted cytosine deaminase in combination with 5-fluorocytosine had no effect on growth of MCTS due to an intrinsic resistance of HT-29 cells to 5-fluorouracil, i.e. the converted drug. However, a combination of the prodrug CB1954 and a strain expressing a secreted chromate reductase effectively inhibited MCTS growth. Collectively, the presented results indicate that MCTS are a suitable and reliable model to investigate live bacteria as gene delivery vectors for cancer therapy in vitro.

A planning and delivery study of a rotational IMRT technique with burst delivery

International Nuclear Information System (INIS)

Kainz, Kristofer; Chen, Guang-Pei; Chang, Yu-Wen; Prah, Douglas; Sharon Qi, X.; Shukla, Himanshu P.; Stahl, Johannes; Allen Li, X.

2011-01-01

Purpose: A novel rotational IMRT (rIMRT) technique using burst delivery (continuous gantry rotation with beam off during MLC repositioning) is investigated. The authors evaluate the plan quality and delivery efficiency and accuracy of this dynamic technique with a conventional flat 6 MV photon beam. Methods: Burst-delivery rIMRT was implemented in a planning system and delivered with a 160-MLC linac. Ten rIMRT plans were generated for five anonymized patient cases encompassing head and neck, brain, prostate, and prone breast. All plans were analyzed retrospectively and not used for treatment. Among the varied plan parameters were the number of optimization points, number of arcs, gantry speed, and gantry angle range (alpha) over which the beam is turned on at each optimization point. Combined rotational/step-and-shoot rIMRT plans were also created by superimposing multiple-segment static fields at several optimization points. The rIMRT trial plans were compared with each other and with plans generated using helical tomotherapy and VMAT. Burst-mode rotational IMRT plans were delivered and verified using a diode array, ionization chambers, thermoluminescent dosimeters, and film. Results: Burst-mode rIMRT can achieve plan quality comparable to helical tomotherapy, while the former may lead to slightly better OAR sparing for certain cases and the latter generally achieves slightly lower hot spots. Few instances were found in which increasing the number of optimization points above 36, or superimposing step-and-shoot IMRT segments, led to statistically significant improvements in OAR sparing. Using an additional rIMRT partial arc yielded substantial OAR dose improvements for the brain case. Measured doses from the rIMRT plan delivery were within 4% of the plan calculation in low dose gradient regions. Delivery time range was 228-375 s for single-arc rIMRT 200-cGy prescription with a 300 MU/min dose rate, comparable to tomotherapy and VMAT. Conclusions: Rotational IMRT

Effect of thiol pendant conjugates on plasmid DNA binding, release, and stability of polymeric delivery vectors.

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Bacalocostantis, Irene; Mane, Viraj P; Kang, Michael S; Goodley, Addison S; Muro, Silvia; Kofinas, Peter

2012-05-14

Polymers have attracted much attention as potential gene delivery vectors due to their chemical and structural versatility. However, several challenges associated with polymeric carriers, including low transfection efficiencies, insufficient cargo release, and high cytotoxicity levels have prevented clinical implementation. Strong electrostatic interactions between polymeric carriers and DNA cargo can prohibit complete cargo release within the cell. As a result, cargo DNA never reaches the cell's nucleus where gene expression takes place. In addition, highly charged cationic polymers have been correlated with high cytotoxicity levels, making them unsuitable carriers in vivo. Using poly(allylamine) (PAA) as a model, we investigated how pH-sensitive disulfide cross-linked polymer networks can improve the delivery potential of cationic polymer carriers. To accomplish this, we conjugated thiol-terminated pendant chains onto the primary amines of PAA using 2-iminothiolane, developing three new polymer vectors with 5, 13, or 20% thiol modification. Unmodified PAA and thiol-conjugated polymers were tested for their ability to bind and release plasmid DNA, their capacity to protect genetic cargo from enzymatic degradation, and their potential for endolysosomal escape. Our results demonstrate that polymer-plasmid complexes (polyplexes) formed by the 13% thiolated polymer demonstrate the greatest delivery potential. At high N/P ratios, all thiolated polymers (but not unmodified counterparts) were able to resist decomplexation in the presence of heparin, a negatively charged polysaccharide used to mimic in vivo polyplex-protein interactions. Further, all thiolated polymers exhibited higher buffering capacities than unmodified PAA and, therefore, have a greater potential for endolysosomal escape. However, 5 and 20% thiolated polymers exhibited poor DNA binding-release kinetics, making them unsuitable carriers for gene delivery. The 13% thiolated polymers, on the other hand

Polydnaviruses of Parasitic Wasps: Domestication of Viruses To Act as Gene Delivery Vectors

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Michael R. Strand

2012-01-01

Full Text Available Symbiosis is a common phenomenon in which associated organisms can cooperate in ways that increase their ability to survive, reproduce, or utilize hostile environments. Here, we discuss polydnavirus symbionts of parasitic wasps. These viruses are novel in two ways: (1 they have become non-autonomous domesticated entities that cannot replicate outside of wasps; and (2 they function as a delivery vector of genes that ensure successful parasitism of host insects that wasps parasitize. In this review we discuss how these novelties may have arisen, which genes are potentially involved, and what the consequences have been for genome evolution.

Adaptive proxy map server for efficient vector spatial data rendering

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Sayar, Ahmet

2013-01-01

The rapid transmission of vector map data over the Internet is becoming a bottleneck of spatial data delivery and visualization in web-based environment because of increasing data amount and limited network bandwidth. In order to improve both the transmission and rendering performances of vector spatial data over the Internet, we propose a proxy map server enabling parallel vector data fetching as well as caching to improve the performance of web-based map servers in a dynamic environment. Proxy map server is placed seamlessly anywhere between the client and the final services, intercepting users' requests. It employs an efficient parallelization technique based on spatial proximity and data density in case distributed replica exists for the same spatial data. The effectiveness of the proposed technique is proved at the end of the article by the application of creating map images enriched with earthquake seismic data records.

Peripheral non-viral MIDGE vector-driven delivery of β-endorphin in inflammatory pain

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Busch Melanie

2009-12-01

Full Text Available Abstract Background Leukocytes infiltrating inflamed tissue produce and release opioid peptides such as β-endorphin, which activate opioid receptors on peripheral terminals of sensory nerves resulting in analgesia. Gene therapy is an attractive strategy to enhance continuous production of endogenous opioids. However, classical viral and plasmid vectors for gene delivery are hampered by immunogenicity, recombination, oncogene activation, anti-bacterial antibody production or changes in physiological gene expression. Non-viral, non-plasmid minimalistic, immunologically defined gene expression (MIDGE vectors may overcome these problems as they carry only elements needed for gene transfer. Here, we investigated the effects of a nuclear localization sequence (NLS-coupled MIDGE encoding the β-endorphin precursor proopiomelanocortin (POMC on complete Freund's adjuvant-induced inflammatory pain in rats. Results POMC-MIDGE-NLS injected into inflamed paws appeared to be taken up by leukocytes resulting in higher concentrations of β-endorphin in these cells. POMC-MIDGE-NLS treatment reversed enhanced mechanical sensitivity compared with control MIDGE-NLS. However, both effects were moderate, not always statistically significant or directly correlated with each other. Also, the anti-hyperalgesic actions could not be increased by enhancing β-endorphin secretion or by modifying POMC-MIDGE-NLS to code for multiple copies of β-endorphin. Conclusion Although MIDGE vectors circumvent side-effects associated with classical viral and plasmid vectors, the current POMC-MIDGE-NLS did not result in reliable analgesic effectiveness in our pain model. This was possibly associated with insufficient and variable efficacy in transfection and/or β-endorphin production. Our data point at the importance of the reproducibility of gene therapy strategies for the control of chronic pain.

Shallow water bathymetry mapping using Support Vector Machine (SVM) technique and multispectral imagery

NARCIS (Netherlands)

Misra, Ankita; Vojinovic, Zoran; Ramakrishnan, Balaji; Luijendijk, Arjen; Ranasinghe, Roshanka

2018-01-01

Satellite imagery along with image processing techniques prove to be efficient tools for bathymetry retrieval as they provide time and cost-effective alternatives to traditional methods of water depth estimation. In this article, a nonlinear machine learning technique of Support Vector Machine (SVM)

Chitosan-based DNA delivery vector targeted to gonadotropin-releasing hormone (GnRH) receptor.

Science.gov (United States)

Boonthum, Chatwalee; Namdee, Katawut; Boonrungsiman, Suwimon; Chatdarong, Kaywalee; Saengkrit, Nattika; Sajomsang, Warayuth; Ponglowhapan, Suppawiwat; Yata, Teerapong

2017-02-10

The main purpose of this study was to investigate the application of modified chitosan as a potential vector for gene delivery to gonadotropin-releasing hormone receptor (GnRHR)-expressing cells. Such design of gene carrier could be useful in particular for gene therapy for cancers related to the reproductive system, gene disorders of sexual development, and contraception and fertility control. In this study, a decapeptide GnRH was successfully conjugated to chitosan (CS) as confirmed by proton nuclear magnetic resonance spectroscopy ( 1 H NMR) and Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The synthesized GnRH-conjugated chitosan (GnRH-CS) was able to condense DNA to form positively charged nanoparticles and specifically deliver plasmid DNA to targeted cells in both two-dimensional (2D) and three-dimensional (3D) cell cultures systems. Importantly, GnRH-CS exhibited higher transfection activity compared to unmodified CS. In conclusion, GnRH-conjugated chitosan can be a promising carrier for targeted DNA delivery to GnRHR-expressing cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

Selective Inhibition of Histone Deacetylation in Melanoma Increases Targeted Gene Delivery by a Bacteriophage Viral Vector

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Samuel Campbell

2018-04-01

Full Text Available The previously developed adeno-associated virus/phage (AAVP vector, a hybrid between M13 bacteriophage (phage viruses that infect bacteria only and human Adeno-Associated Virus (AAV, is a promising tool in targeted gene therapy against cancer. AAVP can be administered systemically and made tissue specific through the use of ligand-directed targeting. Cancer cells and tumor-associated blood vessels overexpress the αν integrin receptors, which are involved in tumor angiogenesis and tumor invasion. AAVP is targeted to these integrins via a double cyclic RGD4C ligand displayed on the phage capsid. Nevertheless, there remain significant host-defense hurdles to the use of AAVP in targeted gene delivery and subsequently in gene therapy. We previously reported that histone deacetylation in cancer constitutes a barrier to AAVP. Herein, to improve AAVP-mediated gene delivery to cancer cells, we combined the vector with selective adjuvant chemicals that inhibit specific histone deacetylases (HDAC. We examined the effects of the HDAC inhibitor C1A that mainly targets HDAC6 and compared this to sodium butyrate, a pan-HDAC inhibitor with broad spectrum HDAC inhibition. We tested the effects on melanoma, known for HDAC6 up-regulation, and compared this side by side with a normal human kidney HEK293 cell line. Varying concentrations were tested to determine cytotoxic levels as well as effects on AAVP gene delivery. We report that the HDAC inhibitor C1A increased AAVP-mediated transgene expression by up to ~9-fold. These findings indicate that selective HDAC inhibition is a promising adjuvant treatment for increasing the therapeutic value of AAVP.

Nano-scale gene delivery systems; current technology, obstacles, and future directions.

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Garcia-Guerra, Antonio; Dunwell, Thomas L; Trigueros, Sonia

2018-01-07

Within the different applications of nanomedicine currently being developed, nano-gene delivery is appearing as an exciting new technique with the possibility to overcome recognised hurdles and fulfill several biological and medical needs. The central component of all delivery systems is the requirement for the delivery of genetic material into cells, and for them to eventually reside in the nucleus where their desired function will be exposed. However, genetic material does not passively enter cells; thus, a delivery system is necessary. The emerging field of nano-gene delivery exploits the use of new materials and the properties that arise at the nanometre-scale to produce delivery vectors that can effectively deliver genetic material into a variety of different types of cells. The novel physicochemical properties of the new delivery vectors can be used to address the current challenges existing in nucleic acid delivery in vitro and in vivo. While there is a growing interest in nanostructure-based gene delivery, the field is still in its infancy, and there is yet much to discover about nanostructures and their physicochemical properties in a biological context. We carry out an organized and focused search of bibliographic databases. Our results suggest that despite new breakthroughs in nanostructure synthesis and advanced characterization techniques, we still face many barriers in producing highly efficient and non-toxic delivery systems. In this review, we overview the types of systems currently used for clinical and biomedical research applications along with their advantages and disadvantages, as well as discussing barriers that arise from nano-scale interactions with biological material. In conclusion, we hope that by bringing the far reaching multidisciplinary nature of nano-gene delivery to light, new targeted nanotechnology-bases strategies are developed to overcome the major challenges covered in this review. Copyright© Bentham Science Publishers; For

Neuroprotection from NMDA excitotoxic lesion by Cu/Zn superoxide dismutase gene delivery to the postnatal rat brain by a modular protein vector

OpenAIRE

Peluffo, Hugo; Acarin, Laia; Arís, Anna; González, Pau; Villaverde, Antoni; Castellano, Bernardo; González, Berta

2006-01-01

Abstract Background Superoxide mediated oxidative stress is a key neuropathologic mechanism in acute central nervous system injuries. We have analyzed the neuroprotective efficacy of the transient overexpression of antioxidant enzyme Cu/Zn Superoxide dismutase (SOD) after excitotoxic injury to the immature rat brain by using a recently constructed modular protein vector for non-viral gene delivery termed NLSCt. For this purpose, animals were injected with the NLSCt vector carrying the Cu/Zn S...

Recombinant human parvovirus B19 vectors: erythroid cell-specific delivery and expression of transduced genes.

Science.gov (United States)

Ponnazhagan, S; Weigel, K A; Raikwar, S P; Mukherjee, P; Yoder, M C; Srivastava, A

1998-06-01

A novel packaging strategy combining the salient features of two human parvoviruses, namely the pathogenic parvovirus B19 and the nonpathogenic adeno-associated virus type 2 (AAV), was developed to achieve erythroid cell-specific delivery as well as expression of the transduced gene. The development of such a chimeric vector system was accomplished by packaging heterologous DNA sequences cloned within the inverted terminal repeats of AAV and subsequently packaging the DNA inside the capsid structure of B19 virus. Recombinant B19 virus particles were assembled, as evidenced by electron microscopy as well as DNA slot blot analyses. The hybrid vector failed to transduce nonerythroid human cells, such as 293 cells, as expected. However, MB-02 cells, a human megakaryocytic leukemia cell line which can be infected by B19 virus following erythroid differentiation with erythropoietin (N. C. Munshi, S. Z. Zhou, M. J. Woody, D. A. Morgan, and A. Srivastava, J. Virol. 67:562-566, 1993) but lacks the putative receptor for AAV (S. Ponnazhagan, X.-S. Wang, M. J. Woody, F. Luo, L. Y. Kang, M. L. Nallari, N. C. Munshi, S. Z. Zhou, and A. Srivastava, J. Gen. Virol. 77:1111-1122, 1996), were readily transduced by this vector. The hybrid vector was also found to specifically target the erythroid population in primary human bone marrow cells as well as more immature hematopoietic progenitor cells following erythroid differentiation, as evidenced by selective expression of the transduced gene in these target cells. Preincubation with anticapsid antibodies against B19 virus, but not anticapsid antibodies against AAV, inhibited transduction of primary human erythroid cells. The efficiency of transduction of primary human erythroid cells by the recombinant B19 virus vector was significantly higher than that by the recombinant AAV vector. Further development of the AAV-B19 virus hybrid vector system should prove beneficial in gene therapy protocols aimed at the correction of inherited and

Recombinant Human Parvovirus B19 Vectors: Erythroid Cell-Specific Delivery and Expression of Transduced Genes

Science.gov (United States)

Ponnazhagan, Selvarangan; Weigel, Kirsten A.; Raikwar, Sudhanshu P.; Mukherjee, Pinku; Yoder, Mervin C.; Srivastava, Arun

1998-01-01

A novel packaging strategy combining the salient features of two human parvoviruses, namely the pathogenic parvovirus B19 and the nonpathogenic adeno-associated virus type 2 (AAV), was developed to achieve erythroid cell-specific delivery as well as expression of the transduced gene. The development of such a chimeric vector system was accomplished by packaging heterologous DNA sequences cloned within the inverted terminal repeats of AAV and subsequently packaging the DNA inside the capsid structure of B19 virus. Recombinant B19 virus particles were assembled, as evidenced by electron microscopy as well as DNA slot blot analyses. The hybrid vector failed to transduce nonerythroid human cells, such as 293 cells, as expected. However, MB-02 cells, a human megakaryocytic leukemia cell line which can be infected by B19 virus following erythroid differentiation with erythropoietin (N. C. Munshi, S. Z. Zhou, M. J. Woody, D. A. Morgan, and A. Srivastava, J. Virol. 67:562–566, 1993) but lacks the putative receptor for AAV (S. Ponnazhagan, X.-S. Wang, M. J. Woody, F. Luo, L. Y. Kang, M. L. Nallari, N. C. Munshi, S. Z. Zhou, and A. Srivastava, J. Gen. Virol. 77:1111–1122, 1996), were readily transduced by this vector. The hybrid vector was also found to specifically target the erythroid population in primary human bone marrow cells as well as more immature hematopoietic progenitor cells following erythroid differentiation, as evidenced by selective expression of the transduced gene in these target cells. Preincubation with anticapsid antibodies against B19 virus, but not anticapsid antibodies against AAV, inhibited transduction of primary human erythroid cells. The efficiency of transduction of primary human erythroid cells by the recombinant B19 virus vector was significantly higher than that by the recombinant AAV vector. Further development of the AAV-B19 virus hybrid vector system should prove beneficial in gene therapy protocols aimed at the correction of inherited

Perinatal systemic gene delivery using adeno-associated viral vectors

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Rajvinder eKarda

2014-11-01

Full Text Available Neurodegenerative monogenic diseases can also affect a broad range of tissues and organs throughout the body. An effective treatment would require a systemic approach. The intravenous administration of novel therapies is ideal but is hampered by the inability of such drugs to cross the blood-brain barrier and precludes efficacy in the central nervous system. A number of these early lethal intractable diseases also present devastating irreversible pathology at birth or soon after. Therefore, any therapy would ideally be administered during the perinatal period to prevent, stop or ameliorate disease progression. The concept of perinatal gene therapy has moved a step further towards being a feasible approach to treating such disorders. This has primarily been driven by the recent discoveries that particular serotypes of adeno-associated virus (AAV gene delivery vectors have the ability to cross the blood-brain barrier following intravenous administration. Furthermore, this has been safely demonstrated in perinatal mice and non-human primates. This review focuses on the progress made in using AAV to achieve systemic transduction and what this means for developing perinatal gene therapy for early lethal neurodegenerative diseases.

Generation of a Vero-Based Packaging Cell Line to Produce SV40 Gene Delivery Vectors for Use in Clinical Gene Therapy Studies

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Miguel G. Toscano

2017-09-01

Full Text Available Replication-defective (RD recombinant simian virus 40 (SV40-based gene delivery vectors hold a great potential for clinical applications because of their presumed non-immunogenicity and capacity to induce immune tolerance to the transgene products in humans. However, the clinical use of SV40 vectors has been hampered by the lack of a packaging cell line that produces replication-competent (RC free SV40 particles in the vector production process. To solve this problem, we have adapted the current SV40 vector genome used for the production of vector particles and generated a novel Vero-based packaging cell line named SuperVero that exclusively expresses the SV40 large T antigen. SuperVero cells produce similar numbers of SV40 vector particles compared to the currently used packaging cell lines, albeit in the absence of contaminating RC SV40 particles. Our unique SV40 vector platform named SVac paves the way to clinically test a whole new generation of SV40-based therapeutics for a broad range of important diseases.

AAV Vectorization of DSB-mediated Gene Editing Technologies.

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Moser, Rachel J; Hirsch, Matthew L

2016-01-01

Recent work both at the bench and the bedside demonstrate zinc-finger nucleases (ZFNs), CRISPR/Cas9, and other programmable site-specific endonuclease technologies are being successfully utilized within and alongside AAV vectors to induce therapeutically relevant levels of directed gene editing within the human chromosome. Studies from past decades acknowledge that AAV vector genomes are enhanced substrates for homology-directed repair in the presence or absence of targeted DNA damage within the host genome. Additionally, AAV vectors are currently the most efficient format for in vivo gene delivery with no vector related complications in >100 clinical trials for diverse diseases. At the same time, advancements in the design of custom-engineered site-specific endonucleases and the utilization of elucidated endonuclease formats have resulted in efficient and facile genetic engineering for basic science and for clinical therapies. AAV vectors and gene editing technologies are an obvious marriage, using AAV for the delivery of repair substrate and/or a gene encoding a designer endonuclease; however, while efficient delivery and enhanced gene targeting by vector genomes are advantageous, other attributes of AAV vectors are less desirable for gene editing technologies. This review summarizes the various roles that AAV vectors play in gene editing technologies and provides insight into its trending applications for the treatment of genetic diseases.

Current vector control challenges in the fight against malaria.

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Benelli, Giovanni; Beier, John C

2017-10-01

The effective and eco-friendly control of Anopheles vectors plays a key role in any malaria management program. Integrated Vector Management (IVM) suggests making use of the full range of vector control tools available. The strategies for IVM require novel technologies to control outdoor transmission of malaria. Despite the wide number of promising control tools tested against mosquitoes, current strategies for malaria vector control used in most African countries are not sufficient to achieve successful malaria control. The majority of National Malaria Control Programs in Africa still rely on indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs). These methods reduce malaria incidence but generally have little impact on malaria prevalence. In addition to outdoor transmission, growing levels of insecticide resistance in targeted vectors threaten the efficacy of LLINs and IRS. Larvicidal treatments can be useful, but are not recommended for rural areas. The research needed to improve the quality and delivery of mosquito vector control should focus on (i) optimization of processes and methods for vector control delivery; (ii) monitoring of vector populations and biting activity with reliable techniques; (iii) the development of effective and eco-friendly tools to reduce the burden or locally eliminate malaria and other mosquito-borne diseases; (iv) the careful evaluation of field suitability and efficacy of new mosquito control tools to prove their epidemiological impact; (v) the continuous monitoring of environmental changes which potentially affect malaria vector populations; (vi) the cooperation among different disciplines, with main emphasis on parasitology, tropical medicine, ecology, entomology, and ecotoxicology. A better understanding of behavioral ecology of malaria vectors is required. Key ecological obstacles that limit the effectiveness of vector control include the variation in mosquito behavior, development of insecticide resistance

Design and application of cationic amphiphilic β-cyclodextrin derivatives as gene delivery vectors

Science.gov (United States)

Wan, Ning; Huan, Meng-Lei; Ma, Xi-Xi; Jing, Zi-Wei; Zhang, Ya-Xuan; Li, Chen; Zhou, Si-Yuan; Zhang, Bang-Le

2017-11-01

The nano self-assembly profiles of amphiphilic gene delivery vectors could improve the density of local cationic head groups to promote their DNA condensation capability and enhance the interaction between cell membrane and hydrophobic tails, thus increasing cellular uptake and gene transfection. In this paper, two series of cationic amphiphilic β-cyclodextrin (β-CD) derivatives were designed and synthesized by using 6-mono-OTs-β-CD (1) as the precursor to construct amphiphilic gene vectors with different building blocks in a selective and controlled manner. The effect of different type and degree of cationic head groups on transfection and the endocytic mechanism of β-CD derivatives/DNA nanocomplexes were also investigated. The results demonstrated that the designed β-cyclodextrin derivatives were able to compact DNA to form stable nanocomplexes and exhibited low cytotoxicity. Among them, PEI-1 with PEI head group showed enhanced transfection activity, significantly higher than commercially available agent PEI25000 especially in the presence of serum, showing potential application prospects in clinical trials. Moreover, the endocytic uptake mechanism involved in the gene transfection of PEI-1 was mainly through caveolae-mediated endocytosis, which could avoid the lysosomal degradation of loaded gene, and had great importance for improving gene transfection activity.

New techniques for the scientific visualization of three-dimensional multi-variate and vector fields

Energy Technology Data Exchange (ETDEWEB)

Crawfis, Roger A. [Univ. of California, Davis, CA (United States)

1995-10-01

Volume rendering allows us to represent a density cloud with ideal properties (single scattering, no self-shadowing, etc.). Scientific visualization utilizes this technique by mapping an abstract variable or property in a computer simulation to a synthetic density cloud. This thesis extends volume rendering from its limitation of isotropic density clouds to anisotropic and/or noisy density clouds. Design aspects of these techniques are discussed that aid in the comprehension of scientific information. Anisotropic volume rendering is used to represent vector based quantities in scientific visualization. Velocity and vorticity in a fluid flow, electric and magnetic waves in an electromagnetic simulation, and blood flow within the body are examples of vector based information within a computer simulation or gathered from instrumentation. Understand these fields can be crucial to understanding the overall physics or physiology. Three techniques for representing three-dimensional vector fields are presented: Line Bundles, Textured Splats and Hair Splats. These techniques are aimed at providing a high-level (qualitative) overview of the flows, offering the user a substantial amount of information with a single image or animation. Non-homogenous volume rendering is used to represent multiple variables. Computer simulations can typically have over thirty variables, which describe properties whose understanding are useful to the scientist. Trying to understand each of these separately can be time consuming. Trying to understand any cause and effect relationships between different variables can be impossible. NoiseSplats is introduced to represent two or more properties in a single volume rendering of the data. This technique is also aimed at providing a qualitative overview of the flows.

A technique to identify some typical radio frequency interference using support vector machine

Science.gov (United States)

Wang, Yuanchao; Li, Mingtao; Li, Dawei; Zheng, Jianhua

2017-07-01

In this paper, we present a technique to automatically identify some typical radio frequency interference from pulsar surveys using support vector machine. The technique has been tested by candidates. In these experiments, to get features of SVM, we use principal component analysis for mosaic plots and its classification accuracy is 96.9%; while we use mathematical morphology operation for smog plots and horizontal stripes plots and its classification accuracy is 86%. The technique is simple, high accurate and useful.

Three axis vector atomic magnetometer utilizing polarimetric technique

Energy Technology Data Exchange (ETDEWEB)

Pradhan, Swarupananda, E-mail: spradhan@barc.gov.in, E-mail: pradhans75@gmail.com [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 400085, India and Homi Bhabha National Institute, Department of Atomic Energy, Mumbai 400094 (India)

2016-09-15

The three axis vector magnetic field measurement based on the interaction of a single elliptically polarized light beam with an atomic system is described. The magnetic field direction dependent atomic responses are extracted by the polarimetric detection in combination with laser frequency modulation and magnetic field modulation techniques. The magnetometer geometry offers additional critical requirements like compact size and large dynamic range for space application. Further, the three axis magnetic field is measured using only the reflected signal (one polarization component) from the polarimeter and thus can be easily expanded to make spatial array of detectors and/or high sensitivity field gradient measurement as required for biomedical application.

Prospects for Foamy Viral Vector Anti-HIV Gene Therapy

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Arun K. Nalla

2016-03-01

Full Text Available Stem cell gene therapy approaches for Human Immunodeficiency Virus (HIV infection have been explored in clinical trials and several anti-HIV genes delivered by retroviral vectors were shown to block HIV replication. However, gammaretroviral and lentiviral based retroviral vectors have limitations for delivery of anti-HIV genes into hematopoietic stem cells (HSC. Foamy virus vectors have several advantages including efficient delivery of transgenes into HSC in large animal models, and a potentially safer integration profile. This review focuses on novel anti-HIV transgenes and the potential of foamy virus vectors for HSC gene therapy of HIV.

Microneedle Coating Techniques for Transdermal Drug Delivery

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Rita Haj-Ahmad

2015-11-01

Full Text Available Drug administration via the transdermal route is an evolving field that provides an alternative to oral and parenteral routes of therapy. Several microneedle (MN based approaches have been developed. Among these, coated MNs (typically where drug is deposited on MN tips are a minimally invasive method to deliver drugs and vaccines through the skin. In this review, we describe several processes to coat MNs. These include dip coating, gas jet drying, spray coating, electrohydrodynamic atomisation (EHDA based processes and piezoelectric inkjet printing. Examples of process mechanisms, conditions and tested formulations are provided. As these processes are independent techniques, modifications to facilitate MN coatings are elucidated. In summary, the outcomes and potential value for each technique provides opportunities to overcome formulation or dosage form limitations. While there are significant developments in solid degradable MNs, coated MNs (through the various techniques described have potential to be utilized in personalized drug delivery via controlled deposition onto MN templates.

Subxyphoid access of the normal pericardium: a novel drug delivery technique.

Science.gov (United States)

Laham, R J; Simons, M; Hung, D

1999-05-01

The pericardial space may potentially serve as a drug delivery reservoir that might be used to deliver therapeutic substances to the heart. This study describes a novel delivery technique that enables safe and rapid percutaneous subxyphoid access of the normal pericardium in a large animal model (49 Yorkshire pigs). An epidural introducer needle (Tuohy-17) is advanced gently under fluoroscopic guidance with a continuous positive pressure of 20-30 mm Hg (achieved by saline infusion using an intraflow system). The positive pressure is intended to push the right ventricle (with a lower pressure) away from the needle's path. Entry of the pericardial space is suspected after an increase in the saline flow through the intraflow system. Access to the pericardial space is confirmed by the injection of 1 ml of diluted contrast under fluoroscopy. A soft floppy-tip 0.025" guidewire is then advanced to the pericardial space and the needle is exchanged for an infusion catheter. Access of the pericardial space was achieved in all animals without any adverse events and without any hemodynamic compromise even with the delivery of fluid volumes as large as 50 ml. Histologic examination in 15 animals 4 weeks after pericardial access did not reveal any delivery-related myocardial damage. The safety, ease, and absence of hemodynamic compromise make this technique a potentially useful method for intrapericardial drug delivery and a good alternative to standard pericardiocentesis in patients with small pericardial effusions at higher risk for complications.

Investigation of a thiolated polymer in gene delivery

Science.gov (United States)

Bacalocostantis, Irene

Thiol-containing bioreducible polymers show significant potential as delivery vectors in gene therapy, a rapidly growing field which seeks to treat genetic-based disorders by delivering functional synthetic genes to diseased cells. Studies have shown that thiolated polymers exhibit improved biodegradability and prolonged in vivo circulation times over non-thiolated polymers. However, the extent to which thiol concentrations impact the carrier's delivery potential has not been well explored. The aim of this dissertation is to investigate how relative concentrations of free thiols and disulfide crosslinks impact a polymeric carriers delivery performance with respect to DNA packaging, complex stability, cargo protection, gene release, internalization efficiency and cytotoxicity. To accomplish this goal, several fluorescent polymers containing varying concentrations of thiol groups were synthesized by conjugating thiol-pendant chains onto the primary amines of cationic poly(allylamine). In vitro delivery assays and characterization techniques were employed to assess the effect of thiols in gene delivery.

Listeria monocytogenes as a vector for anti-cancer therapies.

LENUS (Irish Health Repository)

Tangney, Mark

2012-01-31

The intracellular pathogen Listeria monocytogenes represents a promising therapeutic vector for the delivery of DNA, RNA or protein to cancer cells or to prime immune responses against tumour-specific antigens. A number of biological properties make L. monocytogenes a promising platform for development as a vector for either gene therapy or as an anti-cancer vaccine vector. L. monocytogenes is particularly efficient in mediating internalization into host cells. Once inside cells, the bacterium produces specific virulence factors which lyse the vaculolar membrane and allow escape into the cytoplasm. Once in the cytosol, L. monocytogenes is capable of actin-based motility and cell-to-cell spread without an extracellular phase. The cytoplasmic location of L. monocytogenes is significant as this potentiates entry of antigens into the MHC Class I antigen processing pathway leading to priming of specific CD8(+) T cell responses. The cytoplasmic location is also beneficial for the delivery of DNA (bactofection) by L. monocytogenes whilst cell-to-cell spread may facilitate access of the vector to cells throughout the tumour. Several preclinical studies have demonstrated the ability of L. monocytogenes for intracellular gene or protein delivery in vitro and in vivo, and this vector has also displayed safety and efficacy in clinical trial. Here, we review the features of the L. monocytogenes host-pathogen interaction that make this bacterium such an attractive candidate with which to induce appropriate therapeutic responses. We focus primarily upon work that has led to attenuation of the pathogen, demonstrated DNA, RNA or protein delivery to tumour cells as well as research that shows the efficacy of L. monocytogenes as a vector for tumour-specific vaccine delivery.

Enhancement techniques for improving 5-aminolevulinic acid delivery through the skin

Directory of Open Access Journals (Sweden)

Li-Wen Zhang

2011-03-01

Full Text Available Photodynamic therapy (PDT is a popular technique for skin cancer treatment. Protoporphyrin IX, which is a photosensitizing agent, converted enzymatically from the prodrug 5-aminolevulinic acid (ALA, is used as a photosensitizer in PDT for cancer. However, ALA penetrates with difficulty through intact skin; therefore, improving delivery systems for ALA in the skin will play an important role in ALA-PDT. Enhancement of ALA skin penetration can be achieved by physical methods, such as iontophoresis, laser, microneedles, ultrasound, and by adding chemical penetration enhancers, such as, dimethyl sulfoxide, oleic acid, and others, whereas some researches used lipophilic ALA derivatives and different vehicles to improve the transdermal delivery of ALA. This review introduces several enhancement techniques for increasing ALA permeation through the skin.

Gene delivery to skeletal muscle results in sustained expression and systemic delivery of a therapeutic protein.

Science.gov (United States)

Kessler, P D; Podsakoff, G M; Chen, X; McQuiston, S A; Colosi, P C; Matelis, L A; Kurtzman, G J; Byrne, B J

1996-11-26

Somatic gene therapy has been proposed as a means to achieve systemic delivery of therapeutic proteins. However, there is limited evidence that current methods of gene delivery can practically achieve this goal. In this study, we demonstrate that, following a single intramuscular administration of a recombinant adeno-associated virus (rAAV) vector containing the beta-galactosidase (AAV-lacZ) gene into adult BALB/c mice, protein expression was detected in myofibers for at least 32 weeks. A single intramuscular administration of an AAV vector containing a gene for human erythropoietin (AAV-Epo) into mice resulted in dose-dependent secretion of erythropoietin and corresponding increases in red blood cell production that persisted for up to 40 weeks. Primary human myotubes transduced in vitro with the AAV-Epo vector also showed dose-dependent production of Epo. These results demonstrate that rAAV vectors are able to transduce skeletal muscle and are capable of achieving sustained expression and systemic delivery of a therapeutic protein following a single intramuscular administration. Gene therapy using AAV vectors may provide a practical strategy for the treatment of inherited and acquired protein deficiencies.

Gene delivery to skeletal muscle results in sustained expression and systemic delivery of a therapeutic protein

Science.gov (United States)

Kessler, Paul D.; Podsakoff, Gregory M.; Chen, Xiaojuan; McQuiston, Susan A.; Colosi, Peter C.; Matelis, Laura A.; Kurtzman, Gary J.; Byrne, Barry J.

1996-01-01

Somatic gene therapy has been proposed as a means to achieve systemic delivery of therapeutic proteins. However, there is limited evidence that current methods of gene delivery can practically achieve this goal. In this study, we demonstrate that, following a single intramuscular administration of a recombinant adeno-associated virus (rAAV) vector containing the β-galactosidase (AAV-lacZ) gene into adult BALB/c mice, protein expression was detected in myofibers for at least 32 weeks. A single intramuscular administration of an AAV vector containing a gene for human erythropoietin (AAV-Epo) into mice resulted in dose-dependent secretion of erythropoietin and corresponding increases in red blood cell production that persisted for up to 40 weeks. Primary human myotubes transduced in vitro with the AAV-Epo vector also showed dose-dependent production of Epo. These results demonstrate that rAAV vectors are able to transduce skeletal muscle and are capable of achieving sustained expression and systemic delivery of a therapeutic protein following a single intramuscular administration. Gene therapy using AAV vectors may provide a practical strategy for the treatment of inherited and acquired protein deficiencies. PMID:8943064

Lentiviral vectors in cancer immunotherapy.

Science.gov (United States)

Oldham, Robyn Aa; Berinstein, Elliot M; Medin, Jeffrey A

2015-01-01

Basic science advances in cancer immunotherapy have resulted in various treatments that have recently shown success in the clinic. Many of these therapies require the insertion of genes into cells to directly kill them or to redirect the host's cells to induce potent immune responses. Other analogous therapies work by modifying effector cells for improved targeting and enhanced killing of tumor cells. Initial studies done using γ-retroviruses were promising, but safety concerns centered on the potential for insertional mutagenesis have highlighted the desire to develop other options for gene delivery. Lentiviral vectors (LVs) have been identified as potentially more effective and safer alternative delivery vehicles. LVs are now in use in clinical trials for many different types of inherited and acquired disorders, including cancer. This review will discuss current knowledge of LVs and the applications of this viral vector-based delivery vehicle to cancer immunotherapy.

Using support vector machines in the multivariate state estimation technique

International Nuclear Information System (INIS)

Zavaljevski, N.; Gross, K.C.

1999-01-01

One approach to validate nuclear power plant (NPP) signals makes use of pattern recognition techniques. This approach often assumes that there is a set of signal prototypes that are continuously compared with the actual sensor signals. These signal prototypes are often computed based on empirical models with little or no knowledge about physical processes. A common problem of all data-based models is their limited ability to make predictions on the basis of available training data. Another problem is related to suboptimal training algorithms. Both of these potential shortcomings with conventional approaches to signal validation and sensor operability validation are successfully resolved by adopting a recently proposed learning paradigm called the support vector machine (SVM). The work presented here is a novel application of SVM for data-based modeling of system state variables in an NPP, integrated with a nonlinear, nonparametric technique called the multivariate state estimation technique (MSET), an algorithm developed at Argonne National Laboratory for a wide range of nuclear plant applications

Calibrated delivery drape versus indirect gravimetric technique for the measurement of blood loss after delivery: a randomized trial.

Science.gov (United States)

Ambardekar, Shubha; Shochet, Tara; Bracken, Hillary; Coyaji, Kurus; Winikoff, Beverly

2014-08-15

Trials of interventions for PPH prevention and treatment rely on different measurement methods for the quantification of blood loss and identification of PPH. This study's objective was to compare measures of blood loss obtained from two different measurement protocols frequently used in studies. Nine hundred women presenting for vaginal delivery were randomized to a direct method (a calibrated delivery drape) or an indirect method (a shallow bedpan placed below the buttocks and weighing the collected blood and blood-soaked gauze/pads). Blood loss was measured from immediately after delivery for at least one hour or until active bleeding stopped. Significantly greater mean blood loss was recorded by the direct than by the indirect measurement technique (253.9 mL and 195.3 mL, respectively; difference = 58.6 mL (95% CI: 31-86); p 500 mL (8.7% vs. 4.7%, p = 0.02). The study suggests a real and significant difference in blood loss measurement between these methods. Research using blood loss measurement as an endpoint needs to be interpreted taking measurement technique into consideration. This study has been registered at clinicaltrials.gov as NCT01885845.

Induction of CD8(+) T cell responses and protective efficacy following microneedle-mediated delivery of a live adenovirus-vectored malaria vaccine.

Science.gov (United States)

Pearson, Frances E; O'Mahony, Conor; Moore, Anne C; Hill, Adrian V S

2015-06-22

There is an urgent need for improvements in vaccine delivery technologies. This is particularly pertinent for vaccination programmes within regions of limited resources, such as those required for adequate provision for disposal of used needles. Microneedles are micron-sized structures that penetrate the stratum corneum of the skin, creating temporary conduits for the needle-free delivery of drugs or vaccines. Here, we aimed to investigate immunity induced by the recombinant simian adenovirus-vectored vaccine ChAd63.ME-TRAP; currently undergoing clinical assessment as a candidate malaria vaccine, when delivered percutaneously by silicon microneedle arrays. In mice, we demonstrate that microneedle-mediated delivery of ChAd63.ME-TRAP induced similar numbers of transgene-specific CD8(+) T cells compared to intradermal (ID) administration with needle-and-syringe, following a single immunisation and after a ChAd63/MVA heterologous prime-boost schedule. When mice immunised with ChAd63/MVA were challenged with live Plasmodium berghei sporozoites, microneedle-mediated ChAd63.ME-TRAP priming demonstrated equivalent protective efficacy as did ID immunisation. Furthermore, responses following ChAd63/MVA immunisation correlated with a specific design parameter of the array used ('total array volume'). The level of transgene expression at the immunisation site and skin-draining lymph node (dLN) was also linked to total array volume. These findings have implications for defining silicon microneedle array design for use with live, vectored vaccines. Copyright © 2015 Elsevier Ltd. All rights reserved.

ROBUSTNESS OF A FACE-RECOGNITION TECHNIQUE BASED ON SUPPORT VECTOR MACHINES

OpenAIRE

Prashanth Harshangi; Koshy George

2010-01-01

The ever-increasing requirements of security concerns have placed a greater demand for face recognition surveillance systems. However, most current face recognition techniques are not quite robust with respect to factors such as variable illumination, facial expression and detail, and noise in images. In this paper, we demonstrate that face recognition using support vector machines are sufficiently robust to different kinds of noise, does not require image pre-processing, and can be used with...

Fast implementations of 3D PET reconstruction using vector and parallel programming techniques

International Nuclear Information System (INIS)

Guerrero, T.M.; Cherry, S.R.; Dahlbom, M.; Ricci, A.R.; Hoffman, E.J.

1993-01-01

Computationally intensive techniques that offer potential clinical use have arisen in nuclear medicine. Examples include iterative reconstruction, 3D PET data acquisition and reconstruction, and 3D image volume manipulation including image registration. One obstacle in achieving clinical acceptance of these techniques is the computational time required. This study focuses on methods to reduce the computation time for 3D PET reconstruction through the use of fast computer hardware, vector and parallel programming techniques, and algorithm optimization. The strengths and weaknesses of i860 microprocessor based workstation accelerator boards are investigated in implementations of 3D PET reconstruction

An efficient nonviral gene-delivery vector based on hyperbranched cationic glycogen derivatives

Directory of Open Access Journals (Sweden)

Liang X

2014-01-01

Full Text Available Xuan Liang,1,* Xianyue Ren,2,* Zhenzhen Liu,1 Yingliang Liu,1 Jue Wang,2 Jingnan Wang,2 Li-Ming Zhang,1 David YB Deng,2 Daping Quan,1 Liqun Yang1 1Institute of Polymer Science, School of Chemistry and Chemical Engineering, Key Laboratory of Designed Synthesis and Application of Polymer Material, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Sun Yat-Sen University, Guangzhou, People's Republic of China; 2Research Center of Translational Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, People's Republic of China *Both these authors contributed equally to this work Background: The purpose of this study was to synthesize and evaluate hyperbranched cationic glycogen derivatives as an efficient nonviral gene-delivery vector. Methods: A series of hyperbranched cationic glycogen derivatives conjugated with 3-(dimethylamino-1-propylamine (DMAPA-Glyp and 1-(2-aminoethyl piperazine (AEPZ-Glyp residues were synthesized and characterized by Fourier-transform infrared and hydrogen-1 nuclear magnetic resonance spectroscopy. Their buffer capacity was assessed by acid–base titration in aqueous NaCl solution. Plasmid deoxyribonucleic acid (pDNA condensation ability and protection against DNase I degradation of the glycogen derivatives were assessed using agarose gel electrophoresis. The zeta potentials and particle sizes of the glycogen derivative/pDNA complexes were measured, and the images of the complexes were observed using atomic force microscopy. Blood compatibility and cytotoxicity were evaluated by hemolysis assay and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, respectively. pDNA transfection efficiency mediated by the cationic glycogen derivatives was evaluated by flow cytometry and fluorescence microscopy in the 293T (human embryonic kidney and the CNE2 (human nasopharyngeal carcinoma cell lines. In vivo delivery of pDNA in model animals (Sprague Dawley

An adenovirus vector incorporating carbohydrate binding domains utilizes glycans for gene transfer.

Directory of Open Access Journals (Sweden)

Julius W Kim

Full Text Available Vectors based on human adenovirus serotype 5 (HAdV-5 continue to show promise as delivery vehicles for cancer gene therapy. Nevertheless, it has become clear that therapeutic benefit is directly linked to tumor-specific vector localization, highlighting the need for tumor-targeted gene delivery. Aberrant glycosylation of cell surface glycoproteins and glycolipids is a central feature of malignant transformation, and tumor-associated glycoforms are recognized as cancer biomarkers. On this basis, we hypothesized that cancer-specific cell-surface glycans could be the basis of a novel paradigm in HAdV-5-based vector targeting.As a first step toward this goal, we constructed a novel HAdV-5 vector encoding a unique chimeric fiber protein that contains the tandem carbohydrate binding domains of the fiber protein of the NADC-1 strain of porcine adenovirus type 4 (PAdV-4. This glycan-targeted vector displays augmented CAR-independent gene transfer in cells with low CAR expression. Further, we show that gene transfer is markedly decreased in cells with genetic glycosylation defects and by inhibitors of glycosylation in normal cells.These data provide the initial proof-of-concept for HAdV-5 vector-mediated gene delivery based on the presence of cell-surface carbohydrates. Further development of this new targeting paradigm could provide targeted gene delivery based on vector recognition of disease-specific glycan biomarkers.

Coordination analysis of players' distribution in football using cross-correlation and vector coding techniques.

Science.gov (United States)

Moura, Felipe Arruda; van Emmerik, Richard E A; Santana, Juliana Exel; Martins, Luiz Eduardo Barreto; Barros, Ricardo Machado Leite de; Cunha, Sergio Augusto

2016-12-01

The purpose of this study was to investigate the coordination between teams spread during football matches using cross-correlation and vector coding techniques. Using a video-based tracking system, we obtained the trajectories of 257 players during 10 matches. Team spread was calculated as functions of time. For a general coordination description, we calculated the cross-correlation between the signals. Vector coding was used to identify the coordination patterns between teams during offensive sequences that ended in shots on goal or defensive tackles. Cross-correlation showed that opponent teams have a tendency to present in-phase coordination, with a short time lag. During offensive sequences, vector coding results showed that, although in-phase coordination dominated, other patterns were observed. We verified that during the early stages, offensive sequences ending in shots on goal present greater anti-phase and attacking team phase periods, compared to sequences ending in tackles. Results suggest that the attacking team may seek to present a contrary behaviour of its opponent (or may lead the adversary behaviour) in the beginning of the attacking play, regarding to the distribution strategy, to increase the chances of a shot on goal. The techniques allowed detecting the coordination patterns between teams, providing additional information about football dynamics and players' interaction.

Circumventing antivector immunity: potential use of nonhuman adenoviral vectors.

Science.gov (United States)

Lopez-Gordo, Estrella; Podgorski, Iva I; Downes, Nicholas; Alemany, Ramon

2014-04-01

Adenoviruses are efficient gene delivery vectors based on their ability to transduce a wide variety of cell types and drive high-level transient transgene expression. While there have been advances in modifying human adenoviral (HAdV) vectors to increase their safety profile, there are still pitfalls that need to be further addressed. Preexisting humoral and cellular immunity against common HAdV serotypes limits the efficacy of gene transfer and duration of transgene expression. As an alternative, nonhuman AdV (NHAdV) vectors can circumvent neutralizing antibodies against HAdVs in immunized mice and monkeys and in human sera, suggesting that NHAdV vectors could circumvent preexisting humoral immunity against HAdVs in a clinical setting. Consequently, there has been an increased interest in developing NHAdV vectors for gene delivery in humans. In this review, we outline the recent advances and limitations of HAdV vectors for gene therapy and describe examples of NHAdV vectors focusing on their immunogenicity, tropism, and potential as effective gene therapy vehicles.

Vector optimization technique in the problems of interaction between an enterprise and its counteragents

Directory of Open Access Journals (Sweden)

Oleg Igorevich Nikonov

2011-09-01

Full Text Available This paper reviews vector optimization goals related to the selection of efficient portfolios of a company's counterparties. In the first part of the research, the costs to minimize of providing goods and risk of late delivery have been selected as the optimization criteria. It is assumed that the risks are random in nature and are characterized by a random amount of damage being made to the firm due to late delivery of products. It is assumed that the amount of damage is proportional to the quantity of goods ordered. The second section is devoted to the optimization of working with bank clients through the formation of an effective portfolio of banking products. The following resources of the bank are considered as risky assets: placed interbank loans, securities (bonds, stocks, bonds, corporate loans, loans to small and medium-sized businesses, factoring and loans to individuals. Methodologically, the approach developed here is adjacent to the theory of portfolio investment, which goes back to a paper by G. Markowitz, however, this approach is applied for objects other than capital market instruments.

Hexon-chimaeric adenovirus serotype 5 vectors circumvent pre-existing anti-vector immunity

NARCIS (Netherlands)

Roberts, Diane M.; Nanda, Anjali; Havenga, Menzo J. E.; Abbink, Peter; Lynch, Diana M.; Ewald, Bonnie A.; Liu, Jinyan; Thorner, Anna R.; Swanson, Patricia E.; Gorgone, Darci A.; Lifton, Michelle A.; Lemckert, Angelique A. C.; Holterman, Lennart; Chen, Bing; Dilraj, Athmanundh; Carville, Angela; Mansfield, Keith G.; Goudsmit, Jaap; Barouch, Dan H.

2006-01-01

A common viral immune evasion strategy involves mutating viral surface proteins in order to evade host neutralizing antibodies. Such immune evasion tactics have not previously been intentionally applied to the development of novel viral gene delivery vectors that overcome the critical problem of

New Theoretical Analysis of the LRRM Calibration Technique for Vector Network Analyzers

OpenAIRE

Purroy Martín, Francesc; Pradell i Cara, Lluís

2001-01-01

In this paper, a new theoretical analysis of the four-standards line-reflect-reflect-match (LRRM) vector network-analyzer (VNA) calibration technique is presented. As a result, it is shown that the reference-impedance (to which the LRRM calibration is referred) cannot generally be defined whenever nonideal standards are used. Based on this consideration, a new algorithm to determine the on-wafer match standard is proposed that improves the LRRM calibration accuracy. Experimental verification ...

Live-Attenuated Bacterial Vectors: Tools for Vaccine and Therapeutic Agent Delivery

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Ivan Y. C. Lin

2015-11-01

Full Text Available Genetically attenuated microorganisms, including pathogenic and commensal bacteria, can be engineered to carry and deliver heterologous antigens to elicit host immunity against both the vector as well as the pathogen from which the donor gene is derived. These live attenuated bacterial vectors have been given much attention due to their capacity to induce a broad range of immune responses including localized mucosal, as well as systemic humoral and/or cell-mediated immunity. In addition, the unique tumor-homing characteristics of these bacterial vectors has also been exploited for alternative anti-tumor vaccines and therapies. In such approach, tumor-associated antigen, immunostimulatory molecules, anti-tumor drugs, or nucleotides (DNA or RNA are delivered. Different potential vectors are appropriate for specific applications, depending on their pathogenic routes. In this review, we survey and summarize the main features of the different types of live bacterial vectors and discussed the clinical applications in the field of vaccinology. In addition, different approaches for using live attenuated bacterial vectors for anti-cancer therapy is discussed, and some promising pre-clinical and clinical studies in this field are outlined.

Amplatzer Vascular Plug Anchoring Technique to Stabilize the Delivery System for Microcoil Embolization

International Nuclear Information System (INIS)

Onozawa, Shiro; Murata, Satoru; Mine, Takahiko; Sugihara, Fumie; Yasui, Daisuke; Kumita, Shin-ichiro

2016-01-01

PurposeTo evaluate the feasibility of a novel embolization technique, the Amplatzer vascular plug (AVP) anchoring technique, to stabilize the delivery system for microcoil embolization.Materials and methodsThree patients were enrolled in this study, including two cases of internal iliac artery aneurysms and one case of internal iliac arterial occlusion prior to endovascular aortic repair. An AVP was used in each case for embolization of one target artery, and the AVP was left in place. The AVP detachment wire was then used as an anchor to stabilize the delivery system for microcoil embolization to embolize the second target artery adjacent to the first target artery. The microcatheter for the microcoils was inserted parallel to the AVP detachment wire in the guiding sheath or catheter used for the AVP.ResultsThe AVP anchoring technique was achieved and the microcatheter was easily advanced to the second target artery in all three cases.ConclusionThe AVP anchoring technique was found to be feasible to advance the microcatheter into the neighboring artery of an AVP-embolized artery.

Synthesis and optimization of cholesterol-based diquaternary ammonium Gemini Surfactant (Chol-GS) as a new gene delivery vector.

Science.gov (United States)

Kim, Bieong-Kil; Doh, Kyung-Oh; Bae, Yun-Ui; Seu, Young-Bae

2011-01-01

Amongst a number of potential nonviral vectors, cationic liposomes have been actively researched, with both gemini surfactants and bola amphiphiles reported as being in possession of good structures in terms of cell viability and in vitro transfection. In this study, a cholesterol-based diquaternary ammonium gemini surfactant (Chol-GS) was synthesized and assessed as a novel nonviral gene vector. Chol-GS was synthesized from cholesterol by way of four reaction steps. The optimal efficiency was found to be at a weight ratio of 1:4 of lipid:DOPE (1,2-dioleoyl-L-alpha- glycero-3-phosphatidylethanolamine), and at a ratio of between 10:1~15:1 of liposome:DNA. The transfection efficiency was compared with commercial liposomes and with Lipofectamine, 1,2-dimyristyloxypropyl-3-dimethylhydroxyethylammonium bromide (DMRIE-C), and N-[1-(2,3-dioleoyloxy)propyl]- N,N,N-trimethylammonium chloride (DOTAP). The results indicate that the efficiency of Chol-GS is greater than that of all the tested commercial liposomes in COS7 and Huh7 cells, and higher than DOTAP and Lipofectamine in A549 cells. Confirmation of these findings was observed through the use of green fluorescent protein expression. Chol-GS exhibited a moderate level of cytotoxicity, at optimum concentrations for efficient transfection, indicating cell viability. Hence, the newly synthesized Chol-GS liposome has the potential of being an excellent nonviral vector for gene delivery.

Balancing Instructional Techniques and Delivery Formats in Capstone Business Strategy Courses

Science.gov (United States)

Alstete, Jeffrey W.; Beutell, Nicholas J.

2016-01-01

Purpose: The purpose of this paper is to contend that collegiate programs should carefully plan their capstone courses in light of the educational mission, pedagogical content knowledge, instructional techniques and delivery formats. Design/methodology/approach: This is a concept paper with elements of theory building from the case of business…

Space Vector Modulation Technique to Reduce Leakage Current of a Transformerless Three-Phase Four-Leg Photovoltaic System

Directory of Open Access Journals (Sweden)

F. Hasanzad

2017-06-01

Full Text Available Photovoltaic systems integrated to the grid have received considerable attention around the world. They can be connected to the electrical grid via galvanic isolation (transformer or without it (transformerless. Despite making galvanic isolation, low frequency transformer increases size, cost and losses. On the other hand, transformerless PV systems increase the leakage current (common-mode current, (CMC through the parasitic capacitors of the PV array. Inverter topology and switching technique are the most important parameters the leakage current depends on. As there is no need to extra hardware for switching scheme modification, it's an economical method for reducing leakage current. This paper evaluates the effect of different space vector modulation techniques on leakage current for a two-level three-phase four-leg inverter used in PV system. It proposes an efficient space vector modulation method which decreases the leakage current to below the quantity specified in VDE-0126-1-1 standard. furthermore, some other characteristics of the space vector modulation schemes that have not been significantly discussed for four-leg inverter, are considered, such as, modulation index, switching actions per period, common-mode voltage (CMV, and total harmonic distortion (THD. An extend software simulation using MATLAB/Simulink is performed to verify the effectiveness of the modulation technique.

Neuroprotection from NMDA excitotoxic lesion by Cu/Zn superoxide dismutase gene delivery to the postnatal rat brain by a modular protein vector

Science.gov (United States)

Peluffo, Hugo; Acarin, Laia; Arís, Anna; González, Pau; Villaverde, Antoni; Castellano, Bernardo; González, Berta

2006-01-01

Background Superoxide mediated oxidative stress is a key neuropathologic mechanism in acute central nervous system injuries. We have analyzed the neuroprotective efficacy of the transient overexpression of antioxidant enzyme Cu/Zn Superoxide dismutase (SOD) after excitotoxic injury to the immature rat brain by using a recently constructed modular protein vector for non-viral gene delivery termed NLSCt. For this purpose, animals were injected with the NLSCt vector carrying the Cu/Zn SOD or the control GFP transgenes 2 hours after intracortical N-methyl-D-aspartate (NMDA) administration, and daily functional evaluation was performed. Moreover, 3 days after, lesion volume, neuronal degeneration and nitrotyrosine immunoreactivity were evaluated. Results Overexpression of Cu/Zn SOD transgene after NMDA administration showed improved functional outcome and a reduced lesion volume at 3 days post lesion. In secondary degenerative areas, increased neuronal survival as well as decreased numbers of degenerating neurons and nitrotyrosine immunoreactivity was seen. Interestingly, injection of the NLSCt vector carrying the control GFP transgene also displayed a significant neuroprotective effect but less pronounced. Conclusion When the appropriate levels of Cu/Zn SOD are expressed transiently after injury using the non-viral modular protein vector NLSCt a neuroprotective effect is seen. Thus recombinant modular protein vectors may be suitable for in vivo gene therapy, and Cu/Zn SOD should be considered as an interesting therapeutic transgene. PMID:16638118

Neuroprotection from NMDA excitotoxic lesion by Cu/Zn superoxide dismutase gene delivery to the postnatal rat brain by a modular protein vector

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Castellano Bernardo

2006-04-01

Full Text Available Abstract Background Superoxide mediated oxidative stress is a key neuropathologic mechanism in acute central nervous system injuries. We have analyzed the neuroprotective efficacy of the transient overexpression of antioxidant enzyme Cu/Zn Superoxide dismutase (SOD after excitotoxic injury to the immature rat brain by using a recently constructed modular protein vector for non-viral gene delivery termed NLSCt. For this purpose, animals were injected with the NLSCt vector carrying the Cu/Zn SOD or the control GFP transgenes 2 hours after intracortical N-methyl-D-aspartate (NMDA administration, and daily functional evaluation was performed. Moreover, 3 days after, lesion volume, neuronal degeneration and nitrotyrosine immunoreactivity were evaluated. Results Overexpression of Cu/Zn SOD transgene after NMDA administration showed improved functional outcome and a reduced lesion volume at 3 days post lesion. In secondary degenerative areas, increased neuronal survival as well as decreased numbers of degenerating neurons and nitrotyrosine immunoreactivity was seen. Interestingly, injection of the NLSCt vector carrying the control GFP transgene also displayed a significant neuroprotective effect but less pronounced. Conclusion When the appropriate levels of Cu/Zn SOD are expressed transiently after injury using the non-viral modular protein vector NLSCt a neuroprotective effect is seen. Thus recombinant modular protein vectors may be suitable for in vivo gene therapy, and Cu/Zn SOD should be considered as an interesting therapeutic transgene.

Gene therapy for human glioblastoma using neurotropic JC virus-like particles as a gene delivery vector.

Science.gov (United States)

Chao, Chun-Nun; Yang, Yu-Hsuan; Wu, Mu-Sheng; Chou, Ming-Chieh; Fang, Chiung-Yao; Lin, Mien-Chun; Tai, Chien-Kuo; Shen, Cheng-Huang; Chen, Pei-Lain; Chang, Deching; Wang, Meilin

2018-02-02

Glioblastoma multiforme (GBM), the most common malignant brain tumor, has a short period of survival even with recent multimodality treatment. The neurotropic JC polyomavirus (JCPyV) infects glial cells and oligodendrocytes and causes fatal progressive multifocal leukoencephalopathy in patients with AIDS. In this study, a possible gene therapy strategy for GBM using JCPyV virus-like particles (VLPs) as a gene delivery vector was investigated. We found that JCPyV VLPs were able to deliver the GFP reporter gene into tumor cells (U87-MG) for expression. In an orthotopic xenograft model, nude mice implanted with U87 cells expressing the near-infrared fluorescent protein and then treated by intratumoral injection of JCPyV VLPs carrying the thymidine kinase suicide gene, combined with ganciclovir administration, exhibited significantly prolonged survival and less tumor fluorescence during the experiment compared with controls. Furthermore, JCPyV VLPs were able to protect and deliver a suicide gene to distal subcutaneously implanted U87 cells in nude mice via blood circulation and inhibit tumor growth. These findings show that metastatic brain tumors can be targeted by JCPyV VLPs carrying a therapeutic gene, thus demonstrating the potential of JCPyV VLPs to serve as a gene therapy vector for the far highly treatment-refractory GBM.

Percutaneous Vaccination as an Effective Method of Delivery of MVA and MVA-Vectored Vaccines.

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Clement A Meseda

Full Text Available The robustness of immune responses to an antigen could be dictated by the route of vaccine inoculation. Traditional smallpox vaccines, essentially vaccinia virus strains, that were used in the eradication of smallpox were administered by percutaneous inoculation (skin scarification. The modified vaccinia virus Ankara is licensed as a smallpox vaccine in Europe and Canada and currently undergoing clinical development in the United States. MVA is also being investigated as a vector for the delivery of heterologous genes for prophylactic or therapeutic immunization. Since MVA is replication-deficient, MVA and MVA-vectored vaccines are often inoculated through the intramuscular, intradermal or subcutaneous routes. Vaccine inoculation via the intramuscular, intradermal or subcutaneous routes requires the use of injection needles, and an estimated 10 to 20% of the population of the United States has needle phobia. Following an observation in our laboratory that a replication-deficient recombinant vaccinia virus derived from the New York City Board of Health strain elicited protective immune responses in a mouse model upon inoculation by tail scarification, we investigated whether MVA and MVA recombinants can elicit protective responses following percutaneous administration in mouse models. Our data suggest that MVA administered by percutaneous inoculation, elicited vaccinia-specific antibody responses, and protected mice from lethal vaccinia virus challenge, at levels comparable to or better than subcutaneous or intramuscular inoculation. High titers of specific neutralizing antibodies were elicited in mice inoculated with a recombinant MVA expressing the herpes simplex type 2 glycoprotein D after scarification. Similarly, a recombinant MVA expressing the hemagglutinin of attenuated influenza virus rgA/Viet Nam/1203/2004 (H5N1 elicited protective immune responses when administered at low doses by scarification. Taken together, our data suggest that

Percutaneous Vaccination as an Effective Method of Delivery of MVA and MVA-Vectored Vaccines.

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Meseda, Clement A; Atukorale, Vajini; Kuhn, Jordan; Schmeisser, Falko; Weir, Jerry P

2016-01-01

The robustness of immune responses to an antigen could be dictated by the route of vaccine inoculation. Traditional smallpox vaccines, essentially vaccinia virus strains, that were used in the eradication of smallpox were administered by percutaneous inoculation (skin scarification). The modified vaccinia virus Ankara is licensed as a smallpox vaccine in Europe and Canada and currently undergoing clinical development in the United States. MVA is also being investigated as a vector for the delivery of heterologous genes for prophylactic or therapeutic immunization. Since MVA is replication-deficient, MVA and MVA-vectored vaccines are often inoculated through the intramuscular, intradermal or subcutaneous routes. Vaccine inoculation via the intramuscular, intradermal or subcutaneous routes requires the use of injection needles, and an estimated 10 to 20% of the population of the United States has needle phobia. Following an observation in our laboratory that a replication-deficient recombinant vaccinia virus derived from the New York City Board of Health strain elicited protective immune responses in a mouse model upon inoculation by tail scarification, we investigated whether MVA and MVA recombinants can elicit protective responses following percutaneous administration in mouse models. Our data suggest that MVA administered by percutaneous inoculation, elicited vaccinia-specific antibody responses, and protected mice from lethal vaccinia virus challenge, at levels comparable to or better than subcutaneous or intramuscular inoculation. High titers of specific neutralizing antibodies were elicited in mice inoculated with a recombinant MVA expressing the herpes simplex type 2 glycoprotein D after scarification. Similarly, a recombinant MVA expressing the hemagglutinin of attenuated influenza virus rgA/Viet Nam/1203/2004 (H5N1) elicited protective immune responses when administered at low doses by scarification. Taken together, our data suggest that MVA and MVA-vectored

On the Vectorization of FIR Filterbanks

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Barbedo Jayme Garcia Arnal

2007-01-01

Full Text Available This paper presents a vectorization technique to implement FIR filterbanks. The word vectorization, in the context of this work, refers to a strategy in which all iterative operations are replaced by equivalent vector and matrix operations. This approach allows that the increasing parallelism of the most recent computer processors and systems be properly explored. The vectorization techniques are applied to two kinds of FIR filterbanks (conventional and recursi ve, and are presented in such a way that they can be easily extended to any kind of FIR filterbanks. The vectorization approach is compared to other kinds of implementation that do not explore the parallelism, and also to a previous FIR filter vectorization approach. The tests were performed in Matlab and , in order to explore different aspects of the proposed technique.

On the Vectorization of FIR Filterbanks

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Amauri Lopes

2007-01-01

Full Text Available This paper presents a vectorization technique to implement FIR filterbanks. The word vectorization, in the context of this work, refers to a strategy in which all iterative operations are replaced by equivalent vector and matrix operations. This approach allows that the increasing parallelism of the most recent computer processors and systems be properly explored. The vectorization techniques are applied to two kinds of FIR filterbanks (conventional and recursi ve, and are presented in such a way that they can be easily extended to any kind of FIR filterbanks. The vectorization approach is compared to other kinds of implementation that do not explore the parallelism, and also to a previous FIR filter vectorization approach. The tests were performed in Matlab and C, in order to explore different aspects of the proposed technique.

Dendrimers as Carriers for siRNA Delivery and Gene Silencing: A Review

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Jiangyu Wu

2013-01-01

Full Text Available RNA interference (RNAi was first literaturally reported in 1998 and has become rapidly a promising tool for therapeutic applications in gene therapy. In a typical RNAi process, small interfering RNAs (siRNA are used to specifically downregulate the expression of the targeted gene, known as the term “gene silencing.” One key point for successful gene silencing is to employ a safe and efficient siRNA delivery system. In this context, dendrimers are emerging as potential nonviral vectors to deliver siRNA for RNAi purpose. Dendrimers have attracted intense interest since their emanating research in the 1980s and are extensively studied as efficient DNA delivery vectors in gene transfer applications, due to their unique features based on the well-defined and multivalent structures. Knowing that DNA and RNA possess a similar structure in terms of nucleic acid framework and the electronegative nature, one can also use the excellent DNA delivery properties of dendrimers to develop effective siRNA delivery systems. In this review, the development of dendrimer-based siRNA delivery vectors is summarized, focusing on the vector features (siRNA delivery efficiency, cytotoxicity, etc. of different types of dendrimers and the related investigations on structure-activity relationship to promote safe and efficient siRNA delivery system.

Dendrimers as Carriers for siRNA Delivery and Gene Silencing: A Review

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Huang, Weizhe; He, Ziying

2013-01-01

RNA interference (RNAi) was first literaturally reported in 1998 and has become rapidly a promising tool for therapeutic applications in gene therapy. In a typical RNAi process, small interfering RNAs (siRNA) are used to specifically downregulate the expression of the targeted gene, known as the term “gene silencing.” One key point for successful gene silencing is to employ a safe and efficient siRNA delivery system. In this context, dendrimers are emerging as potential nonviral vectors to deliver siRNA for RNAi purpose. Dendrimers have attracted intense interest since their emanating research in the 1980s and are extensively studied as efficient DNA delivery vectors in gene transfer applications, due to their unique features based on the well-defined and multivalent structures. Knowing that DNA and RNA possess a similar structure in terms of nucleic acid framework and the electronegative nature, one can also use the excellent DNA delivery properties of dendrimers to develop effective siRNA delivery systems. In this review, the development of dendrimer-based siRNA delivery vectors is summarized, focusing on the vector features (siRNA delivery efficiency, cytotoxicity, etc.) of different types of dendrimers and the related investigations on structure-activity relationship to promote safe and efficient siRNA delivery system. PMID:24288498

A Comparison Study of Sinusoidal PWM and Space Vector PWM Techniques for Voltage Source Inverter

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Ömer Türksoy

2017-06-01

Full Text Available In this paper, the methods used to control voltage source inverters which have been intensively investigated in recent years are compared. Although the most efficient result is obtained with the least number of switching elements in the inverter topologies, the method used in the switching is at least as effective as the topology. Besides, the selected switching method to control the inverter will play an effective role in suppressing harmonic components while producing the ideal output voltage. There are many derivatives of pulse width modulation techniques that are commonly used to control voltage source inverters. Some of widespread methods are sinusoidal pulse width modulation and space vector pulse width modulation techniques. These modulation techniques used for generating variable frequency and amplitude output voltage in voltage source inverters, have been simulated by using MATLAB/SIMULINK. And, the total harmonic distortions of the output voltages are compared. As a result of simulation studies, sinusoidal pulse width modulation has been found to have more total harmonic distortion in output voltages of voltage source inverters in the simulation. Space vector pulse width modulation has been shown to produce a more efficient output voltage with less total harmonic distortion.

Hybrid Lentivirus-transposon Vectors With a Random Integration Profile in Human Cells

DEFF Research Database (Denmark)

Staunstrup, Nicklas H; Moldt, Brian; Mátés, Lajos

2009-01-01

Gene delivery by human immunodeficiency virus type 1 (HIV-1)-based lentiviral vectors (LVs) is efficient, but genomic integration of the viral DNA is strongly biased toward transcriptionally active loci resulting in an increased risk of insertional mutagenesis in gene therapy protocols. Nonviral...... Sleeping Beauty (SB) transposon vectors have a significantly safer insertion profile, but efficient delivery into relevant cell/tissue types is a limitation. In an attempt to combine the favorable features of the two vector systems we established a novel hybrid vector technology based on SB transposase......-mediated insertion of lentiviral DNA circles generated during transduction of target cells with integrase (IN)-defective LVs (IDLVs). By construction of a lentivirus-transposon hybrid vector allowing transposition exclusively from circular viral DNA substrates, we demonstrate that SB transposase added in trans...

Viral vector-based influenza vaccines

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de Vries, Rory D.; Rimmelzwaan, Guus F.

2016-01-01

ABSTRACT Antigenic drift of seasonal influenza viruses and the occasional introduction of influenza viruses of novel subtypes into the human population complicate the timely production of effective vaccines that antigenically match the virus strains that cause epidemic or pandemic outbreaks. The development of game-changing vaccines that induce broadly protective immunity against a wide variety of influenza viruses is an unmet need, in which recombinant viral vectors may provide. Use of viral vectors allows the delivery of any influenza virus antigen, or derivative thereof, to the immune system, resulting in the optimal induction of virus-specific B- and T-cell responses against this antigen of choice. This systematic review discusses results obtained with vectored influenza virus vaccines and advantages and disadvantages of the currently available viral vectors. PMID:27455345

Non-viral Nucleic Acid Delivery Strategies to the Central Nervous System

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James-Kevin Tan

2016-11-01

Full Text Available With an increased prevalence and understanding of central nervous system injuries and neurological disorders, nucleic acid therapies are gaining promise as a way to regenerate lost neurons or halt disease progression. While more viral vectors have been used clinically as tools for gene delivery, non-viral vectors are gaining interest due to lower safety concerns and the ability to deliver all types of nucleic acids. Nevertheless, there are still a number of barriers to nucleic acid delivery. In this focused review, we explore the in vivo challenges hindering non-viral nucleic acid delivery to the central nervous system and the strategies and vehicles used to overcome them. Advantages and disadvantages of different routes of administration including: systemic injection, cerebrospinal fluid injection, intraparenchymal injection, and peripheral administration are discussed. Non-viral vehicles and treatment strategies that have overcome delivery barriers and demonstrated in vivo gene transfer to the central nervous system are presented. These approaches can be used as guidelines in developing synthetic gene delivery vectors for central nervous system applications and will ultimately bring non-viral vectors closer to clinical application.

Genetic modification of hematopoietic cells using retroviral and lentiviral vectors: safety considerations for vector design and delivery into target cells.

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Dropulic, Boro

2005-07-01

The recent development of leukemia in three patients following retroviral vector gene transfer in hematopoietic stem cells, resulting in the death of one patient, has raised safety concerns for the use of integrating gene transfer vectors for human gene therapy. This review discusses these serious adverse events from the perspective of whether restrictions on vector design and vector-modified target cells are warranted at this time. A case is made against presently establishing specific restrictions for vector design and transduced cells; rather, their safety should be ascertained by empiric evaluation in appropriate preclinical models on a case-by-case basis. Such preclinical data, coupled with proper informed patient consent and a risk-benefit ratio analysis, provide the best available prospective evaluation of gene transfer vectors prior to their translation into the clinic.

Chitosan-Graft-Polyethylenimine/DNA Nanoparticles as Novel Non-Viral Gene Delivery Vectors Targeting Osteoarthritis

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Lv, Lulu; Zhao, Huiqing

2014-01-01

The development of safe and efficient gene carriers is the key to the clinical success of gene therapy. The present study was designed to develop and evaluate the chitosan-graft-polyethylenimine (CP)/DNA nanoparticles as novel non-viral gene vectors for gene therapy of osteoarthritis. The CP/DNA nanoparticles were produced through a complex coacervation of the cationic polymers with pEGFP after grafting chitosan (CS) with a low molecular weight (Mw) PEI (Mw = 1.8 kDa). Particle size and zeta potential were related to the weight ratio of CP:DNA, where decreases in nanoparticle size and increases in surface charge were observed as CP content increased. The buffering capacity of CP was significantly greater than that of CS. The transfection efficiency of CP/DNA nanoparticles was similar with that of the Lipofectamine™ 2000, and significantly higher than that of CS/DNA and PEI (25 kDa)/DNA nanoparticles. The transfection efficiency of the CP/DNA nanoparticles was dependent on the weight ratio of CP:DNA (w/w). The average cell viability after the treatment with CP/DNA nanoparticles was over 90% in both chondrocytes and synoviocytes, which was much higher than that of PEI (25 kDa)/DNA nanoparticles. The CP copolymers efficiently carried the pDNA inside chondrocytes and synoviocytes, and the pDNA was detected entering into nucleus. These results suggest that CP/DNA nanoparticles with improved transfection efficiency and low cytotoxicity might be a safe and efficient non-viral vector for gene delivery to both chondrocytes and synoviocytes. PMID:24392152

Polyamidoamine-Decorated Nanodiamonds as a Hybrid Gene Delivery Vector and siRNA Structural Characterization at the Charged Interfaces.

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Lim, Dae Gon; Rajasekaran, Nirmal; Lee, Dukhee; Kim, Nam Ah; Jung, Hun Soon; Hong, Sungyoul; Shin, Young Kee; Kang, Eunah; Jeong, Seong Hoon

2017-09-20

Nanodiamonds have been discovered as a new exogenous material source in biomedical applications. As a new potent form of nanodiamond (ND), polyamidoamine-decorated nanodiamonds (PAMAM-NDs) were prepared for E7 or E6 oncoprotein-suppressing siRNA gene delivery for high risk human papillomavirus-induced cervical cancer, such as types 16 and 18. It is critical to understand the physicochemical properties of siRNA complexes immobilized on cationic solid ND surfaces in the aspect of biomolecular structural and conformational changes, as the new inert carbon material can be extended into the application of a gene delivery vector. A spectral study of siRNA/PAMAM-ND complexes using differential scanning calorimetry and circular dichroism spectroscopy proved that the hydrogen bonding and electrostatic interactions between siRNA and PAMAM-NDs decreased endothermic heat capacity. Moreover, siRNA/PAMAM-ND complexes showed low cell cytotoxicity and significant suppressing effects for forward target E6 and E7 oncogenic genes, proving functional and therapeutic efficacy. The cellular uptake of siRNA/PAMAM-ND complexes at 8 h was visualized by macropinocytes and direct endosomal escape of the siRNA/PAMAM-ND complexes. It is presumed that PAMAM-NDs provided a buffering cushion to adjust the pH and hard mechanical stress to escape endosomes. siRNA/PAMAM-ND complexes provide a potential organic/inorganic hybrid material source for gene delivery carriers.

Self-assembled pentablock copolymers for selective and sustained gene delivery

Energy Technology Data Exchange (ETDEWEB)

Zhang, Bingqi [Iowa State Univ., Ames, IA (United States)

2011-05-15

The poly(diethylaminoethyl methacrylate) (PDEAEM) - Pluronic F127 - PDEAEM pentablock copolymer (PB) gene delivery vector system has been found to possess an inherent selectivity in transfecting cancer cells over non-cancer cells in vitro, without attaching any targeting ligands. In order to understand the mechanism of this selective transfection, three possible intracellular barriers to transfection were investigated in both cancer and non-cancer cells. We concluded that escape from the endocytic pathway served as the primary intracellular barrier for PB-mediated transfection. Most likely, PB vectors were entrapped and rendered non-functional in acidic lysosomes of non-cancer cells, but survived in less acidic lysosomes of cancer cells. The work highlights the importance of identifying intracellular barriers for different gene delivery systems and provides a new paradigm for designing targeting vectors based on intracellular differences between cell types, rather than through the use of targeting ligands. The PB vector was further developed to simultaneously deliver anticancer drugs and genes, which showed a synergistic effect demonstrated by significantly enhanced gene expression in vitro. Due to the thermosensitive gelation behavior, the PB vector packaging both drug and gene was also investigated for its in vitro sustained release properties by using polyethylene glycol diacrylate as a barrier gel to mimic the tumor matrix in vivo. Overall, this work resulted in the development of a gene delivery vector for sustained and selective gene delivery to tumor cells for cancer therapy.

Distribution of AAV-TK following intracranial convection-enhanced delivery into rats.

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Cunningham, J; Oiwa, Y; Nagy, D; Podsakoff, G; Colosi, P; Bankiewicz, K S

2000-01-01

Adeno-associated virus (AAV)-based vectors are being tested in animal models as viable treatments for glioma and neurodegenerative disease and could potentially be employed to target a variety of central nervous system disorders. The relationship between dose of injected vector and its resulting distribution in brain tissue has not been previously reported nor has the most efficient method of delivery been determined. Here we report that convection-enhanced delivery (CED) of 2.5 x 10(8), 2.5 x 10(9), or 2.5 x 10(10) particles of AAV-thymidine kinase (AAV-TK) into rat brain revealed a clear dose response. In the high-dose group, a volume of 300 mm3 of brain tissue was partially transduced. Results showed that infusion pump and subcutaneous osmotic pumps were both capable of delivering vector via CED and that total particle number was the most important determining factor in obtaining efficient expression. Results further showed differences in histopathology between the delivery groups. While administration of vector using infusion pump had relatively benign effects, the use of osmotic pumps resulted in notable toxicity to the surrounding brain tissue. To determine tissue distribution of vector following intracranial delivery, PCR analysis was performed on tissues from rats that received high doses of AAV-TK. Three weeks following CED, vector could be detected in both hemispheres of the brain, spinal cord, spleen, and kidney.

Exploring the role of peptides in polymer-based gene delivery.

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Sun, Yanping; Yang, Zhen; Wang, Chunxi; Yang, Tianzhi; Cai, Cuifang; Zhao, Xiaoyun; Yang, Li; Ding, Pingtian

2017-09-15

Polymers are widely studied as non-viral gene vectors because of their strong DNA binding ability, capacity to carry large payload, flexibility of chemical modifications, low immunogenicity, and facile processes for manufacturing. However, high cytotoxicity and low transfection efficiency substantially restrict their application in clinical trials. Incorporating functional peptides is a promising approach to address these issues. Peptides demonstrate various functions in polymer-based gene delivery systems, such as targeting to specific cells, breaching membrane barriers, facilitating DNA condensation and release, and lowering cytotoxicity. In this review, we systematically summarize the role of peptides in polymer-based gene delivery, and elaborate how to rationally design polymer-peptide based gene delivery vectors. Polymers are widely studied as non-viral gene vectors, but suffer from high cytotoxicity and low transfection efficiency. Incorporating short, bioactive peptides into polymer-based gene delivery systems can address this issue. Peptides demonstrate various functions in polymer-based gene delivery systems, such as targeting to specific cells, breaching membrane barriers, facilitating DNA condensation and release, and lowering cytotoxicity. In this review, we highlight the peptides' roles in polymer-based gene delivery, and elaborate how to utilize various functional peptides to enhance the transfection efficiency of polymers. The optimized peptide-polymer vectors should be able to alter their structures and functions according to biological microenvironments and utilize inherent intracellular pathways of cells, and consequently overcome the barriers during gene delivery to enhance transfection efficiency. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Restoration of central nervous system alpha-N-acetylglucosaminidase activity and therapeutic benefits in mucopolysaccharidosis IIIB mice by a single intracisternal recombinant adeno-associated viral type 2 vector delivery.

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Fu, Haiyan; DiRosario, Julianne; Kang, Lu; Muenzer, Joseph; McCarty, Douglas M

2010-07-01

Finding efficient central nervous system (CNS) delivery approaches has been the major challenge facing therapeutic development for treating diseases with global neurological manifestation, such as mucopolysaccharidosis (MPS) IIIB, a lysosomal storage disease, caused by autosomal recessive defect of alpha-N-acetylglucosaminidase (NaGlu). Previously, we developed an approach, intracisternal (i.c.) injection, to deliver recombinant adeno-associated viral (rAAV) vector to the CNS of mice, leading to a widespread periventricular distribution of transduction. In the present study, we delivered rAAV2 vector expressing human NaGlu into the CNS of MPS IIIB mice by an i.c. injection approach, to test its therapeutic efficacy and feasibility for treating the neurological manifestation of the disease. We demonstrated significant functional neurological benefits of a single i.c. vector infusion in adult MPS IIIB mice. The treatment slowed the disease progression by mediating widespread recombinant NaGlu expression in the CNS, resulting in the reduction of brain lysosomal storage pathology, significantly improved cognitive function and prolonged survival. However, persisting motor function deficits suggested that pathology in areas outside the CNS contributes to the MPS IIIB behavioral phenotype. The therapeutic benefit of i.c. rAAV2 delivery was dose-dependent and could be attribute solely to the CNS transduction because the procedure did not lead to detectable transduction in somatic tissues. A single IC rAAV2 gene delivery is functionally beneficial for treating the CNS disease of MPS IIIB in mice. It is immediately clinically translatable, with the potential of improving the quality of life for patients with MPS IIIB.

PLGA-carbon nanotube conjugates for intercellular delivery of caspase-3 into osteosarcoma cells.

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Qingsu Cheng

Full Text Available Cancer has arisen to be of the most prominent health care issues across the world in recent years. Doctors have used physiological intervention as well as chemical and radioactive therapeutics to treat cancer thus far. As an alternative to current methods, gene delivery systems with high efficiency, specificity, and safety that can reduce side effects such as necrosis of tissue are under development. Although viral vectors are highly efficient, concerns have arisen from the fact that viral vectors are sourced from lethal diseases. With this in mind, rod shaped nano-materials such as carbon nanotubes (CNTs have become an attractive option for drug delivery due to the enhanced permeability and retention effect in tumors as well as the ability to penetrate the cell membrane. Here, we successfully engineered poly (lactic-co-glycolic (PLGA functionalized CNTs to reduce toxicity concerns, provide attachment sites for pro-apoptotic protein caspase-3 (CP3, and tune the temporal release profile of CP3 within bone cancer cells. Our results showed that CP3 was able to attach to functionalized CNTs, forming CNT-PLGA-CP3 conjugates. We show this conjugate can efficiently transduce cells at dosages as low as 0.05 μg/ml and suppress cell proliferation up to a week with no further treatments. These results are essential to showing the capabilities of PLGA functionalized CNTs as a non-viral vector gene delivery technique to tune cell fate.

Effects of Vector Backbone and Pseudotype on Lentiviral Vector-mediated Gene Transfer: Studies in Infant ADA-Deficient Mice and Rhesus Monkeys

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Carbonaro Sarracino, Denise; Tarantal, Alice F; Lee, C Chang I.; Martinez, Michele; Jin, Xiangyang; Wang, Xiaoyan; Hardee, Cinnamon L; Geiger, Sabine; Kahl, Christoph A; Kohn, Donald B

2014-01-01

Systemic delivery of a lentiviral vector carrying a therapeutic gene represents a new treatment for monogenic disease. Previously, we have shown that transfer of the adenosine deaminase (ADA) cDNA in vivo rescues the lethal phenotype and reconstitutes immune function in ADA-deficient mice. In order to translate this approach to ADA-deficient severe combined immune deficiency patients, neonatal ADA-deficient mice and newborn rhesus monkeys were treated with species-matched and mismatched vectors and pseudotypes. We compared gene delivery by the HIV-1-based vector to murine γ-retroviral vectors pseudotyped with vesicular stomatitis virus-glycoprotein or murine retroviral envelopes in ADA-deficient mice. The vesicular stomatitis virus-glycoprotein pseudotyped lentiviral vectors had the highest titer and resulted in the highest vector copy number in multiple tissues, particularly liver and lung. In monkeys, HIV-1 or simian immunodeficiency virus vectors resulted in similar biodistribution in most tissues including bone marrow, spleen, liver, and lung. Simian immunodeficiency virus pseudotyped with the gibbon ape leukemia virus envelope produced 10- to 30-fold lower titers than the vesicular stomatitis virus-glycoprotein pseudotype, but had a similar tissue biodistribution and similar copy number in blood cells. The relative copy numbers achieved in mice and monkeys were similar when adjusted to the administered dose per kg. These results suggest that this approach can be scaled-up to clinical levels for treatment of ADA-deficient severe combined immune deficiency subjects with suboptimal hematopoietic stem cell transplantation options. PMID:24925206

Effects of vector backbone and pseudotype on lentiviral vector-mediated gene transfer: studies in infant ADA-deficient mice and rhesus monkeys.

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Carbonaro Sarracino, Denise; Tarantal, Alice F; Lee, C Chang I; Martinez, Michele; Jin, Xiangyang; Wang, Xiaoyan; Hardee, Cinnamon L; Geiger, Sabine; Kahl, Christoph A; Kohn, Donald B

2014-10-01

Systemic delivery of a lentiviral vector carrying a therapeutic gene represents a new treatment for monogenic disease. Previously, we have shown that transfer of the adenosine deaminase (ADA) cDNA in vivo rescues the lethal phenotype and reconstitutes immune function in ADA-deficient mice. In order to translate this approach to ADA-deficient severe combined immune deficiency patients, neonatal ADA-deficient mice and newborn rhesus monkeys were treated with species-matched and mismatched vectors and pseudotypes. We compared gene delivery by the HIV-1-based vector to murine γ-retroviral vectors pseudotyped with vesicular stomatitis virus-glycoprotein or murine retroviral envelopes in ADA-deficient mice. The vesicular stomatitis virus-glycoprotein pseudotyped lentiviral vectors had the highest titer and resulted in the highest vector copy number in multiple tissues, particularly liver and lung. In monkeys, HIV-1 or simian immunodeficiency virus vectors resulted in similar biodistribution in most tissues including bone marrow, spleen, liver, and lung. Simian immunodeficiency virus pseudotyped with the gibbon ape leukemia virus envelope produced 10- to 30-fold lower titers than the vesicular stomatitis virus-glycoprotein pseudotype, but had a similar tissue biodistribution and similar copy number in blood cells. The relative copy numbers achieved in mice and monkeys were similar when adjusted to the administered dose per kg. These results suggest that this approach can be scaled-up to clinical levels for treatment of ADA-deficient severe combined immune deficiency subjects with suboptimal hematopoietic stem cell transplantation options.

Graphene materials as 2D non-viral gene transfer vector platforms.

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Vincent, M; de Lázaro, I; Kostarelos, K

2017-03-01

Advances in genomics and gene therapy could offer solutions to many diseases that remain incurable today, however, one of the critical reasons halting clinical progress is due to the difficulty in designing efficient and safe delivery vectors for the appropriate genetic cargo. Safety and large-scale production concerns counter-balance the high gene transfer efficiency achieved with viral vectors, while non-viral strategies have yet to become sufficiently efficient. The extraordinary physicochemical, optical and photothermal properties of graphene-based materials (GBMs) could offer two-dimensional components for the design of nucleic acid carrier systems. We discuss here such properties and their implications for the optimization of gene delivery. While the design of such vectors is still in its infancy, we provide here an exhaustive and up-to-date analysis of the studies that have explored GBMs as gene transfer vectors, focusing on the functionalization strategies followed to improve vector performance and on the biological effects attained.

The derivation of vector magnetic fields from Stokes profiles - Integral versus least squares fitting techniques

Science.gov (United States)

Ronan, R. S.; Mickey, D. L.; Orrall, F. Q.

1987-01-01

The results of two methods for deriving photospheric vector magnetic fields from the Zeeman effect, as observed in the Fe I line at 6302.5 A at high spectral resolution (45 mA), are compared. The first method does not take magnetooptical effects into account, but determines the vector magnetic field from the integral properties of the Stokes profiles. The second method is an iterative least-squares fitting technique which fits the observed Stokes profiles to the profiles predicted by the Unno-Rachkovsky solution to the radiative transfer equation. For sunspot fields above about 1500 gauss, the two methods are found to agree in derived azimuthal and inclination angles to within about + or - 20 deg.

Adenoviral vector immunity: its implications and circumvention strategies.

Science.gov (United States)

Ahi, Yadvinder S; Bangari, Dinesh S; Mittal, Suresh K

2011-08-01

Adenoviral (Ad) vectors have emerged as a promising gene delivery platform for a variety of therapeutic and vaccine purposes during last two decades. However, the presence of preexisting Ad immunity and the rapid development of Ad vector immunity still pose significant challenges to the clinical use of these vectors. Innate inflammatory response following Ad vector administration may lead to systemic toxicity, drastically limit vector transduction efficiency and significantly abbreviate the duration of transgene expression. Currently, a number of approaches are being extensively pursued to overcome these drawbacks by strategies that target either the host or the Ad vector. In addition, significant progress has been made in the development of novel Ad vectors based on less prevalent human Ad serotypes and nonhuman Ad. This review provides an update on our current understanding of immune responses to Ad vectors and delineates various approaches for eluding Ad vector immunity. Approaches targeting the host and those targeting the vector are discussed in light of their promises and limitations.

A gene delivery system with a human artificial chromosome vector based on migration of mesenchymal stem cells towards human glioblastoma HTB14 cells.

Science.gov (United States)

Kinoshita, Yusuke; Kamitani, Hideki; Mamun, Mahabub Hasan; Wasita, Brian; Kazuki, Yasuhiro; Hiratsuka, Masaharu; Oshimura, Mitsuo; Watanabe, Takashi

2010-05-01

Mesenchymal stem cells (MSCs) have been expected to become useful gene delivery vehicles against human malignant gliomas when coupled with an appropriate vector system, because they migrate towards the lesion. Human artificial chromosomes (HACs) are non-integrating vectors with several advantages for gene therapy, namely, no limitations on the size and number of genes that can be inserted. We investigated the migration of human immortalized MSCs bearing a HAC vector containing the herpes simplex virus thymidine kinase gene (HAC-tk-hiMSCs) towards malignant gliomas in vivo. Red fluorescence protein-labeled human glioblastoma HTB14 cells were implanted into a subcortical region in nude mice. Four days later, green fluorescence protein-labeled HAC-tk-hiMSCs were injected into a contralateral subcortical region (the HTB14/HAC-tk-hiMSC injection model). Tropism to the glioma mass and the route of migration were visualized by fluorescence microscopy and immunohistochemical staining. HAC-tk-hiMSCs began to migrate toward the HTB14 glioma area via the corpus callosum on day 4, and gathered around the HTB14 glioma mass on day 7. To test whether the delivered gene could effectively treat glioblastoma in vivo, HTB14/HAC-tk-hiMSC injected mice were treated with ganciclovir (GCV) or PBS. The HTB14 glioma mass was significantly reduced by GCV treatment in mice injected with HAC-tk-hiMSCs. It was confirmed that gene delivery by our HAC-hiMSC system was effective after migration of MSCs to the glioma mass in vivo. Therefore, MSCs containing HACs carrying an anticancer gene or genes may provide a new tool for the treatment of malignant gliomas and possibly of other tumor types.

Applications and Challenges for Use of Cell-Penetrating Peptides as Delivery Vectors for Peptide and Protein Cargos

Directory of Open Access Journals (Sweden)

Mie Kristensen

2016-01-01

Full Text Available The hydrophilic nature of peptides and proteins renders them impermeable to cell membranes. Thus, in order to successfully deliver peptide and protein-based therapeutics across the plasma membrane or epithelial and endothelial barriers, a permeation enhancing strategy must be employed. Cell-penetrating peptides (CPPs constitute a promising tool and have shown applications for peptide and protein delivery into cells as well as across various epithelia and the blood-brain barrier (BBB. CPP-mediated delivery of peptides and proteins may be pursued via covalent conjugation of the CPP to the cargo peptide or protein or via physical complexation obtained by simple bulk-mixing of the CPP with its cargo. Both approaches have their pros and cons, and which is the better choice likely relates to the physicochemical properties of the CPP and its cargo as well as the route of administration, the specific barrier and the target cell. Besides the physical barrier, a metabolic barrier must be taken into consideration when applying peptide-based delivery vectors, such as the CPPs, and stability-enhancing strategies are commonly employed to prolong the CPP half-life. The mechanisms by which CPPs translocate cell membranes are believed to involve both endocytosis and direct translocation, but are still widely investigated and discussed. The fact that multiple factors influence the mechanisms responsible for cellular CPP internalization and the lack of sensitive methods for detection of the CPP, and in some cases the cargo, further complicates the design and conduction of conclusive mechanistic studies.

Sleeping Beauty-baculovirus hybrid vectors for long-term gene expression in the eye.

Science.gov (United States)

Turunen, Tytteli Anni Kaarina; Laakkonen, Johanna Päivikki; Alasaarela, Laura; Airenne, Kari Juhani; Ylä-Herttuala, Seppo

2014-01-01

A baculovirus vector is capable of efficiently transducing many nondiving and diving cell types. However, the potential of baculovirus is restricted for many gene delivery applications as a result of the transient gene expression that it mediates. The plasmid-based Sleeping Beauty (SB) transposon system integrates transgenes into target cell genome efficiently with a genomic integration pattern that is generally considered safer than the integration of many other integrating vectors; yet efficient delivery of therapeutic genes into cells of target tissues in vivo is a major challenge for nonviral gene therapy. In the present study, SB was introduced into baculovirus to obtain novel hybrid vectors that would combine the best features of the two vector systems (i.e. effective gene delivery and efficient integration into the genome), thus circumventing the major limitations of these vectors. We constructed and optimized SB-baculovirus hybrid vectors that bear either SB100x transposase or SB transposon in the forward or reverse orientations with respect to the viral backbone The functionality of the novel hybrid vectors was investigated in cell cultures and in a proof-of-concept study in the mouse eye. The hybrid vectors showed high and sustained transgene expression that remained stable and demonstrated no signs of decline during the 2 months follow-up in vitro. These results were verified in the mouse eye where persistent transgene expression was detected two months after intravitreal injection. Our results confirm that (i) SB-baculovirus hybrid vectors mediate long-term gene expression in vitro and in vivo, and (ii) the hybrid vectors are potential new tools for the treatment of ocular diseases. Copyright © 2014 John Wiley & Sons, Ltd.

Vectorization of KENO IV code and an estimate of vector-parallel processing

International Nuclear Information System (INIS)

Asai, Kiyoshi; Higuchi, Kenji; Katakura, Jun-ichi; Kurita, Yutaka.

1986-10-01

The multi-group criticality safety code KENO IV has been vectorized and tested on FACOM VP-100 vector processor. At first the vectorized KENO IV on a scalar processor became slower than the original one by a factor of 1.4 because of the overhead introduced by the vectorization. Making modifications of algorithms and techniques for vectorization, the vectorized version has become faster than the original one by a factor of 1.4 and 3.0 on the vector processor for sample problems of complex and simple geometries, respectively. For further speedup of the code, some improvements on compiler and hardware, especially on addition of Monte Carlo pipelines to the vector processor, are discussed. Finally a pipelined parallel processor system is proposed and its performance is estimated. (author)

Vectorization of phase space Monte Carlo code in FACOM vector processor VP-200

International Nuclear Information System (INIS)

Miura, Kenichi

1986-01-01

This paper describes the vectorization techniques for Monte Carlo codes in Fujitsu's Vector Processor System. The phase space Monte Carlo code FOWL is selected as a benchmark, and scalar and vector performances are compared. The vectorized kernel Monte Carlo routine which contains heavily nested IF tests runs up to 7.9 times faster in vector mode than in scalar mode. The overall performance improvement of the vectorized FOWL code over the original scalar code reaches 3.3. The results of this study strongly indicate that supercomputer can be a powerful tool for Monte Carlo simulations in high energy physics. (Auth.)

Arginine-rich cross-linking peptides with different SV40 nuclear localization signal content as vectors for intranuclear DNA delivery.

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Bogacheva, Mariia; Egorova, Anna; Slita, Anna; Maretina, Marianna; Baranov, Vladislav; Kiselev, Anton

2017-11-01

The major barriers for intracellular DNA transportation by cationic polymers are their toxicity, poor endosomal escape and inefficient nuclear uptake. Therefore, we designed novel modular peptide-based carriers modified with SV40 nuclear localization signal (NLS). Core peptide consists of arginine, histidine and cysteine residues for DNA condensation, endosomal escape promotion and interpeptide cross-linking, respectively. We investigated three polyplexes with different NLS content (10 mol%, 50 mol% and 90 mol% of SV40 NLS) as vectors for intranuclear DNA delivery. All carriers tested were able to condense DNA, to protect it from DNAase I and were not toxic to the cells. We observed that cell cycle arrest by hydroxyurea did not affect transfection efficacy of NLS-modified carriers which we confirmed using quantitative confocal microscopy analysis. Overall, peptide carrier modified with 90 mol% of SV40 NLS provided efficient transfection and nuclear uptake in non-dividing cells. Thus, incorporation of NLS into arginine-rich cross-linking peptides is an adequate approach to the development of efficient intranuclear gene delivery vehicles. Copyright © 2017 Elsevier Ltd. All rights reserved.

AAV vectors as gene delivery vehicles in the central nervous system

NARCIS (Netherlands)

Broekman, M.L.D.

2006-01-01

Recombinant gene delivery vehicles based on the replication-defective AAV have gained a preeminent position in the field of gene delivery to the brain. Efficient global gene delivery to the CNS is beneficial for the study of gene products is the entire CNS as well as for introducing and expressing

Efficient systemic DNA delivery to the tumor by self-assembled nanoparticle

Science.gov (United States)

Tang, Hailin; Xie, Xinhua; Guo, Jiaoli; Wei, Weidong; Wu, Minqing; Liu, Peng; Kong, Yanan; Yang, Lu; Hung, Mien-Chie; Xie, Xiaoming

2014-01-01

There are few delivery agents that could deliver gene with high efficiency and low toxicity, especially for animal experiments. Therefore, creating vectors with good delivery efficiency and safety profile is a meaningful work. We have developed a self-assembled gene delivery system (XM001), which can more efficiently deliver DNA to multiple cell lines and breast tumor, as compared to commercial delivery agents. In addition, systemically administrated XM001-BikDD (BikDD is a mutant form of proapoptotic gene Bik) significantly inhibited the growth of human breast cancer cells and prolonged the life span in implanted nude mice. This study demonstrates that XM001 is an efficient and widespread transfection agent, which could be a promising tumor delivery vector for cancer targeted therapy.

Construction of non-viral vector (mPEG5k-PCL1.2k)1.4-g-PEI10k and its gene delivery efficacy in vitro

OpenAIRE

Wei HUANG; Ming LV; Zhong-gao GAO; Ming-ji JIN; Fei-fei YANG; Yu-li WANG

2011-01-01

Objective To construct(mPEG5k-PCL1.2k)1.4-g-PEI10k,a copolymer designed as delivery vector for non-viral gene therapy,and explore its cytotoxicity and efficacy in delivery of plasmid DNA(pDNA).Methods The copolymer,mPEG5k-PCL1.2k-OH,was prepared by ring-opening polymerization and then followed by a conversion of hydroxyl terminal(-OH) into N-hydroxysuccinimide(NHS) to prepare mPEG5k-PCL1.2k-NHS.One of the branches,PEI10k,was then reacted with mPEG5k-PCL1.2k-NHS to synthesize a ternary copolym...

In-vivo evaluation of three ultrasound vector velocity techniques with MR angiography

DEFF Research Database (Denmark)

Hansen, Kristoffer Lindskov; Udesen, Jesper; Oddershede, Niels

2008-01-01

In conventional Doppler ultrasound (US) the blood velocity is only estimated along the US beam direction. The estimate is angle corrected assuming laminar flow parallel to the vessel boundaries. As the now in the vascular system never is purely laminar, the velocities estimated with conventional...... additionally constructed and mean differences for the three comparisons were: DB/MRA = 0.17 ml; STA/MRA = 0.07 ml; TO/MRA = 0.24 ml. The three US vector velocity techniques yield quantitative insight in to flow dynamics and can potentially give the clinician a powerful tool in cardiovascular disease assessment....

Review of root canal irrigant delivery techniques and devices

Directory of Open Access Journals (Sweden)

Yeon-Jee Yoo

2011-05-01

Full Text Available Introduction Eliminating the residual debris and bacteria in the root canal system is one of the main purposes of the endodontic treatment. However, the complexity on the anatomy of the root canal system makes it difficult to eliminate the bacterial biofilm existing along the root canal surface and necrotic pulp tissue by mechanical instrumentation and chemical irrigation. Recently, more effective irrigant delivery systems for root canal irrigation have been developed. The purpose of this review was to present an overview of root canal irrigant delivery techniques and devices available in endodontics. Review The contents of this paper include as follows; - syringe-needle irrigation, manual dynamic irrigation, brushes - sonic and ultrasonic irrigation, passive ultrasonic irrigation, rotary brush, RinsEndo, EndoVac, Laser Conclusion Though technological advances during the last decade have brought to fruition new agitation devices that rely on various mechanisms, there are few evidence based study to correlate the clinical efficacy of these devices with improved outcomes except syringe irrigation with needle and ultrasonic irrigation. The clinicians should try their best efforts to deliver antimicrobial and tissue solvent solutions in predictable volumes safely to working length.

Phenotypic correction of Fanconi anemia cells in the murine bone marrow after carrier cell mediated delivery of lentiviral vector.

Science.gov (United States)

Chakkaramakkil Verghese, Santhosh; Goloviznina, Natalya A; Kurre, Peter

2016-11-19

Fanconi anemia (FA) is an autosomal-recessive disorder associated with hematopoietic failure and it is a candidate for hematopoietic stem cell (HSC)-directed gene therapy. However, the characteristically reduced HSC numbers found in FA patients, their ineffective mobilization from the marrow, and re-oxygenation damage during ex vivo manipulation have precluded clinical success using conventional in vitro approaches. We previously demonstrated that lentiviral vector (LV) particles reversibly attach to the cell surface where they gain protection from serum complement neutralization. We reasoned that cellular delivery of LV to the bone marrow niche could avoid detrimental losses during FA HSC mobilization and in vitro modification. Here, we demonstrate that a VSV-G pseudotyped lentivector, carrying the FANCC transgene, can be transmitted from carrier to bystander cells. In cell culture and transplantation models of FA, we further demonstrate that LV carrier cells migrate along SDF-1α gradients and transfer vector particles that stably integrate and phenotypically correct the characteristic DNA alkylator sensitivity in murine and human FA-deficient target bystander cells. Altogether, we demonstrate that cellular homing mechanisms can be harnessed for the functional phenotype correction in murine FA hematopoietic cells.

Phenotypic correction of Fanconi anemia cells in the murine bone marrow after carrier cell mediated delivery of lentiviral vector

Directory of Open Access Journals (Sweden)

Santhosh Chakkaramakkil Verghese

2016-11-01

Full Text Available Abstract Fanconi anemia (FA is an autosomal-recessive disorder associated with hematopoietic failure and it is a candidate for hematopoietic stem cell (HSC-directed gene therapy. However, the characteristically reduced HSC numbers found in FA patients, their ineffective mobilization from the marrow, and re-oxygenation damage during ex vivo manipulation have precluded clinical success using conventional in vitro approaches. We previously demonstrated that lentiviral vector (LV particles reversibly attach to the cell surface where they gain protection from serum complement neutralization. We reasoned that cellular delivery of LV to the bone marrow niche could avoid detrimental losses during FA HSC mobilization and in vitro modification. Here, we demonstrate that a VSV-G pseudotyped lentivector, carrying the FANCC transgene, can be transmitted from carrier to bystander cells. In cell culture and transplantation models of FA, we further demonstrate that LV carrier cells migrate along SDF-1α gradients and transfer vector particles that stably integrate and phenotypically correct the characteristic DNA alkylator sensitivity in murine and human FA-deficient target bystander cells. Altogether, we demonstrate that cellular homing mechanisms can be harnessed for the functional phenotype correction in murine FA hematopoietic cells.

Lentiviral Delivery of Proteins for Genome Engineering.

Science.gov (United States)

Cai, Yujia; Mikkelsen, Jacob Giehm

2016-01-01

Viruses have evolved to traverse cellular barriers and travel to the nucleus by mechanisms that involve active transport through the cytoplasm and viral quirks to resist cellular restriction factors and innate immune responses. Virus-derived vector systems exploit the capacity of viruses to ferry genetic information into cells, and now - more than three decades after the discovery of HIV - lentiviral vectors based on HIV-1 have become instrumental in biomedical research and gene therapies that require genomic insertion of transgenes. By now, the efficacy of lentiviral gene delivery to stem cells, cells of the immune system including T cells, hepatic cells, and many other therapeutically relevant cell types is well established. Along with nucleic acids, HIV-1 virions carry the enzymatic tools that are essential for early steps of infection. Such capacity to package enzymes, even proteins of nonviral origin, has unveiled new ways of exploiting cellular intrusion of HIV-1. Based on early findings demonstrating the packaging of heterologous proteins into virus particles as part of the Gag and GagPol polypeptides, we have established lentiviral protein transduction for delivery of DNA transposases and designer nucleases. This strategy for delivering genome-engineering proteins facilitates high enzymatic activity within a short time frame and may potentially improve the safety of genome editing. Exploiting the full potential of lentiviral vectors, incorporation of foreign protein can be combined with the delivery of DNA transposons or a donor sequence for homology-directed repair in so-called 'all-in-one' lentiviral vectors. Here, we briefly describe intracellular restrictions that may affect lentiviral gene and protein delivery and review the current status of lentiviral particles as carriers of tool kits for genome engineering.

Bacillus subtilis as a tool for vaccine development: from antigen factories to delivery vectors

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Luís C.S. Ferreira

2005-03-01

Full Text Available Bacillus subtilis and some of its close relatives have a long history of industrial and biotechnological applications. Search for antigen expression systems based on recombinant B. subtilis strains sounds attractive both by the extensive genetic knowledge and the lack of an outer membrane, which simplify the secretion and purification of heterologous proteins. More recently, genetically modified B. subtilis spores have been described as indestructible delivery vehicles for vaccine antigens. Nonetheless both production and delivery of antigens by B. subtilis strains face some inherent obstacles, as unstable gene expression and reduced immunogenicity that, otherwise, can be overcome by already available gene technology approaches. In the present review we present the status of B. subtilis-based vaccine research, either as protein factories or delivery vectors, and discuss some alternatives for a better use of genetically modified strains.Bacillus subtilis e alguns de seus parentes mais próximos possuem uma longa história de aplicações industriais e biotecnológicas. A busca de sistemas de expressão de antígenos baseados em linhagens recombinants de B. subtilis mostra-se atrativa em função do conhecimento genético disponível e ausência de uma membrana externa, o que simplifica a secreção e a purificação de proteínas heterólogas. Mais recentemente, esporos geneticamente modificados de B. subtilis foram descritos com veículos indestrutíveis para o transporte de antígenos vacinais. Todavia a produção e o transporte de antígenos por linhagens de B. subtilis encontra obstáculos, como a expressão gênica instável e imunogenicidade reduzida, que podem ser superados com o auxílio de tecnologias genéticas atualmente disponíveis. Apresentamos nesta revisão o estado atual da pesquisa em vacinas baseadas em B. subtilis, empregado tanto como fábrica de proteínas ou veículos, e discute algumas alternativas para o uso mais

Image Coding Based on Address Vector Quantization.

Science.gov (United States)

Feng, Yushu

Image coding is finding increased application in teleconferencing, archiving, and remote sensing. This thesis investigates the potential of Vector Quantization (VQ), a relatively new source coding technique, for compression of monochromatic and color images. Extensions of the Vector Quantization technique to the Address Vector Quantization method have been investigated. In Vector Quantization, the image data to be encoded are first processed to yield a set of vectors. A codeword from the codebook which best matches the input image vector is then selected. Compression is achieved by replacing the image vector with the index of the code-word which produced the best match, the index is sent to the channel. Reconstruction of the image is done by using a table lookup technique, where the label is simply used as an address for a table containing the representative vectors. A code-book of representative vectors (codewords) is generated using an iterative clustering algorithm such as K-means, or the generalized Lloyd algorithm. A review of different Vector Quantization techniques are given in chapter 1. Chapter 2 gives an overview of codebook design methods including the Kohonen neural network to design codebook. During the encoding process, the correlation of the address is considered and Address Vector Quantization is developed for color image and monochrome image coding. Address VQ which includes static and dynamic processes is introduced in chapter 3. In order to overcome the problems in Hierarchical VQ, Multi-layer Address Vector Quantization is proposed in chapter 4. This approach gives the same performance as that of the normal VQ scheme but the bit rate is about 1/2 to 1/3 as that of the normal VQ method. In chapter 5, a Dynamic Finite State VQ based on a probability transition matrix to select the best subcodebook to encode the image is developed. In chapter 6, a new adaptive vector quantization scheme, suitable for color video coding, called "A Self -Organizing

Design, synthesis and evaluation of VEGF-siRNA/CRS as a novel vector for gene delivery

Directory of Open Access Journals (Sweden)

Zhao W

2016-11-01

Full Text Available Wen Zhao, Yifan Zhang, Xueyun Jiang, Chunying Cui School of Chemical Biology and Pharmaceutical Sciences, Capital Medical University, Beijing, China Abstract: Small interfering RNA (siRNA delivery is a prospective method in gene therapy, but it has application limitations such as negative charge, water solubility and high molecular weight. In this study, a safe and efficient nano-vector, CRS, was designed and synthesized to facilitate siRNA delivery. Physical and chemical properties of VEGF-siRNA/CRS were characterized by methods including scanning electron microscopy (SEM, transmission electron microscopy, zeta potential (ζ measurement, drug-releasing rate measurement, gel electrophoresis and confocal microscopy. The biological activities were evaluated using cell viability assay, gene-silencing efficacy assay in vitro, real-time polymerase chain reaction, enzyme-linked immunosorbent assay (ELISA and antitumor tests in vivo. The mean nanoparticle size of VEGF-siRNA/CRS was 121.4±0.3 nm with positive ζ potential of 7.69±4.47 mV. The release rate of VEGF-siRNA from VEGF-siRNA/CRS was 82.50% sustained for 48 h in Tris-ethylenediaminetetraacetic acid buffer (pH 8.0. Real-time polymerase chain reaction was used to analyze the efficiency of the transfection, and the result showed that VEGF mRNA expression had been knocked down by 82.36%. The expression of VEGF protein was also recorded to be downregulated to 14.83% using ELISA. The results of cytotoxicity measured by Cell Counting Kit-8 assay showed that VEGF-siRNA/CRS had significant inhibitory effect on HeLa cells. The results of antitumor assays indicated that VEGF-siRNA/CRS exhibited tumor cell growth inhibition in vivo. The results demonstrated that VEGF-siRNA could be delivered and transported by the designed carrier, while siRNA could be released constantly and led to an increasing gene-silencing effect against VEGF gene. In conclusion, VEGF-siRNA/CRS is a promising carrier for si

Progress in developing cationic vectors for non-viral systemic gene therapy against cancer.

Science.gov (United States)

Morille, Marie; Passirani, Catherine; Vonarbourg, Arnaud; Clavreul, Anne; Benoit, Jean-Pierre

2008-01-01

Initially, gene therapy was viewed as an approach for treating hereditary diseases, but its potential role in the treatment of acquired diseases such as cancer is now widely recognized. The understanding of the molecular mechanisms involved in cancer and the development of nucleic acid delivery systems are two concepts that have led to this development. Systemic gene delivery systems are needed for therapeutic application to cells inaccessible by percutaneous injection and for multi-located tumor sites, i.e. metastases. Non-viral vectors based on the use of cationic lipids or polymers appear to have promising potential, given the problems of safety encountered with viral vectors. Using these non-viral vectors, the current challenge is to obtain a similarly effective transfection to viral ones. Based on the advantages and disadvantages of existing vectors and on the hurdles encountered with these carriers, the aim of this review is to describe the "perfect vector" for systemic gene therapy against cancer.

Virus-Vectored Influenza Virus Vaccines

Science.gov (United States)

Tripp, Ralph A.; Tompkins, S. Mark

2014-01-01

Despite the availability of an inactivated vaccine that has been licensed for >50 years, the influenza virus continues to cause morbidity and mortality worldwide. Constant evolution of circulating influenza virus strains and the emergence of new strains diminishes the effectiveness of annual vaccines that rely on a match with circulating influenza strains. Thus, there is a continued need for new, efficacious vaccines conferring cross-clade protection to avoid the need for biannual reformulation of seasonal influenza vaccines. Recombinant virus-vectored vaccines are an appealing alternative to classical inactivated vaccines because virus vectors enable native expression of influenza antigens, even from virulent influenza viruses, while expressed in the context of the vector that can improve immunogenicity. In addition, a vectored vaccine often enables delivery of the vaccine to sites of inductive immunity such as the respiratory tract enabling protection from influenza virus infection. Moreover, the ability to readily manipulate virus vectors to produce novel influenza vaccines may provide the quickest path toward a universal vaccine protecting against all influenza viruses. This review will discuss experimental virus-vectored vaccines for use in humans, comparing them to licensed vaccines and the hurdles faced for licensure of these next-generation influenza virus vaccines. PMID:25105278

Efficient Vector-Based Forwarding for Underwater Sensor Networks

Directory of Open Access Journals (Sweden)

Peng Xie

2010-01-01

Full Text Available Underwater Sensor Networks (UWSNs are significantly different from terrestrial sensor networks in the following aspects: low bandwidth, high latency, node mobility, high error probability, and 3-dimensional space. These new features bring many challenges to the network protocol design of UWSNs. In this paper, we tackle one fundamental problem in UWSNs: robust, scalable, and energy efficient routing. We propose vector-based forwarding (VBF, a geographic routing protocol. In VBF, the forwarding path is guided by a vector from the source to the target, no state information is required on the sensor nodes, and only a small fraction of the nodes is involved in routing. To improve the robustness, packets are forwarded in redundant and interleaved paths. Further, a localized and distributed self-adaptation algorithm allows the nodes to reduce energy consumption by discarding redundant packets. VBF performs well in dense networks. For sparse networks, we propose a hop-by-hop vector-based forwarding (HH-VBF protocol, which adapts the vector-based approach at every hop. We evaluate the performance of VBF and HH-VBF through extensive simulations. The simulation results show that VBF achieves high packet delivery ratio and energy efficiency in dense networks and HH-VBF has high packet delivery ratio even in sparse networks.

Construction of a new shuttle vector for DNA delivery into mammalian cells using non-invasive Lactococcus lactis.

Science.gov (United States)

Yagnik, Bhrugu; Padh, Harish; Desai, Priti

2016-04-01

Use of food grade Lactococcus lactis (L. lactis) is fast emerging as a safe alternative for delivery of DNA vaccine. To attain efficient DNA delivery, L. lactis, a non-invasive bacterium is converted to invasive strain either by expressing proteins like Internalin A (InlA) or Fibronectin binding protein A (FnBPA) or through chemical treatments. However the safety status of invasive L. lactis is questionable. In the present report, we have shown that non-invasive L. lactis efficiently delivered the newly constructed reporter plasmid pPERDBY to mammalian cells without any chemical enhancers. The salient features of the vector are; I) Ability to replicate in two different hosts; Escherichia coli (E. coli) and Lactic Acid Bacteria (LAB), II) One of the smallest reporter plasmid for DNA vaccine, III) Enhanced Green Fluorescence Protein (EGFP) linked to Multiple Cloning Site (MCS), IV) Immunostimulatory CpG motifs functioning as an adjuvant. Expression of EGFP in pPERDBY transfected CHO-K1 and Caco-2 cells demonstrates its functionality. Non-invasive r-L. lactis was found efficient in delivering pPERDBY to Caco-2 cells. The in vitro data presented in this article supports the hypothesis that in the absence of invasive proteins or relevant chemical treatment, L. lactis was found efficient in delivering DNA to mammalian cells. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Vectorization at the KENO-IV code

International Nuclear Information System (INIS)

Asai, K.; Higuchi, K.; Katakura, J.

1986-01-01

The multigroup criticality safety code KENO-IV has been vectorized and tested on the FACOM VP-100 vector processor. At first, the vectorized KENO-IV on a scalar processor was slower than the original one by a factor of 1.4 because of the overhead introduced by vectorization. Making modifications of algorithms and techniques for vectorization, the vectorized version has become faster than the original one by a factor of 1.4 on the vector processor. For further speedup of the code, some improvements on compiler and hardware, especially on addition of Monte Carlo pipelines to the vector processor, are discussed

Dendrimers in drug delivery and targeting: Drug-dendrimer interactions and toxicity issues

Directory of Open Access Journals (Sweden)

Kanika Madaan

2014-01-01

Full Text Available Dendrimers are the emerging polymeric architectures that are known for their defined structures, versatility in drug delivery and high functionality whose properties resemble with biomolecules. These nanostructured macromolecules have shown their potential abilities in entrapping and/or conjugating the high molecular weight hydrophilic/hydrophobic entities by host-guest interactions and covalent bonding (prodrug approach respectively. Moreover, high ratio of surface groups to molecular volume has made them a promising synthetic vector for gene delivery. Owing to these properties dendrimers have fascinated the researchers in the development of new drug carriers and they have been implicated in many therapeutic and biomedical applications. Despite of their extensive applications, their use in biological systems is limited due to toxicity issues associated with them. Considering this, the present review has focused on the different strategies of their synthesis, drug delivery and targeting, gene delivery and other biomedical applications, interactions involved in formation of drug-dendrimer complex along with characterization techniques employed for their evaluation, toxicity problems and associated approaches to alleviate their inherent toxicity.

Dendrimers in drug delivery and targeting: Drug-dendrimer interactions and toxicity issues

Science.gov (United States)

Madaan, Kanika; Kumar, Sandeep; Poonia, Neelam; Lather, Viney; Pandita, Deepti

2014-01-01

Dendrimers are the emerging polymeric architectures that are known for their defined structures, versatility in drug delivery and high functionality whose properties resemble with biomolecules. These nanostructured macromolecules have shown their potential abilities in entrapping and/or conjugating the high molecular weight hydrophilic/hydrophobic entities by host-guest interactions and covalent bonding (prodrug approach) respectively. Moreover, high ratio of surface groups to molecular volume has made them a promising synthetic vector for gene delivery. Owing to these properties dendrimers have fascinated the researchers in the development of new drug carriers and they have been implicated in many therapeutic and biomedical applications. Despite of their extensive applications, their use in biological systems is limited due to toxicity issues associated with them. Considering this, the present review has focused on the different strategies of their synthesis, drug delivery and targeting, gene delivery and other biomedical applications, interactions involved in formation of drug-dendrimer complex along with characterization techniques employed for their evaluation, toxicity problems and associated approaches to alleviate their inherent toxicity. PMID:25035633

Gene delivery systems by the combination of lipid bubbles and ultrasound.

Science.gov (United States)

Negishi, Yoichi; Endo-Takahashi, Yoko; Maruyama, Kazuo

2016-11-28

Gene therapy is promising for the treatment of many diseases including cancers and genetic diseases. From the viewpoint of safety, ultrasound (US)-mediated gene delivery with nano/ microbubbles was recently developed as a novel non-viral vector system. US-mediated gene delivery using nano/microbubbles are able to produce transient changes in the permeability of the cell membrane after US-induced cavitation while reducing cellular damage and enables the tissue-specific or the site-specific intracellular delivery of gene both in vitro and in vivo. We have recently developed novel lipid nanobubbles (Lipid Bubbles). These nanobubbles can also be used to enhance the efficacy of the US-mediated genes (plasmid DNA, siRNA, and miRNA etc.) delivery. In this review, we describe US-mediated delivery systems combined with nano/microbubbles and discuss their feasibility as non-viral vector systems.

Application of Vector Triggering Random Decrement

DEFF Research Database (Denmark)

Asmussen, J. C.; Ibrahim, S. R.; Brincker, Rune

result is a Random Decrement function from each measurement. In traditional Random Decrement estimation the triggering condition is a scalar condition, which should only be fulfilled in a single measurement. In vector triggering Random Decrement the triggering condition is a vector condition......This paper deals with applications of the vector triggering Random Decrement technique. This technique is new and developed with the aim of minimizing estimation time and identification errors. The theory behind the technique is discussed in an accompanying paper. The results presented...... in this paper should be regarded as a further documentation of the technique. The key point in Random Decrement estimation is the formulation of a triggering condition. If the triggering condition is fulfilled a time segment from each measurement is picked out and averaged with previous time segments. The final...

Application of Vector Triggering Random Decrement

DEFF Research Database (Denmark)

Asmussen, J. C.; Ibrahim, S. R.; Brincker, Rune

1997-01-01

result is a Random Decrement function from each measurement. In traditional Random Decrement estimation the triggering condition is a scalar condition, which should only be fulfilled in a single measurement. In vector triggering Random Decrement the triggering condition is a vector condition......This paper deals with applications of the vector triggering Random Decrement technique. This technique is new and developed with the aim of minimizing estimation time and identification errors. The theory behind the technique is discussed in an accompanying paper. The results presented...... in this paper should be regarded as a further documentation of the technique. The key point in Random Decrement estimation is the formulation of a triggering condition. If the triggering condition is fulfilled a time segment from each measurement is picked out and averaged with previous time segments. The final...

Gene transfer to chicks using lentiviral vectors administered via the embryonic chorioallantoic membrane.

Directory of Open Access Journals (Sweden)

Gideon Hen

Full Text Available The lack of affordable techniques for gene transfer in birds has inhibited the advancement of molecular studies in avian species. Here we demonstrate a new approach for introducing genes into chicken somatic tissues by administration of a lentiviral vector, derived from the feline immunodeficiency virus (FIV, into the chorioallantoic membrane (CAM of chick embryos on embryonic day 11. The FIV-derived vectors carried yellow fluorescent protein (YFP or recombinant alpha-melanocyte-stimulating hormone (α-MSH genes, driven by the cytomegalovirus (CMV promoter. Transgene expression, detected in chicks 2 days after hatch by quantitative real-time PCR, was mostly observed in the liver and spleen. Lower expression levels were also detected in the brain, kidney, heart and breast muscle. Immunofluorescence and flow cytometry analyses confirmed transgene expression in chick tissues at the protein level, demonstrating a transduction efficiency of ∼0.46% of liver cells. Integration of the viral vector into the chicken genome was demonstrated using genomic repetitive (CR1-PCR amplification. Viability and stability of the transduced cells was confirmed using terminal deoxynucleotidyl transferase (dUTP nick end labeling (TUNEL assay, immunostaining with anti-proliferating cell nuclear antigen (anti-PCNA, and detection of transgene expression 51 days post transduction. Our approach led to only 9% drop in hatching efficiency compared to non-injected embryos, and all of the hatched chicks expressed the transgenes. We suggest that the transduction efficiency of FIV vectors combined with the accessibility of the CAM vasculature as a delivery route comprise a new powerful and practical approach for gene delivery into somatic tissues of chickens. Most relevant is the efficient transduction of the liver, which specializes in the production and secretion of proteins, thereby providing an optimal target for prolonged study of secreted hormones and peptides.

Selection vector filter framework

Science.gov (United States)

Lukac, Rastislav; Plataniotis, Konstantinos N.; Smolka, Bogdan; Venetsanopoulos, Anastasios N.

2003-10-01

We provide a unified framework of nonlinear vector techniques outputting the lowest ranked vector. The proposed framework constitutes a generalized filter class for multichannel signal processing. A new class of nonlinear selection filters are based on the robust order-statistic theory and the minimization of the weighted distance function to other input samples. The proposed method can be designed to perform a variety of filtering operations including previously developed filtering techniques such as vector median, basic vector directional filter, directional distance filter, weighted vector median filters and weighted directional filters. A wide range of filtering operations is guaranteed by the filter structure with two independent weight vectors for angular and distance domains of the vector space. In order to adapt the filter parameters to varying signal and noise statistics, we provide also the generalized optimization algorithms taking the advantage of the weighted median filters and the relationship between standard median filter and vector median filter. Thus, we can deal with both statistical and deterministic aspects of the filter design process. It will be shown that the proposed method holds the required properties such as the capability of modelling the underlying system in the application at hand, the robustness with respect to errors in the model of underlying system, the availability of the training procedure and finally, the simplicity of filter representation, analysis, design and implementation. Simulation studies also indicate that the new filters are computationally attractive and have excellent performance in environments corrupted by bit errors and impulsive noise.

Short Hairpin RNA (shRNA): Design, Delivery, and Assessment of Gene Knockdown

Science.gov (United States)

Moore, Chris B.; Guthrie, Elizabeth H.; Huang, Max Tze-Han; Taxman, Debra J.

2013-01-01

Shortly after the cellular mechanism of RNA interference (RNAi) was first described, scientists began using this powerful technique to study gene function. This included designing better methods for the successful delivery of small interfering RNAs (siRNAs) and short hairpin RNAs (shRNAs) into mammalian cells. While the simplest method for RNAi is the cytosolic delivery of siRNA oligonucleotides, this technique is limited to cells capable of transfection and is primarily utilized during transient in vitro studies. The introduction of shRNA into mammalian cells through infection with viral vectors allows for stable integration of shRNA and long-term knockdown of the targeted gene; however, several challenges exist with the implementation of this technology. Here we describe some well-tested protocols which should increase the chances of successful design, delivery, and assessment of gene knockdown by shRNA. We provide suggestions for designing shRNA targets and controls, a protocol for sequencing through the secondary structure of the shRNA hairpin structure, and protocols for packaging and delivery of shRNA lentiviral particles. Using real-time PCR and functional assays we demonstrate the successful knockdown of ASC, an inflammatory adaptor molecule. These studies demonstrate the practicality of including two shRNAs with different efficacies of knockdown to provide an additional level of control and to verify dose dependency of functional effects. Along with the methods described here, as new techniques and algorithms are designed in the future, shRNA is likely to include further promising application and continue to be a critical component of gene discovery. PMID:20387148

Neuron-specific RNA interference using lentiviral vectors

DEFF Research Database (Denmark)

Nielsen, Troels Tolstrup; Marion, Ingrid van; Hasholt, Lis

2009-01-01

BACKGROUND: Viral vectors have been used in several different settings for the delivery of small hairpin (sh) RNAs. However, most vectors have utilized ubiquitously-expressing polymerase (pol) III promoters to drive expression of the hairpin as a result of the strict requirement for precise...... transcriptional initiation and termination. Recently, pol II promoters have been used to construct vectors for RNA interference (RNAi). By embedding the shRNA into a micro RNA-context (miRNA) the endogenous miRNA processing machinery is exploited to achieve the mature synthetic miRNA (smiRNA), thereby expanding...... the possible promoter choices and eventually allowing cell type specific down-regulation of target genes. METHODS: In the present study, we constructed lentiviral vectors expressing smiRNAs under the control of pol II promoters to knockdown gene expression in cell culture and in the brain. RESULTS: We...

Optimal construction and delivery of dual-functioning lentiviral vectors for type I collagen-suppressed chondrogenesis in synovium-derived mesenchymal stem cells.

Science.gov (United States)

Zhang, Feng; Yao, Yongchang; Zhou, Ruijie; Su, Kai; Citra, Fudiman; Wang, Dong-An

2011-06-01

This study aims to deliver both transforming growth factor β3 (TGF-β3) and shRNA targeting type I collagen (Col I) by optimal construction and application of various dual-functioning lentiviral vectors to induce Col I-suppressed chondrogenesis in synovium-derived mesenchymal stem cells (SMSCs). We constructed four lentiviral vectors (LV-1, LV-2, LV-3 and LV-4) with various arrangements of the two expression cassettes in different positions and orientations. Col I inhibition efficiency and chondrogenic markers were assessed with qPCR, ELISA and staining techniques. Among the four vectors, LV-1 has two distant and reversely oriented cassettes, LV-2 has two distant and same-oriented cassettes, LV-3 has two proximal and reversely oriented cassettes, and LV-4 has two proximal and same-oriented cassettes. Col I and chondrogenic markers, including type II collagen (Col II), aggrecan and glycosaminoglycan (GAG), were examined in SMSCs cultured in 3-D alginate hydrogel. All of the four vectors showed distinct effects in Col I level as well as diverse inductive efficiencies in upregulation of the cartilaginous markers. Based on real-time PCR results, LV-1 was optimal towards Col I-suppressed chondrogenesis. LV-1 vector is competent to promote Col I-suppressed chondrogenesis in SMSCs.

Microencapsulation: A promising technique for controlled drug delivery.

Science.gov (United States)

Singh, M N; Hemant, K S Y; Ram, M; Shivakumar, H G

2010-07-01

MICROPARTICLES OFFER VARIOUS SIGNIFICANT ADVANTAGES AS DRUG DELIVERY SYSTEMS, INCLUDING: (i) an effective protection of the encapsulated active agent against (e.g. enzymatic) degradation, (ii) the possibility to accurately control the release rate of the incorporated drug over periods of hours to months, (iii) an easy administration (compared to alternative parenteral controlled release dosage forms, such as macro-sized implants), and (iv) Desired, pre-programmed drug release profiles can be provided which match the therapeutic needs of the patient. This article gives an overview on the general aspects and recent advances in drug-loaded microparticles to improve the efficiency of various medical treatments. An appropriately designed controlled release drug delivery system can be a foot ahead towards solving problems concerning to the targeting of drug to a specific organ or tissue, and controlling the rate of drug delivery to the target site. The development of oral controlled release systems has been a challenge to formulation scientist due to their inability to restrain and localize the system at targeted areas of gastrointestinal tract. Microparticulate drug delivery systems are an interesting and promising option when developing an oral controlled release system. The objective of this paper is to take a closer look at microparticles as drug delivery devices for increasing efficiency of drug delivery, improving the release profile and drug targeting. In order to appreciate the application possibilities of microcapsules in drug delivery, some fundamental aspects are briefly reviewed.

A new technique for reversible permeabilization of live cells for intracellular delivery of quantum dots

International Nuclear Information System (INIS)

Medepalli, Krishnakiran; Alphenaar, Bruce W; Keynton, Robert S; Sethu, Palaniappan

2013-01-01

A major challenge with the use of quantum dots (QDs) for cellular imaging and biomolecular delivery is the attainment of QDs freely dispersed inside the cells. Conventional methods such as endocytosis, lipids based delivery and electroporation are associated with delivery of QDs in vesicles and/or as aggregates that are not monodispersed. In this study, we demonstrate a new technique for reversible permeabilization of cells to enable the introduction of freely dispersed QDs within the cytoplasm. Our approach combines osmosis driven fluid transport into cells achieved by creating a hypotonic environment and reversible permeabilization using low concentrations of cell permeabilization agents like Saponin. Our results confirm that highly efficient endocytosis-free intracellular delivery of QDs can be accomplished using this method. The best results were obtained when the cells were treated with 50 μg ml −1 Saponin in a hypotonic buffer at a 3:2 physiological buffer:DI water ratio for 5 min at 4 ° C. (paper)

Vector choice determines immunogenicity and potency of genetic vaccines against Angola Marburg virus in nonhuman primates

NARCIS (Netherlands)

Geisbert, Thomas W.; Bailey, Michael; Geisbert, Joan B.; Asiedu, Clement; Roederer, Mario; Grazia-Pau, Maria; Custers, Jerome; Jahrling, Peter; Goudsmit, Jaap; Koup, Richard; Sullivan, Nancy J.

2010-01-01

The immunogenicity and durability of genetic vaccines are influenced by the composition of gene inserts and choice of delivery vector. DNA vectors are a promising vaccine approach showing efficacy when combined in prime-boost regimens with recombinant protein or viral vectors, but they have shown

Effective SIMD Vectorization for Intel Xeon Phi Coprocessors

Directory of Open Access Journals (Sweden)

Xinmin Tian

2015-01-01

Full Text Available Efficiently exploiting SIMD vector units is one of the most important aspects in achieving high performance of the application code running on Intel Xeon Phi coprocessors. In this paper, we present several effective SIMD vectorization techniques such as less-than-full-vector loop vectorization, Intel MIC specific alignment optimization, and small matrix transpose/multiplication 2D vectorization implemented in the Intel C/C++ and Fortran production compilers for Intel Xeon Phi coprocessors. A set of workloads from several application domains is employed to conduct the performance study of our SIMD vectorization techniques. The performance results show that we achieved up to 12.5x performance gain on the Intel Xeon Phi coprocessor. We also demonstrate a 2000x performance speedup from the seamless integration of SIMD vectorization and parallelization.

A novel Listeria monocytogenes-based DNA delivery system for cancer gene therapy.

LENUS (Irish Health Repository)

van Pijkeren, Jan Peter

2012-01-31

Bacteria-mediated transfer of plasmid DNA to mammalian cells (bactofection) has been shown to have significant potential as an approach to express heterologous proteins in various cell types. This is achieved through entry of the entire bacterium into cells, followed by release of plasmid DNA. In a murine model, we show that Listeria monocytogenes can invade and spread in tumors, and establish the use of Listeria to deliver genes to tumors in vivo. A novel approach to vector lysis and release of plasmid DNA through antibiotic administration was developed. Ampicillin administration facilitated both plasmid transfer and safety control of vector. To further improve on the gene delivery system, we selected a Listeria monocytogenes derivative that is more sensitive to ampicillin, and less pathogenic than the wild-type strain. Incorporation of a eukaryotic-transcribed lysin cassette in the plasmid further increased bacterial lysis. Successful gene delivery of firefly luciferase to growing tumors in murine models and to patient breast tumor samples ex vivo was achieved. The model described encompasses a three-phase treatment regimen, involving (1) intratumoral administration of vector followed by a period of vector spread, (2) systemic ampicillin administration to induce vector lysis and plasmid transfer, and (3) systemic administration of combined moxifloxacin and ampicillin to eliminate systemic vector. For the first time, our results reveal the potential of Listeria monocytogenes for in vivo gene delivery.

Video Vectorization via Tetrahedral Remeshing.

Science.gov (United States)

Wang, Chuan; Zhu, Jie; Guo, Yanwen; Wang, Wenping

2017-02-09

We present a video vectorization method that generates a video in vector representation from an input video in raster representation. A vector-based video representation offers the benefits of vector graphics, such as compactness and scalability. The vector video we generate is represented by a simplified tetrahedral control mesh over the spatial-temporal video volume, with color attributes defined at the mesh vertices. We present novel techniques for simplification and subdivision of a tetrahedral mesh to achieve high simplification ratio while preserving features and ensuring color fidelity. From an input raster video, our method is capable of generating a compact video in vector representation that allows a faithful reconstruction with low reconstruction errors.

Virtual-vector-based space vector pulse width modulation of the DC-AC multilevel-clamped multilevel converter (MLC²)

DEFF Research Database (Denmark)

Rodriguez, Pedro; Busquets-Monge, Sergio; Blaabjerg, Frede

2011-01-01

This work presents the development of the space vector pulse width modulation (SVPWM) of a new multi-level converter topology. First, the proposed converter and its natural space vector diagram are presented. Secondly, a modified space vector diagram based on the virtual-vectors technique is show...

Stable Dispersions of Covalently Tethered Polymer Improved Graphene Oxide Nanoconjugates as an Effective Vector for siRNA Delivery.

Science.gov (United States)

Yadav, Nisha; Kumar, Naveen; Prasad, Peeyush; Shirbhate, Shivani; Sehrawat, Seema; Lochab, Bimlesh

2018-05-02

Conjugates of poly(amidoamine) (PAMAM) with modified graphene oxide (GO) are attractive nonviral vectors for gene-based cancer therapeutics. GO protects siRNA from enzymatic cleavage and showed reasonable transfection efficiency along with simultaneous benefits of low cost and large scale production. PAMAM is highly effective in siRNA delivery but suffers from high toxicity with poor in vivo efficacy. Co-reaction of GO and PAMAM led to aggregation and more importantly, have detrimental effect on stability of dispersion at physiological pH preventing their exploration at clinical level. In the current work, we have designed, synthesized, characterized and explored a new type of hybrid vector (GPD), using GO synthesized via improved method which was covalently tethered with poly(ethylene glycol) (PEG) and PAMAM. The existence of covalent linkage, relative structural changes and properties of GPD is well supported by Fourier transform infrared (FTIR), UV-visible (UV-vis), Raman, X-ray photoelectron (XPS), elemental analysis, powder X-ray diffraction (XRD), thermogravimetry analysis (TGA), dynamic light scattering (DLS), and zeta potential. Scanning electron microscopy (SEM), and transmission electron microscopy (TEM) of GPD showed longitudinally aligned columnar self-assembled ∼10 nm thick polymeric nanoarchitectures onto the GO surface accounting to an average size reduction to ∼20 nm. GPD revealed an outstanding stability in both phosphate buffer saline (PBS) and serum containing cell medium. The binding efficiency of EPAC1 siRNA to GPD was supported by gel retardation assay, DLS, zeta potential and photoluminescence (PL) studies. A lower cytotoxicity with enhanced cellular uptake and homogeneous intracellular distribution of GPD/siRNA complex is confirmed by imaging studies. GPD exhibited a higher transfection efficiency with remarkable inhibition of cell migration and lower invasion than PAMAM and Lipofectamine 2000 suggesting its role in prevention of breast

One-Pot Parallel Synthesis of Lipid Library via Thiolactone Ring Opening and Screening for Gene Delivery.

Science.gov (United States)

Molla, Mijanur R; Böser, Alexander; Rana, Akshita; Schwarz, Karina; Levkin, Pavel A

2018-04-18

Efficient delivery of nucleic acids into cells is of great interest in the field of cell biology and gene therapy. Despite a lot of research, transfection efficiency and structural diversity of gene-delivery vectors are still limited. A better understanding of the structure-function relationship of gene delivery vectors is also essential for the design of novel and intelligent delivery vectors, efficient in "difficult-to-transfect" cells and in vivo clinical applications. Most of the existing strategies for the synthesis of gene-delivery vectors require multiple steps and lengthy procedures. Here, we demonstrate a facile, three-component one-pot synthesis of a combinatorial library of 288 structurally diverse lipid-like molecules termed "lipidoids" via a thiolactone ring opening reaction. This strategy introduces the possibility to synthesize lipidoids with hydrophobic tails containing both unsaturated bonds and reducible disulfide groups. The whole synthesis and purification are convenient, extremely fast, and can be accomplished within a few hours. Screening of the produced lipidoids using HEK293T cells without addition of helper lipids resulted in identification of highly stable liposomes demonstrating ∼95% transfection efficiency with low toxicity.

Geminivirus vectors for high-level expression of foreign proteins in plant cells.

Science.gov (United States)

Mor, Tsafrir S; Moon, Yong-Sun; Palmer, Kenneth E; Mason, Hugh S

2003-02-20

Bean yellow dwarf virus (BeYDV) is a monopartite geminivirus that can infect dicotyledonous plants. We have developed a high-level expression system that utilizes elements of the replication machinery of this single-stranded DNA virus. The replication initiator protein (Rep) mediates release and replication of a replicon from a DNA construct ("LSL vector") that contains an expression cassette for a gene of interest flanked by cis-acting elements of the virus. We used tobacco NT1 cells and biolistic delivery of plasmid DNA for evaluation of replication and expression of reporter genes contained within an LSL vector. By codelivery of a GUS reporter-LSL vector and a Rep-supplying vector, we obtained up to 40-fold increase in expression levels compared to delivery of the reporter-LSL vectors alone. High-copy replication of the LSL vector was correlated with enhanced expression of GUS. Rep expression using a whole BeYDV clone, a cauliflower mosaic virus 35S promoter driving either genomic rep or an intron-deleted rep gene, or 35S-rep contained in the LSL vector all achieved efficient replication and enhancement of GUS expression. We anticipate that this system can be adapted for use in transgenic plants or plant cell cultures with appropriately regulated expression of Rep, with the potential to greatly increase yield of recombinant proteins. Copyright 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 430-437, 2003.

Generation of arbitrary vector beams

Science.gov (United States)

Perez-Garcia, Benjamin; López-Mariscal, Carlos; Hernandez-Aranda, Raul I.; Gutiérrez-Vega, Julio C.

2017-08-01

Optical vector beams arise from point to point spatial variations of the electric component of an electromagnetic field over the transverse plane. In this work, we present a novel experimental technique to generate arbitrary vec- tor beams, and provide sufficient evidence to validate their state of polarization. This technique takes advantage of the capability of a Spatial Light Modulator to simultaneously generate two components of an electromagnetic field by halving the screen of the device and subsequently recombining them in a Sagnac interferometer. Our experimental results show the versatility and robustness of this technique for the generation of vector beams.

Vector Quantization of Harmonic Magnitudes in Speech Coding Applications—A Survey and New Technique

Directory of Open Access Journals (Sweden)

Wai C. Chu

2004-12-01

Full Text Available A harmonic coder extracts the harmonic components of a signal and represents them efficiently using a few parameters. The principles of harmonic coding have become quite successful and several standardized speech and audio coders are based on it. One of the key issues in harmonic coder design is in the quantization of harmonic magnitudes, where many propositions have appeared in the literature. The objective of this paper is to provide a survey of the various techniques that have appeared in the literature for vector quantization of harmonic magnitudes, with emphasis on those adopted by the major speech coding standards; these include constant magnitude approximation, partial quantization, dimension conversion, and variable-dimension vector quantization (VDVQ. In addition, a refined VDVQ technique is proposed where experimental data are provided to demonstrate its effectiveness.

The feasibility of using Pareto fronts for comparison of treatment planning systems and delivery techniques

International Nuclear Information System (INIS)

Ottosson, Rickard O.; Sjoestroem, David; Behrens, Claus F.; Karlsson, Anna; Engstroem, Per E.; Knoeoes, Tommy; Ceberg, Crister

2009-01-01

Pareto optimality is a concept that formalises the trade-off between a given set of mutually contradicting objectives. A solution is said to be Pareto optimal when it is not possible to improve one objective without deteriorating at least one of the other. A set of Pareto optimal solutions constitute the Pareto front. The Pareto concept applies well to the inverse planning process, which involves inherently contradictory objectives, high and uniform target dose on one hand, and sparing of surrounding tissue and nearby organs at risk (OAR) on the other. Due to the specific characteristics of a treatment planning system (TPS), treatment strategy or delivery technique, Pareto fronts for a given case are likely to differ. The aim of this study was to investigate the feasibility of using Pareto fronts as a comparative tool for TPSs, treatment strategies and delivery techniques. In order to sample Pareto fronts, multiple treatment plans with varying target conformity and dose sparing of OAR were created for a number of prostate and head and neck IMRT cases. The DVHs of each plan were evaluated with respect to target coverage and dose to relevant OAR. Pareto fronts were successfully created for all studied cases. The results did indeed follow the definition of the Pareto concept, i.e. dose sparing of the OAR could not be improved without target coverage being impaired or vice versa. Furthermore, various treatment techniques resulted in distinguished and well separated Pareto fronts. Pareto fronts may be used to evaluate a number of parameters within radiotherapy. Examples are TPS optimization algorithms, the variation between accelerators or delivery techniques and the degradation of a plan during the treatment planning process. The issue of designing a model for unbiased comparison of parameters with such large inherent discrepancies, e.g. different TPSs, is problematic and should be carefully considered

The feasibility of using Pareto fronts for comparison of treatment planning systems and delivery techniques.

Science.gov (United States)

Ottosson, Rickard O; Engstrom, Per E; Sjöström, David; Behrens, Claus F; Karlsson, Anna; Knöös, Tommy; Ceberg, Crister

2009-01-01

Pareto optimality is a concept that formalises the trade-off between a given set of mutually contradicting objectives. A solution is said to be Pareto optimal when it is not possible to improve one objective without deteriorating at least one of the other. A set of Pareto optimal solutions constitute the Pareto front. The Pareto concept applies well to the inverse planning process, which involves inherently contradictory objectives, high and uniform target dose on one hand, and sparing of surrounding tissue and nearby organs at risk (OAR) on the other. Due to the specific characteristics of a treatment planning system (TPS), treatment strategy or delivery technique, Pareto fronts for a given case are likely to differ. The aim of this study was to investigate the feasibility of using Pareto fronts as a comparative tool for TPSs, treatment strategies and delivery techniques. In order to sample Pareto fronts, multiple treatment plans with varying target conformity and dose sparing of OAR were created for a number of prostate and head & neck IMRT cases. The DVHs of each plan were evaluated with respect to target coverage and dose to relevant OAR. Pareto fronts were successfully created for all studied cases. The results did indeed follow the definition of the Pareto concept, i.e. dose sparing of the OAR could not be improved without target coverage being impaired or vice versa. Furthermore, various treatment techniques resulted in distinguished and well separated Pareto fronts. Pareto fronts may be used to evaluate a number of parameters within radiotherapy. Examples are TPS optimization algorithms, the variation between accelerators or delivery techniques and the degradation of a plan during the treatment planning process. The issue of designing a model for unbiased comparison of parameters with such large inherent discrepancies, e.g. different TPSs, is problematic and should be carefully considered.

[Construction and identification of Nogo extra cellular peptide residues 1-40 gene lentiviral vector].

Science.gov (United States)

Yuan, Haifeng; Song, Yueming; Liu, Hao; Zhou, Chunguang; Kong, Qingquan; Liu, Liming; Gong, Quan

2012-02-01

To construct a lentiviral expression vector carrying Nogo extra cellular peptide residues 1-40 (NEP1-40) and to obtain NEP1-40 efficient and stable expression in mammalian cells. The DNA fragment of NEP1-40 coding sequence was amplified by PCR with designed primer from the cDNA library including NEP1-40 gene, and then subcloned into pGC-FU vector with in-fusion technique to generate the lentiviral expression vector, pGC-FU-NEP1-40. The positive clones were screened by PCR and the correct NEP1-40 was confirmed by sequencing. Recombinant lentiviruses were produced in 293T cells after the cotransfection of pGC-FU-NEP1-40, and packaging plasmids of pHelper 1.0 and pHelper 2.0. Green fluorescent protein (GFP) expression of infected 293T cells was observed to evaluate gene delivery efficiency. NEP1-40 protein expression in 293T cells was detected by Western blot. The lentiviral expression vector carrying NEP1-40 was successfully constructed by GFP observation, and NEP1-40 protein expression was detected in 293T cells by Western blot. The recombinant lentivirus pGC-FU-NEP1-40 is successfully constructed and it lays a foundation for further molecular function study of NEP 1-40.

Preclinical evaluation of gene delivery methods for the treatment of loco-regional disease in breast cancer.

LENUS (Irish Health Repository)

Rajendran, Simon

2011-04-01

Preclinical results with various gene therapy strategies indicate significant potential for new cancer treatments. However, many therapeutics fail at clinical trial, often due to differences in tissue physiology between animal models and humans, and tumor phenotype variation. Clinical data relevant to treatment strategies may be generated prior to clinical trial through experimentation using intact patient tissue ex vivo. We developed a novel tumor slice model culture system that is universally applicable to gene delivery methods, using a realtime luminescence detection method to assess gene delivery. Methods investigated include viruses (adenovirus [Ad] and adeno-associated virus), lipofection, ultrasound (US), electroporation and naked DNA. Viability and tumor populations within the slices were well maintained for seven days, and gene delivery was qualitatively and quantitatively examinable for all vectors. Ad was the most efficient gene delivery vector with transduction efficiency >50%. US proved the optimal non-viral gene delivery method in human tumor slices. The nature of the ex vivo culture system permitted examination of specific elements. Parameters shown to diminish Ad gene delivery included blood, regions of low viability and secondary disease. US gene delivery was significantly reduced by blood and skin, while tissue hyperthermia improved gene delivery. US achieved improved efficacy for secondary disease. The ex vivo model was also suitable for examination of tissue-specific effects on vector expression, with Ad expression mediated by the CXCR4 promoter shown to provide a tumor selective advantage over the ubiquitously active cytomegalovirus promoter. In conclusion, this is the first study incorporating patient tissue models in comparing gene delivery from various vectors, providing knowledge on cell-type specificity and examining the crucial biological factors determining successful gene delivery. The results highlight the importance of in

Preclinical evaluation of gene delivery methods for the treatment of loco-regional disease in breast cancer.

LENUS (Irish Health Repository)

Rajendran, Simon

2012-01-31

Preclinical results with various gene therapy strategies indicate significant potential for new cancer treatments. However, many therapeutics fail at clinical trial, often due to differences in tissue physiology between animal models and humans, and tumor phenotype variation. Clinical data relevant to treatment strategies may be generated prior to clinical trial through experimentation using intact patient tissue ex vivo. We developed a novel tumor slice model culture system that is universally applicable to gene delivery methods, using a realtime luminescence detection method to assess gene delivery. Methods investigated include viruses (adenovirus [Ad] and adeno-associated virus), lipofection, ultrasound (US), electroporation and naked DNA. Viability and tumor populations within the slices were well maintained for seven days, and gene delivery was qualitatively and quantitatively examinable for all vectors. Ad was the most efficient gene delivery vector with transduction efficiency >50%. US proved the optimal non-viral gene delivery method in human tumor slices. The nature of the ex vivo culture system permitted examination of specific elements. Parameters shown to diminish Ad gene delivery included blood, regions of low viability and secondary disease. US gene delivery was significantly reduced by blood and skin, while tissue hyperthermia improved gene delivery. US achieved improved efficacy for secondary disease. The ex vivo model was also suitable for examination of tissue-specific effects on vector expression, with Ad expression mediated by the CXCR4 promoter shown to provide a tumor selective advantage over the ubiquitously active cytomegalovirus promoter. In conclusion, this is the first study incorporating patient tissue models in comparing gene delivery from various vectors, providing knowledge on cell-type specificity and examining the crucial biological factors determining successful gene delivery. The results highlight the importance of in

Polymeric nanoparticles: potent vectors for vaccine delivery targeting cancer and infectious diseases.

Science.gov (United States)

Bolhassani, Azam; Javanzad, Shabnam; Saleh, Tayebeh; Hashemi, Mehrdad; Aghasadeghi, Mohammad Reza; Sadat, Seyed Mehdi

2014-01-01

Nanocarriers with various compositions and biological properties have been extensively applied for in vitro/in vivo drug and gene delivery. The family of nanocarriers includes polymeric nanoparticles, lipid-based carriers (liposomes/micelles), dendrimers, carbon nanotubes, and gold nanoparticles (nanoshells/nanocages). Among different delivery systems, polymeric carriers have several properties such as: easy to synthesize, inexpensive, biocompatible, biodegradable, non-immunogenic, non-toxic, and water soluble. In addition, cationic polymers seem to produce more stable complexes led to a more protection during cellular trafficking than cationic lipids. Nanoparticles often show significant adjuvant effects in vaccine delivery since they may be easily taken up by antigen presenting cells (APCs). Natural polymers such as polysaccharides and synthetic polymers have demonstrated great potential to form vaccine nanoparticles. The development of new adjuvants or delivery systems for DNA and protein immunization is an expanding research field. This review describes polymeric carriers especially PLGA, chitosan, and PEI as vaccine delivery systems.

Bioreducible poly(amido amine)s for non-viral gene delivery

NARCIS (Netherlands)

Lin, C.

2008-01-01

This thesis describes the design and development of bioreducible poly(amido amine)s as non-viral vectors for gene delivery in vitro and in vivo. The structural influences of these polymers on their physico-chemical properties and gene delivery properties, transfection capability and cytotoxicity in

Robust Lentiviral Gene Delivery But Limited Transduction Capacity of Commonly Used Adeno-Associated Viral Serotypes in Xenotransplanted Human Skin.

Science.gov (United States)

Jakobsen, Maria; Askou, Anne Louise; Stenderup, Karin; Rosada, Cecilia; Dagnæs-Hansen, Frederik; Jensen, Thomas G; Corydon, Thomas J; Mikkelsen, Jacob Giehm; Aagaard, Lars

2015-08-01

Skin is an easily accessible organ, and therapeutic gene transfer to skin remains an attractive alternative for the treatment of skin diseases. Although we have previously documented potent lentiviral gene delivery to human skin, vectors based on adeno-associated virus (AAV) rank among the most promising gene delivery tools for in vivo purposes. Thus, we compared the potential usefulness of various serotypes of recombinant AAV vectors and lentiviral vectors for gene transfer to human skin in a xenotransplanted mouse model. Vector constructs encoding firefly luciferase were packaged in AAV capsids of serotype 1, 2, 5, 6, 8, and 9 and separately administered by intradermal injection in human skin transplants. For all serotypes, live bioimaging demonstrated low levels of transgene expression in the human skin graft, and firefly luciferase expression was observed primarily in neighboring tissue outside of the graft. In contrast, gene delivery by intradermally injected lentiviral vectors was efficient and led to extensive and persistent firefly luciferase expression within the human skin graft only. The study demonstrates the limited capacity of single-stranded AAV vectors of six commonly used serotypes for gene delivery to human skin in vivo.

A novel dendrimer based on poly (L-glutamic acid) derivatives as an efficient and biocompatible gene delivery vector

International Nuclear Information System (INIS)

Zeng Xin; Pan Shirong; Wang Chi; Wen Yuting; Wu Hongmei; Wang Cuifeng; Wu Chuanbin; Feng Min; Li Jie

2011-01-01

Non-viral gene delivery systems based on cationic polymers have faced limitations related to their relative low gene transfer efficiency, cytotoxicity and system instability in vivo. In this paper, a flexible and pompon-like dendrimer composed of poly (amidoamine) (PAMAM) G4.0 as the inner core and poly (L-glutamic acid) grafted low-molecular-weight polyethylenimine (PLGE) as the surrounding multiple arms was synthesized (MGI dendrimer). The novel MGI dendrimer was designed to combine the merits of size-controlled PAMAM G4.0 and the low toxicity and flexible chains of PLGE. In phosphate-buffered saline dispersions the well-defined DNA/MGI complex above a N/P ratio of 30 showed good stability with particle sizes of approximately 200 nm and a comparatively low polydispersity index. However, the particle size of the DNA/25 kDa polyethylenimine (DNA/PEI 25K) complex was larger than 700 nm under the same salt conditions. The shielding of the compact amino groups at the periphery of flexible PAMAM and biocompatible PLGE chains in MGI resulted in a dramatic decrease of the cytotoxicity compared to native PAMAM G4.0 dendrimer. The in vitro transfection efficiency of DNA/MGI dendrimer complex was higher than that of PAMAM G4.0 dendrimer. Importantly, in serum-containing medium, DNA/MGI complexes at their optimal N/P ratio maintained the same high levels of transfection efficiency as in serum-free medium, while the transfection efficiency of native PAMAM G4.0, PEI 25K and Lipofectamine 2000 were sharply decreased. In vivo gene delivery of pVEGF165/MGI complex into balloon-injured rabbit carotid arteries resulted in significant inhibition of restenosis by increasing VEGF165 expression in local vessels. Therefore, the pompon-like MGI dendrimer may be a promising vector candidate for efficient gene delivery in vivo.

Microencapsulation techniques to develop formulations of insulin for oral delivery: a review.

Science.gov (United States)

Cárdenas-Bailón, Fernando; Osorio-Revilla, Guillermo; Gallardo-Velázquez, Tzayhrí

2013-01-01

Oral insulin delivery represents one of the most challenging goals for pharmaceutical industry. In general, it is accepted that oral administration of insulin would be more accepted by patients and insulin would be delivered in a more physiological way than the parenteral route. From all strategies to deliverer insulin orally, microencapsulation or nanoencapsulation of insulin are the most promising approaches because these techniques protect insulin from enzymatic degradation in stomach, show a good release profile at intestine pH values, maintain biological activity during formulation and enhance intestinal permeation at certain extent. From different microencapsulation techniques, it seems that complex coacervation, multiple emulsion and internal gelation are the most appropriate techniques to encapsulate insulin due to their relative ease of preparation. Besides that, the use of organic solvents is not required and can be scaled up at low cost; however, relative oral bioavailability still needs to be improved.

Noninvasive gene delivery to foveal cones for vision restoration

Science.gov (United States)

Khabou, Hanen; Garita-Hernandez, Marcela; Jaillard, Céline; Brazhnikova, Elena; Bertin, Stéphane; Forster, Valérie; Desrosiers, Mélissa; Winckler, Céline; Goureau, Olivier; Duebel, Jens; Sahel, José-Alain

2018-01-01

Intraocular injection of adeno-associated viral (AAV) vectors has been an evident route for delivering gene drugs into the retina. However, gaps in our understanding of AAV transduction patterns within the anatomically unique environments of the subretinal and intravitreal space of the primate eye impeded the establishment of noninvasive and efficient gene delivery to foveal cones in the clinic. Here, we establish new vector-promoter combinations to overcome the limitations associated with AAV-mediated cone transduction in the fovea with supporting studies in mouse models, human induced pluripotent stem cell–derived organoids, postmortem human retinal explants, and living macaques. We show that an AAV9 variant provides efficient foveal cone transduction when injected into the subretinal space several millimeters away from the fovea, without detaching this delicate region. An engineered AAV2 variant provides gene delivery to foveal cones with a well-tolerated dose administered intravitreally. Both delivery modalities rely on a cone-specific promoter and result in high-level transgene expression compatible with optogenetic vision restoration. The model systems described here provide insight into the behavior of AAV vectors across species to obtain safety and efficacy needed for gene therapy in neurodegenerative disorders. PMID:29367457

Chitosan for gene delivery and orthopedic tissue engineering applications.

Science.gov (United States)

Raftery, Rosanne; O'Brien, Fergal J; Cryan, Sally-Ann

2013-05-15

Gene therapy involves the introduction of foreign genetic material into cells in order exert a therapeutic effect. The application of gene therapy to the field of orthopaedic tissue engineering is extremely promising as the controlled release of therapeutic proteins such as bone morphogenetic proteins have been shown to stimulate bone repair. However, there are a number of drawbacks associated with viral and synthetic non-viral gene delivery approaches. One natural polymer which has generated interest as a gene delivery vector is chitosan. Chitosan is biodegradable, biocompatible and non-toxic. Much of the appeal of chitosan is due to the presence of primary amine groups in its repeating units which become protonated in acidic conditions. This property makes it a promising candidate for non-viral gene delivery. Chitosan-based vectors have been shown to transfect a number of cell types including human embryonic kidney cells (HEK293) and human cervical cancer cells (HeLa). Aside from its use in gene delivery, chitosan possesses a range of properties that show promise in tissue engineering applications; it is biodegradable, biocompatible, has anti-bacterial activity, and, its cationic nature allows for electrostatic interaction with glycosaminoglycans and other proteoglycans. It can be used to make nano- and microparticles, sponges, gels, membranes and porous scaffolds. Chitosan has also been shown to enhance mineral deposition during osteogenic differentiation of MSCs in vitro. The purpose of this review is to critically discuss the use of chitosan as a gene delivery vector with emphasis on its application in orthopedic tissue engineering.

rAAV Vectors as Safe and Efficient Tools for the Stable Delivery of Genes to Primary Human Chondrosarcoma Cells In Vitro and In Situ

Directory of Open Access Journals (Sweden)

Henning Madry

2012-01-01

Full Text Available Treatment of chondrosarcoma remains a major challenge in orthopaedic oncology. Gene transfer strategies based on recombinant adenoassociated viral (rAAV vectors may provide powerful tools to develop new, efficient therapeutic options against these tumors. In the present study, we tested the hypothesis that rAAV is adapted for a stable and safe delivery of foreign sequences in human chondrosarcoma tissue by transducing primary human chondrosarcoma cells in vitro and in situ with different reporter genes (E. coli lacZ, firefly luc, Discosoma sp. RFP. The effects of rAAV administration upon cell survival and metabolic activities were also evaluated to monitor possibly detrimental effects of the gene transfer method. Remarkably, we provide evidence that efficient and prolonged expression of transgene sequences via rAAV can be safely achieved in all the systems investigated, demonstrating the potential of the approach of direct application of therapeutic gene vectors as a means to treat chondrosarcoma.

PGMA-Based Cationic Nanoparticles with Polyhydric Iodine Units for Advanced Gene Vectors.

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Sun, Yue; Hu, Hao; Yu, Bingran; Xu, Fu-Jian

2016-11-16

It is crucial for successful gene delivery to develop safe, effective, and multifunctional polycations. Iodine-based small molecules are widely used as contrast agents for CT imaging. Herein, a series of star-like poly(glycidyl methacrylate) (PGMA)-based cationic vectors (II-PGEA/II) with abundant flanking polyhydric iodine units are prepared for multifunctional gene delivery systems. The proposed II-PGEA/II star vector is composed of one iohexol intermediate (II) core and five ethanolamine (EA) and II-difunctionalized PGMA arms. The amphipathic II-PGEA/II vectors readily self-assemble into well-defined cationic nanoparticles, where massive hydroxyl groups can establish a hydration shell to stabilize the nanoparticles. The II introduction improves cell viabilities of polycations. Moreover, by controlling the suitable amount of introduced II units, the resultant II-PGEA/II nanoparticles can produce fairly good transfection performances in different cell lines. Particularly, the II-PGEA/II nanoparticles induce much better in vitro CT imaging abilities in tumor cells than iohexol (one commonly used commercial CT contrast agent). The present design of amphipathic PGMA-based nanoparticles with CT contrast agents would provide useful information for the development of new multifunctional gene delivery systems.

A technique for measurement of vector and tensor polarization in solid spin one polarized targets

International Nuclear Information System (INIS)

Kielhorn, W.F.

1991-06-01

Vector and tensor polarizations are explicitly defined and used to characterize the polarization states of spin one polarized targets, and a technique for extracting these polarizations from nuclear magnetic resonance (NMR) data is developed. This technique is independent of assumptions about spin temperature, but assumes the target's crystal structure induces a quadrupole interaction with the spin one particles. Analysis of the NMR signals involves a computer curve fitting algorithm implemented with a fast Fourier transform method which speeds and simplifies curve fitting algorithms used previously. For accurate curve fitting, the NMR electronic circuit must be modeled by the fitting algorithm. Details of a circuit, its model, and data collected from this circuit are given for a solid deuterated ammonia target. 37 refs., 19 figs., 3 tabs

Structuring polymers for delivery of DNA-based therapeutics: updated insights.

Science.gov (United States)

Gupta, Madhu; Tiwari, Shailja; Vyas, Suresh

2012-01-01

Gene therapy offers greater opportunities for treating numerous incurable diseases from genetic disorders, infections, and cancer. However, development of appropriate delivery systems could be one of the most important factors to overcome numerous biological barriers for delivery of various therapeutic molecules. A number of nonviral polymer-mediated vectors have been developed for DNA delivery and offer the potential to surmount the associated problems of their viral counterpart. To address the concerns associated with safety issues, a wide range of polymeric vectors are available and have been utilized successfully to deliver their therapeutics in vivo. Today's research is mainly focused on the various natural or synthetic polymer-based delivery carriers that protect the DNA molecule from degradation, which offer specific targeting to the desired cells after systemic administration, have transfection efficiencies equivalent to virus-mediated gene delivery, and have long-term gene expression through sustained-release mechanisms. This review explores an updated overview of different nonviral polymeric delivery system for delivery of DNA-based therapeutics. These polymeric carriers have been evaluated in vitro and in vivo and are being utilized in various stages of clinical evaluation. Continued research and understanding of the principles of polymer-based gene delivery systems will enable us to develop new and efficient delivery systems for the delivery of DNA-based therapeutics to achieve the goal of efficacious and specific gene therapy for a vast array of clinical disorders as the therapeutic solutions of tomorrow.

Gene Therapy Vectors with Enhanced Transfection Based on Hydrogels Modified with Affinity Peptides

Science.gov (United States)

Shepard, Jaclyn A.; Wesson, Paul J.; Wang, Christine E.; Stevans, Alyson C.; Holland, Samantha J.; Shikanov, Ariella; Grzybowski, Bartosz A.; Shea, Lonnie D.

2011-01-01

Regenerative strategies for damaged tissue aim to present biochemical cues that recruit and direct progenitor cell migration and differentiation. Hydrogels capable of localized gene delivery are being developed to provide a support for tissue growth, and as a versatile method to induce the expression of inductive proteins; however, the duration, level, and localization of expression isoften insufficient for regeneration. We thus investigated the modification of hydrogels with affinity peptides to enhance vector retention and increase transfection within the matrix. PEG hydrogels were modified with lysine-based repeats (K4, K8), which retained approximately 25% more vector than control peptides. Transfection increased 5- to 15-fold with K8 and K4 respectively, over the RDG control peptide. K8- and K4-modified hydrogels bound similar quantities of vector, yet the vector dissociation rate was reduced for K8, suggesting excessive binding that limited transfection. These hydrogels were subsequently applied to an in vitro co-culture model to induce NGF expression and promote neurite outgrowth. K4-modified hydrogels promoted maximal neurite outgrowth, likely due to retention of both the vector and the NGF. Thus, hydrogels modified with affinity peptides enhanced vector retention and increased gene delivery, and these hydrogels may provide a versatile scaffold for numerous regenerative medicine applications. PMID:21514659

Introduction of optical reporter gene into cancer and immune cells using lentiviral vector

International Nuclear Information System (INIS)

Min, Jung Joon; Le, Uyenchi N.; Moon, Sung Min; Heo, Young Jun; Song, Ho Chun; Bom, Hee Seung; Kim, Yeon Soo

2004-01-01

For some applications such as gene therapy or reporter gene imaging, a gene has to be introduced into the organism of interest. Adenoviral vectors are capable of transducing both replicating and non-dividing cells. The adenoviral vectors do not integrate their DNA into host DNA, but do lead to an immune response. Lentiviruses belong to the retrovirus family and are capable of infecting both dividing and non-dividing cells. The human immunodeficiency virus (HIV) is an example of a lentavirus. A disabled HIV virus has been developed and could be used for in vivo gene delivery. A portion of the viral genome which encodes for accessory proteins canbe deleted without affecting production of the vector and efficiency of infection. Lentiviral delivery into various rodent tissues shows sustained expression of the transgene of up to six months. Furthermore, there seems to be little or no immune response with these vectors. These lentiviral vectors hold significant promise for in vivo gene delivery. We constructed lentiviral vector encoding firefly luciferase (Fluc) and eGFP. Fluc-eGFP fusion gene was inserted into multiple cloning sites of pLentiM1.3 vector. Reporter gene (Fluc-eGFP) was designed to be driven by murine CMV promoter with enhanced efficacy of transgene expression as compared to human CMV promoter. We transfected pLenti1.3-Fluc into human cervix cancer cell line (HeLa) and murine T lymphocytes. We also constructed adenovirus encoding Fluc and transfected to HeLa and T cells. This LentiM1.3-Fluc was transfected into HeLa cells and murine T lymphocytes in vitro, showing consistent expression of eGFP under the fluorescence microscopy from the 2nd day of transfection. Firefly luciferase reporter gene was not expressed in immune cells when it is mediated by adenovirus. Lentivirus was validated as a useful vector for both immune and cancer cells

Applying Toyota production system techniques for medication delivery: improving hospital safety and efficiency.

Science.gov (United States)

Newell, Terry L; Steinmetz-Malato, Laura L; Van Dyke, Deborah L

2011-01-01

The inpatient medication delivery system used at a large regional acute care hospital in the Midwest had become antiquated and inefficient. The existing 24-hr medication cart-fill exchange process with delivery to the patients' bedside did not always provide ordered medications to the nursing units when they were needed. In 2007 the principles of the Toyota Production System (TPS) were applied to the system. Project objectives were to improve medication safety and reduce the time needed for nurses to retrieve patient medications. A multidisciplinary team was formed that included representatives from nursing, pharmacy, informatics, quality, and various operational support departments. Team members were educated and trained in the tools and techniques of TPS, and then designed and implemented a new pull system benchmarking the TPS Ideal State model. The newly installed process, providing just-in-time medication availability, has measurably improved delivery processes as well as patient safety and satisfaction. Other positive outcomes have included improved nursing satisfaction, reduced nursing wait time for delivered medications, and improved efficiency in the pharmacy. After a successful pilot on two nursing units, the system is being extended to the rest of the hospital. © 2010 National Association for Healthcare Quality.

A relevance vector machine technique for the automatic detection of clustered microcalcifications (Honorable Mention Poster Award)

Science.gov (United States)

Wei, Liyang; Yang, Yongyi; Nishikawa, Robert M.

2005-04-01

Microcalcification (MC) clusters in mammograms can be important early signs of breast cancer in women. Accurate detection of MC clusters is an important but challenging problem. In this paper, we propose the use of a recently developed machine learning technique -- relevance vector machine (RVM) -- for automatic detection of MCs in digitized mammograms. RVM is based on Bayesian estimation theory, and as a feature it can yield a decision function that depends on only a very small number of so-called relevance vectors. We formulate MC detection as a supervised-learning problem, and use RVM to classify if an MC object is present or not at each location in a mammogram image. MC clusters are then identified by grouping the detected MC objects. The proposed method is tested using a database of 141 clinical mammograms, and compared with a support vector machine (SVM) classifier which we developed previously. The detection performance is evaluated using the free-response receiver operating characteristic (FROC) curves. It is demonstrated that the RVM classifier matches closely with the SVM classifier in detection performance, and does so with a much sparser kernel representation than the SVM classifier. Consequently, the RVM classifier greatly reduces the computational complexity, making it more suitable for real-time processing of MC clusters in mammograms.

Efficient morse decompositions of vector fields.

Science.gov (United States)

Chen, Guoning; Mischaikow, Konstantin; Laramee, Robert S; Zhang, Eugene

2008-01-01

Existing topology-based vector field analysis techniques rely on the ability to extract the individual trajectories such as fixed points, periodic orbits, and separatrices that are sensitive to noise and errors introduced by simulation and interpolation. This can make such vector field analysis unsuitable for rigorous interpretations. We advocate the use of Morse decompositions, which are robust with respect to perturbations, to encode the topological structures of a vector field in the form of a directed graph, called a Morse connection graph (MCG). While an MCG exists for every vector field, it need not be unique. Previous techniques for computing MCG's, while fast, are overly conservative and usually results in MCG's that are too coarse to be useful for the applications. To address this issue, we present a new technique for performing Morse decomposition based on the concept of tau-maps, which typically provides finer MCG's than existing techniques. Furthermore, the choice of tau provides a natural tradeoff between the fineness of the MCG's and the computational costs. We provide efficient implementations of Morse decomposition based on tau-maps, which include the use of forward and backward mapping techniques and an adaptive approach in constructing better approximations of the images of the triangles in the meshes used for simulation.. Furthermore, we propose the use of spatial tau-maps in addition to the original temporal tau-maps. These techniques provide additional trade-offs between the quality of the MCGs and the speed of computation. We demonstrate the utility of our technique with various examples in the plane and on surfaces including engine simulation data sets.

A technique for measurement of vector and tensor polarization in solid spin one polarized targets

Energy Technology Data Exchange (ETDEWEB)

Kielhorn, W.F.

1991-06-01

Vector and tensor polarizations are explicitly defined and used to characterize the polarization states of spin one polarized targets, and a technique for extracting these polarizations from nuclear magnetic resonance (NMR) data is developed. This technique is independent of assumptions about spin temperature, but assumes the target's crystal structure induces a quadrupole interaction with the spin one particles. Analysis of the NMR signals involves a computer curve fitting algorithm implemented with a fast Fourier transform method which speeds and simplifies curve fitting algorithms used previously. For accurate curve fitting, the NMR electronic circuit must be modeled by the fitting algorithm. Details of a circuit, its model, and data collected from this circuit are given for a solid deuterated ammonia target. 37 refs., 19 figs., 3 tabs.

Adeno-Associated Virus Vectors and Stem Cells: Friends or Foes?

Science.gov (United States)

Brown, Nolan; Song, Liujiang; Kollu, Nageswara R; Hirsch, Matthew L

2017-06-01

The infusion of healthy stem cells into a patient-termed "stem-cell therapy"-has shown great promise for the treatment of genetic and non-genetic diseases, including mucopolysaccharidosis type 1, Parkinson's disease, multiple sclerosis, numerous immunodeficiency disorders, and aplastic anemia. Stem cells for cell therapy can be collected from the patient (autologous) or collected from another "healthy" individual (allogeneic). The use of allogenic stem cells is accompanied with the potentially fatal risk that the transplanted donor T cells will reject the patient's cells-a process termed "graft-versus-host disease." Therefore, the use of autologous stem cells is preferred, at least from the immunological perspective. However, an obvious drawback is that inherently as "self," they contain the disease mutation. As such, autologous cells for use in cell therapies often require genetic "correction" (i.e., gene addition or editing) prior to cell infusion and therefore the requirement for some form of nucleic acid delivery, which sets the stage for the AAV controversy discussed herein. Despite being the most clinically applied gene delivery context to date, unlike other more concerning integrating and non-integrating vectors such as retroviruses and adenovirus, those based on adeno-associated virus (AAV) have not been employed in the clinic. Furthermore, published data regarding AAV vector transduction of stem cells are inconsistent in regards to vector transduction efficiency, while the pendulum swings far in the other direction with demonstrations of AAV vector-induced toxicity in undifferentiated cells. The variation present in the literature examining the transduction efficiency of AAV vectors in stem cells may be due to numerous factors, including inconsistencies in stem-cell collection, cell culture, vector preparation, and/or transduction conditions. This review summarizes the controversy surrounding AAV vector transduction of stem cells, hopefully setting the

Characteristic vector analysis of inflection ratio spectra: New technique for analysis of ocean color data

Science.gov (United States)

Grew, G. W.

1985-01-01

Characteristic vector analysis applied to inflection ratio spectra is a new approach to analyzing spectral data. The technique applied to remote data collected with the multichannel ocean color sensor (MOCS), a passive sensor, simultaneously maps the distribution of two different phytopigments, chlorophyll alpha and phycoerythrin, the ocean. The data set presented is from a series of warm core ring missions conducted during 1982. The data compare favorably with a theoretical model and with data collected on the same mission by an active sensor, the airborne oceanographic lidar (AOL).

Analysis of nifedipine content in transdermal drug delivery system using non-destructive visible spectrophotometry technique

International Nuclear Information System (INIS)

Normaizira Hamidi; Normaizira Hamidi; Normaizira Hamidi; Mohd Nasir Taib; Mohd Nasir Taib; Wui, Wong Tin; Wui, Wong Tin

2008-01-01

The applicability of visible spectrophotometry technique as a tool to determine the drug content of polymeric film for use as a transdermal drug delivery system was investigated. Hydroxypropylmethycellulose (HPMC) was selected as the matrix polymer and nifedipine as the model drug. Blank and nifedipine-loaded HPMC films were prepared using the solvent evaporation method. The absorbance spectra of these films under the visible wavelengths between 400 and 800 nm were assessed and compared against the drug content values obtained by means of the conventional destructive UV- spectrophotometry technique. The latter required the use of a solvent system which contained methanol, a harmful organic component in pharmaceutical applications. The results indicated that the absorbance values, attributed to nifedipine, at the wavelengths of 545, 585, 638 and 755nm were significantly correlated to the drug content values obtained using the chemical assay method (Pearson correlation value: r = 0.990 and p < 0.01). The visible spectrophotometry technique is potentially suitable for use to determine the nifedipine content of films owing to its nature of characterization of transdermal drug delivery system which does not require sample destruction during the process of measurement. The samples are recoverable from test and analysis of the entire batch of samples is possible without the need of solvents and chemical reagents. (author)

Lipid microbubbles as a vehicle for targeted drug delivery using focused ultrasound-induced blood-brain barrier opening.

Science.gov (United States)

Sierra, Carlos; Acosta, Camilo; Chen, Cherry; Wu, Shih-Ying; Karakatsani, Maria E; Bernal, Manuel; Konofagou, Elisa E

2017-04-01

Focused ultrasound in conjunction with lipid microbubbles has fully demonstrated its ability to induce non-invasive, transient, and reversible blood-brain barrier opening. This study was aimed at testing the feasibility of our lipid-coated microbubbles as a vector for targeted drug delivery in the treatment of central nervous system diseases. These microbubbles were labeled with the fluorophore 5-dodecanoylaminfluorescein. Focused ultrasound targeted mouse brains in vivo in the presence of these microbubbles for trans-blood-brain barrier delivery of 5-dodecanoylaminfluorescein. This new approach, compared to previously studies of our group, where fluorescently labeled dextrans and microbubbles were co-administered, represents an appreciable improvement in safety outcome and targeted drug delivery. This novel technique allows the delivery of 5-dodecanoylaminfluorescein at the region of interest unlike the alternative of systemic exposure. 5-dodecanoylaminfluorescein delivery was assessed by ex vivo fluorescence imaging and by in vivo transcranial passive cavitation detection. Stable and inertial cavitation doses were quantified. The cavitation dose thresholds for estimating, a priori, successful targeted drug delivery were, for the first time, identified with inertial cavitation were concluded to be necessary for successful delivery. The findings presented herein indicate the feasibility and safety of the proposed microbubble-based targeted drug delivery and that, if successful, can be predicted by cavitation detection in vivo.

Gene Delivery into Plant Cells for Recombinant Protein Production

Directory of Open Access Journals (Sweden)

Qiang Chen

2015-01-01

Full Text Available Recombinant proteins are primarily produced from cultures of mammalian, insect, and bacteria cells. In recent years, the development of deconstructed virus-based vectors has allowed plants to become a viable platform for recombinant protein production, with advantages in versatility, speed, cost, scalability, and safety over the current production paradigms. In this paper, we review the recent progress in the methodology of agroinfiltration, a solution to overcome the challenge of transgene delivery into plant cells for large-scale manufacturing of recombinant proteins. General gene delivery methodologies in plants are first summarized, followed by extensive discussion on the application and scalability of each agroinfiltration method. New development of a spray-based agroinfiltration and its application on field-grown plants is highlighted. The discussion of agroinfiltration vectors focuses on their applications for producing complex and heteromultimeric proteins and is updated with the development of bridge vectors. Progress on agroinfiltration in Nicotiana and non-Nicotiana plant hosts is subsequently showcased in context of their applications for producing high-value human biologics and low-cost and high-volume industrial enzymes. These new advancements in agroinfiltration greatly enhance the robustness and scalability of transgene delivery in plants, facilitating the adoption of plant transient expression systems for manufacturing recombinant proteins with a broad range of applications.

Potent spinal parenchymal AAV9-mediated gene delivery by subpial injection in adult rats and pigs

Directory of Open Access Journals (Sweden)

Atsushi Miyanohara

2016-01-01

Full Text Available Effective in vivo use of adeno-associated virus (AAV-based vectors to achieve gene-specific silencing or upregulation in the central nervous system has been limited by the inability to provide more than limited deep parenchymal expression in adult animals using delivery routes with the most clinical relevance (intravenous or intrathecal. Here, we demonstrate that the spinal pia membrane represents the primary barrier limiting effective AAV9 penetration into the spinal parenchyma after intrathecal AAV9 delivery. We develop a novel subpial AAV9 delivery technique and AAV9-dextran formulation. We use these in adult rats and pigs to show (i potent spinal parenchymal transgene expression in white and gray matter including neurons, glial and endothelial cells after single bolus subpial AAV9 delivery; (ii delivery to almost all apparent descending motor axons throughout the length of the spinal cord after cervical or thoracic subpial AAV9 injection; (iii potent retrograde transgene expression in brain motor centers (motor cortex and brain stem; and (iv the relative safety of this approach by defining normal neurological function for up to 6 months after AAV9 delivery. Thus, subpial delivery of AAV9 enables gene-based therapies with a wide range of potential experimental and clinical utilizations in adult animals and human patients.

Transient foreign gene expression in chloroplasts of cultured tobacco cells after biolistic delivery of chloroplast vectors.

Science.gov (United States)

Daniell, H; Vivekananda, J; Nielsen, B L; Ye, G N; Tewari, K K; Sanford, J C

1990-01-01

Expression of chloramphenicol acetyltransferase (cat) by suitable vectors in chloroplasts of cultured tobacco cells, delivered by high-velocity microprojectiles, is reported here. Several chloroplast expression vectors containing bacterial cat genes, placed under the control of either psbA promoter region from pea (pHD series) or rbcL promoter region from maize (pAC series) have been used in this study. In addition, chloroplast expression vectors containing replicon fragments from pea, tobacco, or maize chloroplast DNA have also been tested for efficiency and duration of cat expression in chloroplasts of tobacco cells. Cultured NT1 tobacco cells collected on filter papers were bombarded with tungsten particles coated with pUC118 (negative control), 35S-CAT (nuclear expression vector), pHD312 (repliconless chloroplast expression vector), and pHD407, pACp18, and pACp19 (chloroplast expression vectors with replicon). Sonic extracts of cells bombarded with pUC118 showed no detectable cat activity in the autoradiograms. Nuclear expression of cat reached two-thirds of the maximal 48 hr after bombardment and the maximal at 72 hr. Cells bombarded with chloroplast expression vectors showed a low level of expression until 48 hr of incubation. A dramatic increase in the expression of cat was observed 24 hr after the addition of fresh medium to cultured cells in samples bombarded with pHD407; the repliconless vector pHD312 showed about 50% of this maximal activity. The expression of nuclear cat and the repliconless chloroplast vector decreased after 72 hr, but a high level of chloroplast cat expression was maintained in cells bombarded with pHD407. Organelle-specific expression of cat in appropriate compartments was checked by introducing various plasmid constructions into tobacco protoplasts by electroporation. Although the nuclear expression vector 35S-CAT showed expression of cat, no activity was observed with any chloroplast vectors.

Low cytotoxicity fluorescent PAMAM dendrimer as gene carriers for monitoring the delivery of siRNA

Energy Technology Data Exchange (ETDEWEB)

Guan, Lingmei [Sichuan University, State Key Laboratory of Bio-resources and Eco-environment, The Ministry of Education, College of Life Sciences (China); Huang, Saipeng [Chinese Academy of Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Center for Molecular Sciences, Institute of Chemistry (China); Chen, Zhao [Xi’an Jiaotong University, School of Science (China); Li, Yanchao [Chinese Academy of Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Center for Molecular Sciences, Institute of Chemistry (China); Liu, Ke [Sichuan University, State Key Laboratory of Bio-resources and Eco-environment, The Ministry of Education, College of Life Sciences (China); Liu, Yang, E-mail: yliu@iccas.ac.cn; Du, Libo, E-mail: dulibo@iccas.ac.cn [Chinese Academy of Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Center for Molecular Sciences, Institute of Chemistry (China)

2015-09-15

Visual detection of gene vectors has attracted a great deal of attention due to the application of these vectors in monitoring and evaluating the effect of gene carriers in living cells. A non-viral vector, the fluorescent PAMAM dendrimer (F-PAMAM), was synthesized through conjugation of PAMAM dendrimers and fluorescein. In vitro and ex vivo experiments show that F-PAMAM exhibits superphotostability, low cytotoxicity and facilitates endocytosis by A549 cells. The vector has a high siRNA binding affinity and it increases the efficiency of cy5-siRNA delivery in A549 cells, in comparison with a cy5-siRNA monomer. Our results provide a new method for simultaneously monitoring the delivery of siRNA and its non-viral carriers in living cells.

Effective SIMD Vectorization for Intel Xeon Phi Coprocessors

OpenAIRE

Tian, Xinmin; Saito, Hideki; Preis, Serguei V.; Garcia, Eric N.; Kozhukhov, Sergey S.; Masten, Matt; Cherkasov, Aleksei G.; Panchenko, Nikolay

2015-01-01

Efficiently exploiting SIMD vector units is one of the most important aspects in achieving high performance of the application code running on Intel Xeon Phi coprocessors. In this paper, we present several effective SIMD vectorization techniques such as less-than-full-vector loop vectorization, Intel MIC specific alignment optimization, and small matrix transpose/multiplication 2D vectorization implemented in the Intel C/C++ and Fortran production compilers for Intel Xeon Phi coprocessors. A ...

Relevance vector machine technique for the inverse scattering problem

International Nuclear Information System (INIS)

Wang Fang-Fang; Zhang Ye-Rong

2012-01-01

A novel method based on the relevance vector machine (RVM) for the inverse scattering problem is presented in this paper. The nonlinearity and the ill-posedness inherent in this problem are simultaneously considered. The nonlinearity is embodied in the relation between the scattered field and the target property, which can be obtained through the RVM training process. Besides, rather than utilizing regularization, the ill-posed nature of the inversion is naturally accounted for because the RVM can produce a probabilistic output. Simulation results reveal that the proposed RVM-based approach can provide comparative performances in terms of accuracy, convergence, robustness, generalization, and improved performance in terms of sparse property in comparison with the support vector machine (SVM) based approach. (general)

Non-viral delivery systems for CRISPR/Cas9-based genome editing: Challenges and opportunities.

Science.gov (United States)

Li, Ling; Hu, Shuo; Chen, Xiaoyuan

2018-07-01

In recent years, CRISPR (clustered regularly interspaced short palindromic repeat)/Cas (CRISPR-associated) genome editing systems have become one of the most robust platforms in basic biomedical research and therapeutic applications. To date, efficient in vivo delivery of the CRISPR/Cas9 system to the targeted cells remains a challenge. Although viral vectors have been widely used in the delivery of the CRISPR/Cas9 system in vitro and in vivo, their fundamental shortcomings, such as the risk of carcinogenesis, limited insertion size, immune responses and difficulty in large-scale production, severely limit their further applications. Alternative non-viral delivery systems for CRISPR/Cas9 are urgently needed. With the rapid development of non-viral vectors, lipid- or polymer-based nanocarriers have shown great potential for CRISPR/Cas9 delivery. In this review, we analyze the pros and cons of delivering CRISPR/Cas9 systems in the form of plasmid, mRNA, or protein and then discuss the limitations and challenges of CRISPR/Cas9-based genome editing. Furthermore, current non-viral vectors that have been applied for CRISPR/Cas9 delivery in vitro and in vivo are outlined in details. Finally, critical obstacles for non-viral delivery of CRISPR/Cas9 system are highlighted and promising strategies to overcome these barriers are proposed. Published by Elsevier Ltd.

Integrated pest management and allocation of control efforts for vector-borne diseases

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Ginsberg, H.S.

2001-01-01

Applications of various control methods were evaluated to determine how to integrate methods so as to minimize the number of human cases of vector-borne diseases. These diseases can be controlled by lowering the number of vector-human contacts (e.g., by pesticide applications or use of repellents), or by lowering the proportion of vectors infected with pathogens (e.g., by lowering or vaccinating reservoir host populations). Control methods should be combined in such a way as to most efficiently lower the probability of human encounter with an infected vector. Simulations using a simple probabilistic model of pathogen transmission suggest that the most efficient way to integrate different control methods is to combine methods that have the same effect (e.g., combine treatments that lower the vector population; or combine treatments that lower pathogen prevalence in vectors). Combining techniques that have different effects (e.g., a technique that lowers vector populations with a technique that lowers pathogen prevalence in vectors) will be less efficient than combining two techniques that both lower vector populations or combining two techniques that both lower pathogen prevalence, costs being the same. Costs of alternative control methods generally differ, so the efficiency of various combinations at lowering human contact with infected vectors should be estimated at available funding levels. Data should be collected from initial trials to improve the effects of subsequent interventions on the number of human cases.

Gestational obesity as a determinant of general anesthesia technique for caesarean delivery: a case report.

Directory of Open Access Journals (Sweden)

José Ricardo Navarro Vargas

2009-07-01

Full Text Available Background. The incidence of obesity has undergone a dramatic increase around the world during the last few years. Such epidemic behavior has been associated with obstetric patient’s frequent presentation of different stages of obesity when undergoing anesthetic procedure. Obesity in pregnant women involves the risk of adverse maternal and fetal outcomes. Hypertension and preeclampsia, diabetes, fetal macrosomia, caesarean delivery, difficult airway management and neuroaxial techniques are more likely to be performed in this group of patients. Materials and methods. This is a case report of a morbid obese patient scheduled for caesarean delivery and tubal ligation. Regional, spinal and epidural techniques were attempted for surgery with unsuccessful results; this entails general anesthesia for surgery. The literature on complications due to obesity during pregnancy was reviewed, emphasising relevance for the anesthesiologist. Conclusion. Obesity, especially morbid obesity in pregnant women, represents a challenge for anesthesia management. Updated knowledge of physiology and the conditions related to obesity in pregnancy is necessary; medical services must be prepared to provide optimum and safe obstetric anesthesia, analgesia and post-operation care.

Efficient transduction of equine adipose-derived mesenchymal stem cells by VSV-G pseudotyped lentiviral vectors.

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Petersen, Gayle F; Hilbert, Bryan; Trope, Gareth; Kalle, Wouter; Strappe, Padraig

2014-12-01

Equine adipose-derived mesenchymal stem cells (EADMSC) provide a unique cell-based approach for treatment of a variety of equine musculoskeletal injuries, via regeneration of diseased or damaged tissue, or the secretion of immunomodulatory molecules. These capabilities can be further enhanced by genetic modification using lentiviral vectors, which provide a safe and efficient method of gene delivery. We investigated the suitability of lentiviral vector technology for gene delivery into EADMSC, using GFP expressing lentiviral vectors pseudotyped with the G glycoprotein from the vesicular stomatitis virus (V-GFP) or, for the first time, the baculovirus gp64 envelope protein (G-GFP). In this study, we produced similarly high titre V-GFP and G-GFP lentiviral vectors. Flow cytometric analysis showed efficient transduction using V-GFP; however G-GFP exhibited a poor ability to transduce EADMSC. Transduction resulted in sustained GFP expression over four passages, with minimal effects on cell viability and doubling time, and an unaltered chondrogenic differentiation potential. Copyright © 2014 Elsevier Ltd. All rights reserved.

Synthetic sustained gene delivery systems.

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Agarwal, Ankit; Mallapragada, Surya K

2008-01-01

Gene therapy today is hampered by the need of a safe and efficient gene delivery system that can provide a sustained therapeutic effect without cytotoxicity or unwanted immune responses. Bolus gene delivery in solution results in the loss of delivered factors via lymphatic system and may cause undesired effects by the escape of bioactive molecules to distant sites. Controlled gene delivery systems, acting as localized depot of genes, provide an extended sustained release of genes, giving prolonged maintenance of the therapeutic level of encoded proteins. They also limit the DNA degradation in the nuclease rich extra-cellular environment. While attempts have been made to adapt existing controlled drug delivery technologies, more novel approaches are being investigated for controlled gene delivery. DNA encapsulated in nano/micro spheres of polymers have been administered systemically/orally to be taken up by the targeted tissues and provide sustained release once internalized. Alternatively, DNA entrapped in hydrogels or scaffolds have been injected/implanted in tissues/cavities as platforms for gene delivery. The present review examines these different modalities for sustained delivery of viral and non-viral gene-delivery vectors. Design parameters and release mechanisms of different systems made with synthetic or natural polymers are presented along with their prospective applications and opportunities for continuous development.

Acoustic Biometric System Based on Preprocessing Techniques and Linear Support Vector Machines.

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del Val, Lara; Izquierdo-Fuente, Alberto; Villacorta, Juan J; Raboso, Mariano

2015-06-17

Drawing on the results of an acoustic biometric system based on a MSE classifier, a new biometric system has been implemented. This new system preprocesses acoustic images, extracts several parameters and finally classifies them, based on Support Vector Machine (SVM). The preprocessing techniques used are spatial filtering, segmentation-based on a Gaussian Mixture Model (GMM) to separate the person from the background, masking-to reduce the dimensions of images-and binarization-to reduce the size of each image. An analysis of classification error and a study of the sensitivity of the error versus the computational burden of each implemented algorithm are presented. This allows the selection of the most relevant algorithms, according to the benefits required by the system. A significant improvement of the biometric system has been achieved by reducing the classification error, the computational burden and the storage requirements.

Renormalizable Electrodynamics of Scalar and Vector Mesons. Part II

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Salam, Abdus; Delbourgo, Robert

1964-01-01

The "gauge" technique" for solving theories introduced in an earlier paper is applied to scalar and vector electrodynamics. It is shown that for scalar electrodynamics, there is no {lambda}φ*2φ2 infinity in the theory, while with conventional subtractions vector electrodynamics is completely finite. The essential ideas of the gauge technique are explained in section 3, and a preliminary set of rules for finite computation in vector electrodynamics is set out in Eqs. (7.28) - (7.34).

The inter- and intrafraction reproducibilities of three common IMRT delivery techniques

International Nuclear Information System (INIS)

Buckey, Courtney R.; Stathakis, Sotirios; Papanikolaou, Niko

2010-01-01

Purpose: Intensity modulated radiation therapy (IMRT) treatment delivery requires higher precision than conventional 3D treatment delivery because of the sensitivity of the resulting dose to small geometric misalignment of the modulated beamlets. The chosen treatment delivery technique will affect the treatment precision in different ways, based on the characteristics of the delivery method. Delivery using a multileaf collimator (MLC) can reduce treatment time and therapist workload, but typically requires a greater number of monitor units and the fields are prone to both systematic and random leaf positioning errors. An alternative to MLC-based fields, patient specific brass compensators, do not suffer from these leaf positioning errors. In our study, we set out to investigate which delivery method will provide the highest levels of dosimetric reproducibility and the minimum amount of interfraction variability. Methods: In our study, a seven field IMRT plan for a head and neck treatment was created using the Pinnacle 3 treatment planning system and the intensity maps for each field were obtained. The intensity maps of the fields were delivered with a Varian 2100C/D linear accelerator, using solid compensators and sliding window (SW) and step-and-shoot (SS) MLC segments. Three fields were selected from the seven-beam IMRT plan for comparison. Analysis was carried out using the MatriXX ion chamber array, radiochromic film, and Varian dynalog files. Results: Our results show that the error in MLC leaf positioning has no gantry angle dependence. The compensator and SW deliveries showed excellent agreement, even when stricter than usual gamma criteria were applied. However, we noted that under these strict conditions, the SS fields had at least ten times more pixels out of range than did the compensators. When using step-and-shoot MLC fields, it was observed that the increase in dose rate or the increase of MU/segment degrades the quality of the plan. Analysis of the

Plasmid DNA Delivery: Nanotopography Matters.

Science.gov (United States)

Song, Hao; Yu, Meihua; Lu, Yao; Gu, Zhengying; Yang, Yannan; Zhang, Min; Fu, Jianye; Yu, Chengzhong

2017-12-20

Plasmid DNA molecules with unique loop structures have widespread bioapplications, in many cases relying heavily on delivery vehicles to introduce them into cells and achieve their functions. Herein, we demonstrate that control over delicate nanotopography of silica nanoparticles as plasmid DNA vectors has significant impact on the transfection efficacy. For silica nanoparticles with rambutan-, raspberry-, and flower-like morphologies composed of spike-, hemisphere-, and bowl-type subunit nanotopographies, respectively, the rambutan-like nanoparticles with spiky surfaces demonstrate the highest plasmid DNA binding capability and transfection efficacy of 88%, higher than those reported for silica-based nanovectors. Moreover, it is shown that the surface spikes of rambutan nanoparticles provide a continuous open space to bind DNA chains via multivalent interactions and protect the gene molecules sheltered in the spiky layer against nuclease degradation, exhibiting no significant transfection decay. This unique protection feature is in great contrast to a commercial transfection agent with similar transfection performance but poor protection capability against enzymatic cleavage. Our study provides new understandings in the rational design of nonviral vectors for efficient gene delivery.

Gene therapy prospects--intranasal delivery of therapeutic genes.

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Podolska, Karolina; Stachurska, Anna; Hajdukiewicz, Karolina; Małecki, Maciej

2012-01-01

Gene therapy is recognized to be a novel method for the treatment of various disorders. Gene therapy strategies involve gene manipulation on broad biological processes responsible for the spreading of diseases. Cancer, monogenic diseases, vascular and infectious diseases are the main targets of gene therapy. In order to obtain valuable experimental and clinical results, sufficient gene transfer methods are required. Therapeutic genes can be administered into target tissues via gene carriers commonly defined as vectors. The retroviral, adenoviral and adeno-associated virus based vectors are most frequently used in the clinic. So far, gene preparations may be administered directly into target organs or by intravenous, intramuscular, intratumor or intranasal injections. It is common knowledge that the number of gene therapy clinical trials has rapidly increased. However, some limitations such as transfection efficiency and stable and long-term gene expression are still not resolved. Consequently, great effort is focused on the evaluation of new strategies of gene delivery. There are many expectations associated with intranasal delivery of gene preparations for the treatment of diseases. Intranasal delivery of therapeutic genes is regarded as one of the most promising forms of pulmonary gene therapy research. Gene therapy based on inhalation of gene preparations offers an alternative way for the treatment of patients suffering from such lung diseases as cystic fibrosis, alpha-1-antitrypsin defect, or cancer. Experimental and first clinical trials based on plasmid vectors or recombinant viruses have revealed that gene preparations can effectively deliver therapeutic or marker genes to the cells of the respiratory tract. The noninvasive intranasal delivery of gene preparations or conventional drugs seems to be very encouraging, although basic scientific research still has to continue.

Synthesis, and Characterization, and Evaluation of Cellular Effects of the FOL-PEG-g-PEI-GAL Nanoparticles as a Potential Non-Viral Vector for Gene Delivery

International Nuclear Information System (INIS)

Ghiamkazemi, S.; Amanzadeh, A.; Dinarvand, R.; Rafiee-Tehrani, M.; Amini, M.; Ghiamkazemi, S.; Dinarvand, R.; Rafiee-Tehrani, M.; Ghiamkazemi, S.; Rafiee-Tehrani, M.; Amanzadeh, A.; Rafiee-Tehrani, M.

2010-01-01

In this manuscript, we synthesized the potential non viral vector for gene delivery with proper transfection efficiency and low cytotoxicity. Polyethylenimine (PEI) is a well-known cationic polymer which has high positive surface charge for condensing plasmid DNA. However; it is highly cytotoxic in many cell lines because of the high surface charge, non-biodegradability and non-biocompatibility. To enhance PEI biodegradability, the graft copolymer PEG-g-PEI was synthesized. To target cancer liver cells, two targeting ligands folic acid and galactose (lactobionic acid) which are over expressed on human hepatocyte carcinoma were attached to graft copolymer and FOL-PEG-g-PEI-GAL copolymer was synthesized. Composition of this grafted copolymer was characterized using 1H-NMR and FTIR spectra. The molecular weight and zeta potential of this copolymer was compared to PEI. The particle size and zeta potential of FOL-PEG-g-PEI-GAL/DNA complexes at various N/P ratio were measured using dynamic light scattering (DLS). Cytotoxicity of the copolymer was also studied in cultured HepG2 human hepatoblastoma cell line. The FOL-PEG-g-PEI-GAL/DNA complexes at various N/P ratios exhibited no cytotoxicity in HepG2 cell line compared to PEI 25K as a control. The novel copolymer showed enhanced biodegradability in physiological conditions in compared with PEI and targeted cultured HepG2 cells. More importantly, significant transfection efficiency was exhibited in cancer liver cells. Together, our results showed that FOL-PEG-g-PEI-GAL nanoparticles could be considered as a useful non-viral vector for targeted gene delivery.

Highly efficient retrograde gene transfer into motor neurons by a lentiviral vector pseudotyped with fusion glycoprotein.

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Miyabi Hirano

Full Text Available The development of gene therapy techniques to introduce transgenes that promote neuronal survival and protection provides effective therapeutic approaches for neurological and neurodegenerative diseases. Intramuscular injection of adenoviral and adeno-associated viral vectors, as well as lentiviral vectors pseudotyped with rabies virus glycoprotein (RV-G, permits gene delivery into motor neurons in animal models for motor neuron diseases. Recently, we developed a vector with highly efficient retrograde gene transfer (HiRet by pseudotyping a human immunodeficiency virus type 1 (HIV-1-based vector with fusion glycoprotein B type (FuG-B or a variant of FuG-B (FuG-B2, in which the cytoplasmic domain of RV-G was replaced by the corresponding part of vesicular stomatitis virus glycoprotein (VSV-G. We have also developed another vector showing neuron-specific retrograde gene transfer (NeuRet with fusion glycoprotein C type, in which the short C-terminal segment of the extracellular domain and transmembrane/cytoplasmic domains of RV-G was substituted with the corresponding regions of VSV-G. These two vectors afford the high efficiency of retrograde gene transfer into different neuronal populations in the brain. Here we investigated the efficiency of the HiRet (with FuG-B2 and NeuRet vectors for retrograde gene transfer into motor neurons in the spinal cord and hindbrain in mice after intramuscular injection and compared it with the efficiency of the RV-G pseudotype of the HIV-1-based vector. The main highlight of our results is that the HiRet vector shows the most efficient retrograde gene transfer into both spinal cord and hindbrain motor neurons, offering its promising use as a gene therapeutic approach for the treatment of motor neuron diseases.

Integrase-Deficient Lentiviral Vector as an All-in-One Platform for Highly Efficient CRISPR/Cas9-Mediated Gene Editing

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Pavel I. Ortinski

2017-06-01

Full Text Available The CRISPR/Cas9 systems have revolutionized the field of genome editing by providing unprecedented control over gene sequences and gene expression in many species, including humans. Lentiviral vectors (LVs are one of the primary delivery platforms for the CRISPR/Cas9 system due to their ability to accommodate large DNA payloads and sustain robust expression in a wide range of dividing and non-dividing cells. However, long-term expression of LV-delivered Cas9/guide RNA may lead to undesirable off-target effects characterized by non-specific RNA-DNA interactions and off-target DNA cleavages. Integrase-deficient lentiviral vectors (IDLVs present an attractive means for delivery of CRISPR/Cas9 components because: (1 they are capable of transducing a broad range of cells and tissues, (2 have superior packaging capacity compared to other vectors (e.g., adeno-associated viral vectors, and (3 they are expressed transiently and demonstrate very weak integration capability. In this manuscript, we aimed to establish IDLVs as a means for safe and efficient delivery of CRISPR/Cas9. To this end, we developed an all-in-one vector cassette with increased production efficacy and demonstrated that CRISPR/Cas9 delivered by the improved IDLV vectors can mediate rapid and robust gene editing in human embryonic kidney (HEK293T cells and post-mitotic brain neurons in vivo, via transient expression and with higher gene-targeting specificity than the corresponding integrase-competent vectors.

Non-viral gene delivery strategies for cancer therapy, tissue engineering and regenerative medicine

Science.gov (United States)

Bhise, Nupura S.

Gene therapy involves the delivery of deoxyribonucleic acid (DNA) into cells to override or replace a malfunctioning gene for treating debilitating genetic diseases, including cancer and neurodegenerative diseases. In addition to its use as a therapeutic, it can also serve as a technology to enable regenerative medicine strategies. The central challenge of the gene therapy research arena is developing a safe and effective delivery agent. Since viral vectors have critical immunogenic and tumorogenic safety issues that limit their clinical use, recent efforts have focused on developing non-viral biomaterial based delivery vectors. Cationic polymers are an attractive class of gene delivery vectors due to their structural versatility, ease of synthesis, biodegradability, ability to self-complex into nanoparticles with negatively charged DNA, capacity to carry large cargo, cellular uptake and endosomal escape capacity. In this thesis, we hypothesized that developing a biomaterial library of poly(betaamino esters) (PBAE), a newer class of cationic polymers consisting of biodegradable ester groups, would allow investigating vector design parameters and formulating effective non-viral gene delivery strategies for cancer drug delivery, tissue engineering and stem cell engineering. Consequently, a high-throughput transfection assay was developed to screen the PBAE-based nanoparticles in hard to transfect fibroblast cell lines. To gain mechanistic insights into the nanoparticle formulation process, biophysical properties of the vectors were characterized in terms of molecular weight (MW), nanoparticle size, zeta potential and plasmid per particle count. We report a novel assay developed for quantifying the plasmid per nanoparticle count and studying its implications for co-delivery of multiple genes. The MW of the polymers ranged from 10 kDa to 100 kDa, nanoparticle size was about 150 run, zeta potential was about 30 mV in sodium acetate buffer (25 mM, pH 5) and 30 to 100

Synergistic effect of amino acids modified on dendrimer surface in gene delivery.

Science.gov (United States)

Wang, Fei; Wang, Yitong; Wang, Hui; Shao, Naimin; Chen, Yuanyuan; Cheng, Yiyun

2014-11-01

Design of an efficient gene vector based on dendrimer remains a great challenge due to the presence of multiple barriers in gene delivery. Single-functionalization on dendrimer cannot overcome all the barriers. In this study, we synthesized a list of single-, dual- and triple-functionalized dendrimers with arginine, phenylalanine and histidine for gene delivery using a one-pot approach. The three amino acids play different roles in gene delivery: arginine is essential in formation of stable complexes, phenylalanine improves cellular uptake efficacy, and histidine increases pH-buffering capacity and minimizes cytotoxicity of the cationic dendrimer. A combination of these amino acids on dendrimer generates a synergistic effect in gene delivery. The dual- and triple-functionalized dendrimers show minimal cytotoxicity on the transfected NIH 3T3 cells. Using this combination strategy, we can obtain triple-functionalized dendrimers with comparable transfection efficacy to several commercial transfection reagents. Such a combination strategy should be applicable to the design of efficient and biocompatible gene vectors for gene delivery. Copyright © 2014 Elsevier Ltd. All rights reserved.

Application of Vectors to Relative Velocity

Science.gov (United States)

Tin-Lam, Toh

2004-01-01

The topic 'relative velocity' has recently been introduced into the Cambridge Ordinary Level Additional Mathematics syllabus under the application of Vectors. In this note, the results of relative velocity and the 'reduction to rest' technique of teaching relative velocity are derived mathematically from vector algebra, in the hope of providing…

GPU Accelerated Vector Median Filter

Science.gov (United States)

Aras, Rifat; Shen, Yuzhong

2011-01-01

Noise reduction is an important step for most image processing tasks. For three channel color images, a widely used technique is vector median filter in which color values of pixels are treated as 3-component vectors. Vector median filters are computationally expensive; for a window size of n x n, each of the n(sup 2) vectors has to be compared with other n(sup 2) - 1 vectors in distances. General purpose computation on graphics processing units (GPUs) is the paradigm of utilizing high-performance many-core GPU architectures for computation tasks that are normally handled by CPUs. In this work. NVIDIA's Compute Unified Device Architecture (CUDA) paradigm is used to accelerate vector median filtering. which has to the best of our knowledge never been done before. The performance of GPU accelerated vector median filter is compared to that of the CPU and MPI-based versions for different image and window sizes, Initial findings of the study showed 100x improvement of performance of vector median filter implementation on GPUs over CPU implementations and further speed-up is expected after more extensive optimizations of the GPU algorithm .

Design and Simulation of Control Technique for Permanent Magnet Synchronous Motor Using Space Vector Pulse Width Modulation

Science.gov (United States)

Khan, Mansoor; Yong, Wang; Mustafa, Ehtasham

2017-07-01

After the rapid advancement in the field of power electronics devices and drives for last few decades, there are different kinds of Pulse Width Modulation techniques which have been brought to the market. The applications ranging from industrial appliances to military equipment including the home appliances. The vey common application for the PWM is three phase voltage source inverter, which is used to convert DC to AC in the homes to supply the power to the house in case electricity failure, usually named as Un-interrupted Power Supply. In this paper Space Vector Pulse Width Modulation techniques is discussed and analysed under the control technique named as Field Oriented Control. The working and implementation of this technique has been studied by implementing on the three phase bridge inverter. The technique is used to control the Permanente Magnet Synchronous Motor. The drive system is successfully implemented in MATLAB/Simulink using the mathematical equation and algorithm to achieve the satisfactory results. PI type of controller is used to tuned ers of the motothe parametr i.e. torque and current.

Pancreatic Cancer Gene Therapy: From Molecular Targets to Delivery Systems

Energy Technology Data Exchange (ETDEWEB)

Fillat, Cristina, E-mail: cristina.fillat@crg.es; Jose, Anabel; Ros, Xavier Bofill-De; Mato-Berciano, Ana; Maliandi, Maria Victoria; Sobrevals, Luciano [Programa Gens i Malaltia, Centre de Regulació Genòmica-CRG, UPF, Parc de Recerca Biomedica de Barcelona-PRBB and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona (Spain)

2011-01-18

The continuous identification of molecular changes deregulating critical pathways in pancreatic tumor cells provides us with a large number of novel candidates to engineer gene-targeted approaches for pancreatic cancer treatment. Targets—both protein coding and non-coding—are being exploited in gene therapy to influence the deregulated pathways to facilitate cytotoxicity, enhance the immune response or sensitize to current treatments. Delivery vehicles based on viral or non-viral systems as well as cellular vectors with tumor homing characteristics are a critical part of the design of gene therapy strategies. The different behavior of tumoral versus non-tumoral cells inspires vector engineering with the generation of tumor selective products that can prevent potential toxic-associated effects. In the current review, a detailed analysis of the different targets, the delivery vectors, the preclinical approaches and a descriptive update on the conducted clinical trials are presented. Moreover, future possibilities in pancreatic cancer treatment by gene therapy strategies are discussed.

Vibration vector monitoring of rotating machinery: A predictive/preventative maintenance technique

International Nuclear Information System (INIS)

Humes, B.R.

1990-01-01

Monitoring of overall vibration amplitudes to indicate machinery faults is a standard practice in most industries. The appearance of shaft cracks in machines retrofitted for extended life have prompted development of higher levels of machinery monitoring. Part 1 of this paper discusses vibration vector monitoring for machinery malfunction prediction and failure prevention. Machinery faults which can be diagnosed by this type of monitoring, such as rotor rubs, loose parts, shaft cracks, ..., are presented along with their most common characteristics. The newest, most effective methods of permanent machinery monitoring are presented and critiqued. An extensive case history is presented in Part 2 in which a potentially disastrous machinery fault was predicted using vibration vector monitoring and analysis. The addition of vector monitoring to the normal, overall vibration monitoring proved more effective in diagnosing the machinery fault and predicting impending failure

Quantum dot coating of baculoviral vectors enables visualization of transduced cells and tissues

International Nuclear Information System (INIS)

Zhao, Ying; Lo, Seong Loong; Zheng, Yuangang; Lam, Dang Hoang; Wu, Chunxiao; Han, Ming Yong; Wang, Shu

2013-01-01

Highlights: •The use of quantum dot (QD)-labeled viral vectors for in vivo imaging is not well investigated. •A new method to label enveloped baculovirus with glutathione-capped CdTe QDs is developed. •The labeling enables the identification of transduced, cultured cells based on fluorescence. •The labeling also allows evaluation of viral transduction in a real-time manner in living mice. •The method has the potential to assess viral vector-based gene therapy protocols in future. -- Abstract: Imaging of transduced cells and tissues is valuable in developing gene transfer vectors and evaluating gene therapy efficacy. We report here a simple method to use bright and photostable quantum dots to label baculovirus, an emerging gene therapy vector. The labeling was achieved through the non-covalent interaction of glutathione-capped CdTe quantum dots with the virus envelope, without the use of chemical conjugation. The quantum dot labeling was nondestructive to viral transduction function and enabled the identification of baculoviral vector-transduced, living cells based on red fluorescence. When the labeled baculoviral vectors were injected intravenously or intraventricularly for in vivo delivery of a transgene into mice, quantum dot fluorescence signals allow us monitor whether or not the injected tissues were transduced. More importantly, using a dual-color whole-body imaging technology, we demonstrated that in vivo viral transduction could be evaluated in a real-time manner in living mice. Thus, our method of labeling a read-to-use gene delivery vector with quantum dots could be useful towards the improvement of vector design and will have the potential to assess baculovirus-based gene therapy protocols in future

An introduction to vectors, vector operators and vector analysis

CERN Document Server

Joag, Pramod S

2016-01-01

Ideal for undergraduate and graduate students of science and engineering, this book covers fundamental concepts of vectors and their applications in a single volume. The first unit deals with basic formulation, both conceptual and theoretical. It discusses applications of algebraic operations, Levi-Civita notation, and curvilinear coordinate systems like spherical polar and parabolic systems and structures, and analytical geometry of curves and surfaces. The second unit delves into the algebra of operators and their types and also explains the equivalence between the algebra of vector operators and the algebra of matrices. Formulation of eigen vectors and eigen values of a linear vector operator are elaborated using vector algebra. The third unit deals with vector analysis, discussing vector valued functions of a scalar variable and functions of vector argument (both scalar valued and vector valued), thus covering both the scalar vector fields and vector integration.

Efficiency improvement of the maximum power point tracking for PV systems using support vector machine technique

International Nuclear Information System (INIS)

Kareim, Ameer A; Mansor, Muhamad Bin

2013-01-01

The aim of this paper is to improve efficiency of maximum power point tracking (MPPT) for PV systems. The Support Vector Machine (SVM) was proposed to achieve the MPPT controller. The theoretical, the perturbation and observation (P and O), and incremental conductance (IC) algorithms were used to compare with proposed SVM algorithm. MATLAB models for PV module, theoretical, SVM, P and O, and IC algorithms are implemented. The improved MPPT uses the SVM method to predict the optimum voltage of the PV system in order to extract the maximum power point (MPP). The SVM technique used two inputs which are solar radiation and ambient temperature of the modeled PV module. The results show that the proposed SVM technique has less Root Mean Square Error (RMSE) and higher efficiency than P and O and IC methods.

Evaluation of two tomotherapy-based techniques for the delivery of whole-breast intensity-modulated radiation therapy

International Nuclear Information System (INIS)

Gonzalez, Victor J.; Buchholz, Daniel J.; Langen, Katja M.; Olivera, Gustavo H.; Chauhan, Bhavin; Meeks, Sanford L.; Ruchala, Kenneth J.; Haimerl, Jason; Lu Weiguo; Kupelian, Patrick A.

2006-01-01

Purpose: To evaluate two different techniques for whole-breast treatments delivered using the Hi-ART II tomotherapy device. Methods and Materials: Tomotherapy uses the standard rotational helical delivery. Topotherapy uses a stationary gantry while delivering intensity-modulated treatments. CT scans from 5 breast cancer patients were used. The prescription dose was 50.4 Gy. Results: On average, 99% of the target volume received 95% of prescribed dose with either technique. If treatment times are restricted to less than 9 min, the average percentage ipsilateral lung receiving ≥20 Gy was 22% for tomotherapy vs. 10% for topotherapy. The ipsilateral lung receiving ≥50.4 Gy was 4 cc for tomotherapy vs. 27 cc for topotherapy. The percentage of left ventricle receiving ≥30 Gy was 14% with tomotherapy vs. 4% for topotherapy. The average doses to the contralateral breast and lung were 0.6 and 0.8 Gy, respectively, for tomotherapy vs. 0.4 and 0.3 Gy for topotherapy. Conclusions: Tomotherapy provides improved target dose homogeneity and conformality over topotherapy. If delivery times are restricted, topotherapy reduces the amount of heart and ipsilateral lung volumes receiving low doses. For whole-breast treatments, topotherapy is an efficient technique that achieves adequate target uniformity while maintaining low doses to sensitive structures

Cell-type-specific gene delivery into neuronal cells in vitro and in vivo

International Nuclear Information System (INIS)

Parveen, Zahida; Mukhtar, Muhammad; Rafi, Mohammed; Wenger, David A.; Siddiqui, Khwaja M.; Siler, Catherine A.; Dietzschold, Bernhard; Pomerantz, Roger J.; Schnell, Matthias J.; Dornburg, Ralph

2003-01-01

The avian retroviruses reticuloendotheliosis virus strain A (REV-A) and spleen necrosis virus (SNV) are not naturally infectious in human cells. However, REV-A-derived viral vectors efficiently infect human cells when they are pseudotyped with envelope proteins displaying targeting ligands specific for human cell-surface receptors. Here we report that vectors containing the gag region of REV-A and pol of SNV can be pseudotyped with the envelope protein of vesicular stomatitis virus (VSV) and the glycoproteins of different rabies virus (RV) strains. Vectors pseudotyped with the envelope protein of the highly neurotropic RV strain CVS-N2c facilitated cell type-specific gene delivery into mouse and human neurons, but did not infect other human cell types. Moreover, when such vector particles were injected into the brain of newborn mice, only neuronal cells were infected in vivo. Cell-type-specific gene delivery into neurons may present quite specific gene therapy approaches for many degenerative diseases of the brain

Lipid microbubbles as a vehicle for targeted drug delivery using focused ultrasound-induced blood–brain barrier opening

Science.gov (United States)

Sierra, Carlos; Acosta, Camilo; Chen, Cherry; Wu, Shih-Ying; Karakatsani, Maria E; Bernal, Manuel

2016-01-01

Focused ultrasound in conjunction with lipid microbubbles has fully demonstrated its ability to induce non-invasive, transient, and reversible blood–brain barrier opening. This study was aimed at testing the feasibility of our lipid-coated microbubbles as a vector for targeted drug delivery in the treatment of central nervous system diseases. These microbubbles were labeled with the fluorophore 5-dodecanoylaminfluorescein. Focused ultrasound targeted mouse brains in vivo in the presence of these microbubbles for trans-blood–brain barrier delivery of 5-dodecanoylaminfluorescein. This new approach, compared to previously studies of our group, where fluorescently labeled dextrans and microbubbles were co-administered, represents an appreciable improvement in safety outcome and targeted drug delivery. This novel technique allows the delivery of 5-dodecanoylaminfluorescein at the region of interest unlike the alternative of systemic exposure. 5-dodecanoylaminfluorescein delivery was assessed by ex vivo fluorescence imaging and by in vivo transcranial passive cavitation detection. Stable and inertial cavitation doses were quantified. The cavitation dose thresholds for estimating, a priori, successful targeted drug delivery were, for the first time, identified with inertial cavitation were concluded to be necessary for successful delivery. The findings presented herein indicate the feasibility and safety of the proposed microbubble-based targeted drug delivery and that, if successful, can be predicted by cavitation detection in vivo. PMID:27278929

ESTIMATING ELECTRIC FIELDS FROM VECTOR MAGNETOGRAM SEQUENCES

International Nuclear Information System (INIS)

Fisher, G. H.; Welsch, B. T.; Abbett, W. P.; Bercik, D. J.

2010-01-01

Determining the electric field distribution on the Sun's photosphere is essential for quantitative studies of how energy flows from the Sun's photosphere, through the corona, and into the heliosphere. This electric field also provides valuable input for data-driven models of the solar atmosphere and the Sun-Earth system. We show how observed vector magnetogram time series can be used to estimate the photospheric electric field. Our method uses a 'poloidal-toroidal decomposition' (PTD) of the time derivative of the vector magnetic field. These solutions provide an electric field whose curl obeys all three components of Faraday's Law. The PTD solutions are not unique; the gradient of a scalar potential can be added to the PTD electric field without affecting consistency with Faraday's Law. We then present an iterative technique to determine a potential function consistent with ideal MHD evolution; but this field is also not a unique solution to Faraday's Law. Finally, we explore a variational approach that minimizes an energy functional to determine a unique electric field, a generalization of Longcope's 'Minimum Energy Fit'. The PTD technique, the iterative technique, and the variational technique are used to estimate electric fields from a pair of synthetic vector magnetograms taken from an MHD simulation; and these fields are compared with the simulation's known electric fields. The PTD and iteration techniques compare favorably to results from existing velocity inversion techniques. These three techniques are then applied to a pair of vector magnetograms of solar active region NOAA AR8210, to demonstrate the methods with real data. Careful examination of the results from all three methods indicates that evolution of the magnetic vector by itself does not provide enough information to determine the true electric field in the photosphere. Either more information from other measurements, or physical constraints other than those considered here are necessary to find

Lipid nanoparticles as drug/gene delivery systems to the retina.

Science.gov (United States)

del Pozo-Rodríguez, Ana; Delgado, Diego; Gascón, Alicia R; Solinís, Maria Ángeles

2013-03-01

This review highlights the application of lipid nanoparticles (Solid Lipid Nanoparticles, Nanostructured Lipid Carriers, or Lipid Drug Conjugates) as effective drug/gene delivery systems for retinal diseases. Most drug products for ocular disease treatment are marketed as eye drop formulations but, due to ocular barriers, the drug concentration in the retina hardly ever turns out to be effective. Up to this date, several delivery systems have been designed to deliver drugs to the retina. Drug delivery strategies may be classified into 3 groups: noninvasive techniques, implants, and colloidal carriers. The best known systems for drug delivery to the posterior eye are intravitreal implants; in fact, some of them are being clinically used. However, their long-term accumulation might impact the patient's vision. On the contrary, colloidal drug delivery systems (microparticles, liposomes, or nanoparticles) can be easily administered in a liquid form. Nanoparticular systems diffuse rapidly and are better internalized in ocular tissues than microparticles. In comparison with liposomes, nanoparticles have a higher loading capacity and are more stable in biological fluids and during storage. In addition, their capacity to adhere to the ocular surface and interact with the endothelium makes these drug delivery systems interesting as new therapeutic tools in ophthalmology. Within the group of nanoparticles, those composed of lipids (Solid Lipid Nanoparticles, Nanostructred Lipid Carriers, and Lipid Drug Conjugates) are more biocompatible, easy to produce at large scale, and they may be autoclaved or sterilized. The present review summarizes scientific results that evidence the potential application of lipid nanoparticles as drug delivery systems for the retina and also as nonviral vectors in gene therapy of retina disorders, although much more effort is still needed before these lipidic systems could be available in the market.

Controlling Aedes aegypti population as DHF vector with radiation based-sterile insect technique in Banjarnegara Regency, Central Java

International Nuclear Information System (INIS)

Siti Nurhayati; Bambang Yunianto; Tri Ramadhani; Bina Ikawati; Budi Santoso; Ali Rahayu

2013-01-01

The control program of dengue hemorrhagic fever (DHF) in Indonesia is still a problem due to the incomplete integrated handling. Sterile insect technique (SIT) for Aedes aegypti as DHF vector was considered as a potential strategy for controlling the DHF. A preliminary survey was carried out to determine the characteristic of A aegypti population in the study site before the implementation of SIT. The implementation of radiation based-SIT was carried out in Krandegan and Kutabanjar Villages of Banjarnegara Regency, Central Java which involved 99 houses. One hundred gamma rays irradiated male mosquitoes were released to each house up to five times. The eggs, larvae and adult mosquitoes were collected using ovitrap and weekly observed. The initial population density of A. aegypti in the studied area was obtained to be 6 mosquitoes per house with the mean index of house was 15.86% and the mean sterility of sterilized mosquitoes was 79.16%. The SIT effectively reduced A. aegypti population after the fifth release of irradiated mosquitoes into the houses. It can be assumed that the SIT was effective in controlling DHF vector in the studied area, nevertheless, it will be more effective if it is combined with other handling techniques. (author)

Adenoviral vectors as genome editing tools : repairing defective DMD alleles

NARCIS (Netherlands)

Maggio, Ignazio

2016-01-01

Adenoviral vectors (AdVs) constitute powerful gene delivery vehicles. However, so far, their potential for genome editing has not been extensively investigated. By tailoring AdVs as carriers of designer nucleases and donor DNA sequences, the research presented in this thesis expands the utility of

Search for vector-like quarks using jet substructure techniques with the CMS experiment

International Nuclear Information System (INIS)

Nowatschin, Dominik

2017-01-01

In this thesis, a search for pair produced vector-like T quarks in pp collision data from the LRC at √(s)=13 TeV is presented. The data were collected with the CMS detector and correspond to an integrated luminosity of up to 2.6 fb"-"1. Vector-like quarks are hypothetical new particles predicted by many extensions of the Standard Model in which the Higgs boson is a composite state of an unknown strong interaction. Vector-like T quarks are assumed to decay via three different decay modes to either bW, tZ or tH, with branching fractions that are not fixed and can vary depending on the particular model featuring vector-like quarks. This search focuses on decays of the T anti T system in which at least one muon or electron is present in the final state, and in which at least one of the T quarks decays to a top quark and a Higgs boson. As the T quarks are expected to be quite heavy, their decay products are significantly Lorentz-boasted in the reference frame of the T anti T system. The subsequent decay products of the Higgs boson are then emitted with a very small angle between them. This search is optimised for the main decay channel of the Higgs boson to two bottom quarks and attempts to reconstruct the two b quarks within a single jet with a large cone size. Dedicated jet substructure techniques, in combination with algorithms to identify jets originating from the fragmentation of a b quark, are then used to reconstruct the entire H→b anti b decay. The event categories of this search are also combined with the categories of a search for pair-produced T quarks that focuses on the T→bW decay. This approach provides a high sensitivity to T anti T production for many different combinations of branching fractions to the three possible decay modes. No excess of the data above the expected background contribution from the Standard Model is observed in any of the final event categories. Upper limits on the T anti T production cross section are calculated at 95

Search for vector-like quarks using jet substructure techniques with the CMS experiment

Energy Technology Data Exchange (ETDEWEB)

Nowatschin, Dominik

2017-07-03

In this thesis, a search for pair produced vector-like T quarks in pp collision data from the LRC at √(s)=13 TeV is presented. The data were collected with the CMS detector and correspond to an integrated luminosity of up to 2.6 fb{sup -1}. Vector-like quarks are hypothetical new particles predicted by many extensions of the Standard Model in which the Higgs boson is a composite state of an unknown strong interaction. Vector-like T quarks are assumed to decay via three different decay modes to either bW, tZ or tH, with branching fractions that are not fixed and can vary depending on the particular model featuring vector-like quarks. This search focuses on decays of the T anti T system in which at least one muon or electron is present in the final state, and in which at least one of the T quarks decays to a top quark and a Higgs boson. As the T quarks are expected to be quite heavy, their decay products are significantly Lorentz-boasted in the reference frame of the T anti T system. The subsequent decay products of the Higgs boson are then emitted with a very small angle between them. This search is optimised for the main decay channel of the Higgs boson to two bottom quarks and attempts to reconstruct the two b quarks within a single jet with a large cone size. Dedicated jet substructure techniques, in combination with algorithms to identify jets originating from the fragmentation of a b quark, are then used to reconstruct the entire H→b anti b decay. The event categories of this search are also combined with the categories of a search for pair-produced T quarks that focuses on the T→bW decay. This approach provides a high sensitivity to T anti T production for many different combinations of branching fractions to the three possible decay modes. No excess of the data above the expected background contribution from the Standard Model is observed in any of the final event categories. Upper limits on the T anti T production cross section are calculated at 95

A unified development of several techniques for the representation of random vectors and data sets

Science.gov (United States)

Bundick, W. T.

1973-01-01

Linear vector space theory is used to develop a general representation of a set of data vectors or random vectors by linear combinations of orthonormal vectors such that the mean squared error of the representation is minimized. The orthonormal vectors are shown to be the eigenvectors of an operator. The general representation is applied to several specific problems involving the use of the Karhunen-Loeve expansion, principal component analysis, and empirical orthogonal functions; and the common properties of these representations are developed.

A Safe Bacterial Microsyringe for In Vivo Antigen Delivery and Immunotherapy

Science.gov (United States)

Le Gouëllec, Audrey; Chauchet, Xavier; Laurin, David; Aspord, Caroline; Verove, Julien; Wang, Yan; Genestet, Charlotte; Trocme, Candice; Ahmadi, Mitra; Martin, Sandrine; Broisat, Alexis; Cretin, François; Ghezzi, Catherine; Polack, Benoit; Plumas, Joël; Toussaint, Bertrand

2013-01-01

The industrial development of active immunotherapy based on live-attenuated bacterial vectors has matured. We developed a microsyringe for antigen delivery based on the type III secretion system (T3SS) of P. aeruginosa. We applied the “killed but metabolically active” (KBMA) attenuation strategy to make this bacterial vector suitable for human use. We demonstrate that attenuated P. aeruginosa has the potential to deliver antigens to human antigen-presenting cells in vitro via T3SS with considerable attenuated cytotoxicity as compared with the wild-type vector. In a mouse model of cancer, we demonstrate that this KBMA strain, which cannot replicate in its host, efficiently disseminates into lymphoid organs and delivers its heterologous antigen. The attenuated strain effectively induces a cellular immune response to the cancerous cells while lowering the systemic inflammatory response. Hence, a KBMA P. aeruginosa microsyringe is an efficient and safe tool for in vivo antigen delivery. PMID:23531551

Non-viral gene delivery strategies for gene therapy: a “ménage à trois” among nucleic acids, materials, and the biological environment

International Nuclear Information System (INIS)

Pezzoli, Daniele; Candiani, Gabriele

2013-01-01

Gene delivery is the science of transferring genetic material into cells by means of a vector to alter cellular function or structure at a molecular level. In this context, a number of nucleic acid-based drugs have been proposed and experimented so far and, as they act on distinct steps along the gene transcription–translation pathway, specific delivery strategies are required to elicit the desired outcome. Cationic lipids and polymers, collectively known as non-viral delivery systems, have thus made their breakthrough in basic and medical research. Albeit they are promising alternatives to viral vectors, their therapeutic application is still rather limited as high transfection efficiencies are normally associated to adverse cytotoxic side effects. In this scenario, drawing inspiration from processes naturally occurring in vivo, major strides forward have been made in the development of more effective materials for gene delivery applications. Specifically, smart vectors sensitive to a variety of physiological stimuli such as cell enzymes, redox status, and pH are substantially changing the landscape of gene delivery by helping to overcome some of the systemic and intracellular barriers that viral vectors naturally evade. Herein, after summarizing the state-of-the-art information regarding the use of nucleic acids as drugs, we review the main bottlenecks still limiting the overall effectiveness of non-viral gene delivery systems. Finally, we provide a critical outline of emerging stimuli-responsive strategies and discuss challenges still existing on the road toward conceiving more efficient and safer multifunctional vectors.

Efficient in vivo gene transfer to xenotransplanted human skin by lentivirus-mediated, but not by AAV-directed, gene delivery

DEFF Research Database (Denmark)

Jakobsen, Maria Vad; Askou, Anne Louise; Dokkedahl, Karin Stenderup

skin graft, and firefly luciferase expression was observed primarily in neighboring tissue beneath or surrounding the graft. In contrast, gene delivery by intradermally injected lentiviral vectors was efficient and led to extensive and persistent firefly luciferase expression within the human skin...... graft only. The study demonstrates limited capacity of single-stranded AAV vectors of six commonly used serotypes for gene delivery to human skin in vivo....

Measurements of Solar Vector Magnetic Fields

Science.gov (United States)

Hagyard, M. J. (Editor)

1985-01-01

Various aspects of the measurement of solar magnetic fields are presented. The four major subdivisions of the study are: (1) theoretical understanding of solar vector magnetic fields; (3) techniques for interpretation of observational data; and (4) techniques for data display.

Measurements of Solar Vector Magnetic Fields

International Nuclear Information System (INIS)

Hagyard, M.J.

1985-05-01

Various aspects of the measurement of solar magnetic fields are presented. The four major subdivisions of the study are: (1) theoretical understanding of solar vector magnetic fields; (3) techniques for interpretation of observational data; and (4) techniques for data display

Biophotonic techniques for manipulation and characterization of drug delivery nanosystems in cancer therapy.

Science.gov (United States)

Spyratou, E; Makropoulou, M; Mourelatou, E A; Demetzos, C

2012-12-31

Reactive oxygen species (ROS) are usually involved in two opposite procedures related to cancer: initiation, progression and metastasis of cancer, as well as in all non-surgical therapeutic approaches for cancer, including chemotherapy, radiotherapy and photodynamic therapy. This review is concentrated in new therapeutic strategies that take advantage of increased ROS in cancer cells to enhance therapeutic activity and selectivity. Novel biophotonic techniques for manipulation and characterization of drug delivery nanosystems in cancer therapy are discussed, including optical tweezers and atomic force microscopy. This review highlights how these techniques are playing a critical role in recent and future cancer fighting applications. We can conclude that Biophotonics and nanomedicine are the future for cancer biology and disease management, possessing unique potential for early detection, accurate diagnosis, dosimetry and personalized treatment of biomedical applications targeting cancer. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Baculoviral delivery of CRISPR/Cas9 facilitates efficient genome editing in human cells

NARCIS (Netherlands)

Hindriksen, Sanne; Bramer, Arne J; Truong, My Anh; Vromans, Martijn J M; Post, Jasmin B; Verlaan-Klink, Ingrid; Snippert, Hugo J; Lens, Susanne M A; Hadders, Michael A

2017-01-01

The CRISPR/Cas9 system is a highly effective tool for genome editing. Key to robust genome editing is the efficient delivery of the CRISPR/Cas9 machinery. Viral delivery systems are efficient vehicles for the transduction of foreign genes but commonly used viral vectors suffer from a limited

ON THE ISSUE OF VECTOR CONTROL OF THE ASYNCHRONOUS MOTORS

Directory of Open Access Journals (Sweden)

B. I. Firago

2015-01-01

Full Text Available The paper considers the issue of one of the widespread types of vector control realization for the asynchronous motors with a short-circuited rotor. Of all more than 20 vector control types known presently, the following are applied most frequently: direct vector control with velocity pickup (VP, direct vector control without VP, indirect vector control with VP and indirect vector control without VP. Despite the fact that the asynchronous-motor indirect vector control without VP is the easiest and most spread, the absence of VP does not allow controlling the motor electromagnetic torque at zero velocity. This is the reason why for electric motor drives of such requirements they utilize the vector control with a velocity transducer. The systems of widest dissemination became the direct and indirect vector control systems with X-axis alignment of the synchronously rotating x–y-coordinate frame along the rotor flux-linkage vector inasmuch as this provides the simplest correlations for controlling variables. Although these two types of vector control are well presented in literature, a number of issues concerning their realization and practical application require further elaboration. These include: the block schemes adequate representation as consisted with the modern realization of vector control and clarification of the analytical expressions for evaluating the regulator parameters.The authors present a technique for evaluating the dynamics of an asynchronous electric motor drive with direct vector control and x-axis alignment along the vector of rotor flux linkage. The article offers a generalized structure of this vector control type with detailed description of its principal blocks: controlling system, frequency converter, and the asynchronous motor.The paper presents a direct vector control simulating model developed in the MatLab environment on the grounds of this structure. The authors illustrate the described technique with the results

Coated microneedle arrays for transcutaneous delivery of live virus vaccines.

Science.gov (United States)

Vrdoljak, Anto; McGrath, Marie G; Carey, John B; Draper, Simon J; Hill, Adrian V S; O'Mahony, Conor; Crean, Abina M; Moore, Anne C

2012-04-10

Vaccines are sensitive biologics that require continuous refrigerated storage to maintain their viability. The vast majority of vaccines are also administered using needles and syringes. The need for cold chain storage and the significant logistics surrounding needle-and-syringe vaccination is constraining the success of immunization programs. Recombinant live viral vectors are a promising platform for the development of vaccines against a number of infectious diseases, however these viruses must retain infectivity to be effective. Microneedles offer an effective and painless method for delivery of vaccines directly into skin that in the future could provide solutions to current vaccination issues. Here we investigated methods of coating live recombinant adenovirus and modified vaccinia virus Ankara (MVA) vectors onto solid microneedle arrays. An effective spray-coating method, using conventional pharmaceutical processes, was developed, in tandem with suitable sugar-based formulations, which produces arrays with a unique coating of viable virus in a dry form around the shaft of each microneedle on the array. Administration of live virus-coated microneedle arrays successfully resulted in virus delivery, transcutaneous infection and induced an antibody or CD8(+) T cell response in mice that was comparable to that obtained by needle-and-syringe intradermal immunization. To our knowledge, this is the first report of successful vaccination with recombinant live viral vectored vaccines coated on microneedle delivery devices. Copyright © 2011 Elsevier B.V. All rights reserved.

Coated microneedle arrays for transcutaneous delivery of live virus vaccines

Science.gov (United States)

Vrdoljak, Anto; McGrath, Marie G.; Carey, John B.; Draper, Simon J.; Hill, Adrian V.S.; O’Mahony, Conor; Crean, Abina M.; Moore, Anne C.

2016-01-01

Vaccines are sensitive biologics that require continuous refrigerated storage to maintain their viability. The vast majority of vaccines are also administered using needles and syringes. The need for cold chain storage and the significant logistics surrounding needle-and-syringe vaccination is constraining the success of immunization programs. Recombinant live viral vectors are a promising platform for the development of vaccines against a number of infectious diseases, however these viruses must retain infectivity to be effective. Microneedles offer an effective and painless method for delivery of vaccines directly into skin that in the future could provide solutions to current vaccination issues. Here we investigated methods of coating live recombinant adenovirus and modified vaccinia virus Ankara (MVA) vectors onto solid microneedle arrays. An effective spray-coating method, using conventional pharmaceutical processes, was developed, in tandem with suitable sugar-based formulations, which produces arrays with a unique coating of viable virus in a dry form around the shaft of each microneedle on the array. Administration of live virus-coated microneedle arrays successfully resulted in virus delivery, transcutaneous infection and induced an antibody or CD8+ T cell response in mice that was comparable to that obtained by needle-and-syringe intradermal immunization. To our knowledge, this is the first report of successful vaccination with recombinant live viral vectored vaccines coated on microneedle delivery devices. PMID:22245683

Retroviral packaging cells encapsulated in TheraCyte immunoisolation devices enable long-term in vivo gene delivery.

Science.gov (United States)

Krupetsky, Anna; Parveen, Zahida; Marusich, Elena; Goodrich, Adrienne; Dornburg, Ralph

2003-05-01

The method of delivering a therapeutic gene into a patient is still one of the major obstacles towards successful human gene therapy. Here we describe a novel gene delivery approach using TheraCyte immunoisolation devices. Retroviral vector producing cells, derived from the avian retrovirus spleen necrosis virus, SNV, were encapsulated in TheraCyte devices and tested for the release of retroviral vectors. In vitro experiments show that such devices release infectious retroviral vectors into the tissue culture medium for up to 4 months. When such devices were implanted subcutaneously in SCID mice, infectious virus was released into the blood stream. There, the vectors were transported to and infected tumors, which had been induced by subcutaneous injection of tissue culture cells. Thus, this novel concept of a continuous, long-term gene delivery may constitute an attractive approach for future in vivo human gene therapy.

Transient foreign gene expression in chloroplasts of cultured tobacco cells after biolistic delivery of chloroplast vectors.

OpenAIRE

Daniell, H; Vivekananda, J; Nielsen, B L; Ye, G N; Tewari, K K; Sanford, J C

1990-01-01

Expression of chloramphenicol acetyltransferase (cat) by suitable vectors in chloroplasts of cultured tobacco cells, delivered by high-velocity microprojectiles, is reported here. Several chloroplast expression vectors containing bacterial cat genes, placed under the control of either psbA promoter region from pea (pHD series) or rbcL promoter region from maize (pAC series) have been used in this study. In addition, chloroplast expression vectors containing replicon fragments from pea, tobacc...

Membrane-bound SIV envelope trimers are immunogenic in ferrets after intranasal vaccination with a replication-competent canine distemper virus vector.

Science.gov (United States)

Zhang, Xinsheng; Wallace, Olivia; Wright, Kevin J; Backer, Martin; Coleman, John W; Koehnke, Rebecca; Frenk, Esther; Domi, Arban; Chiuchiolo, Maria J; DeStefano, Joanne; Narpala, Sandeep; Powell, Rebecca; Morrow, Gavin; Boggiano, Cesar; Zamb, Timothy J; Richter King, C; Parks, Christopher L

2013-11-01

We are investigating canine distemper virus (CDV) as a vaccine vector for the delivery of HIV envelope (Env) that closely resembles the native trimeric spike. We selected CDV because it will promote vaccine delivery to lymphoid tissues, and because human exposure is infrequent, reducing potential effects of pre-existing immunity. Using SIV Env as a model, we tested a number of vector and gene insert designs. Vectors containing a gene inserted between the CDV H and L genes, which encoded Env lacking most of its cytoplasmic tail, propagated efficiently in Vero cells, expressed the immunogen on the cell surface, and incorporated the SIV glycoprotein into progeny virus particles. When ferrets were vaccinated intranasally, there were no signs of distress, vector replication was observed in the gut-associated lymphoid tissues, and the animals produced anti-SIV Env antibodies. These data show that live CDV-SIV Env vectors can safely induce anti-Env immune responses following intranasal vaccination. © 2013 Elsevier Inc. All rights reserved.

A non-pathogenic live vector as an efficient delivery system in vaccine design for the prevention of HPV16 E7-overexpressing cancers.

Science.gov (United States)

Hosseinzadeh, Sahar; Bolhassani, Azam; Rafati, Sima; Taheri, Tahereh; Zahedifard, Farnaz; Daemi, Amin; Taslimi, Yasaman; Hashemi, Mehrdad; Memarnejadian, Arash

2013-01-01

The attenuated or non-pathogenic live vectors have been evolved specifically to deliver DNA into cells as efficient delivery tools in gene therapy. Recently, a non-pathogenic protozoan, Leishmania tarentolae (L.tar) has attracted a great attention. In current study, we used Leishmania expression system (LEXSY) for stable expression of HPV16 E7 linked to different mini-chaperones [N-/C-terminal of gp96] and compared their immunogenicity and protective effects in C57BL/6 mice against TC-1 challenge. TC-1 murine model is primary C57BL/6 mice lung epithelial cells co-transformed with HPV16 E6, HPV16 E7 and ras oncogenes. Our results showed that subcutaneous administration of mice with both the recombinant L.tar-E7-NT (gp96) and L.tar-E7-CT (gp96) led to enhance the levels of IFN-γ and also IgG2a before and after challenge with TC-1. Furthermore, L.tar-E7-CT (gp96) live vaccine indicated significant protective effects as compared to control groups as well as group vaccinated with L.tar-E7. Indeed, the recombinant live vector is capable of eliciting effective humoral and cellular immune responses in mice, but however, further studies are required to increase their efficacy.

Novel adjuvants & delivery vehicles for vaccines development: a road ahead.

Science.gov (United States)

Mohan, Teena; Verma, Priyanka; Rao, D Nageswara

2013-11-01

The pure recombinant and synthetic antigens used in modern day vaccines are generally less immunogenic than older style live/attenuated and killed whole organism vaccines. One can improve the quality of vaccine production by incorporating immunomodulators or adjuvants with modified delivery vehicles viz. liposomes, immune stimulating complexes (ISCOMs), micro/nanospheres apart from alum, being used as gold standard. Adjuvants are used to augment the effect of a vaccine by stimulating the immune system to respond to the vaccine, more vigorously, and thus providing increased immunity to a particular disease. Adjuvants accomplish this task by mimicking specific sets of evolutionary conserved molecules which include lipopolysaccharides (LPS), components of bacterial cell wall, endocytosed nucleic acids such as dsRNA, ssDNA and unmethylated CpG dinucleotide containing DNA. This review provides information on various vaccine adjuvants and delivery vehicles being developed to date. From literature, it seems that the humoral immune responses have been observed for most adjuvants and delivery platforms while viral-vector, ISCOMs and Montanides have shown cytotoxic T-cell response in the clinical trials. MF59 and MPL® have elicited Th1 responses, and virus-like particles (VLPs), non-degradable nanoparticle and liposomes have also generated cellular immunity. Such vaccine components have also been evaluated for alternative routes of administration with clinical success reported for intranasal delivery of viral-vectors and proteosomes and oral delivery of VLP vaccines.

Polyploidization without mitosis improves in vivo liver transduction with lentiviral vectors.

Science.gov (United States)

Pichard, Virginie; Couton, Dominique; Desdouets, Chantal; Ferry, Nicolas

2013-02-01

Lentiviral vectors are efficient gene delivery vehicles for therapeutic and research applications. In contrast to oncoretroviral vectors, they are able to infect most nonproliferating cells. In the liver, induction of cell proliferation dramatically improved hepatocyte transduction using all types of retroviral vectors. However, the precise relationship between hepatocyte division and transduction efficiency has not been determined yet. Here we compared gene transfer efficiency in the liver after in vivo injection of recombinant lentiviral or Moloney murine leukemia viral (MoMuLV) vectors in hepatectomized rats treated or not with retrorsine, an alkaloid that blocks hepatocyte division and induces megalocytosis. Partial hepatectomy alone resulted in a similar increase in hepatocyte transduction using either vector. In retrorsine-treated and partially hepatectomized rats, transduction with MoMuLV vectors dropped dramatically. In contrast, we observed that retrorsine treatment combined with partial hepatectomy increased lentiviral transduction to higher levels than hepatectomy alone. Analysis of nuclear ploidy in single cells showed that a high level of transduction was associated with polyploidization. In conclusion, endoreplication could be exploited to improve the efficiency of liver-directed lentiviral gene therapy.

Techniques in Vascular and Interventional Radiology Drug Delivery Technologies in the Superficial Femoral Artery

Science.gov (United States)

Brahmbhatt, Akshaar; Misra, Sanjay

2016-01-01

Peripheral Arterial Disease (PAD) affects over 8 million people in the United States alone. While great strides have been made in reducing the burden of cardiovascular disease the prevalence of PAD is expected to rise as the global population ages. PAD characterized by narrowing of arterial blood can be asymptomatic or cause acute limb threatening claudication. It has been classically treated with bypass, but these techniques have been supplanted by endovascular therapy. Plain old Balloon Angioplasty (POBA) has been successful in helping revascularize lesions, but its effect has not been durable due to restenosis. This prompted the creation of several technologies aimed at reducing restenosis. These advances slowly improved outcomes and the durability of endovascular management. Amongst the main tools used in current endovascular practice are drug delivery devices aimed at inhibiting the inflammatory and proliferative pathways that lead to restenosis. This review will examine the current drug delivery technologies used in the SFA. PMID:27423996

Novel recombinant alphaviral and adenoviral vectors for cancer immunotherapy.

Science.gov (United States)

Osada, Takuya; Morse, Michael A; Hobeika, Amy; Lyerly, H Kim

2012-06-01

Although cellular immunotherapy based on autolgous dendritic cells (DCs) targeting antigens expressed by metastatic cancer has demonstrated clinical efficacy, the logistical challenges in generating an individualized cell product create an imperative to develop alternatives to DC-based cancer vaccines. Particularly attractive alternatives include in situ delivery of antigen and activation signals to resident antigen-presenting cells (APCs), which can be achieved by novel fusion molecules targeting the mannose receptor and by recombinant viral vectors expressing the antigen of interest and capable of infecting DCs. A particular challenge in the use of viral vectors is the well-appreciated clinical obstacles to their efficacy, specifically vector-specific neutralizing immune responses. Because heterologous prime and boost strategies have been demonstrated to be particularly potent, we developed two novel recombinant vectors based on alphaviral replicon particles and a next-generation adenovirus encoding an antigen commonly overexpressed in many human cancers, carcinoembryonic antigen (CEA). The rationale for developing these vectors, their unique characteristics, the preclinical studies and early clinical experience with each, and opportunities to enhance their effectiveness will be reviewed. The potential of each of these potent recombinant vectors to efficiently generate clinically active anti-tumor immune response alone, or in combination, will be discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

Decationized polyplexes for targeted delivery of nucleic acids : from carrier design to in vivo evaluation

NARCIS (Netherlands)

Novo, Luís

2014-01-01

Gene therapy is considered a promising treatment for current intractable diseases. However, the clinical applicability of gene therapy is highly dependent on the development of safe and efficient gene delivery vectors. So far, viral vectors have been used for clinical applications, but due to severe

Search for vector-like quarks

CERN Document Server

Varnes, Erich; The ATLAS collaboration

2017-01-01

Vector like quarks appear in many theories beyond the Standard Model as a way to cancel the mass divergence for the Higgs boson. The current status of the ATLAS searches for the production of vector like quarks will be reviewed for proton-proton collisions at 13 TeV. This presentation will address the analysis techniques, in particular the selection criteria, the background modeling and the related experimental uncertainties. The phenomenological implications of the obtained results will also be discussed.

A Performance Management Initiative for Local Health Department Vector Control Programs.

Science.gov (United States)

Gerding, Justin; Kirshy, Micaela; Moran, John W; Bialek, Ron; Lamers, Vanessa; Sarisky, John

2016-01-01

Local health department (LHD) vector control programs have experienced reductions in funding and capacity. Acknowledging this situation and its potential effect on the ability to respond to vector-borne diseases, the U.S. Centers for Disease Control and Prevention and the Public Health Foundation partnered on a performance management initiative for LHD vector control programs. The initiative involved 14 programs that conducted a performance assessment using the Environmental Public Health Performance Standards. The programs, assisted by quality improvement (QI) experts, used the assessment results to prioritize improvement areas that were addressed with QI projects intended to increase effectiveness and efficiency in the delivery of services such as responding to mosquito complaints and educating the public about vector-borne disease prevention. This article describes the initiative as a process LHD vector control programs may adapt to meet their performance management needs. This study also reviews aggregate performance assessment results and QI projects, which may reveal common aspects of LHD vector control program performance and priority improvement areas. LHD vector control programs interested in performance assessment and improvement may benefit from engaging in an approach similar to this performance management initiative.

Application of pulsed-magnetic field enhances non-viral gene delivery in primary cells from different origins

Energy Technology Data Exchange (ETDEWEB)

Kamau Chapman, Sarah W. [Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Winterthurerstr. 190, 8057 Zurich (Switzerland); Hassa, Paul O. [Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Winterthurerstr. 190, 8057 Zurich (Switzerland); European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstrasse 1, 69117 Heidelberg (Germany); Koch-Schneidemann, Sabine; Rechenberg, Brigitte von [Musculoskeletal Research Unit, Equine Hospital, Vetsuisse Faculty Zurich, University of Zurich, Winterthurerstr. 260, 8057 Zurich (Switzerland); Hofmann-Amtenbrink, Margarethe [MatSearch, Chemin Jean Pavillard 14, 1009 Pully (Switzerland); Steitz, Benedikt; Petri-Fink, Alke; Hofmann, Heinrich [Laboratory of Powder Technology, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne (Switzerland); Hottiger, Michael O. [Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Winterthurerstr. 190, 8057 Zurich (Switzerland)], E-mail: hottiger@vetbio.uzh.ch

2008-04-15

Primary cell lines are more difficult to transfect when compared to immortalized/transformed cell lines, and hence new techniques are required to enhance the transfection efficiency in these cells. We isolated and established primary cultures of synoviocytes, chondrocytes, osteoblasts, melanocytes, macrophages, lung fibroblasts, and embryonic fibroblasts. These cells differed in several properties, and hence were a good representative sample of cells that would be targeted for expression and delivery of therapeutic genes in vivo. The efficiency of gene delivery in all these cells was enhanced using polyethylenimine-coated polyMAG magnetic nanoparticles, and the rates (17-84.2%) surpassed those previously achieved using other methods, especially in cells that are difficult to transfect. The application of permanent and pulsating magnetic fields significantly enhanced the transfection efficiencies in synoviocytes, chondrocytes, osteoblasts, melanocytes and lung fibroblasts, within 5 min of exposure to these magnetic fields. This is an added advantage for future in vivo applications, where rapid gene delivery is required before systemic clearance or filtration of the gene vectors occurs.

Transcellular targeting of fiber- and hexon-modified adenovirus vectors across the brain microvascular endothelial cells in vitro.

Directory of Open Access Journals (Sweden)

Johanna P Laakkonen

Full Text Available In central nervous system (CNS-directed gene therapy, efficient targeting of brain parenchyma through the vascular route is prevented by the endothelium and the epithelium of the blood-brain and the blood-cerebrospinal fluid barriers, respectively. In this study, we evaluated the feasibility of the combined genetic and chemical adenovirus capsid modification technology to enable transcellular delivery of targeted adenovirus (Ad vectors across the blood-brain barrier (BBB in vitro models. As a proof-of-principle ligand, maleimide-activated full-length human transferrin (hTf was covalently attached to cysteine-modified Ad serotype 5 vectors either to its fiber or hexon protein. In transcytosis experiments, hTf-coupled vectors were shown to be redirected across the BBB models, the transcytosis activity of the vectors being dependent on the location of the capsid modification and the in vitro model used. The transduction efficiency of hTf-targeted vectors decreased significantly in confluent, polarized cells, indicating that the intracellular route of the vectors differed between unpolarized and polarized cells. After transcellular delivery the majority of the hTf-modified vectors remained intact and partly capable of gene transfer. Altogether, our results demonstrate that i covalent attachment of a ligand to Ad capsid can mediate transcellular targeting across the cerebral endothelium in vitro, ii the attachment site of the ligand influences its transcytosis efficiency and iii combined genetic/chemical modification of Ad vector can be used as a versatile platform for the development of Ad vectors for transcellular targeting.

A data-driven predictive approach for drug delivery using machine learning techniques.

Directory of Open Access Journals (Sweden)

Yuanyuan Li

Full Text Available In drug delivery, there is often a trade-off between effective killing of the pathogen, and harmful side effects associated with the treatment. Due to the difficulty in testing every dosing scenario experimentally, a computational approach will be helpful to assist with the prediction of effective drug delivery methods. In this paper, we have developed a data-driven predictive system, using machine learning techniques, to determine, in silico, the effectiveness of drug dosing. The system framework is scalable, autonomous, robust, and has the ability to predict the effectiveness of the current drug treatment and the subsequent drug-pathogen dynamics. The system consists of a dynamic model incorporating both the drug concentration and pathogen population into distinct states. These states are then analyzed using a temporal model to describe the drug-cell interactions over time. The dynamic drug-cell interactions are learned in an adaptive fashion and used to make sequential predictions on the effectiveness of the dosing strategy. Incorporated into the system is the ability to adjust the sensitivity and specificity of the learned models based on a threshold level determined by the operator for the specific application. As a proof-of-concept, the system was validated experimentally using the pathogen Giardia lamblia and the drug metronidazole in vitro.

Functionalized nanoparticles for AMF-induced gene and drug delivery

Science.gov (United States)

Biswas, Souvik

The properties and broad applications of nano-magnetic colloids have generated much interest in recent years. Specially, Fe3O4 nanoparticles have attracted a great deal of attention since their magnetic properties can be used for hyperthermia treatment or drug targeting. For example, enhanced levels of intracellular gene delivery can be achieved using Fe3O4 nano-vectors in the presence of an external magnetic field, a process known as 'magnetofection'. The low cytotoxicity, tunable particle size, ease of surface functionalization, and ability to generate thermal energy using an external alternating magnetic field (AMF) are properties have propelled Fe3O4 research to the forefront of nanoparticle research. The strategy of nanoparticle-mediated, AMF-induced heat generation has been used to effect intracellular hyperthermia. One application of this 'magnetic hyperthermia' is heat activated local delivery of a therapeutic effector (e.g.; drug or polynucleotide). This thesis describes the development of a magnetic nano-vector for AMF-induced, heat-activated pDNA and small molecule delivery. The use of heat-inducible vectors, such as heat shock protein ( hsp) genes, is a promising mode of gene therapy that would restrict gene expression to a local region by focusing a heat stimulus only at a target region. We thus aimed to design an Fe3O4 nanoparticle-mediated gene transfer vehicle for AMF-induced localized gene expression. We opted to use 'click' oximation techniques to assemble the magnetic gene transfer vector. Chapter 2 describes the synthesis, characterization, and transfection studies of the oxime ether lipid-based nano-magnetic vectors MLP and dMLP. The synthesis and characterization of a novel series of quaternary ammonium aminooxy reagents (2.1--2.4) is described. These cationic aminooxy compounds were loaded onto nanoparticles for ligation with carbonyl groups and also to impart a net positive charge on the nanoparticle surface. Our studies indicated that the

Simplified lentivirus vector production in protein-free media using polyethylenimine-mediated transfection.

Science.gov (United States)

Kuroda, Hitoshi; Kutner, Robert H; Bazan, Nicolas G; Reiser, Jakob

2009-05-01

During the past 12 years, lentiviral vectors have emerged as valuable tools for transgene delivery because of their ability to transduce nondividing cells and their capacity to sustain long-term transgene expression. Despite significant progress, the production of high-titer high-quality lentiviral vectors is cumbersome and costly. The most commonly used method to produce lentiviral vectors involves transient transfection using calcium phosphate (CaP)-mediated precipitation of plasmid DNAs. However, inconsistencies in pH can cause significant batch-to-batch variations in lentiviral vector titers, making this method unreliable. This study describes optimized protocols for lentiviral vector production based on polyethylenimine (PEI)-mediated transfection, resulting in more consistent lentiviral vector stocks. To achieve this goal, simple production methods for high-titer lentiviral vector production involving transfection of HEK 293T cells immediately after plating were developed. Importantly, high titers were obtained with cell culture media lacking serum or other protein additives altogether. As a consequence, large-scale lentiviral vector stocks can now be generated with fewer batch-to-batch variations and at reduced costs and with less labor compared to the standard protocols.

Polarization coupling of vector Bessel–Gaussian beams

International Nuclear Information System (INIS)

Takeuchi, Ryushi; Kozawa, Yuichi; Sato, Shunichi

2013-01-01

We report polarization coupling of radial and azimuthal electric field components of a vector light beam as predicted by the fact that the vector Helmholtz equation is expressed as coupled differential equations in cylindrical coordinates. To clearly observe the polarization variation of a beam as it propagates, higher order transverse modes of a vector Bessel–Gaussian beam were generated by a gain distribution modulation technique, which created a narrow ring-shaped gain region in a Nd:YVO 4 crystal. The polarization coupling was confirmed by the observation that the major polarization component of a vector Bessel–Gaussian beam alternates between radial and azimuthal components along with the propagation. (paper)

DNA Minicircle Technology Improves Purity of Adeno-associated Viral Vector Preparations

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Maria Schnödt

2016-01-01

Full Text Available Adeno-associated viral (AAV vectors are considered as one of the most promising delivery systems in human gene therapy. In addition, AAV vectors are frequently applied tools in preclinical and basic research. Despite this success, manufacturing pure AAV vector preparations remains a difficult task. While empty capsids can be removed from vector preparations owing to their lower density, state-of-the-art purification strategies as of yet failed to remove antibiotic resistance genes or other plasmid backbone sequences. Here, we report the development of minicircle (MC constructs to replace AAV vector and helper plasmids for production of both, single-stranded (ss and self-complementary (sc AAV vectors. As bacterial backbone sequences are removed during MC production, encapsidation of prokaryotic plasmid backbone sequences is avoided. This is of particular importance for scAAV vector preparations, which contained an unproportionally high amount of plasmid backbone sequences (up to 26.1% versus up to 2.9% (ssAAV. Replacing standard packaging plasmids by MC constructs not only allowed to reduce these contaminations below quantification limit, but in addition improved transduction efficiencies of scAAV preparations up to 30-fold. Thus, MC technology offers an easy to implement modification of standard AAV packaging protocols that significantly improves the quality of AAV vector preparations.

MRI in ocular drug delivery

OpenAIRE

Li, S. Kevin; Lizak, Martin J.; Jeong, Eun-Kee

2008-01-01

Conventional pharmacokinetic methods for studying ocular drug delivery are invasive and cannot be conveniently applied to humans. The advancement of MRI technology has provided new opportunities in ocular drug-delivery research. MRI provides a means to non-invasively and continuously monitor ocular drug-delivery systems with a contrast agent or compound labeled with a contrast agent. It is a useful technique in pharmacokinetic studies, evaluation of drug-delivery methods, and drug-delivery de...

Energy Reduction Multipath Routing Protocol for MANET Using Recoil Technique

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Rakesh Kumar Sahu

2018-04-01

Full Text Available In Mobile Ad-hoc networks (MANET, power conservation and utilization is an acute problem and has received significant attention from academics and industry in recent years. Nodes in MANET function on battery power, which is a rare and limited energy resource. Hence, its conservation and utilization should be done judiciously for the effective functioning of the network. In this paper, a novel protocol namely Energy Reduction Multipath Routing Protocol for MANET using Recoil Technique (AOMDV-ER is proposed, which conserves the energy along with optimal network lifetime, routing overhead, packet delivery ratio and throughput. It performs better than any other AODV based algorithms, as in AOMDV-ER the nodes transmit packets to their destination smartly by using a varying recoil off time technique based on their geographical location. This concept reduces the number of transmissions, which results in the improvement of network lifetime. In addition, the local level route maintenance reduces the additional routing overhead. Lastly, the prediction based link lifetime of each node is estimated which helps in reducing the packet loss in the network. This protocol has three subparts: an optimal route discovery algorithm amalgamation with the residual energy and distance mechanism; a coordinated recoiled nodes algorithm which eliminates the number of transmissions in order to reduces the data redundancy, traffic redundant, routing overhead, end to end delay and enhance the network lifetime; and a last link reckoning and route maintenance algorithm to improve the packet delivery ratio and link stability in the network. The experimental results show that the AOMDV-ER protocol save at least 16% energy consumption, 12% reduction in routing overhead, significant achievement in network lifetime and packet delivery ratio than Ad hoc on demand multipath distance vector routing protocol (AOMDV, Ad hoc on demand multipath distance vector routing protocol life

Vector Volume Flow in Arteriovenous Fistulas

DEFF Research Database (Denmark)

Hansen, Peter Møller; Heerwagen, Søren; Pedersen, Mads Møller

2013-01-01

, but is very challenging due to the angle dependency of the Doppler technique and the anatomy of the fistula. The angle independent vector ultrasound technique Transverse Oscillation provides a new and more intuitive way to measure volume flow in an arteriovenous fistula. In this paper the Transverse...

IMRT delivery to a moving target by dynamic MLC tracking: delivery for targets moving in two dimensions in the beam's eye view

International Nuclear Information System (INIS)

McQuaid, D; Webb, S

2006-01-01

A new modification of the dynamic multileaf collimator (dMLC) delivery technique for intensity-modulated therapy (IMRT) is outlined. This technique enables the tracking of a target moving through rigid-body translations in a 2D trajectory in the beam's eye view. The accuracy of the delivery versus that of deliveries with no tracking and of 1D tracking techniques is quantified with clinically derived intensity-modulated beams (IMBs). Leaf trajectories calculated in the target-reference frame were iteratively synchronized assuming regular target motion. This allowed the leaves defined in the lab-reference frame to simultaneously follow the target motion and to deliver the required IMB without violation of the leaf maximum-velocity constraint. The leaves are synchronized until the gradient of the leaf position at every instant is less than a calculated maximum. The delivered fluence in the target-reference frame was calculated with a simple primary-fluence model. The new 2D tracking technique was compared with the delivered fluence produced by no-tracking deliveries and by 1D tracking deliveries for 33 clinical IMBs. For the clinical IMBs normalized to a maximum fluence of 200 MUs, the rms difference between the desired and the delivered IMB was 15.6 ± 3.3 MU for the case of a no-tracking delivery, 7.9 ± 1.6 MU for the case where only the primary component of motion was corrected and 5.1 ± 1.1 MU for the 2D tracking delivery. The residual error is due to interpolation and sampling effects. The 2D tracking delivery technique requires an increase in the delivery time evaluated as between 0 and 50% of the unsynchronized delivery time for each beam with a mean increase of 13% for the IMBs tested. The 2D tracking dMLC delivery technique allows an optimized IMB to be delivered to moving targets with increased accuracy and with acceptable increases in delivery time. When combined with real-time knowledge of the target motion at delivery time, this technique facilitates

Design of colon targeting drug delivery systems using natural polymeric carriers and their evaluation by gamma scintigraphy technique

International Nuclear Information System (INIS)

Soni, P.S.; Sawarkar, S.P.; Deshpande, S.G.; Bajaj, A.N.

2004-01-01

Of late, there has been a great awareness in the concept of drug targeting and delivery to a specific site (organ, tissue or cell) in the body to maximize therapeutic effect and reduce toxicity. The various approaches of site-specific drug delivery are implantable pumps, adhesive patches impregnated with drugs, vesicle enclosed drugs and drug carriers. Colonic drug delivery is intended for local and systemic treatment in the diseases of colon like inflammatory bowel conditions. Several approaches using viz. pro-drugs, biodegradable polymers and pH sensitive polymer coatings have been used to achieve colonic delivery. Natural polysaccarides like guar gum and pectin are promising candidates because they are susceptible to degradation by colonic bacteria and thus can release the entrapped drug in the colonic region. These indigenous natural polymers are cheaply and readily available. They comprise of polygalactouronic acid and refractory to host enzymes present in the upper gastrointestinal tract and are degraded by the enzymes produced by the colonic microflora. They were evaluated as a colonic carrier using 5-amino salicylic acid (5-ASA) as a model drug. After successful in vitro testing, gamma scintigraphy technique was used to assess in-vivo behavior of the colon specific drug delivery after a coat of Guar gum and Pectin

Probabilistic Extraction Of Vectors In PIV

Science.gov (United States)

Humphreys, William M., Jr.

1994-01-01

Probabilistic technique for extraction of velocity vectors in particle-image velocimetry (PIV) implemented with much less computation. Double-exposure photograph of particles in flow illuminated by sheet of light provides data on velocity field of flow. Photograph converted into video image then digitized and processed by computer into velocity-field data. Velocity vectors in interrogation region chosen from magnitude and angle histograms constructed from centroid map of region.

Genetic stability of attenuated mengovirus vectors with duplicate primary cleavage sequences

International Nuclear Information System (INIS)

Binder, J.J.; Hoffman, M.A.; Palmenberg, A.C.

2003-01-01

Short poly(C)-tract Mengoviruses have proven vaccine efficacy in many species of animals. A novel vector for the delivery of foreign proteins was created by insertion of a second autoproteolytic primary cleavage cassette linked to a multiple cloning site (MCS) into an attenuated variant of Mengo. Nineteen cDNAs from foreign sequences that ranged from 39 to 1653 bases were cloned into the MCS. The viral reading frame was maintained and translation resulted in dual, autocatalytic excision of the foreign peptides without disruption of any Mengo proteins. All cDNAs except those with the largest insertions produced viable virus. Active proteins such as GFP, CAT, and SIV p27 were expressed within infected cells. Relative to parental Mengo, the growth kinetics and genetic stability of each vector was inversely proportional to the size of the inserted sequence. While segments up to 1000 bases could be carried, inserts greater than 500-600 bases were usually reduced in size during serial passage. The limit on carrying capacity was probably due to difficulties in virion assembly or particle stability. Yet for inserts less than 500-600 bases, the Mengo vectors provided an effective system for the delivery of foreign epitopes into cells and mice

Tailoring the dendrimer core for efficient gene delivery.

Science.gov (United States)

Hu, Jingjing; Hu, Ke; Cheng, Yiyun

2016-04-15

Dendrimers have been widely used as non-viral gene vectors due to well-defined chemical structures, high density of cationic charges and ease of surface modification. Although a large number of studies have reported the important roles of dendrimer architecture, component, generation and surface functionality in gene delivery, the effect of dendrimer core on this issue still remains unclear. Recent literatures suggest that a slight alternation in dendrimer core has a profound effect in the transfection efficacy and biocompatibility. In this review, we will discuss the transfection mechanism of dendrimers with different types of cores in respect of flexibility, hydrophobicity and functionality. We hope to open a possibility of designing efficient dendrimers for gene delivery by choosing a proper dendrimer core. As a branch of researches on dendrimers and dendritic polymers, the design of biocompatible and high efficient polymeric gene carriers has attracted increasing attentions during these years. Although the effect of dendrimer generation, species, architecture and surface functionality on gene delivery have been widely reported, the effect of dendrimer core on this issue still remains unclear. Recent literatures suggest that a minor variation on the dendrimer core has a profound effect in the transfection efficacy and biocompatibility. This critical review summarized the dendrimers with different types of cores and discussed the transfection mechanism with particular focus on the flexibility, hydrophobicity, and functionality. It is hoped to provide a new insight to design efficient and safe dendrimer-based gene vectors by choosing a proper core. To the best of our knowledge, this is the first review on the effect of dendrimer core on gene delivery. The findings obtained in this filed are of central importance in the design of efficient polymeric gene vectors. This article will appeal a wide readership such as physical chemist, dendrimer chemist, biological

Transcutaneous delivery of T Cell-inducing viral vector Malaria vaccines by microneedle patches

OpenAIRE

2011-01-01

There is an urgent need for improvements to existing vaccine delivery technologies to run parallel with the development of new-generation vaccines. The burdens of needle-based immunisation strategies are exacerbated by poor resource provision in such areas as sub-Saharan Africa, where annual malaria mortality stands at 860,000. Needle-free delivery of vaccine to the skin holds promise for improved immunogenicity with lower doses of vaccine, in addition to significant logistical advantages. Va...

Speech Data Compression using Vector Quantization

OpenAIRE

H. B. Kekre; Tanuja K. Sarode

2008-01-01

Mostly transforms are used for speech data compressions which are lossy algorithms. Such algorithms are tolerable for speech data compression since the loss in quality is not perceived by the human ear. However the vector quantization (VQ) has a potential to give more data compression maintaining the same quality. In this paper we propose speech data compression algorithm using vector quantization technique. We have used VQ algorithms LBG, KPE and FCG. The results table s...

Ces-VP: consultation expert system for vector programming of nuclear codes

International Nuclear Information System (INIS)

Fujisaki, Masahide; Makino, Mitsuhiro; Ishiguro, Misako

1988-08-01

Ces-VP is a prototype rule-based expert system for consulting the vector programming, based on the knowledge of vectorization of nuclear codes at JAERI during these 10 years. Experts in vectorization can restructure nuclear codes with high performance on vector processors, since they have know-how for choosing the best technique among a lot of techniques that were acquired from the experience of vectorization in the past. Frequency in trial and error will be reduced if a beginner can easily use the know-how of experts. In this report, at first the contents of Ces-VP and its intention are shown. Then, the method for acquiring the know-how of vectorization and the method for making rules from the know-how are described. The outline of Ces-VP implemented on Fujitsu expert tool ESHELL is described. Finally, the availability of Ces-VP is evaluated from the data gathered from practical use and its present problems are discussed. (author)

"Trying, But Failing" - The Role of Inhaler Technique and Mode of Delivery in Respiratory Medication Adherence.

Science.gov (United States)

Braido, Fulvio; Chrystyn, Henry; Baiardini, Ilaria; Bosnic-Anticevich, Sinthia; van der Molen, Thys; Dandurand, Ronald J; Chisholm, Alison; Carter, Victoria; Price, David

2016-01-01

Inhaled therapies are the backbone of asthma and chronic obstructive pulmonary disease management, helping to target therapy at the airways. Adherence to prescribed treatment is necessary to ensure achievement of the clinician's desired therapeutic effect. In the case of inhaled therapies, this requires patients' acceptance of their need for inhaled therapy together with successful mastery of the inhaler technique specific to their device(s). This article reviews a number of challenges and barriers that inhaled mode of delivery can pose to optimum adherence-to therapy initiation and, thereafter, to successful implementation and persistence. The potential effects on adherence of different categories of devices, their use in multiplicity, and the mixing of device categories are discussed. Common inhaler errors identified by the international Implementing Helping Asthma in Real People (iHARP) study are summarized, and adherence intervention opportunities for health care professionals are offered. Better knowledge of common errors can help practicing clinicians identify their occurrence among patients and prompt remedial actions, such as tailored education, inhaler technique retraining, and/or shared decision making with patients regarding suitable alternatives. Optimizing existing therapy delivery, or switching to a suitable alternative, can help avoid unnecessary escalation of treatment and health care resources. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Effects of Chemical and Physical Enhancement Techniques on Transdermal Delivery of Cyanocobalamin (Vitamin B12 In Vitro

Directory of Open Access Journals (Sweden)

Ajay K. Banga

2011-08-01

Full Text Available Vitamin B12 deficiency, which may result in anemia and nerve damage if left untreated, is currently treated by administration of cyanocobalamin via oral or intramuscular routes. However, these routes are associated with absorption and compliance issues which have prompted us to investigate skin as an alternative site of administration. Delivery through skin, however, is restricted to small and moderately lipophilic molecules due to the outermost barrier, the stratum corneum (SC. In this study, we have investigated the effect of different enhancement techniques, chemical enhancers (ethanol, oleic acid, propylene glycol, iontophoresis (anodal iontophoresis and microneedles (soluble maltose microneedles, which may overcome this barrier and improve cyanocobalamin delivery. Studies with different chemical enhancer formulations indicated that ethanol and oleic acid decreased the lag time while propylene glycol based formulations increased the lag time. The formulation with ethanol (50%, oleic acid (10% and propylene glycol (40% showed the maximum improvement in delivery. Iontophoresis and microneedle treatments resulted in enhanced permeation levels compared to passive controls. These enhancement approaches can be explored further to develop alternative treatment regimens.

Methods of treating Parkinson's disease using viral vectors

Energy Technology Data Exchange (ETDEWEB)

Bankiewicz, Krystof; Cunningham, Janet

2016-11-15

Methods of delivering viral vectors, particularly recombinant adeno-associated virus (rAAV) virions, to the central nervous system (CNS) using convection enhanced delivery (CED) are provided. The rAAV virions include a nucleic acid sequence encoding a therapeutic polypeptide. The methods can be used for treating CNS disorders such as for treating Parkinson's Disease.

Bioresponsive nanoparticles based on poly(amidoamine)s for protein delivery

NARCIS (Netherlands)

Coué, G.M.J.P.C.

2011-01-01

This study describes the design and development of multifuctional poly(amidoamine)s (PAAs) capable to form self-assembled nanocomplexes with peptides and proteins, as functional bioresponsive vectors for protein delivery to targeting cells in vitro and in vivo. The representative examples of this

Evaluation of helper-dependent canine adenovirus vectors in a 3D human CNS model

Science.gov (United States)

Simão, Daniel; Pinto, Catarina; Fernandes, Paulo; Peddie, Christopher J.; Piersanti, Stefania; Collinson, Lucy M.; Salinas, Sara; Saggio, Isabella; Schiavo, Giampietro; Kremer, Eric J.; Brito, Catarina; Alves, Paula M.

2017-01-01

Gene therapy is a promising approach with enormous potential for treatment of neurodegenerative disorders. Viral vectors derived from canine adenovirus type 2 (CAV-2) present attractive features for gene delivery strategies in the human brain, by preferentially transducing neurons, are capable of efficient axonal transport to afferent brain structures, have a 30-kb cloning capacity and have low innate and induced immunogenicity in pre-clinical tests. For clinical translation, in-depth pre-clinical evaluation of efficacy and safety in a human setting is primordial. Stem cell-derived human neural cells have a great potential as complementary tools by bridging the gap between animal models, which often diverge considerably from human phenotype, and clinical trials. Herein, we explore helper-dependent CAV-2 (hd-CAV-2) efficacy and safety for gene delivery in a human stem cell-derived 3D neural in vitro model. Assessment of hd-CAV-2 vector efficacy was performed at different multiplicities of infection, by evaluating transgene expression and impact on cell viability, ultrastructural cellular organization and neuronal gene expression. Under optimized conditions, hd-CAV-2 transduction led to stable long-term transgene expression with minimal toxicity. hd-CAV-2 preferentially transduced neurons, while human adenovirus type 5 (HAdV5) showed increased tropism towards glial cells. This work demonstrates, in a physiologically relevant 3D model, that hd-CAV-2 vectors are efficient tools for gene delivery to human neurons, with stable long-term transgene expression and minimal cytotoxicity. PMID:26181626

Reporter gene expression in fish following cutaneous infection with pantropic retroviral vectors.

Science.gov (United States)

Paul, T A; Burns, J C; Shike, H; Getchell, R; Bowser, P R; Whitlock, K E; Casey, J W

2001-06-01

A central issue in gene delivery systems is choosing promoters that will direct defined and sustainable levels of gene expression. Pantropic retroviral vectors provide a means to insert genes into either somatic or germline cells. In this study, we focused on somatic cell infection by evaluating the activity of 3 promoters inserted by vectors into fish cell lines and fish skin using pantropic retroviruses. In bluegill and zebrafish cell lines, the highest levels of luciferase expression were observed from the 5' murine leukemia virus long terminal repeat of the retroviral vector. The Rous sarcoma virus long terminal repeat and cytomegalovirus early promoter, as internal promoters, generated lower levels of luciferase. Luciferase reporter vectors infected zebrafish skin, as measured by the presence of viral DNA, and expressed luciferase. We infected developing walleye dermal sarcomas with retroviral vectors to provide an environment with enhanced cell proliferation, a condition necessary for integration of the provirus into the host genome. We demonstrated a 4-fold to 7-fold increase in luciferase gene expression in tumor tissue over infections in normal walleye skin.

Safety and Efficacy of AAV Retrograde Pancreatic Ductal Gene Delivery in Normal and Pancreatic Cancer Mice.

Science.gov (United States)

Quirin, Kayla A; Kwon, Jason J; Alioufi, Arafat; Factora, Tricia; Temm, Constance J; Jacobsen, Max; Sandusky, George E; Shontz, Kim; Chicoine, Louis G; Clark, K Reed; Mendell, Joshua T; Korc, Murray; Kota, Janaiah

2018-03-16

Recombinant adeno-associated virus (rAAV)-mediated gene delivery shows promise to transduce the pancreas, but safety/efficacy in a neoplastic context is not well established. To identify an ideal AAV serotype, route, and vector dose and assess safety, we have investigated the use of three AAV serotypes (6, 8, and 9) expressing GFP in a self-complementary (sc) AAV vector under an EF1α promoter (scAAV.GFP) following systemic or retrograde pancreatic intraductal delivery. Systemic delivery of scAAV9.GFP transduced the pancreas with high efficiency, but gene expression did not exceed >45% with the highest dose, 5 × 10 12 viral genomes (vg). Intraductal delivery of 1 × 10 11 vg scAAV6.GFP transduced acini, ductal cells, and islet cells with >50%, ∼48%, and >80% efficiency, respectively, and >80% pancreatic transduction was achieved with 5 × 10 11 vg. In a Kras G12D -driven pancreatic cancer mouse model, intraductal delivery of scAAV6.GFP targeted acini, epithelial, and stromal cells and exhibited persistent gene expression 5 months post-delivery. In normal mice, intraductal delivery induced a transient increase in serum amylase/lipase that resolved within a day of infusion with no sustained pancreatic inflammation or fibrosis. Similarly, in PDAC mice, intraductal delivery did not increase pancreatic intraepithelial neoplasia progression/fibrosis. Our study demonstrates that scAAV6 targets the pancreas/neoplasm efficiently and safely via retrograde pancreatic intraductal delivery.

Safety and Efficacy of AAV Retrograde Pancreatic Ductal Gene Delivery in Normal and Pancreatic Cancer Mice

Directory of Open Access Journals (Sweden)

Kayla A. Quirin

2018-03-01

Full Text Available Recombinant adeno-associated virus (rAAV-mediated gene delivery shows promise to transduce the pancreas, but safety/efficacy in a neoplastic context is not well established. To identify an ideal AAV serotype, route, and vector dose and assess safety, we have investigated the use of three AAV serotypes (6, 8, and 9 expressing GFP in a self-complementary (sc AAV vector under an EF1α promoter (scAAV.GFP following systemic or retrograde pancreatic intraductal delivery. Systemic delivery of scAAV9.GFP transduced the pancreas with high efficiency, but gene expression did not exceed >45% with the highest dose, 5 × 1012 viral genomes (vg. Intraductal delivery of 1 × 1011 vg scAAV6.GFP transduced acini, ductal cells, and islet cells with >50%, ∼48%, and >80% efficiency, respectively, and >80% pancreatic transduction was achieved with 5 × 1011 vg. In a KrasG12D-driven pancreatic cancer mouse model, intraductal delivery of scAAV6.GFP targeted acini, epithelial, and stromal cells and exhibited persistent gene expression 5 months post-delivery. In normal mice, intraductal delivery induced a transient increase in serum amylase/lipase that resolved within a day of infusion with no sustained pancreatic inflammation or fibrosis. Similarly, in PDAC mice, intraductal delivery did not increase pancreatic intraepithelial neoplasia progression/fibrosis. Our study demonstrates that scAAV6 targets the pancreas/neoplasm efficiently and safely via retrograde pancreatic intraductal delivery.

Bioinspired Star-Shaped Poly(l-lysine) Polypeptides: Efficient Polymeric Nanocarriers for the Delivery of DNA to Mesenchymal Stem Cells.

Science.gov (United States)

Walsh, David P; Murphy, Robert D; Panarella, Angela; Raftery, Rosanne M; Cavanagh, Brenton; Simpson, Jeremy C; O'Brien, Fergal J; Heise, Andreas; Cryan, Sally-Ann

2018-05-07

The field of tissue engineering is increasingly recognizing that gene therapy can be employed for modulating in vivo cellular response thereby guiding tissue regeneration. However, the field lacks a versatile and biocompatible gene delivery platform capable of efficiently delivering transgenes to mesenchymal stem cells (MSCs), a cell type often refractory to transfection. Herein, we describe the extensive and systematic exploration of three architectural variations of star-shaped poly(l-lysine) polypeptide (star-PLL) with varying number and length of poly(l-lysine) arms as potential nonviral gene delivery vectors for MSCs. We demonstrate that star-PLL vectors are capable of self-assembling with pDNA to form stable, cationic nanomedicines. Utilizing high content screening, live cell imaging, and mechanistic uptake studies we confirm the intracellular delivery of pDNA by star-PLLs to MSCs is a rapid process, which likely proceeds via a clathrin-independent mechanism. We identify a star-PLL composition with 64 poly(l-lysine) arms and five l-lysine subunits per arm as a particularly efficient vector that is capable of delivering both reporter genes and the therapeutic transgenes bone morphogenetic protein-2 and vascular endothelial growth factor to MSCs. This composition facilitated a 1000-fold increase in transgene expression in MSCs compared to its linear analogue, linear poly(l-lysine). Furthermore, it demonstrated comparable transgene expression to the widely used vector polyethylenimine using a lower pDNA dose with significantly less cytotoxicity. Overall, this study illustrates the ability of the star-PLL vectors to facilitate efficient, nontoxic nucleic acid delivery to MSCs thereby functioning as an innovative nanomedicine platform for tissue engineering applications.

Viruses vector control proposal: genus Aedes emphasis

Directory of Open Access Journals (Sweden)

Nelson Nogueira Reis

2017-07-01

Full Text Available The dengue fever is a major public health problem in the world. In Brazil, in 2015, there were 1,534,932 cases, being 20,320 cases of severe form, and 811 deaths related to this disease. The distribution of Aedes aegypti, the vector, is extensive. Recently, Zika and Chikungunya viruses had arisen, sharing the same vector as dengue and became a huge public health issue. Without specific treatment, it is urgently required as an effective vector control. This article is focused on reviewing vector control strategies, their effectiveness, viability and economical impact. Among all, the Sterile Insect Technique is highlighted as the best option to be adopted in Brazil, once it is largely effectively used in the USA and Mexico for plagues related to agribusiness.

Vector wind and vector wind shear models 0 to 27 km altitude for Cape Kennedy, Florida, and Vandenberg AFB, California

Science.gov (United States)

Smith, O. E.

1976-01-01

The techniques are presented to derive several statistical wind models. The techniques are from the properties of the multivariate normal probability function. Assuming that the winds can be considered as bivariate normally distributed, then (1) the wind components and conditional wind components are univariate normally distributed, (2) the wind speed is Rayleigh distributed, (3) the conditional distribution of wind speed given a wind direction is Rayleigh distributed, and (4) the frequency of wind direction can be derived. All of these distributions are derived from the 5-sample parameter of wind for the bivariate normal distribution. By further assuming that the winds at two altitudes are quadravariate normally distributed, then the vector wind shear is bivariate normally distributed and the modulus of the vector wind shear is Rayleigh distributed. The conditional probability of wind component shears given a wind component is normally distributed. Examples of these and other properties of the multivariate normal probability distribution function as applied to Cape Kennedy, Florida, and Vandenberg AFB, California, wind data samples are given. A technique to develop a synthetic vector wind profile model of interest to aerospace vehicle applications is presented.

Feasibility of baculovirus-mediated reporter gene delivery for efficient monitoring of islet transplantation in vivo

International Nuclear Information System (INIS)

Liu, Shuai; Pan, Yu; Lv, Jing; Wu, Haifei; Tian, Jingyan; Zhang, Yifan

2014-01-01

Objective: The objective of this study was to explore the feasibility of baculovirus vector-mediated sodium iodide symporter (NIS) gene delivery to monitor islet transplantation. Methods: Baculovirus vectors expressing green fluorescent protein (GFP) or NIS (Bac-GFP and Bac-NIS) were established using the Bac-to-Bac baculovirus expression system. The GFP expression of Bac-GFP-infected rat islets was observed in vitro by fluorescence microscopy. Iodine uptake and inhibition of iodine uptake by NaClO 4 in Bac-NIS-infected islets were dynamically monitored in vitro. Bac-GFP- or Bac-NIS-infected islets were implanted into the left axillary cavity of NOD-SCID mice, and fluorescence imaging and 125 I NanoSPECT/CT imaging were subsequently performed in vivo. Results: Bac-GFP efficiently infected rat islets (over 95% infected at MOI = 40), and the expression of GFP lasted approximately two weeks. NaClO 4 could inhibit iodine uptake by Bac-NIS-infected islets. In vivo imaging revealed that the fluorescence intensity of the transplant sites in Bac-GFP-infected groups was significantly higher than in the non-infected group. Grafts could be clearly observed by 125 I NanoSPECT/CT imaging for up to 8 h. Conclusion: Baculovirus vectors are powerful vehicles for studying rat islets in gene delivery. It is feasible to use a baculovirus vector to delivery an NIS gene for non-invasive monitoring transplanted islets in vivo by the expression of the target gene

Efficient implementations of block sparse matrix operations on shared memory vector machines

International Nuclear Information System (INIS)

Washio, T.; Maruyama, K.; Osoda, T.; Doi, S.; Shimizu, F.

2000-01-01

In this paper, we propose vectorization and shared memory-parallelization techniques for block-type random sparse matrix operations in finite element (FEM) applications. Here, a block corresponds to unknowns on one node in the FEM mesh and we assume that the block size is constant over the mesh. First, we discuss some basic vectorization ideas (the jagged diagonal (JAD) format and the segmented scan algorithm) for the sparse matrix-vector product. Then, we extend these ideas to the shared memory parallelization. After that, we show that the techniques can be applied not only to the sparse matrix-vector product but also to the sparse matrix-matrix product, the incomplete or complete sparse LU factorization and preconditioning. Finally, we report the performance evaluation results obtained on an NEC SX-4 shared memory vector machine for linear systems in some FEM applications. (author)

Introduction to the ultrasound targeted microbubble destruction technique.

Science.gov (United States)

Walton, Chad B; Anderson, Cynthia D; Boulay, Rachel; Shohet, Ralph V

2011-06-12

In UTMD, bioactive molecules, such as negatively charged plasmid DNA vectors encoding a gene of interest, are added to the cationic shells of lipid microbubble contrast agents. In mice these vector-carrying microbubbles can be administered intravenously or directly to the left ventricle of the heart. In larger animals they can also be infused through an intracoronary catheter. The subsequent delivery from the circulation to a target organ occurs by acoustic cavitation at a resonant frequency of the microbubbles. It seems likely that the mechanical energy generated by the microbubble destruction results in transient pore formation in or between the endothelial cells of the microvasculature of the targeted region. As a result of this sonoporation effect, the transfection efficiency into and across the endothelial cells is enhanced, and transgene-encoding vectors are deposited into the surrounding tissue. Plasmid DNA remaining in the circulation is rapidly degraded by nucleases in the blood, which further reduces the likelihood of delivery to non-sonicated tissues and leads to highly specific target-organ transfection.

Large-scale production of lentiviral vector in a closed system hollow fiber bioreactor

Directory of Open Access Journals (Sweden)

Jonathan Sheu

Full Text Available Lentiviral vectors are widely used in the field of gene therapy as an effective method for permanent gene delivery. While current methods of producing small scale vector batches for research purposes depend largely on culture flasks, the emergence and popularity of lentiviral vectors in translational, preclinical and clinical research has demanded their production on a much larger scale, a task that can be difficult to manage with the numbers of producer cell culture flasks required for large volumes of vector. To generate a large scale, partially closed system method for the manufacturing of clinical grade lentiviral vector suitable for the generation of induced pluripotent stem cells (iPSCs, we developed a method employing a hollow fiber bioreactor traditionally used for cell expansion. We have demonstrated the growth, transfection, and vector-producing capability of 293T producer cells in this system. Vector particle RNA titers after subsequent vector concentration yielded values comparable to lentiviral iPSC induction vector batches produced using traditional culture methods in 225 cm2 flasks (T225s and in 10-layer cell factories (CF10s, while yielding a volume nearly 145 times larger than the yield from a T225 flask and nearly three times larger than the yield from a CF10. Employing a closed system hollow fiber bioreactor for vector production offers the possibility of manufacturing large quantities of gene therapy vector while minimizing reagent usage, equipment footprint, and open system manipulation.

Development of Novel Adenoviral Vectors to Overcome Challenges Observed With HAdV-5–based Constructs

Science.gov (United States)

Alonso-Padilla, Julio; Papp, Tibor; Kaján, Győző L; Benkő, Mária; Havenga, Menzo; Lemckert, Angelique; Harrach, Balázs; Baker, Andrew H

2016-01-01

Recombinant vectors based on human adenovirus serotype 5 (HAdV-5) have been extensively studied in preclinical models and clinical trials over the past two decades. However, the thorough understanding of the HAdV-5 interaction with human subjects has uncovered major concerns about its product applicability. High vector-associated toxicity and widespread preexisting immunity have been shown to significantly impede the effectiveness of HAdV-5–mediated gene transfer. It is therefore that the in-depth knowledge attained working on HAdV-5 is currently being used to develop alternative vectors. Here, we provide a comprehensive overview of data obtained in recent years disqualifying the HAdV-5 vector for systemic gene delivery as well as novel strategies being pursued to overcome the limitations observed with particular emphasis on the ongoing vectorization efforts to obtain vectors based on alternative serotypes. PMID:26478249

Novel Drug Delivery Technique for Breast Cancer Therapy

National Research Council Canada - National Science Library

Esenaliev, Rinat O

2004-01-01

.... We proposed to complete Task 3 and to implement Task 4 in the third year of the project. Task 3 focuses on in vivo studies of efficacy of cancer therapy with the use of ultrasound-enhanced delivery of anti-cancer drug 5-FU...

“Marker of Self” CD47 on lentiviral vectors decreases macrophage-mediated clearance and increases delivery to SIRPA-expressing lung carcinoma tumors

Directory of Open Access Journals (Sweden)

Nisha G Sosale

2016-01-01

Full Text Available Lentiviruses infect many cell types and are now widely used for gene delivery in vitro, but in vivo uptake of these foreign vectors by macrophages is a limitation. Lentivectors are produced here from packaging cells that overexpress “Marker of Self” CD47, which inhibits macrophage uptake of cells when prophagocytic factors are also displayed. Single particle analyses show “hCD47-Lenti” display properly oriented human-CD47 for interactions with the macrophage's inhibitory receptor SIRPA. Macrophages derived from human and NOD/SCID/Il2rg−/− (NSG mice show a SIRPA-dependent decrease in transduction, i.e., transgene expression, by hCD47-Lenti compared to control Lenti. Consistent with known “Self” signaling pathways, macrophage transduction by control Lenti is decreased by drug inhibition of Myosin-II to the same levels as hCD47-Lenti. In contrast, human lung carcinoma cells express SIRPA and use it to enhance transduction by hCD47-Lenti- as illustrated by more efficient gene deletion using CRISPR/Cas9. Intravenous injection of hCD47-Lenti into NSG mice shows hCD47 prolongs circulation, unless a blocking anti-SIRPA is preinjected. In vivo transduction of spleen and liver macrophages also decreases for hCD47-Lenti while transduction of lung carcinoma xenografts increases. hCD47 could be useful when macrophage uptake is limiting on other viral vectors that are emerging in cancer treatments (e.g., Measles glycoprotein-pseudotyped lentivectors and also in targeting various SIRPA-expressing tumors such as glioblastomas.

Cell-penetrating peptides as tools to enhance non-injectable delivery of biopharmaceuticals

DEFF Research Database (Denmark)

Kristensen, Mie; Nielsen, Hanne Mørck

2016-01-01

Non-injectable delivery of peptide and protein drugs is hampered by their labile nature, hydrophilicity, and large molecular size; thus limiting their permeation across mucosae, which represent major biochemical and physical barriers to drugs administered via e.g. the oral, nasal, and pulmonary...... routes. However, in recent years cell-penetrating peptides (CPP) have emerged as promising tools to enhance mucosal delivery of co-administered or conjugated peptide and protein cargo and more advanced CPP-cargo formulations are emerging. CPPs act as transepithelial delivery vectors, but the mechanism...... understanding, documentation of CPP-mediated delivery in higher animal species than rodent as well as extensive toxicological studies are necessary for CPP-containing non-injectable DDSs to reach the clinic....

Iontophoresis Transcorneal Delivery Technique for Transepithelial Corneal Collagen Crosslinking With Riboflavin in a Rabbit Model.

Science.gov (United States)

Cassagne, Myriam; Laurent, Camille; Rodrigues, Magda; Galinier, Anne; Spoerl, Eberhard; Galiacy, Stéphane D; Soler, Vincent; Fournié, Pierre; Malecaze, François

2016-02-01

We compared an iontophoresis riboflavin delivery technique for transepithelial corneal collagen crosslinking (I-CXL) with a conventional CXL (C-CXL). We designed three experimental sets using 152 New Zealand rabbits to study riboflavin application by iontophoresis using charged riboflavin solution (Ricrolin+) with a 1-mA current for 5 minutes. The first set was to compare riboflavin concentration measured by HPLC in corneas after iontophoresis or conventional riboflavin application. The second set was to analyze autofluorescence and stromal collagen modification immediately and 14 days after I-CXL or C-CXL, by using nonlinear two-photon microscopy (TP) and second harmonic generation (SHG). In the third set, physical modifications after I-CXL and C-CXL were evaluated by stress-strain measurements and by studying corneal resistance against collagenase digestion. Based on HPLC analysis, we found that iontophoresis allowed riboflavin diffusion with 2-fold less riboflavin concentration than conventional application (936.2 ± 312.5 and 1708 ± 908.3 ng/mL, respectively, P riboflavin delivery in crosslinking treatments, preserving the epithelium.

Vectorization of nuclear codes 90-1

International Nuclear Information System (INIS)

Nonomiya, Iwao; Nemoto, Toshiyuki; Ishiguro, Misako; Harada, Hiroo; Hori, Takeo.

1990-09-01

The vectorization has been made for four codes: SONATINA-2V HTTR version, TRIDOSE, VIENUS, and SCRYU. SONATINA-2V HTTR version is a code for analyzing the dynamic behavior of fuel blocks in the vertical slice of the HTGR (High Temperature Gas-cooled Reactor) core under seismic perturbation, TRIDOSE is a code for calculating environmental tritium concentration and dose, VIENUS is a code for analyzing visco elastic stress of the fuel block of HTTR (High Temperature gas-cooled Test Reactor), and SCRYU is a thermal-hydraulics code with boundary fitted coordinate system. The total speedup ratio of the vectorized versions to the original scalar ones is 5.2 for SONATINA-2V HTTR version. 5.9 ∼ 6.9 for TRIDOSE, 6.7 for VIENUS, 7.6 for SCRYU, respectively. In this report, we describe outline of codes, techniques used for the vectorization, verification of computed results, and speedup effect on the vectorized codes. (author)

Utilization of combined remote sensing techniques to detect environmental variables influencing malaria vector densities in rural West Africa

Directory of Open Access Journals (Sweden)

Dambach Peter

2012-03-01

Full Text Available Abstract Introduction The use of remote sensing has found its way into the field of epidemiology within the last decades. With the increased sensor resolution of recent and future satellites new possibilities emerge for high resolution risk modeling and risk mapping. Methods A SPOT 5 satellite image, taken during the rainy season 2009 was used for calculating indices by combining the image's spectral bands. Besides the widely used Normalized Difference Vegetation Index (NDVI other indices were tested for significant correlation against field observations. Multiple steps, including the detection of surface water, its breeding appropriateness for Anopheles and modeling of vector imagines abundance, were performed. Data collection on larvae, adult vectors and geographic parameters in the field, was amended by using remote sensing techniques to gather data on altitude (Digital Elevation Model = DEM, precipitation (Tropical Rainfall Measurement Mission = TRMM, land surface temperatures (LST. Results The DEM derived altitude as well as indices calculations combining the satellite's spectral bands (NDTI = Normalized Difference Turbidity Index, NDWI Mac Feeters = Normalized Difference Water Index turned out to be reliable indicators for surface water in the local geographic setting. While Anopheles larvae abundance in habitats is driven by multiple, interconnected factors - amongst which the NDVI - and precipitation events, the presence of vector imagines was found to be correlated negatively to remotely sensed LST and positively to the cumulated amount of rainfall in the preceding 15 days and to the Normalized Difference Pond Index (NDPI within the 500 m buffer zone around capture points. Conclusions Remotely sensed geographical and meteorological factors, including precipitations, temperature, as well as vegetation, humidity and land cover indicators could be used as explanatory variables for surface water presence, larval development and imagines

Delivery and evaluation of recombinant adeno-associated viral vectors in the equine distal extremity for the treatment of laminitis.

Science.gov (United States)

Mason, J B; Gurda, B L; Van Wettere, A; Engiles, J B; Wilson, J M; Richardson, D W

2017-01-01

Our long-term aim is to develop a gene therapy approach for the prevention of laminitis in the contralateral foot of horses with major musculoskeletal injuries and non-weightbearing lameness. The goal of this study was to develop a practical method to efficiently deliver therapeutic proteins deep within the equine foot. Randomised in vivo experiment. We used recombinant adeno-associated viral vectors (rAAVs) to deliver marker genes using regional limb perfusion through the palmar digital artery of the horse. Vector serotypes rAAV2/1, 2/8 and 2/9 all successfully transduced equine foot tissues and displayed similar levels and patterns of transduction. The regional distribution of transduction within the foot decreased with decreasing vector dose. The highest transduction values were seen in the sole and coronary regions and the lowest transduction values were detected in the dorsal hoof-wall region. The use of a surfactant-enriched vector diluent increased regional distribution of the vector and improved the transduction in the hoof-wall region. The hoof-wall region of the foot, which exhibited the lowest levels of transduction using saline as the vector diluent, displayed a dramatic increase in transduction when surfactant was included in the vector diluent (9- to 81-fold increase). In transduced tissues, no significant difference was observed between promoters (chicken β-actin vs. cytomegalovirus) for gene expression. All horses tested for vector-neutralising antibodies were positive for serotype-specific neutralising antibodies to rAAV2/5. The current experiments demonstrate that transgenes can be successfully delivered to the equine distal extremity using rAAV vectors and that serotypes 2/8, 2/9 and 2/1 can successfully transduce tissues of the equine foot. When the vector was diluted with surfactant-containing saline, the level of transduction increased dramatically. The increased level of transduction due to the addition of surfactant also improved the

Bioreducible Fluorinated Peptide Dendrimers Capable of Circumventing Various Physiological Barriers for Highly Efficient and Safe Gene Delivery.

Science.gov (United States)

Cai, Xiaojun; Jin, Rongrong; Wang, Jiali; Yue, Dong; Jiang, Qian; Wu, Yao; Gu, Zhongwei

2016-03-09

Polymeric vectors have shown great promise in the development of safe and efficient gene delivery systems; however, only a few have been developed in clinical settings due to poor transport across multiple physiological barriers. To address this issue and promote clinical translocation of polymeric vectors, a new type of polymeric vector, bioreducible fluorinated peptide dendrimers (BFPDs), was designed and synthesized by reversible cross-linking of fluorinated low generation peptide dendrimers. Through masterly integration all of the features of reversible cross-linking, fluorination, and polyhedral oligomeric silsesquioxane (POSS) core-based peptide dendrimers, this novel vector exhibited lots of unique features, including (i) inactive surface to resist protein interactions; (ii) virus-mimicking surface topography to augment cellular uptake; (iii) fluorination-mediated efficient cellular uptake, endosome escape, cytoplasm trafficking, and nuclear entry, and (iv) disulfide-cleavage-mediated polyplex disassembly and DNA release that allows efficient DNA transcription. Noteworthy, all of these features are functionally important and can synergistically facilitate DNA transport from solution to the nucleus. As a consequences, BFPDs showed excellent gene transfection efficiency in several cell lines (∼95% in HEK293 cells) and superior biocompatibility compared with polyethylenimine (PEI). Meanwhile BFPDs provided excellent serum resistance in gene delivery. More importantly, BFPDs offer considerable in vivo gene transfection efficiency (in muscular tissues and in HepG2 tumor xenografts), which was approximately 77-fold higher than that of PEI in luciferase activity. These results suggest bioreducible fluorinated peptide dendrimers are a new class of highly efficient and safe gene delivery vectors and should be used in clinical settings.

Vectorization and multitasking with a Monte-Carlo code for neutron transport problems

International Nuclear Information System (INIS)

Chauvet, Y.

1985-04-01

This paper summarizes two improvements of a Monte Carlo code by resorting to vectorization and multitasking techniques. After a short presentation of the physical problem to solve and a description of the main difficulties to produce an efficient coding, this paper introduces the vectorization principles employed and briefly describes how the vectorized algorithm works. Next, measured performances on CRAY 1S, CYBER 205 and CRAY X-MP are compared. The second part of this paper is devoted to multitasking technique. Starting from the standard multitasking tools available with FORTRAN on CRAY X-MP/4, a multitasked algorithm and its measured speed-ups are presented. In conclusion we prove that vector and parallel computers are a great opportunity for such Monte Carlo algorithms

Functionalized linear poly(amidoamine)s are efficient vectors for intracellular protein delivery

NARCIS (Netherlands)

Coué, G.M.J.P.C.; Engbersen, Johannes F.J.

2011-01-01

An effective intracellular protein delivery system was developed based on functionalized linear poly(amidoamine)s (PAAs) that form self-assembled cationic nanocomplexes with oppositely charged proteins. Three differently functionalized PAAs were synthesized, two of these having repetitive disulfide

Optimization of formulation and delivery technology of entomopathogenic fungi for malaria vector control

NARCIS (Netherlands)

Mnyone, L.L.

2010-01-01

Vector control is one of the most effective means of controlling mosquito-borne diseases such as malaria. The broad goal of this strategy is to protect individuals against infective mosquito bites and, at the community level, to reduce the intensity of disease transmission. With the deployment of

Artificial Virus as Trump-card to Resolve Exigencies in Targeted Gene Delivery.

Science.gov (United States)

Ajithkumar, K C; Pramod, Kannissery

2018-01-01

Viruses are potent pathogens that can effectively deliver the genetic material to susceptible host cells. This capability is beneficially utilized to successfully deliver the genetic material. However, the use of virus mediated gene delivery is considered divisive, because the potentially replicable genomes recombine or integrate with the cell DNA resulting in immunogenicity, ranging from inflammation to death. Thus, the need for potentially effective non-viral gene delivery vehicles arises. Non-viral vectors, protein only particles and virus like particles (VLP) can be constructed which contain all the necessary functional moieties. These resemble viruses and are called artificial or synthetic virus. The artificial virus eliminates the disadvantages of viral vectors but retain the beneficial effects of the viruses. Need for further functionalization can be avoided by this approach because incorporation of requisite agents such as cell ligands, membrane active peptides, etc. into proteins is possible. The protein- DNA complexes resemble bacterial inclusion bodies. Nucleic acids influence conformation of protein units which subsequently result in cell uptake and finally to the cell nucleus. Such tunable systems mimic the activities of infected viruses and are used for the safe and effective delivery of drugs and genetic material in gene therapy. The versatility, stability and biocompatible nature of artificial virus along with high transfection efficacy have made it favorite for gene delivery purposes, in addition to being useful for various biomedical and drug delivery applications. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Use of adenoviral vectors as veterinary vaccines.

Science.gov (United States)

Ferreira, T B; Alves, P M; Aunins, J G; Carrondo, M J T

2005-10-01

Vaccines are the most effective and inexpensive prophylactic tool in veterinary medicine. Ideally, vaccines should induce a lifelong protective immunity against the target pathogen while not causing clinical or pathological signs of diseases in the vaccinated animals. However, such ideal vaccines are rare in the veterinary field. Many vaccines are either of limited effectiveness or have harmful side effects. In addition, there are still severe diseases with no effective vaccines. A very important criterion for an ideal vaccine in veterinary medicine is low cost; this is especially important in developing countries and even more so for poultry vaccination, where vaccines must sell for a few cents a dose. Traditional approaches include inactivated vaccines, attenuated live vaccines and subunit vaccines. Recently, genetic engineering has been applied to design new, improved vaccines. Adenovirus vectors are highly efficient for gene transfer in a broad spectrum of cell types and species. Moreover, adenoviruses often induce humoral, mucosal and cellular immune responses to antigens encoded by the inserted foreign genes. Thus, adenoviruses have become a vector of choice for delivery and expression of foreign proteins for vaccination. Consequently, the market requirements for adenovirus vaccines are increasing, creating a need for production methodologies of concentrated vectors with warranted purity and efficacy. This review summarizes recent developments and approaches of adenovirus production and purification as the application of these vectors, including successes and failures in clinical applications to date.

Rapid delivery of small interfering RNA by biosurfactant MEL-A-containing liposomes

International Nuclear Information System (INIS)

Inoh, Yoshikazu; Furuno, Tadahide; Hirashima, Naohide; Kitamoto, Dai; Nakanishi, Mamoru

2011-01-01

Highlights: ► We use MEL-A-containing cationic liposomes for siRNA delivery. ► MEL-A-containing cationic liposomes can efficiently and rapidly deliver siRNA into the cytoplasm. ► Rapid delivery of siRNA is due to the membrane fusion between liposomes and plasma membrane. -- Abstract: The downregulation of gene expression by RNA interference holds great potential for genetic analysis and gene therapy. However, a more efficient delivery system for small interfering RNA (siRNA) into the target cells is required for wide fields such as cell biology, physiology, and clinical application. Non-viral vectors are stronger candidates than viral vectors because they are safer and easier to prepare. We have previously used a new method for gene transfection by combining cationic liposomes with the biosurfactant mannosylerythritol lipid-A (MEL-A). The novel MEL-A-containing cationic liposomes rapidly delivered DNA (plasmids and oligonucleotides) into the cytosol and nucleus through membrane fusion between liposomes and the plasma membrane, and consequently, enhanced the gene transfection efficiency. In this study, we determined the efficiency of MEL-A-containing cationic liposomes for siRNA delivery. We observed that exogenous and endogenous protein expression was suppressed by approximately 60% at 24 h after brief (30 min) incubation of target cells with MEL-A-containing cationic liposome/siRNA complexes. Confocal microscopic analysis showed that suppression of protein expression was caused by rapid siRNA delivery into the cytosol. We found that the MEL-A-containing cationic liposomes directly delivered siRNA into the cytoplasm by the membrane fusion in addition to endocytotic pathway whereas Lipofectamine™ RNAiMax delivered siRNA only by the endocytotic pathway. It seems that the ability to rapidly and directly deliver siRNA into the cytosol using MEL-A-containing cationic liposomes is able to reduce immune responses, cytotoxicity, and other side effects caused by

MANCOVA for one way classification with homogeneity of regression coefficient vectors

Science.gov (United States)

Mokesh Rayalu, G.; Ravisankar, J.; Mythili, G. Y.

2017-11-01

The MANOVA and MANCOVA are the extensions of the univariate ANOVA and ANCOVA techniques to multidimensional or vector valued observations. The assumption of a Gaussian distribution has been replaced with the Multivariate Gaussian distribution for the vectors data and residual term variables in the statistical models of these techniques. The objective of MANCOVA is to determine if there are statistically reliable mean differences that can be demonstrated between groups later modifying the newly created variable. When randomization assignment of samples or subjects to groups is not possible, multivariate analysis of covariance (MANCOVA) provides statistical matching of groups by adjusting dependent variables as if all subjects scored the same on the covariates. In this research article, an extension has been made to the MANCOVA technique with more number of covariates and homogeneity of regression coefficient vectors is also tested.

Development of a Targeted anti-HER2 scFv Chimeric Peptide for Gene Delivery into HER2-Positive Breast Cancer Cells.

Science.gov (United States)

Cheraghi, Roya; Nazari, Mahboobeh; Alipour, Mohsen; Majidi, Asia; Hosseinkhani, Saman

2016-12-30

Chimeric polymers are known as suitable carriers for gene delivery. Certain properties are critical for a polymer to be used as a gene delivery vector. A new polymer was designed for the targeted delivery of genes into breast cancer cell lines, based on MPG peptide. It is composed of different functional domains, including HIV gp41, nuclear localization sequence of SV40 T-antigen, two C-terminus repeats of histone H1, and the scFv of anti-HER2 antibody. The results demonstrated that the vector can effectively condense plasmid DNA into nanoparticles with an average size of 250nm. Moreover, fusion of the scFv portion to the carrier brought about the specific recognition of HER2. Overall, the transfection efficiency of the vector demonstrated that it could deliver the desired gene into BT-474 HER2-positive breast cancer cells. Copyright © 2016 Elsevier B.V. All rights reserved.

Search for vector-like quarks at ATLAS

CERN Document Server

Ellinghaus, Frank; The ATLAS collaboration

2017-01-01

Vector like quarks appear in many theories beyond the Standard Model as a way to cancel the mass divergence for the Higgs boson. The current status of the ATLAS searches for the production of vector-like quarks will be reviewed for proton-proton collisions at 13 TeV. This presentation will address the analysis techniques, in particular, the selection criteria, the background modelling and the related experimental uncertainties. The phenomenological implications of the obtained results will also be discussed.

Baculoviral delivery of CRISPR/Cas9 facilitates efficient genome editing in human cells.

Directory of Open Access Journals (Sweden)

Sanne Hindriksen

Full Text Available The CRISPR/Cas9 system is a highly effective tool for genome editing. Key to robust genome editing is the efficient delivery of the CRISPR/Cas9 machinery. Viral delivery systems are efficient vehicles for the transduction of foreign genes but commonly used viral vectors suffer from a limited capacity in the genetic information they can carry. Baculovirus however is capable of carrying large exogenous DNA fragments. Here we investigate the use of baculoviral vectors as a delivery vehicle for CRISPR/Cas9 based genome-editing tools. We demonstrate transduction of a panel of cell lines with Cas9 and an sgRNA sequence, which results in efficient knockout of all four targeted subunits of the chromosomal passenger complex (CPC. We further show that introduction of a homology directed repair template into the same CRISPR/Cas9 baculovirus facilitates introduction of specific point mutations and endogenous gene tags. Tagging of the CPC recruitment factor Haspin with the fluorescent reporter YFP allowed us to study its native localization as well as recruitment to the cohesin subunit Pds5B.

Baculoviral delivery of CRISPR/Cas9 facilitates efficient genome editing in human cells.

Science.gov (United States)

Hindriksen, Sanne; Bramer, Arne J; Truong, My Anh; Vromans, Martijn J M; Post, Jasmin B; Verlaan-Klink, Ingrid; Snippert, Hugo J; Lens, Susanne M A; Hadders, Michael A

2017-01-01

The CRISPR/Cas9 system is a highly effective tool for genome editing. Key to robust genome editing is the efficient delivery of the CRISPR/Cas9 machinery. Viral delivery systems are efficient vehicles for the transduction of foreign genes but commonly used viral vectors suffer from a limited capacity in the genetic information they can carry. Baculovirus however is capable of carrying large exogenous DNA fragments. Here we investigate the use of baculoviral vectors as a delivery vehicle for CRISPR/Cas9 based genome-editing tools. We demonstrate transduction of a panel of cell lines with Cas9 and an sgRNA sequence, which results in efficient knockout of all four targeted subunits of the chromosomal passenger complex (CPC). We further show that introduction of a homology directed repair template into the same CRISPR/Cas9 baculovirus facilitates introduction of specific point mutations and endogenous gene tags. Tagging of the CPC recruitment factor Haspin with the fluorescent reporter YFP allowed us to study its native localization as well as recruitment to the cohesin subunit Pds5B.

Support vector machine for automatic pain recognition

Science.gov (United States)

Monwar, Md Maruf; Rezaei, Siamak

2009-02-01

Facial expressions are a key index of emotion and the interpretation of such expressions of emotion is critical to everyday social functioning. In this paper, we present an efficient video analysis technique for recognition of a specific expression, pain, from human faces. We employ an automatic face detector which detects face from the stored video frame using skin color modeling technique. For pain recognition, location and shape features of the detected faces are computed. These features are then used as inputs to a support vector machine (SVM) for classification. We compare the results with neural network based and eigenimage based automatic pain recognition systems. The experiment results indicate that using support vector machine as classifier can certainly improve the performance of automatic pain recognition system.

Genetic engineering of cell lines using lentiviral vectors to achieve antibody secretion following encapsulated implantation.

Science.gov (United States)

Lathuilière, Aurélien; Bohrmann, Bernd; Kopetzki, Erhard; Schweitzer, Christoph; Jacobsen, Helmut; Moniatte, Marc; Aebischer, Patrick; Schneider, Bernard L

2014-01-01

The controlled delivery of antibodies by immunoisolated bioimplants containing genetically engineered cells is an attractive and safe approach for chronic treatments. To reach therapeutic antibody levels there is a need to generate renewable cell lines, which can long-term survive in macroencapsulation devices while maintaining high antibody specific productivity. Here we have developed a dual lentiviral vector strategy for the genetic engineering of cell lines compatible with macroencapsulation, using separate vectors encoding IgG light and heavy chains. We show that IgG expression level can be maximized as a function of vector dose and transgene ratio. This approach allows for the generation of stable populations of IgG-expressing C2C12 mouse myoblasts, and for the subsequent isolation of clones stably secreting high IgG levels. Moreover, we demonstrate that cell transduction using this lentiviral system leads to the production of a functional glycosylated antibody by myogenic cells. Subsequent implantation of antibody-secreting cells in a high-capacity macroencapsulation device enables continuous delivery of recombinant antibodies in the mouse subcutaneous tissue, leading to substantial levels of therapeutic IgG detectable in the plasma.

Computer-controlled 3-D treatment delivery

International Nuclear Information System (INIS)

Fraass, Benedick A.

1995-01-01

Purpose/Objective: This course will describe the use of computer-controlled treatment delivery techniques for treatment of patients with sophisticated conformal therapy. In particular, research and implementation issues related to clinical use of computer-controlled conformal radiation therapy (CCRT) techniques will be discussed. The possible/potential advantages of CCRT techniques will be highlighted using results from clinical 3-D planning studies. Materials and Methods: In recent years, 3-D treatment planning has been used to develop and implement 3-D conformal therapy treatment techniques, and studies based on these conformal treatments have begun to show the promise of conformal therapy. This work has been followed by the development of commercially-available multileaf collimator and computer control systems for treatment machines. Using these (and other) CCRT devices, various centers are beginning to clinically use complex computer-controlled treatments. Both research and clinical CCRT treatment techniques will be discussed in this presentation. General concepts and requirements for CCRT will be mentioned. Developmental and clinical experience with CCRT techniques from a number of centers will be utilized. Results: Treatment planning, treatment preparation and treatment delivery must be approached in an integrated fashion in order to clinically implement CCRT treatment techniques, and the entire process will be discussed. Various CCRT treatment methodologies will be reviewed from operational, dosimetric, and technical points of view. The discussion will concentrate on CCRT techniques which are likely to see rather wide dissemination over the next several years, including particularly the use of multileaf collimators (MLC), dynamic and segmental conformal therapy, conformal field shaping, and other related techniques. More advanced CCRT techniques, such as the use of individualized intensity modulation of beams or segments, and the use of computer

Quantification of In Vivo 2D Vector Flow Ultrasound

DEFF Research Database (Denmark)

Pedersen, Mads Møller

2012-01-01

by the vector technique. With the conventional technique, the manual setting of the angle is operator dependent. With the calculated vector angle, this operator is relieved from the angle setting and the measurement is angle corrected by the identical method every time. With study II the carotid bifurcation...... the clinical parameters: peak systole velocity, end diastole velocity, resistive index, and the flow direction. The results showed significant difference on the velocities and the resistive index. However, no significant difference on the manually defined flow angle and the calculated mean flow angle...... including the carotid bulb and the common carotid artery were scanned on 8 healthy volunteers. The flow patterns of the two structures were outlined and presented to each of 5 experienced radiologists. The complexity of the identical areas were calculated by the vector concentration and compared...

Poxvirus-vectored vaccines for rabies--a review.

Science.gov (United States)

Weyer, Jacqueline; Rupprecht, Charles E; Nel, Louis H

2009-11-27

Oral rabies vaccination of target reservoir species has proved to be one of the pillars of successful rabies elimination programs. The use of live attenuated rabies virus vaccines has been extensive but several limitations hamper its future use. A recombinant vaccinia-rabies vaccine has also been successfully used for the oral vaccination of several species. Nevertheless, its lack of efficacy in certain important rabies reservoirs and concerns on the use of this potent live virus as vaccine carrier (vector) impair the expansion of its use for new target species and new areas. Several attenuated and host-restricted poxvirus alternatives, which supposedly offer enhanced safety, have been investigated. Once again, efficacy in certain target species and innocuity through the oral route remain major limitations of these vaccines. Alternative recombinant vaccines using adenovirus as an antigen delivery vector have been extensively investigated and may provide an important addition to the currently available oral rabies vaccine repertoire, but are not the primary subject of this review.

Balancing Cell Migration with Matrix Degradation Enhances Gene Delivery to Cells Cultured Three-Dimensionally Within Hydrogels

Science.gov (United States)

Shepard, Jaclyn A.; Huang, Alyssa; Shikanova, Ariella; Shea, Lonnie D.

2010-01-01

In regenerative medicine, hydrogels are employed to fill defects and support the infiltration of cells that can ultimately regenerate tissue. Gene delivery within hydrogels targeting infiltrating cells has the potential to promote tissue formation, but the delivery efficiency of nonviral vectors within hydrogels is low hindering their applicability in tissue regeneration. To improve their functionality, we have conducted a mechanistic study to investigate the contribution of cell migration and matrix degradation on gene delivery. In this report, lipoplexes were entrapped within hydrogels based on poly(ethylene glycol) (PEG) crosslinked with peptides containing matrix metalloproteinase degradable sequences. The mesh size of these hydrogels is substantially less than the size of the entrapped lipoplexes, which can function to retain vectors. Cell migration and transfection were simultaneously measured within hydrogels with varying density of cell adhesion sites (Arg-Gly-Asp peptides) and solids content. Increasing RGD density increased expression levels up to 100-fold, while greater solids content sustained expression levels for 16 days. Increasing RGD density and decreasing solids content increased cell migration, which indicates expression levels increase with increased cell migration. Initially exposing cells to vector resulted in transient expression that declined after 2 days, verifying the requirement of migration to sustain expression. Transfected cells were predominantly located within the population of migrating cells for hydrogels that supported cell migration. Although the small mesh size retained at least 70% of the lipoplexes in the absence of cells after 32 days, the presence of cells decreased retention to 10% after 16 days. These results indicate that vectors retained within hydrogels contact migrating cells, and that persistent cell migration can maintain elevated expression levels. Thus matrix degradation and cell migration are fundamental design

Manga Vectorization and Manipulation with Procedural Simple Screentone.

Science.gov (United States)

Yao, Chih-Yuan; Hung, Shih-Hsuan; Li, Guo-Wei; Chen, I-Yu; Adhitya, Reza; Lai, Yu-Chi

2017-02-01

Manga are a popular artistic form around the world, and artists use simple line drawing and screentone to create all kinds of interesting productions. Vectorization is helpful to digitally reproduce these elements for proper content and intention delivery on electronic devices. Therefore, this study aims at transforming scanned Manga to a vector representation for interactive manipulation and real-time rendering with arbitrary resolution. Our system first decomposes the patch into rough Manga elements including possible borders and shading regions using adaptive binarization and screentone detector. We classify detected screentone into simple and complex patterns: our system extracts simple screentone properties for refining screentone borders, estimating lighting, compensating missing strokes inside screentone regions, and later resolution independently rendering with our procedural shaders. Our system treats the others as complex screentone areas and vectorizes them with our proposed line tracer which aims at locating boundaries of all shading regions and polishing all shading borders with the curve-based Gaussian refiner. A user can lay down simple scribbles to cluster Manga elements intuitively for the formation of semantic components, and our system vectorizes these components into shading meshes along with embedded Bézier curves as a unified foundation for consistent manipulation including pattern manipulation, deformation, and lighting addition. Our system can real-time and resolution independently render the shading regions with our procedural shaders and drawing borders with the curve-based shader. For Manga manipulation, the proposed vector representation can be not only magnified without artifacts but also deformed easily to generate interesting results.

Supramolecular polypseudorotaxane gels for controlled delivery of rAAV vectors in human mesenchymal stem cells for regenerative medicine.

Science.gov (United States)

Rey-Rico, Ana; Babicz, Heiko; Madry, Henning; Concheiro, Angel; Alvarez-Lorenzo, Carmen; Cucchiarini, Magali

2017-10-15

The aim of this work was to investigate, for the first time, the possibility of using supramolecular polypseudorotaxane gels as scaffolds that can durably deliver rAAV vectors for applications in cartilage regeneration. Dispersions of Pluronic ® F68 (PF68) or Tetronic ® 908 (T908) containing either hyaluronic acid (HA) or chondroitin sulfate (CS) were prepared in PBS. Then, alpha-cyclodextrin (αCD) was added to some dispersions to form polypseudorotaxane gels. Polysaccharides and αCD reinforced the viscoelasticity of the gels, which could withstand autoclaving without changes. In vitro release of rAAV vectors and subsequent transduction of human mesenchymal stem cells (hMSCs) by rAAV vectors from the release medium and from gels in direct contact with the cells were investigated. Compared with free vectors, the gels provided higher levels of transgene expression. CS (or HA)/PF68/αCD gels rapidly released rAAV vectors while CS (or HA)/T908/αCD gels provided sustained release probably due to different interactions with the viral vectors. Incorporation of αCD into CS (or HA)/PF68 gels resulted on higher rAAV concentrations and sustained levels of transgene expression over time. HA increased the bioactivity and cytocompatibility of the gels, especially those based on T908. Overall, combining rAAV gene transfer with polypseudorotaxane gels may provide new, promising tools for human tissue engineering and regenerative medicine strategies. Copyright © 2017 Elsevier B.V. All rights reserved.

Efficient delivery of Cre-recombinase to neurons in vivo and stable transduction of neurons using adeno-associated and lentiviral vectors

Directory of Open Access Journals (Sweden)

Sablitzky Fred

2004-01-01

Full Text Available Abstract Background Inactivating genes in vivo is an important technique for establishing their function in the adult nervous system. Unfortunately, conventional knockout mice may suffer from several limitations including embryonic or perinatal lethality and the compensatory regulation of other genes. One approach to producing conditional activation or inactivation of genes involves the use of Cre recombinase to remove loxP-flanked segments of DNA. We have studied the effects of delivering Cre to the hippocampus and neocortex of adult mice by injecting replication-deficient adeno-associated virus (AAV and lentiviral (LV vectors into discrete regions of the forebrain. Results Recombinant AAV-Cre, AAV-GFP (green fluorescent protein and LV-Cre-EGFP (enhanced GFP were made with the transgene controlled by the cytomegalovirus promoter. Infecting 293T cells in vitro with AAV-Cre and LV-Cre-EGFP resulted in transduction of most cells as shown by GFP fluorescence and Cre immunoreactivity. Injections of submicrolitre quantities of LV-Cre-EGFP and mixtures of AAV-Cre with AAV-GFP into the neocortex and hippocampus of adult Rosa26 reporter mice resulted in strong Cre and GFP expression in the dentate gyrus and moderate to strong labelling in specific regions of the hippocampus and in the neocortex, mainly in neurons. The pattern of expression of Cre and GFP obtained with AAV and LV vectors was very similar. X-gal staining showed that Cre-mediated recombination had occurred in neurons in the same regions of the brain, starting at 3 days post-injection. No obvious toxic effects of Cre expression were detected even after four weeks post-injection. Conclusion AAV and LV vectors are capable of delivering Cre to neurons in discrete regions of the adult mouse brain and producing recombination.

Dendrimers as tunable vectors of drug delivery systems and biomedical and ocular applications

Science.gov (United States)

Kalomiraki, Marina; Thermos, Kyriaki; Chaniotakis, Nikos A

2016-01-01

Dendrimers are large polymeric structures with nanosize dimensions (1–10 nm) and unique physicochemical properties. The major advantage of dendrimers compared with linear polymers is their spherical-shaped structure. During synthesis, the size and shape of the dendrimer can be customized and controlled, so the finished macromolecule will have a specific “architecture” and terminal groups. These characteristics will determine its suitability for drug delivery, diagnostic imaging, and as a genetic material carrier. This review will focus initially on the unique properties of dendrimers and their use in biomedical applications, as antibacterial, antitumor, and diagnostic agents. Subsequently, emphasis will be given to their use in drug delivery for ocular diseases. PMID:26730187

Adenovirus serotype 5 vectors with Tat-PTD modified hexon and serotype 35 fiber show greatly enhanced transduction capacity of primary cell cultures.

Directory of Open Access Journals (Sweden)

Di Yu

Full Text Available Recombinant adenovirus serotype 5 (Ad5 vectors represent one of the most efficient gene delivery vectors in life sciences. However, Ad5 is dependent on expression of the coxsackievirus-adenovirus-receptor (CAR on the surface of target cell for efficient transduction, which limits it's utility for certain cell types. Herein we present a new vector, Ad5PTDf35, which is an Ad5 vector having serotype 35 fiber-specificity and Tat-PTD hexon-modification. This vector shows dramatically increased transduction capacity of primary human cell cultures including T cells, monocytes, macrophages, dendritic cells, pancreatic islets and exocrine cells, mesenchymal stem cells and tumor initiating cells. Biodistribution in mice following systemic administration (tail-vein injection show significantly reduced uptake in the liver and spleen of Ad5PTDf35 compared to unmodified Ad5. Therefore, replication-competent viruses with these modifications may be further developed as oncolytic agents for cancer therapy. User-friendly backbone plasmids containing these modifications were developed for compatibility to the AdEasy-system to facilitate the development of surface-modified adenoviruses for gene delivery to difficult-to-transduce cells in basic, pre-clinical and clinical research.

Hypergraph partitioning implementation for parallelizing matrix-vector multiplication using CUDA GPU-based parallel computing

Science.gov (United States)

Murni, Bustamam, A.; Ernastuti, Handhika, T.; Kerami, D.

2017-07-01

Calculation of the matrix-vector multiplication in the real-world problems often involves large matrix with arbitrary size. Therefore, parallelization is needed to speed up the calculation process that usually takes a long time. Graph partitioning techniques that have been discussed in the previous studies cannot be used to complete the parallelized calculation of matrix-vector multiplication with arbitrary size. This is due to the assumption of graph partitioning techniques that can only solve the square and symmetric matrix. Hypergraph partitioning techniques will overcome the shortcomings of the graph partitioning technique. This paper addresses the efficient parallelization of matrix-vector multiplication through hypergraph partitioning techniques using CUDA GPU-based parallel computing. CUDA (compute unified device architecture) is a parallel computing platform and programming model that was created by NVIDIA and implemented by the GPU (graphics processing unit).

Cationic Bolaamphiphiles for Gene Delivery

Science.gov (United States)

Tan, Amelia Li Min; Lim, Alisa Xue Ling; Zhu, Yiting; Yang, Yi Yan; Khan, Majad

2014-05-01

Advances in medical research have shed light on the genetic cause of many human diseases. Gene therapy is a promising approach which can be used to deliver therapeutic genes to treat genetic diseases at its most fundamental level. In general, nonviral vectors are preferred due to reduced risk of immune response, but they are also commonly associated with low transfection efficiency and high cytotoxicity. In contrast to viral vectors, nonviral vectors do not have a natural mechanism to overcome extra- and intracellular barriers when delivering the therapeutic gene into cell. Hence, its design has been increasingly complex to meet challenges faced in targeting of, penetration of and expression in a specific host cell in achieving more satisfactory transfection efficiency. Flexibility in design of the vector is desirable, to enable a careful and controlled manipulation of its properties and functions. This can be met by the use of bolaamphiphile, a special class of lipid. Unlike conventional lipids, bolaamphiphiles can form asymmetric complexes with the therapeutic gene. The advantage of having an asymmetric complex lies in the different purposes served by the interior and exterior of the complex. More effective gene encapsulation within the interior of the complex can be achieved without triggering greater aggregation of serum proteins with the exterior, potentially overcoming one of the great hurdles faced by conventional single-head cationic lipids. In this review, we will look into the physiochemical considerations as well as the biological aspects of a bolaamphiphile-based gene delivery system.

Use of Lanczos vectors in fluid/structure interaction problems

International Nuclear Information System (INIS)

Jeans, R.; Mathews, I.C.

1992-01-01

The goals of any numerical computational technique used for the solution of structural acoustics problems in the exterior infinite domain should be of accuracy with rapid convergence, robustness, and computational efficiency. A computer program has been developed to achieve each of these three goals. Accuracy and robustness in the numerical representation of the integral equations used to represent the infinite fluid was attained through the use of boundary element implementations of the surface Helmholtz integral equations. The computational efficiency was resolved through the use of Lanczos vectors to model the deformation characteristics of the structure. The authors have developed collocation and variational techniques to overcome the difficulties previously encountered in the numerical implementation of the hypersingular integral operator. The Cauchy singularity present in the integral formulation is made numerically amenable through the use of tangential derivatives in both the collocation and variational techniques. The variational approach has the advantage that the resulting added fluid mass term is symmetric and combines efficiently with a finite element approximation of the structural elastic response. Several different strategies making use of the Lanczos vectors have been investigated. The first involved the use of Lanczos vectors solely to characterize the structural response. This reduced form of the structural dynamical matrix was then substituted back into a Burton and Miller formulation of the acoustic problem. The second strategy investigated involved forming the complex Lanzcos vectors of the dynamical matrix formed from the addition of a symmetrical added fluid matrix to the structural mass matrix. The size of resultant matrix equation set solved at each frequency for this strategy is determined by the number of Lanczos vectors used. 19 refs., 10 figs., 2 tabs

Generation of arbitrary vector beams with liquid crystal polarization converters and vector-photoaligned q-plates

International Nuclear Information System (INIS)

Chen, Peng; Ji, Wei; Wei, Bing-Yan; Hu, Wei; Lu, Yan-Qing; Chigrinov, Vladimir

2015-01-01

Arbitrary vector beams (VBs) are realized by the designed polarization converters and corresponding vector-photoaligned q-plates. The polarization converter is a specific twisted nematic cell with one substrate homogeneously aligned and the other space-variantly aligned. By combining a polarization-sensitive alignment agent with a dynamic micro-lithography system, various categories of liquid crystal polarization converters are demonstrated. Besides, traditional radially/azimuthally polarized light, high-order and multi-ringed VBs, and a VB array with different orders are generated. The obtained converters are further utilized as polarization masks to implement vector-photoaligning. The technique facilitates both the volume duplication of these converters and the generation of another promising optical element, the q-plate, which is suitable for the generation of VBs for coherent lasers. The combination of proposed polarization converters and correspondingly fabricated q-plates would drastically enhance the capability of polarization control and may bring more possibilities for the design of photonic devices

Adeno-associated viral vector serotypes 1 and 5 targeted to the neonatal rat and pig striatum induce widespread transgene expression in the forebrain

DEFF Research Database (Denmark)

Kornum, Birgitte R; Stott, Simon R W; Mattsson, Bengt

2010-01-01

. Our results show that striatal delivery of rAAV5 vectors in the neonatal brain represents a useful tool to express genes of interest both in the basal ganglia and the neocortex. Furthermore, we apply, for the first time, viral vector-mediated gene transfer to the pig brain providing the opportunity...

Floating Microparticulate Oral Diltiazem Hydrochloride Delivery ...

African Journals Online (AJOL)

Purpose: To formulate and evaluate floating microparticulate oral diltiazem delivery system for possible delivery to the heart. Method: Floating microspheres were prepared using cellulose acetate and Eudragit RS100 polymers by emulsion solvent evaporation technique. The dried floating microspheres were evaluated for ...

Current knowledge on biodegradable microspheres in drug delivery.

Science.gov (United States)

Prajapati, Vipul D; Jani, Girish K; Kapadia, Jinita R

2015-08-01

Biodegradable microspheres have gained popularity for delivering a wide variety of molecules via various routes. These types of products have been prepared using various natural and synthetic biodegradable polymers through suitable techniques for desired delivery of various challenging molecules. Selection of biodegradable polymers and technique play a key role in desired drug delivery. This review describes an overview of the fundamental knowledge and status of biodegradable microspheres in effective delivery of various molecules via desired routes with consideration of outlines of various compendial and non-compendial biodegradable polymers, formulation techniques and release mechanism of microspheres, patents and commercial biodegradable microspheres. There are various advantages of using biodegradable polymers including promise of development with different types of molecules. Biocompatibility, low dosage and reduced side effects are some reasons why usage biodegradable microspheres have gained in popularity. Selection of biodegradable polymers and formulation techniques to create microspheres is the biggest challenge in research. In the near future, biodegradable microspheres will become the eco-friendly product for drug delivery of various genes, hormones, proteins and peptides at specific site of body for desired periods of time.

Photodynamic efficacy of hypericin targeted by two delivery techniques to hepatocellular carcinoma cells.

Science.gov (United States)

Fadel, Maha; Kassab, Kawser; Youssef, Tareq

2010-09-01

The photocytotoxic effect of hypericin (Hyp) targeted by two different delivery techniques, namely, liposomes and anti-hepatocyte specific antigen (anti-HSA) was investigated. Optical absorption and steady-state fluorescence were used to analyze the conjugation of Hyp with anti-HSA model and to evaluate the encapsulation capacity and drug release in a liposome model. Particle size and thermal analysis of the prepared liposomes were performed using laser-light scattering and differential scanning calorimetry (DSC), respectively. Viability study of HepG2 cells exposed to Hyp in the two delivery systems, in the dark and following visible light irradiation, was performed in comparison to free Hyp. The intracellular uptake and localization of Hyp in HepG2 cells were analyzed by means of spectrofluorometry and fluorescence microscopy. Spectroscopic measurements demonstrated that Hyp binds to anti-HSA in its monomeric form. The photocytotoxic effect of Hyp depended clearly on the form of Hyp administered, either in free form, loaded into liposomes or conjugated with anti-HSA. While liposomes loaded with Hyp (Lip-Hyp) did not induce significant phototoxicity, both free Hyp or anti-HSA-Hyp inflicted substantial cell mortality, after photoirradiation. The intracellular uptake of Lip-Hyp by HepG2 cells was estimated to be 20% less compared to free Hyp or anti-HSA-Hyp. In spite of the equal uptake of both free Hyp and anti-HSA-Hyp, HepG2 cells demonstrated a relatively higher mortality with anti-HSA-Hyp compared to free Hyp.

Recent advances in genetic modification of adenovirus vectors for cancer treatment.

Science.gov (United States)

Yamamoto, Yuki; Nagasato, Masaki; Yoshida, Teruhiko; Aoki, Kazunori

2017-05-01

Adenoviruses are widely used to deliver genes to a variety of cell types and have been used in a number of clinical trials for gene therapy and oncolytic virotherapy. However, several concerns must be addressed for the clinical use of adenovirus vectors. Selective delivery of a therapeutic gene by adenovirus vectors to target cancer is precluded by the widespread distribution of the primary cellular receptors. The systemic administration of adenoviruses results in hepatic tropism independent of the primary receptors. Adenoviruses induce strong innate and acquired immunity in vivo. Furthermore, several modifications to these vectors are necessary to enhance their oncolytic activity and ensure patient safety. As such, the adenovirus genome has been engineered to overcome these problems. The first part of the present review outlines recent progress in the genetic modification of adenovirus vectors for cancer treatment. In addition, several groups have recently developed cancer-targeting adenovirus vectors by using libraries that display random peptides on a fiber knob. Pancreatic cancer-targeting sequences have been isolated, and these oncolytic vectors have been shown by our group to be associated with a higher gene transduction efficiency and more potent oncolytic activity in cell lines, murine models, and surgical specimens of pancreatic cancer. In the second part of this review, we explain that combining cancer-targeting strategies can be a promising approach to increase the clinical usefulness of oncolytic adenovirus vectors. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Synthesis of star-branched PLA-b-PMPC copolymer micelles as long blood circulation vectors to enhance tumor-targeted delivery of hydrophobic drugs in vivo

Energy Technology Data Exchange (ETDEWEB)

Long, Li-xia [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science & Engineering, Tianjin University, Tianjin 300072 (China); Zhao, Jin, E-mail: zhaojin@tju.edu.cn [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science & Engineering, Tianjin University, Tianjin 300072 (China); Li, Ke; He, Li-gang; Qian, Xiao-ming; Liu, Chao-yong; Wang, Li-mei; Yang, Xin-qi [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science & Engineering, Tianjin University, Tianjin 300072 (China); Sun, Jinjin [Department of General Surgery, The Second Hospital of Tianjin Medical University, Tianjin 300211 (China); Ren, Yu [Tianjin Research Center of Basic Medical Science, Tianjin Medical University, Tianjin 300070 (China); Kang, Chun-sheng, E-mail: kang97061@yahoo.com [Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052 (China); Yuan, Xu-bo, E-mail: xbyuan@tju.edu.cn [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science & Engineering, Tianjin University, Tianjin 300072 (China)

2016-09-01

Star-branched amphiphilic copolymer nanocarriers with high-density zwitterionic shell show great promise in drug delivery due to their controllable small size and excellent anti-biofouling properties. This gives the hydrophobic cargo with high stability and long blood circulation in vivo. In the present study, star-branched polylactic acid and poly(2-methacryloyloxyethyl phosphorylcholine) copolymers with (AB{sub 3}){sub 3}–type architecture (PLA-b-PMPC{sub 3}){sub 3} were conceived as drug vectors, and the copolymers were synthesized by an “arm-first” approach via the combination of ring opening polymerization (ROP), atom transfer radical polymerization (ATRP) and the click reaction. The self-assembled star-branched copolymer micelles (sCPM) had an average diameter of about 64.5 nm and exhibited an ultra-hydrophilic surface with an ultralow water contact angle of about 12.7°, which efficiently suppressed the adhesion of serum proteins. In vivo experiments showed that the sCPM loading strongly enhanced the blood circulation time of DiI and the plasma half-life of DiI in sCPM was 19.3 h. The relative accumulation concentration in tumor of DiI delivered by sCPM was 2.37-fold higher than that of PLA-PEG, at 4 h after intravenous injection. These results demonstrated that the star-branched copolymer (PLA-b-PMPC{sub 3}){sub 3} is a promising alternative carrier material for intravenous delivery versus classic PEG-modified strategies. - Highlights: • Star-branched amphiphilic copolymer micelles (sCPM) with zwitterionic shells were prepared. • sCPM possess an ultra-hydrophilic surface and thus inhibited the protein absorption. • sCPM can effectively prolong the cargo’s plasma circulation time. • sCPM can enhance the cargo’s passive tumor-targeted delivery.

Discovery of Cationic Polymers for Non-viral Gene Delivery using Combinatorial Approaches

Science.gov (United States)

Barua, Sutapa; Ramos, James; Potta, Thrimoorthy; Taylor, David; Huang, Huang-Chiao; Montanez, Gabriela; Rege, Kaushal

2015-01-01

Gene therapy is an attractive treatment option for diseases of genetic origin, including several cancers and cardiovascular diseases. While viruses are effective vectors for delivering exogenous genes to cells, concerns related to insertional mutagenesis, immunogenicity, lack of tropism, decay and high production costs necessitate the discovery of non-viral methods. Significant efforts have been focused on cationic polymers as non-viral alternatives for gene delivery. Recent studies have employed combinatorial syntheses and parallel screening methods for enhancing the efficacy of gene delivery, biocompatibility of the delivery vehicle, and overcoming cellular level barriers as they relate to polymer-mediated transgene uptake, transport, transcription, and expression. This review summarizes and discusses recent advances in combinatorial syntheses and parallel screening of cationic polymer libraries for the discovery of efficient and safe gene delivery systems. PMID:21843141

Gene delivery to pancreatic exocrine cells in vivo and in vitro

Directory of Open Access Journals (Sweden)

Houbracken Isabelle

2012-10-01

Full Text Available Abstract Background Effective gene transfer to the pancreas or to pancreatic cells has remained elusive although it is essential for studies of genetic lineage tracing and modulation of gene expression. Different transduction methods and viral vectors were tested in vitro and in vivo, in rat and mouse pancreas. Results For in vitro transfection/transduction of rat exocrine cells lipofection reagents, adenoviral vectors, and Mokola- and VSV-G pseudotyped lentiviral vectors were used. For in vivo transduction of mouse and rat pancreas adenoviral vectors and VSV-G lentiviral vectors were injected into the parenchymal tissue. Both lipofection of rat exocrine cell cultures and transduction with Mokola pseudotyped lentiviral vectors were inefficient and resulted in less than 4% EGFP expressing cells. Adenoviral transduction was highly efficient but its usefulness for gene delivery to rat exocrine cells in vitro was hampered by a drastic increase in cell death. In vitro transduction of rat exocrine cells was most optimal with VSV-G pseudotyped lentiviral vectors, with stable transgene expression, no significant effect on cell survival and about 40% transduced cells. In vivo, pancreatic cells could not be transduced by intra-parenchymal administration of lentiviral vectors in mouse and rat pancreas. However, a high efficiency could be obtained by adenoviral vectors, resulting in transient transduction of mainly exocrine acinar cells. Injection in immune-deficient animals diminished leukocyte infiltration and prolonged transgene expression. Conclusions In summary, our study remarkably demonstrates that transduction of pancreatic exocrine cells requires lentiviral vectors in vitro but adenoviral vectors in vivo.

A comparative study of peripheral to central circulation delivery times between intraosseous and intravenous injection using a radionuclide technique in normovolemic and hypovolemic canines

International Nuclear Information System (INIS)

Cameron, J.L.; Fontanarosa, P.B.; Passalaqua, A.M.

1989-01-01

Intraosseous infusion is considered a useful technique for administration of medications and fluids in emergency situations when peripheral intravascular access is unobtainable. This study examined the effectiveness of intraosseous infusion for delivery of substances to the central circulation. Central deliveries of a radionuclide tracer administered by the intraosseous and intravenous routes were evaluated during normovolemic and hypovolemic states. Intraosseous infusion achieved peripheral to central circulation transit times comparable to those achieved by the intravenous route. Analysis of variance revealed no statistically significant differences between the peripheral to central delivery times comparing intraosseous and intravenous administration. The results demonstrate that intraosseous infusion is a rapid and effective method of delivery to the central circulation and is an alternative method for intravascular access. This study also suggests that a radionuclide tracer is useful for the evaluation of transit times following intraosseous injection

The index of a vector field under blow ups

International Nuclear Information System (INIS)

Seade, J.

1991-08-01

A useful technique when studying the behaviour of holomorphic vector fields around their isolated singularities is that of blowing up the singular points. On the other hand, the most basic invariant of a vector field with isolated singularities is its local index, as defined by Poincare and Hopf. It is thus natural to ask how does the index of a vector field behaves under blowing ups? The purpose of this work is to study and answer this question, by taking a rather general point of view and bearing in mind that complex manifolds have a powerful birational invariant, the Todd genus. 20 refs

Design of 2D time-varying vector fields.

Science.gov (United States)

Chen, Guoning; Kwatra, Vivek; Wei, Li-Yi; Hansen, Charles D; Zhang, Eugene

2012-10-01

Design of time-varying vector fields, i.e., vector fields that can change over time, has a wide variety of important applications in computer graphics. Existing vector field design techniques do not address time-varying vector fields. In this paper, we present a framework for the design of time-varying vector fields, both for planar domains as well as manifold surfaces. Our system supports the creation and modification of various time-varying vector fields with desired spatial and temporal characteristics through several design metaphors, including streamlines, pathlines, singularity paths, and bifurcations. These design metaphors are integrated into an element-based design to generate the time-varying vector fields via a sequence of basis field summations or spatial constrained optimizations at the sampled times. The key-frame design and field deformation are also introduced to support other user design scenarios. Accordingly, a spatial-temporal constrained optimization and the time-varying transformation are employed to generate the desired fields for these two design scenarios, respectively. We apply the time-varying vector fields generated using our design system to a number of important computer graphics applications that require controllable dynamic effects, such as evolving surface appearance, dynamic scene design, steerable crowd movement, and painterly animation. Many of these are difficult or impossible to achieve via prior simulation-based methods. In these applications, the time-varying vector fields have been applied as either orientation fields or advection fields to control the instantaneous appearance or evolving trajectories of the dynamic effects.

Vacuum Delivery in Jos University Teaching Hospital, Jos, Nigeria ...

African Journals Online (AJOL)

Obstetric practice continues to change, particularly assisted vaginal delivery. Vacuum delivery is a mode of delivery technique in Jos University Teaching Hospital (JUTH) in the maternity unit. The objective of the study was to determine the rate of ventouse delivery, its indications, and maternal and fetal morbidity in our ...

Techniques for assisting difficult delivery at caesarean section.

Science.gov (United States)

Waterfall, Heather; Grivell, Rosalie M; Dodd, Jodie M

2016-01-31

Caesarean section involves making an incision in the woman's abdomen and cutting through the uterine muscle. The baby is then delivered through that incision. Difficult caesarean birth may result in injury for the infant or complications for the mother. Methods to assist with delivery include vacuum or forceps extraction or manual delivery utilising fundal pressure. Medication that relaxes the uterus (tocolytic medication) may facilitate the birth of the baby at caesarean section. Delivery of the impacted head after prolonged obstructed labour can be associated with significant maternal and neonatal complication; to facilitate delivery of the head the surgeon may utilise either reverse breech extraction or head pushing. To compare the use of tocolysis (routine or selective use) with no use of tocolysis or placebo and to compare different extraction methods at the time of caesarean section for outcomes of infant birth trauma, maternal complications (particularly postpartum haemorrhage requiring blood transfusion), and long-term measures of infant and childhood morbidity. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2015) and reference lists of retrieved studies. All published, unpublished, and ongoing randomised controlled trials comparing the use of tocolytic agents (routine or selective) at caesarean section versus no use of tocolytic or placebo at caesarean section to facilitate the birth of the baby. Use of instrument versus manual delivery to facilitate birth of the baby. Reverse breech extraction versus head pushing to facilitate delivery of the deeply impacted fetal head. Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. Seven randomised controlled trials, involving 582 women undergoing caesarean section were included in this review. The risk of bias of included trials was variable, with some trials not adequately describing allocation or

Comparative analysis of DNA nanoparticles and AAVs for ocular gene delivery.

Directory of Open Access Journals (Sweden)

Zongchao Han

Full Text Available Gene therapy is a critical tool for the treatment of monogenic retinal diseases. However, the limited vector capacity of the current benchmark delivery strategy, adeno-associated virus (AAV, makes development of larger capacity alternatives, such as compacted DNA nanoparticles (NPs, critical. Here we conduct a side-by-side comparison of self-complementary AAV and CK30PEG NPs using matched ITR plasmids. We report that although AAVs are more efficient per vector genome (vg than NPs, NPs can drive gene expression on a comparable scale and longevity to AAV. We show that subretinally injected NPs do not leave the eye while some of the AAV-injected animals exhibited vector DNA and GFP expression in the visual pathways of the brain from PI-60 onward. As a result, these NPs have the potential to become a successful alternative for ocular gene therapy, especially for the multitude of genes too large for AAV vectors.

Lentiviral vector-mediated genetic modification of human neural progenitor cells for ex vivo gene therapy.

Science.gov (United States)

Capowski, Elizabeth E; Schneider, Bernard L; Ebert, Allison D; Seehus, Corey R; Szulc, Jolanta; Zufferey, Romain; Aebischer, Patrick; Svendsen, Clive N

2007-07-30

Human neural progenitor cells (hNPC) hold great potential as an ex vivo system for delivery of therapeutic proteins to the central nervous system. When cultured as aggregates, termed neurospheres, hNPC are capable of significant in vitro expansion. In the current study, we present a robust method for lentiviral vector-mediated gene delivery into hNPC that maintains the differentiation and proliferative properties of neurosphere cultures while minimizing the amount of viral vector used and controlling the number of insertion sites per population. This method results in long-term, stable expression even after differentiation of the hNPC to neurons and astrocytes and allows for generation of equivalent transgenic populations of hNPC. In addition, the in vitro analysis presented predicts the behavior of transgenic lines in vivo when transplanted into a rodent model of Parkinson's disease. The methods presented provide a powerful tool for assessing the impact of factors such as promoter systems or different transgenes on the therapeutic utility of these cells.

Emerging Vector-Borne Diseases - Incidence through Vectors.

Science.gov (United States)

Savić, Sara; Vidić, Branka; Grgić, Zivoslav; Potkonjak, Aleksandar; Spasojevic, Ljubica

2014-01-01

Vector-borne diseases use to be a major public health concern only in tropical and subtropical areas, but today they are an emerging threat for the continental and developed countries also. Nowadays, in intercontinental countries, there is a struggle with emerging diseases, which have found their way to appear through vectors. Vector-borne zoonotic diseases occur when vectors, animal hosts, climate conditions, pathogens, and susceptible human population exist at the same time, at the same place. Global climate change is predicted to lead to an increase in vector-borne infectious diseases and disease outbreaks. It could affect the range and population of pathogens, host and vectors, transmission season, etc. Reliable surveillance for diseases that are most likely to emerge is required. Canine vector-borne diseases represent a complex group of diseases including anaplasmosis, babesiosis, bartonellosis, borreliosis, dirofilariosis, ehrlichiosis, and leishmaniosis. Some of these diseases cause serious clinical symptoms in dogs and some of them have a zoonotic potential with an effect to public health. It is expected from veterinarians in coordination with medical doctors to play a fundamental role at primarily prevention and then treatment of vector-borne diseases in dogs. The One Health concept has to be integrated into the struggle against emerging diseases. During a 4-year period, from 2009 to 2013, a total number of 551 dog samples were analyzed for vector-borne diseases (borreliosis, babesiosis, ehrlichiosis, anaplasmosis, dirofilariosis, and leishmaniasis) in routine laboratory work. The analysis was done by serological tests - ELISA for borreliosis, dirofilariosis, and leishmaniasis, modified Knott test for dirofilariosis, and blood smear for babesiosis, ehrlichiosis, and anaplasmosis. This number of samples represented 75% of total number of samples that were sent for analysis for different diseases in dogs. Annually, on average more then half of the samples

Hypoxia-inducible bidirectional shRNA expression vector delivery using PEI/chitosan-TBA copolymers for colorectal Cancer gene therapy.

Science.gov (United States)

Javan, Bita; Atyabi, Fatemeh; Shahbazi, Majid

2018-04-12

This investigation was conducted to construct a hypoxia/colorectal dual-specific bidirectional short hairpin RNA (shRNA) expression vector and to transfect it into the colon cancer cell line HT-29 with PEI/chitosan-TBA nanoparticles for the simultaneous knock down of β-catenin and Bcl-2 under hypoxia. To construct a pRNA-bipHRE-CEA vector, the carcinoma embryonic antigen (CEA) promoter designed in two directions and the vascular endothelial growth factor (VEGF) enhancer were inserted between two promoters for hypoxic cancer specific gene expression. To confirm the therapeutic effect of the dual-specific vector, β-catenin and Bcl-2 shRNAs were inserted downstream of each promoter. The physicochemical properties, the cytotoxicity, and the transfection efficiency of these PEI/chitosan-TBA nanoparticles were investigated. In addition, the antitumor effects of the designed vector on the expression of β-catenin and Bcl-2, cell cycle distribution, and apoptosis were investigated in vitro. The silencing effect of the hypoxia-response shRNA expression vector was relatively low (18%-25%) under normoxia, whereas it was significantly increased to approximately 50%-60% in the HT-29 cell line. Moreover, the cancer cells showed significant G0/G1 arrest and increased apoptosis due to gene silencing under hypoxia. Furthermore, MTS assay, fluorescence microscopy images, and flow cytometry analyses confirmed that the PEI/chitosan-TBA blend system provided effective transfection with low cytotoxicity. This novel hypoxia-responsive shRNA expression vector may be useful for RNA interference (RNAi)-based cancer gene therapy in hypoxic colorectal tumors. Moreover, the PEI/chitosan-TBA copolymer might be a promising gene carrier for use in gene transfer in vivo. Copyright © 2017. Published by Elsevier Inc.

Using Moessbauer spectroscopy as key technique in the investigation of nanosized magnetic particles for drug delivery

Energy Technology Data Exchange (ETDEWEB)

Morais, P. C., E-mail: pcmor@unb.br [Universidade de Brasilia, Nucleo de Fisica Aplicada, Instituto de Fisica (Brazil)

2008-01-15

This paper describes how cobalt ferrite nanoparticles, suspended as ionic or biocompatible magnetic fluids, can be used as a platform to built complex nanosized magnetic materials, more specifically magnetic drug delivery systems. In particular, the paper is addressed to the discussion of the use of the Moessbauer spectroscopy as an extremely useful technique in supporting the investigation of key aspects related to the properties of the hosted magnetic nanosized particle. Example of the use of the Moessbauer spectroscopy in accessing information regarding the nanoparticle modification due to the empirical process which provides long term chemical stability is included in the paper.

Real-time individualized training vectors for experiential learning.

Energy Technology Data Exchange (ETDEWEB)

Willis, Matt; Tucker, Eilish Marie; Raybourn, Elaine Marie; Glickman, Matthew R.; Fabian, Nathan

2011-01-01

Military training utilizing serious games or virtual worlds potentially generate data that can be mined to better understand how trainees learn in experiential exercises. Few data mining approaches for deployed military training games exist. Opportunities exist to collect and analyze these data, as well as to construct a full-history learner model. Outcomes discussed in the present document include results from a quasi-experimental research study on military game-based experiential learning, the deployment of an online game for training evidence collection, and results from a proof-of-concept pilot study on the development of individualized training vectors. This Lab Directed Research & Development (LDRD) project leveraged products within projects, such as Titan (Network Grand Challenge), Real-Time Feedback and Evaluation System, (America's Army Adaptive Thinking and Leadership, DARWARS Ambush! NK), and Dynamic Bayesian Networks to investigate whether machine learning capabilities could perform real-time, in-game similarity vectors of learner performance, toward adaptation of content delivery, and quantitative measurement of experiential learning.

Vector analysis

CERN Document Server

Newell, Homer E

2006-01-01

When employed with skill and understanding, vector analysis can be a practical and powerful tool. This text develops the algebra and calculus of vectors in a manner useful to physicists and engineers. Numerous exercises (with answers) not only provide practice in manipulation but also help establish students' physical and geometric intuition in regard to vectors and vector concepts.Part I, the basic portion of the text, consists of a thorough treatment of vector algebra and the vector calculus. Part II presents the illustrative matter, demonstrating applications to kinematics, mechanics, and e

Visualizing Vector Fields Using Line Integral Convolution and Dye Advection

Science.gov (United States)

Shen, Han-Wei; Johnson, Christopher R.; Ma, Kwan-Liu

1996-01-01

We present local and global techniques to visualize three-dimensional vector field data. Using the Line Integral Convolution (LIC) method to image the global vector field, our new algorithm allows the user to introduce colored 'dye' into the vector field to highlight local flow features. A fast algorithm is proposed that quickly recomputes the dyed LIC images. In addition, we introduce volume rendering methods that can map the LIC texture on any contour surface and/or translucent region defined by additional scalar quantities, and can follow the advection of colored dye throughout the volume.

Vectorization and improvement of nuclear codes. 3. DGR, STREAM V3.1, Cella, GGR

Energy Technology Data Exchange (ETDEWEB)

Nemoto, Toshiyuki; Eguchi, Norikuni; Watanabe, Hideo; Machida, Masahiko; Yokokawa, Mitsuo; Fujii, Minoru [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1995-01-01

Four nuclear codes have been vectorized and improved in order to realize the high speed performance on the VP2600 supercomputer at Computing and Information Systems Center of JAERI in the fiscal year 1993. Molecular Dynamics simulation code DGR which simulates the irradiation damage on diamond crystalline, three-dimensional non-steady compressible fluid dynamics code STREAM V3.1, two-dimensional fluid simulation code using Cell Automaton model Cella and Molecular Dynamics code GGR which simulates the irradiation damage on black carbon crystalline have been vectorized and improved, respectively. Speed up ratios by the vectorization to scalar mode on VP2600 show 2.8, 6.8-14.8, 15-16 and 1.23 times for DGR, STREAM V3.1, Cella and GGR, respectively. In this report, we present vectorization techniques, vectorization effects, evaluations of the numerical results and techniques for the improvement. (author).

Unsupervised learning of binary vectors: A Gaussian scenario

International Nuclear Information System (INIS)

Copelli, Mauro; Van den Broeck, Christian

2000-01-01

We study a model of unsupervised learning where the real-valued data vectors are isotropically distributed, except for a single symmetry-breaking binary direction B(set-membership sign){-1,+1} N , onto which the projections have a Gaussian distribution. We show that a candidate vector J undergoing Gibbs learning in this discrete space, approaches the perfect match J=B exponentially. In addition to the second-order ''retarded learning'' phase transition for unbiased distributions, we show that first-order transitions can also occur. Extending the known result that the center of mass of the Gibbs ensemble has Bayes-optimal performance, we show that taking the sign of the components of this vector (clipping) leads to the vector with optimal performance in the binary space. These upper bounds are shown generally not to be saturated with the technique of transforming the components of a special continuous vector, except in asymptotic limits and in a special linear case. Simulations are presented which are in excellent agreement with the theoretical results. (c) 2000 The American Physical Society

Printing technologies in fabrication of drug delivery systems.

Science.gov (United States)

Kolakovic, Ruzica; Viitala, Tapani; Ihalainen, Petri; Genina, Natalja; Peltonen, Jouko; Sandler, Niklas

2013-12-01

There has been increased activity in the field recently regarding the development and research on various printing techniques in fabrication of dosage forms and drug delivery systems. These technologies may offer benefits and flexibility in manufacturing, potentially paving the way for personalized dosing and tailor-made dosage forms. In this review, the most recent observations and advancements in fabrication of drug delivery systems by utilizing printing technologies are summarized. A general overview of 2D printing techniques is presented including a review of the most recent literature where printing techniques are used in fabrication of drug delivery systems. The future perspectives and possible impacts on formulation strategies, flexible dosing and personalized medication of using printing techniques for fabrication of drug delivery systems are discussed. It is evident that there is an urgent need to meet the challenges of rapidly growing trend of personalization of medicines through development of flexible drug-manufacturing approaches. In this context, various printing technologies, such as inkjet and flexography, can play an important role. Challenges on different levels exist and include: i) technological development of printers and production lines; ii) printable formulations and carrier substrates; iii) quality control and characterization; and iv) regulatory perspectives.

Chemoselective ligation and antigen vectorization.

Science.gov (United States)

Gras-Masse, H

2001-01-01

The interest in cocktail-lipopeptide vaccines has now been confirmed by phase I clinical trials: highly diversified B-, T-helper or cytotoxic T-cell epitopes can be combined with a lipophilic vector for the induction of B- and T-cell responses of predetermined specificity. With the goal of producing an improved vaccine that should ideally induce a multispecific response in non-selected populations, increasing the diversity of the immunizing mixture represents one of the most obvious strategies.The selective delivery of antigens to professional antigen-presenting cells represents another promising approach for the improvement of vaccine efficacy. In this context, the mannose-receptor represents an attractive entry point for the targeting to dendritic cells of antigens linked to clustered glycosides or glycomimetics. In all cases, highly complex but fully characterized molecules must be produced. To develop a modular and flexible strategy which could be generally applicable to a large set of peptide antigens, we elected to explore the potentialities of chemoselective ligation methods. The hydrazone bond was found particularly reliable and fully compatible with sulphide ligation. Hydrazone/thioether orthogonal ligation systems could be developed to account for the nature of the antigens and the solubility of the vector systems. Copyright 2001 The International Association for Biologicals.

Use of Colour and Interactive Animation in Learning 3D Vectors

Science.gov (United States)

Iskander, Wejdan; Curtis, Sharon

2005-01-01

This study investigated the effects of two computer-implemented techniques (colour and interactive animation) on learning 3D vectors. The participants were 43 female Saudi Arabian high school students. They were pre-tested on 3D vectors using a paper questionnaire that consisted of calculation and visualization types of questions. The students…

Vector-Tensor and Vector-Vector Decay Amplitude Analysis of B0→φK*0

International Nuclear Information System (INIS)

Aubert, B.; Bona, M.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Ofte, I.; Stugu, B.; Abrams, G. S.

2007-01-01

We perform an amplitude analysis of the decays B 0 →φK 2 * (1430) 0 , φK * (892) 0 , and φ(Kπ) S-wave 0 with a sample of about 384x10 6 BB pairs recorded with the BABAR detector. The fractions of longitudinal polarization f L of the vector-tensor and vector-vector decay modes are measured to be 0.853 -0.069 +0.061 ±0.036 and 0.506±0.040±0.015, respectively. Overall, twelve parameters are measured for the vector-vector decay and seven parameters for the vector-tensor decay, including the branching fractions and parameters sensitive to CP violation

About vectors

CERN Document Server

Hoffmann, Banesh

1975-01-01

From his unusual beginning in ""Defining a vector"" to his final comments on ""What then is a vector?"" author Banesh Hoffmann has written a book that is provocative and unconventional. In his emphasis on the unresolved issue of defining a vector, Hoffmann mixes pure and applied mathematics without using calculus. The result is a treatment that can serve as a supplement and corrective to textbooks, as well as collateral reading in all courses that deal with vectors. Major topics include vectors and the parallelogram law; algebraic notation and basic ideas; vector algebra; scalars and scalar p

Rapid delivery of small interfering RNA by biosurfactant MEL-A-containing liposomes.

Science.gov (United States)

Inoh, Yoshikazu; Furuno, Tadahide; Hirashima, Naohide; Kitamoto, Dai; Nakanishi, Mamoru

2011-10-28

The downregulation of gene expression by RNA interference holds great potential for genetic analysis and gene therapy. However, a more efficient delivery system for small interfering RNA (siRNA) into the target cells is required for wide fields such as cell biology, physiology, and clinical application. Non-viral vectors are stronger candidates than viral vectors because they are safer and easier to prepare. We have previously used a new method for gene transfection by combining cationic liposomes with the biosurfactant mannosylerythritol lipid-A (MEL-A). The novel MEL-A-containing cationic liposomes rapidly delivered DNA (plasmids and oligonucleotides) into the cytosol and nucleus through membrane fusion between liposomes and the plasma membrane, and consequently, enhanced the gene transfection efficiency. In this study, we determined the efficiency of MEL-A-containing cationic liposomes for siRNA delivery. We observed that exogenous and endogenous protein expression was suppressed by approximately 60% at 24h after brief (30 min) incubation of target cells with MEL-A-containing cationic liposome/siRNA complexes. Confocal microscopic analysis showed that suppression of protein expression was caused by rapid siRNA delivery into the cytosol. We found that the MEL-A-containing cationic liposomes directly delivered siRNA into the cytoplasm by the membrane fusion in addition to endocytotic pathway whereas Lipofectamine RNAiMax delivered siRNA only by the endocytotic pathway. It seems that the ability to rapidly and directly deliver siRNA into the cytosol using MEL-A-containing cationic liposomes is able to reduce immune responses, cytotoxicity, and other side effects caused by viral vectors in clinical applications. Copyright © 2011 Elsevier Inc. All rights reserved.

Energy-exchange collisions of dark-bright-bright vector solitons.

Science.gov (United States)

Radhakrishnan, R; Manikandan, N; Aravinthan, K

2015-12-01

We find a dark component guiding the practically interesting bright-bright vector one-soliton to two different parametric domains giving rise to different physical situations by constructing a more general form of three-component dark-bright-bright mixed vector one-soliton solution of the generalized Manakov model with nine free real parameters. Moreover our main investigation of the collision dynamics of such mixed vector solitons by constructing the multisoliton solution of the generalized Manakov model with the help of Hirota technique reveals that the dark-bright-bright vector two-soliton supports energy-exchange collision dynamics. In particular the dark component preserves its initial form and the energy-exchange collision property of the bright-bright vector two-soliton solution of the Manakov model during collision. In addition the interactions between bound state dark-bright-bright vector solitons reveal oscillations in their amplitudes. A similar kind of breathing effect was also experimentally observed in the Bose-Einstein condensates. Some possible ways are theoretically suggested not only to control this breathing effect but also to manage the beating, bouncing, jumping, and attraction effects in the collision dynamics of dark-bright-bright vector solitons. The role of multiple free parameters in our solution is examined to define polarization vector, envelope speed, envelope width, envelope amplitude, grayness, and complex modulation of our solution. It is interesting to note that the polarization vector of our mixed vector one-soliton evolves in sphere or hyperboloid depending upon the initial parametric choices.

An Overview of the Percutaneous Antibiotic Delivery Technique for Osteomyelitis Treatment and a Case Study of Calcaneal Osteomyelitis.

Science.gov (United States)

Karr, Jeffrey C

2017-11-01

A percutaneous antibiotic delivery technique (PAD-T) used for the adjunctive management of osteomyelitis is presented. This surgical technique incorporates a calcium sulfate and hydroxyapatite (calcium phosphate) bone void filler acting as a carrier vehicle with either an antibiotic or an antifungal medicine, delivering this combination directly into the area of osteomyelitis. The benefit of the PAD-T is reviewed with a case presentation of a successfully treated calcaneal osteomyelitis. No previously reported PAD-T using a simple bone cortex incision in the adjunctive treatment of osteomyelitis has been reported. The PAD-T safely and effectively uses a calcium sulfate and hydroxyapatite bone void filler carrier vehicle to deliver either an antibiotic or an antifungal medicine directly into the area of osteomyelitis.

Design of 2D Time-Varying Vector Fields

KAUST Repository

Chen, Guoning

2012-10-01

Design of time-varying vector fields, i.e., vector fields that can change over time, has a wide variety of important applications in computer graphics. Existing vector field design techniques do not address time-varying vector fields. In this paper, we present a framework for the design of time-varying vector fields, both for planar domains as well as manifold surfaces. Our system supports the creation and modification of various time-varying vector fields with desired spatial and temporal characteristics through several design metaphors, including streamlines, pathlines, singularity paths, and bifurcations. These design metaphors are integrated into an element-based design to generate the time-varying vector fields via a sequence of basis field summations or spatial constrained optimizations at the sampled times. The key-frame design and field deformation are also introduced to support other user design scenarios. Accordingly, a spatial-temporal constrained optimization and the time-varying transformation are employed to generate the desired fields for these two design scenarios, respectively. We apply the time-varying vector fields generated using our design system to a number of important computer graphics applications that require controllable dynamic effects, such as evolving surface appearance, dynamic scene design, steerable crowd movement, and painterly animation. Many of these are difficult or impossible to achieve via prior simulation-based methods. In these applications, the time-varying vector fields have been applied as either orientation fields or advection fields to control the instantaneous appearance or evolving trajectories of the dynamic effects. © 1995-2012 IEEE.

Design of 2D Time-Varying Vector Fields

KAUST Repository

Chen, Guoning; Kwatra, Vivek; Wei, Li-Yi; Hansen, Charles D.; Zhang, Eugene

2012-01-01

Design of time-varying vector fields, i.e., vector fields that can change over time, has a wide variety of important applications in computer graphics. Existing vector field design techniques do not address time-varying vector fields. In this paper, we present a framework for the design of time-varying vector fields, both for planar domains as well as manifold surfaces. Our system supports the creation and modification of various time-varying vector fields with desired spatial and temporal characteristics through several design metaphors, including streamlines, pathlines, singularity paths, and bifurcations. These design metaphors are integrated into an element-based design to generate the time-varying vector fields via a sequence of basis field summations or spatial constrained optimizations at the sampled times. The key-frame design and field deformation are also introduced to support other user design scenarios. Accordingly, a spatial-temporal constrained optimization and the time-varying transformation are employed to generate the desired fields for these two design scenarios, respectively. We apply the time-varying vector fields generated using our design system to a number of important computer graphics applications that require controllable dynamic effects, such as evolving surface appearance, dynamic scene design, steerable crowd movement, and painterly animation. Many of these are difficult or impossible to achieve via prior simulation-based methods. In these applications, the time-varying vector fields have been applied as either orientation fields or advection fields to control the instantaneous appearance or evolving trajectories of the dynamic effects. © 1995-2012 IEEE.

Widespread gene transfer in the central nervous system of cynomolgus macaques following delivery of AAV9 into the cisterna magna

Directory of Open Access Journals (Sweden)

Christian Hinderer

2014-01-01

Full Text Available Adeno-associated virus serotype 9 (AAV9 vectors have recently been shown to transduce cells throughout the central nervous system of nonhuman primates when injected into the cerebrospinal fluid (CSF, a finding which could lead to a minimally invasive approach to treat genetic and acquired diseases affecting the entire CNS. We characterized the transduction efficiency of two routes of vector administration into the CSF of cynomolgus macaques—lumbar puncture, which is typically used in clinical practice, and suboccipital puncture, which is more commonly used in veterinary medicine. We found that delivery of vector into the cisterna magna via suboccipital puncture is up to 100-fold more efficient for achieving gene transfer to the brain. In addition, we evaluated the inflammatory response to AAV9-mediated GFP expression in the nonhuman primate CNS. We found that while CSF lymphocyte counts increased following gene transfer, there were no clinical or histological signs of immune toxicity. Together these data indicate that delivery of AAV9 into the cisterna magna is an effective method for achieving gene transfer in the CNS, and suggest that adapting this uncommon injection method for human trials could vastly increase the efficiency of gene delivery.

Polymeric nanoparticles as cancer-specific DNA delivery vectors to human hepatocellular carcinoma.

Science.gov (United States)

Zamboni, Camila G; Kozielski, Kristen L; Vaughan, Hannah J; Nakata, Maisa M; Kim, Jayoung; Higgins, Luke J; Pomper, Martin G; Green, Jordan J

2017-10-10

Hepatocellular carcinoma (HCC) is the third most deadly cancer in the US, with a meager 5-year survival rate of effective and cancer-specific DNA delivery to human HCC using biodegradable poly(beta-amino ester) (PBAE) nanoparticles (NPs). Varied PBAE NP formulations were evaluated for transfection efficacy and cytotoxicity to a range of human HCC cells as well as healthy human hepatocytes. To address HCC heterogeneity, nine different sources of human HCC cells were utilized. The polymeric NPs composed of 2-((3-aminopropyl)amino) ethanol end-modified poly(1,5-pentanediol diacrylate-co-3-amino-1-propanol) ('536') at a 25 polymer-to-DNA weight-to-weight ratio led to high transfection efficacy to all of the liver cancer lines, but not to hepatocytes. Each individual HCC line had a significantly higher percentage of exogenous gene expression than the healthy liver cells (Peffective DNA transfection in vivo. PBAE-based NPs enabled high and preferential DNA delivery to HCC cells, sparing healthy hepatocytes. These biodegradable and liver cancer-selective NPs are a promising technology to deliver therapeutic genes to liver cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

Pulmonary Delivery of siRNA via Polymeric Vectors as Therapies of Asthma.

Science.gov (United States)

Xie, Yuran; Merkel, Olivia M

2015-10-01

Asthma is a chronic inflammatory disease. Despite the fact that current therapies, such as the combination of inhaled corticosteroids and β2-agonists, can control the symptoms of asthma in most patients, there is still an urgent need for an alternative anti-inflammatory therapy for patients who suffer from severe asthma but lack acceptable response to conventional therapies. Many molecular factors are involved in the inflammatory process in asthma, and thus blocking the function of these factors could efficiently alleviate airway inflammation. RNA interference (RNAi) is often thought to be the answer in the search for more efficient and biocompatible treatments. However, difficulties of efficient delivery of small interference RNA (siRNA), the key factor in RNAi, to target cells and tissues have limited its clinical application. In this review, we summarize cytokines and chemokines, transcription factors, tyrosine kinases, and costimulatory factors that have been reported as targets of siRNA-mediated treatment in experimental asthma. Additionally, we conclude several targeted delivery systems of siRNA to specific cells such as T cells, macrophages, and dendritic cells, which could potentially be applied in asthma therapy. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparison of sampling techniques for Rift Valley Fever virus potential vectors, Aedes aegypti and Culex pipiens complex, in Ngorongoro District in northern Tanzania.

Science.gov (United States)

Mweya, Clement N; Kimera, Sharadhuli I; Karimuribo, Esron D; Mboera, Leonard E G

2013-07-01

We investigated mosquito sampling techniques with two types of traps and attractants at different time for trapping potential vectors for Rift Valley Fever virus. The study was conducted in six villages in Ngorongoro district in Tanzania from September to October 2012. A total of 1814 mosquitoes were collected, of which 738 were collected by CDC light traps and 1076 by Mosquito Magnet trapping technique. Of the collected mosquitoes, 12.46% (N = 226) were Aedes aegypti and 87.54% (N = 1588) were Culex pipiens complex. More mosquitoes were collected outdoors using Mosquito Magnets baited with octenol attractant, 36.38% (N =660) followed by indoor trapping using CDC light traps without attractant, 29.60% (N = 537). Most of Ae. aegypti mosquitoes were collected outdoor using Mosquito Magnets, 95% (N = 214) whereas Cx. pipiens complex were trapped both indoor using CDC light traps without attractant and outdoors using both CDC light traps baited with carbon dioxide (CO2) sachets and Mosquito Magnets. Analysis on the differences in abundance of mosquitoes trapped by different techniques using Generalized Linear Models was statistically significance at p-value < 0.05 for both species. Three hours mosquito collections show differing patterns in activity, most Ae. aegypti species were collected primarily during the first and last quarters of the day. Cx pipiens complex was active throughout the night, early evening and early morning then decreased markedly during the day time. The results presented in this paper emphasize the possibility of using Mosquito Magnets in order to efficiently capture these potential RVF vectors.

Advanced Design of Dumbbell-shaped Genetic Minimal Vectors Improves Non-coding and Coding RNA Expression.

Science.gov (United States)

Jiang, Xiaoou; Yu, Han; Teo, Cui Rong; Tan, Genim Siu Xian; Goh, Sok Chin; Patel, Parasvi; Chua, Yiqiang Kevin; Hameed, Nasirah Banu Sahul; Bertoletti, Antonio; Patzel, Volker

2016-09-01

Dumbbell-shaped DNA minimal vectors lacking nontherapeutic genes and bacterial sequences are considered a stable, safe alternative to viral, nonviral, and naked plasmid-based gene-transfer systems. We investigated novel molecular features of dumbbell vectors aiming to reduce vector size and to improve the expression of noncoding or coding RNA. We minimized small hairpin RNA (shRNA) or microRNA (miRNA) expressing dumbbell vectors in size down to 130 bp generating the smallest genetic expression vectors reported. This was achieved by using a minimal H1 promoter with integrated transcriptional terminator transcribing the RNA hairpin structure around the dumbbell loop. Such vectors were generated with high conversion yields using a novel protocol. Minimized shRNA-expressing dumbbells showed accelerated kinetics of delivery and transcription leading to enhanced gene silencing in human tissue culture cells. In primary human T cells, minimized miRNA-expressing dumbbells revealed higher stability and triggered stronger target gene suppression as compared with plasmids and miRNA mimics. Dumbbell-driven gene expression was enhanced up to 56- or 160-fold by implementation of an intron and the SV40 enhancer compared with control dumbbells or plasmids. Advanced dumbbell vectors may represent one option to close the gap between durable expression that is achievable with integrating viral vectors and short-term effects triggered by naked RNA.

Vectors

DEFF Research Database (Denmark)

Boeriis, Morten; van Leeuwen, Theo

2017-01-01

should be taken into account in discussing ‘reactions’, which Kress and van Leeuwen link only to eyeline vectors. Finally, the question can be raised as to whether actions are always realized by vectors. Drawing on a re-reading of Rudolf Arnheim’s account of vectors, these issues are outlined......This article revisits the concept of vectors, which, in Kress and van Leeuwen’s Reading Images (2006), plays a crucial role in distinguishing between ‘narrative’, action-oriented processes and ‘conceptual’, state-oriented processes. The use of this concept in image analysis has usually focused...

Enhancing gene delivery of adeno-associated viruses by cell-permeable peptides

Directory of Open Access Journals (Sweden)

Yarong Liu

2014-01-01

Full Text Available Adeno-associated virus type 2 (AAV2 is considered a promising gene delivery vector and has been extensively applied in several disease models; however, inefficient transduction in various cells and tissues has limited its widespread application in many areas of gene therapy. In this study, we have developed a general, but efficient, strategy to enhance viral transduction, both in vitro and in vivo, by incubating viral particles with cell-permeable peptides (CPPs. We show that CPPs increase internalization of viral particles into cells by facilitating both energy-independent and energy-dependent endocytosis. Moreover, CPPs can significantly enhance the endosomal escape process of viral particles, thus enhancing viral transduction to those cells that have exhibited very low permissiveness to AAV2 infection as a result of impaired intracellular viral processing. We also demonstrated that this approach could be applicable to other AAV serotypes. Thus, the membrane-penetrating ability of CPPs enables us to generate an efficient method for enhanced gene delivery of AAV vectors, potentially facilitating its applicability to human gene therapy.

Practical utilization of recombinant AAV vector reference standards: focus on vector genomes titration by free ITR qPCR

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Susan D'Costa

2016-01-01

Full Text Available Clinical trials using recombinant adeno-associated virus (rAAV vectors have demonstrated efficacy and a good safety profile. Although the field is advancing quickly, vector analytics and harmonization of dosage units are still a limitation for commercialization. AAV reference standard materials (RSMs can help ensure product safety by controlling the consistency of assays used to characterize rAAV stocks. The most widely utilized unit of vector dosing is based on the encapsidated vector genome. Quantitative polymerase chain reaction (qPCR is now the most common method to titer vector genomes (vg; however, significant inter- and intralaboratory variations have been documented using this technique. Here, RSMs and rAAV stocks were titered on the basis of an inverted terminal repeats (ITRs sequence-specific qPCR and we found an artificial increase in vg titers using a widely utilized approach. The PCR error was introduced by using single-cut linearized plasmid as the standard curve. This bias was eliminated using plasmid standards linearized just outside the ITR region on each end to facilitate the melting of the palindromic ITR sequences during PCR. This new “Free-ITR” qPCR delivers vg titers that are consistent with titers obtained with transgene-specific qPCR and could be used to normalize in-house product-specific AAV vector standards and controls to the rAAV RSMs. The free-ITR method, including well-characterized controls, will help to calibrate doses to compare preclinical and clinical data in the field.

Practical utilization of recombinant AAV vector reference standards: focus on vector genomes titration by free ITR qPCR.

Science.gov (United States)

D'Costa, Susan; Blouin, Veronique; Broucque, Frederic; Penaud-Budloo, Magalie; François, Achille; Perez, Irene C; Le Bec, Christine; Moullier, Philippe; Snyder, Richard O; Ayuso, Eduard

2016-01-01

Clinical trials using recombinant adeno-associated virus (rAAV) vectors have demonstrated efficacy and a good safety profile. Although the field is advancing quickly, vector analytics and harmonization of dosage units are still a limitation for commercialization. AAV reference standard materials (RSMs) can help ensure product safety by controlling the consistency of assays used to characterize rAAV stocks. The most widely utilized unit of vector dosing is based on the encapsidated vector genome. Quantitative polymerase chain reaction (qPCR) is now the most common method to titer vector genomes (vg); however, significant inter- and intralaboratory variations have been documented using this technique. Here, RSMs and rAAV stocks were titered on the basis of an inverted terminal repeats (ITRs) sequence-specific qPCR and we found an artificial increase in vg titers using a widely utilized approach. The PCR error was introduced by using single-cut linearized plasmid as the standard curve. This bias was eliminated using plasmid standards linearized just outside the ITR region on each end to facilitate the melting of the palindromic ITR sequences during PCR. This new "Free-ITR" qPCR delivers vg titers that are consistent with titers obtained with transgene-specific qPCR and could be used to normalize in-house product-specific AAV vector standards and controls to the rAAV RSMs. The free-ITR method, including well-characterized controls, will help to calibrate doses to compare preclinical and clinical data in the field.

pEPito: a significantly improved non-viral episomal expression vector for mammalian cells

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Ogris Manfred

2010-03-01

Full Text Available Abstract Background The episomal replication of the prototype vector pEPI-1 depends on a transcription unit starting from the constitutively expressed Cytomegalovirus immediate early promoter (CMV-IEP and directed into a 2000 bp long matrix attachment region sequence (MARS derived from the human β-interferon gene. The original pEPI-1 vector contains two mammalian transcription units and a total of 305 CpG islands, which are located predominantly within the vector elements necessary for bacterial propagation and known to be counterproductive for persistent long-term transgene expression. Results Here, we report the development of a novel vector pEPito, which is derived from the pEPI-1 plasmid replicon but has considerably improved efficacy both in vitro and in vivo. The pEPito vector is significantly reduced in size, contains only one transcription unit and 60% less CpG motives in comparison to pEPI-1. It exhibits major advantages compared to the original pEPI-1 plasmid, including higher transgene expression levels and increased colony-forming efficiencies in vitro, as well as more persistent transgene expression profiles in vivo. The performance of pEPito-based vectors was further improved by replacing the CMV-IEP with the human CMV enhancer/human elongation factor 1 alpha promoter (hCMV/EF1P element that is known to be less affected by epigenetic silencing events. Conclusions The novel vector pEPito can be considered suitable as an improved vector for biotechnological applications in vitro and for non-viral gene delivery in vivo.

Vector regression introduced

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Mok Tik

2014-06-01

Full Text Available This study formulates regression of vector data that will enable statistical analysis of various geodetic phenomena such as, polar motion, ocean currents, typhoon/hurricane tracking, crustal deformations, and precursory earthquake signals. The observed vector variable of an event (dependent vector variable is expressed as a function of a number of hypothesized phenomena realized also as vector variables (independent vector variables and/or scalar variables that are likely to impact the dependent vector variable. The proposed representation has the unique property of solving the coefficients of independent vector variables (explanatory variables also as vectors, hence it supersedes multivariate multiple regression models, in which the unknown coefficients are scalar quantities. For the solution, complex numbers are used to rep- resent vector information, and the method of least squares is deployed to estimate the vector model parameters after transforming the complex vector regression model into a real vector regression model through isomorphism. Various operational statistics for testing the predictive significance of the estimated vector parameter coefficients are also derived. A simple numerical example demonstrates the use of the proposed vector regression analysis in modeling typhoon paths.

Effects of Cavity on the Performance of Dual Throat Nozzle During the Thrust-Vectoring Starting Transient Process.

Science.gov (United States)

Gu, Rui; Xu, Jinglei

2014-01-01

The dual throat nozzle (DTN) technique is capable to achieve higher thrust-vectoring efficiencies than other fluidic techniques, without compromising thrust efficiency significantly during vectoring operation. The excellent performance of the DTN is mainly due to the concaved cavity. In this paper, two DTNs of different scales have been investigated by unsteady numerical simulations to compare the parameter variations and study the effects of cavity during the vector starting process. The results remind us that during the vector starting process, dynamic loads may be generated, which is a potentially challenging problem for the aircraft trim and control.

The extinction of dengue through natural vulnerability of its vectors.

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Craig R Williams

Full Text Available BACKGROUND: Dengue is the world's most important mosquito-borne viral illness. Successful future management of this disease requires an understanding of the population dynamics of the vector, especially in the context of changing climates. Our capacity to predict future dynamics is reflected in our ability to explain the significant historical changes in the distribution and abundance of the disease and its vector. METHODOLOGY/PRINCIPAL FINDINGS: Here we combine daily weather records with simulation modelling techniques to explain vector (Aedes aegypti (L. persistence within its current and historic ranges in Australia. We show that, in regions where dengue presently occurs in Australia (the Wet Tropics region of Far North Queensland, conditions are persistently suitable for year-round adult Ae. aegypti activity and oviposition. In the historic range, however, the vector is vulnerable to periodic extinction due to the combined influence of adult activity constraints and stochastic loss of suitable oviposition sites. CONCLUSIONS/SIGNIFICANCE: These results, together with changes in water-storage behaviour by humans, can explain the observed historical range contraction of the disease vector. For these reasons, future eradication of dengue in wet tropical regions will be extremely difficult through classical mosquito control methods alone. However, control of Ae. aegypti in sub-tropical and temperate regions will be greatly facilitated by government policy regulating domestic water-storage. Exploitation of the natural vulnerabilities of dengue vectors (e.g., habitat specificity, climatic limitations should be integrated with the emerging novel transgenic and symbiotic bacterial control techniques to develop future control and elimination strategies.

Vectorization of morpholino oligomers by the (R-Ahx-R)4 peptide allows efficient splicing correction in the absence of endosomolytic agents.

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Abes, Saïd; Moulton, Hong M; Clair, Philippe; Prevot, Paul; Youngblood, Derek S; Wu, Rebecca P; Iversen, Patrick L; Lebleu, Bernard

2006-12-01

The efficient and non-toxic nuclear delivery of steric-block oligonucleotides (ON) is a prerequisite for therapeutic strategies involving splice correction or exon skipping. Cationic cell penetrating peptides (CPPs) have given rise to much interest for the intracellular delivery of biomolecules, but their efficiency in promoting cytoplasmic or nuclear delivery of oligonucleotides has been hampered by endocytic sequestration and subsequent degradation of most internalized material in endocytic compartments. In the present study, we compared the splice correction activity of three different CPPs conjugated to PMO(705), a steric-block ON targeted against the mutated splicing site of human beta-globin pre-mRNA in the HeLa pLuc705 splice correction model. In contrast to Tat48-60 (Tat) and oligoarginine (R(9)F(2)) PMO(705) conjugates, the 6-aminohexanoic-spaced oligoarginine (R-Ahx-R)(4)-PMO(705) conjugate was able to promote an efficient splice correction in the absence of endosomolytic agents. Our mechanistic investigations about its uptake mechanisms lead to the conclusion that these three vectors are internalized using the same endocytic route involving proteoglycans, but that the (R-Ahx-R)(4)-PMO(705) conjugate has the unique ability to escape from lysosomial fate and to access to the nuclear compartment. This vector, which has displays an extremely low cytotoxicity, the ability to function without chloroquine adjunction and in the presence of serum proteins. It thus offers a promising lead for the development of vectors able to enhance the delivery of therapeutic steric-block ON in clinically relevant models.

Instantaneous local wave vector estimation from multi-spacecraft measurements using few spatial points

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T. D. Carozzi

2004-07-01

Full Text Available We introduce a technique to determine instantaneous local properties of waves based on discrete-time sampled, real-valued measurements from 4 or more spatial points. The technique is a generalisation to the spatial domain of the notion of instantaneous frequency used in signal processing. The quantities derived by our technique are closely related to those used in geometrical optics, namely the local wave vector and instantaneous phase velocity. Thus, this experimental technique complements ray-tracing. We provide example applications of the technique to electric field and potential data from the EFW instrument on Cluster. Cluster is the first space mission for which direct determination of the full 3-dimensional local wave vector is possible, as described here.

Low-Dose Gene Therapy for Murine PKU Using Episomal Naked DNA Vectors Expressing PAH from Its Endogenous Liver Promoter

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Hiu Man Grisch-Chan

2017-06-01

Full Text Available Limited duration of transgene expression, insertional mutagenesis, and size limitations for transgene cassettes pose challenges and risk factors for many gene therapy vectors. Here, we report on physiological expression of liver phenylalanine hydroxylase (PAH by delivery of naked DNA/minicircle (MC-based vectors for correction of homozygous enu2 mice, a model of human phenylketonuria (PKU. Because MC vectors lack a defined size limit, we constructed a MC vector expressing a codon-optimized murine Pah cDNA that includes a truncated intron and is under the transcriptional control of a 3.6-kb native Pah promoter/enhancer sequence. This vector, delivered via hydrodynamic injection, yielded therapeutic liver PAH activity and sustained correction of blood phenylalanine comparable to viral or synthetic liver promoters. Therapeutic efficacy was seen with vector copy numbers of 95% loss of vector genomes and PAH activity in liver, demonstrating that MC vectors had not integrated into the liver genome. In conclusion, MC vectors, which do not have a defined size-limitation, offer a favorable safety profile for hepatic gene therapy due to their non-integration in combination with native promoters.

AAV9-mediated central nervous system–targeted gene delivery via cisterna magna route in mice

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Vera Lukashchuk

2016-01-01

Full Text Available Current barriers to the use of adeno-associated virus serotype 9 (AAV9 in clinical trials for treating neurological disorders are its high expression in many off-target tissues such as liver and heart, and lack of cell specificity within the central nervous system (CNS when using ubiquitous promoters such as human cytomegalovirus (CMV or chicken-β-actin hybrid (CAG. To enhance targeting the transgene expression in CNS cells, self-complementary (sc AAV9 vectors, scAAV9-GFP vectors carrying neuronal Hb9 and synapsin 1, and nonspecific CMV and CAG promoters were constructed. We demonstrate that synapsin 1 and Hb9 promoters exclusively targeted neurons in vitro, although their strengths were up to 10-fold lower than that of CMV. In vivo analyses of mouse tissue after scAAV9-GFP vector delivery via the cisterna magna revealed a significant advantage of synapsin 1 promoter over both Hb9 variants in targeting neurons throughout the brain, since Hb9 promoters were driving gene expression mainly within the motor-related areas of the brain stem. In summary, this study demonstrates that cisterna magna administration is a safe alternative to intracranial or intracerebroventricular vector delivery route using scAAV9, and introduces a novel utility of the Hb9 promoter for the targeted gene expression for both in vivo and in vitro applications.

Kochen-Specker vectors

International Nuclear Information System (INIS)

Pavicic, Mladen; Merlet, Jean-Pierre; McKay, Brendan; Megill, Norman D

2005-01-01

We give a constructive and exhaustive definition of Kochen-Specker (KS) vectors in a Hilbert space of any dimension as well as of all the remaining vectors of the space. KS vectors are elements of any set of orthonormal states, i.e., vectors in an n-dimensional Hilbert space, H n , n≥3, to which it is impossible to assign 1s and 0s in such a way that no two mutually orthogonal vectors from the set are both assigned 1 and that not all mutually orthogonal vectors are assigned 0. Our constructive definition of such KS vectors is based on algorithms that generate MMP diagrams corresponding to blocks of orthogonal vectors in R n , on algorithms that single out those diagrams on which algebraic (0)-(1) states cannot be defined, and on algorithms that solve nonlinear equations describing the orthogonalities of the vectors by means of statistically polynomially complex interval analysis and self-teaching programs. The algorithms are limited neither by the number of dimensions nor by the number of vectors. To demonstrate the power of the algorithms, all four-dimensional KS vector systems containing up to 24 vectors were generated and described, all three-dimensional vector systems containing up to 30 vectors were scanned, and several general properties of KS vectors were found

A compact dual promoter adeno-associated viral vector for efficient delivery of two genes to dorsal root ganglion neurons

NARCIS (Netherlands)

Fagoe, N D; Eggers, R; Verhaagen, J; Mason, M R J

Adeno-associated viral (AAV) vectors based on serotype 5 are an efficient means to target dorsal root ganglia (DRG) to study gene function in the primary sensory neurons of the peripheral nervous system. In this study, we have developed a compact AAV dual promoter vector composed of the

Dendrimers as tunable vectors of drug delivery systems and biomedical and ocular applications

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Kalomiraki M

2015-12-01

Full Text Available Marina Kalomiraki,1 Kyriaki Thermos,2 Nikos A Chaniotakis1 1Laboratory of Analytical Chemistry, Department of Chemistry, 2Department of Pharmacology, School of Medicine, University of Crete Voutes, Heraklion, Greece Abstract: Dendrimers are large polymeric structures with nanosize dimensions (1–10 nm and unique physicochemical properties. The major advantage of dendrimers compared with linear polymers is their spherical-shaped structure. During synthesis, the size and shape of the dendrimer can be customized and controlled, so the finished macromolecule will have a specific “architecture” and terminal groups. These characteristics will determine its suitability for drug delivery, diagnostic imaging, and as a genetic material carrier. This review will focus initially on the unique properties of dendrimers and their use in biomedical applications, as antibacterial, antitumor, and diagnostic agents. Subsequently, emphasis will be given to their use in drug delivery for ocular diseases. Keywords: nanoparticles, ocular diseases, encapsulation, macromolecule, diagnostic agent

Using viral vectors as gene transfer tools (Cell Biology and Toxicology Special Issue: ETCS-UK 1 day meeting on genetic manipulation of cells).

Science.gov (United States)

Howarth, Joanna L; Lee, Youn Bok; Uney, James B

2010-02-01

In recent years, the development of powerful viral gene transfer techniques has greatly facilitated the study of gene function. This review summarises some of the viral delivery systems routinely used to mediate gene transfer into cell lines, primary cell cultures and in whole animal models. The systems described were originally discussed at a 1-day European Tissue Culture Society (ETCS-UK) workshop that was held at University College London on 1st April 2009. Recombinant-deficient viral vectors (viruses that are no longer able to replicate) are used to transduce dividing and post-mitotic cells, and they have been optimised to mediate regulatable, powerful, long-term and cell-specific expression. Hence, viral systems have become very widely used, especially in the field of neurobiology. This review introduces the main categories of viral vectors, focusing on their initial development and highlighting modifications and improvements made since their introduction. In particular, the use of specific promoters to restrict expression, translational enhancers and regulatory elements to boost expression from a single virion and the development of regulatable systems is described.

Elementary vectors

CERN Document Server

Wolstenholme, E Œ

1978-01-01

Elementary Vectors, Third Edition serves as an introductory course in vector analysis and is intended to present the theoretical and application aspects of vectors. The book covers topics that rigorously explain and provide definitions, principles, equations, and methods in vector analysis. Applications of vector methods to simple kinematical and dynamical problems; central forces and orbits; and solutions to geometrical problems are discussed as well. This edition of the text also provides an appendix, intended for students, which the author hopes to bridge the gap between theory and appl

Barriers to Liposomal Gene Delivery: from Application Site to the Target.

Science.gov (United States)

Saffari, Mostafa; Moghimi, Hamid Reza; Dass, Crispin R

2016-01-01

Gene therapy is a therapeutic approach to deliver genetic material into cells to alter their function in entire organism. One promising form of gene delivery system (DDS) is liposomes. The success of liposome-mediated gene delivery is a multifactorial issue and well-designed liposomal systems might lead to optimized gene transfection particularly in vivo. Liposomal gene delivery systems face different barriers from their site of application to their target, which is inside the cells. These barriers include presystemic obstacles (epithelial barriers), systemic barriers in blood circulation and cellular barriers. Epithelial barriers differ depending on the route of administration. Systemic barriers include enzymatic degradation, binding and opsonisation. Both of these barriers can act as limiting hurdles that genetic material and their vector should overcome before reaching the cells. Finally liposomes should overcome cellular barriers that include cell entrance, endosomal escape and nuclear uptake. These barriers and their impact on liposomal gene delivery will be discussed in this review.

A review on electrospun nanofibers for oral drug delivery

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Abbas Akhgari

2017-10-01

Full Text Available Nowadays, polymer nanofibers have gained attention due to remarkable characteristics such as high porosity and large surface area to volume ratio. Among their fabrication methods, electrospinning technique has been attracted as a simple and reproducible approach. It is a versatile, simple and cost-effective technique for the production of continuous nanofibers with acceptable characteristics such as high porosity, high surface area to volume ratio, high loading capacity and encapsulation efficiency, delivery of multiple drugs, and enhancement of drug solubility. Due to these properties electrospun nanofibers have been extensively used for different biomedical applications including wound dressing, tissue engineering, enzyme immobilization, artificial organs, and drug delivery. Different synthetic and natural polymers have been successfully electrospun into ultrafine fibers. Using electrospun nanofibers as vehicles for oral drug delivery has been investigated in different release manners- fast, biphasic or sustained release. This article presents a review on application of electrospinning technique in oral drug delivery.

Design of a Front– End Amplifier for the Maximum Power Delivery and Required Noise by HBMO with Support Vector Microstrip Model

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F. Guneş

2014-04-01

Full Text Available Honey Bee Mating Optimization (HBMO is a recent swarm-based optimization algorithm to solve highly nonlinear problems, whose based approach combines the powers of simulated annealing, genetic algorithms, and an effective local search heuristic to search for the best possible solution to the problem under investigation within a reasonable computing time. In this work, the HBMO- based design is carried out for a front-end amplifier subject to be a subunit of a radar system in conjunction with a cost effective 3-D SONNET-based Support Vector Regression Machine (SVRM microstrip model. All the matching microstrip widths, lengths are obtained on a chosen substrate to satisfy the maximum power delivery and the required noise over the required bandwidth of a selected transistor. The proposed HBMO- based design is applied to the design of a typical ultra-wide-band low noise amplifier with NE3512S02 on a substrate of Rogers 4350 for the maximum output power and the noise figure F(f=1dB within the 5-12 GHz using the T- type of microstrip matching circuits. Furthermore, the effectiveness and efficiency of the proposed HBMO based design are manifested by comparing it with the Genetic Algorithm (GA, Particle Swarm Optimization (PSO and the simple HBMO based designs.

Well-defined polypeptide-based systems as non-viral vectors for cytosolic delivery

OpenAIRE

Niño Pariente, Amaya

2017-01-01

A convenient cytosolic drug delivery constitutes a very powerful tool for the treatment and/or prevention of several relevant human diseases. Along with recent advances in therapeutic technologies based on biomacromolecules (e.g. oligonucleotides or proteins), we also require the development of technologies which improve the transport of therapeutic molecules to the cell of choice. This has led to the emergence of a variety of promising methods over the last 20 years. Despite significant prog...

Hepatitis virus protein X-Phenylalanine Hydroxylase fusion proteins identified in PKU mice treated with AAV-WPRE vectors

Science.gov (United States)

Utilizing the Pahenu2 mouse model for phenylketonuria (PKU), we developed an improved expression vector containing the Woodchuck Hepatitis Virus post-transcriptional regulatory element inserted into a rAAV-mPAH construct (rAAV-mPAH-WPRE) for treatment of PKU. Following portal vein delivery of these ...

Challenges and opportunities in dermal/transdermal delivery

OpenAIRE

Paudel, Kalpana S; Milewski, Mikolaj; Swadley, Courtney L; Brogden, Nicole K; Ghosh, Priyanka; Stinchcomb, Audra L

2010-01-01

Transdermal drug delivery is an exciting and challenging area. There are numerous transdermal delivery systems currently available on the market. However, the transdermal market still remains limited to a narrow range of drugs. Further advances in transdermal delivery depend on the ability to overcome the challenges faced regarding the permeation and skin irritation of the drug molecules. Emergence of novel techniques for skin permeation enhancement and development of methods to lessen skin i...

Lentiviral vector mediated modification of mesenchymal stem cells & enhanced survival in an in vitro model of ischaemia.

LENUS (Irish Health Repository)

McGinley, Lisa

2012-01-31

INTRODUCTION: A combination of gene and cell therapies has the potential to significantly enhance the therapeutic value of mesenchymal stem cells (MSCs). The development of efficient gene delivery methods is essential if MSCs are to be of benefit using such an approach. Achieving high levels of transgene expression for the required period of time, without adversely affecting cell viability and differentiation capacity, is crucial. In the present study, we investigate lentiviral vector-mediated genetic modification of rat bone-marrow derived MSCs and examine any functional effect of such genetic modification in an in vitro model of ischaemia. METHODS: Transduction efficiency and transgene persistence of second and third generation rHIV-1 based lentiviral vectors were tested using reporter gene constructs. Use of the rHIV-pWPT-EF1-alpha-GFP-W vector was optimised in terms of dose, toxicity, cell species, and storage. The in vivo condition of ischaemia was modelled in vitro by separation into its associated constituent parts i.e. hypoxia, serum and glucose deprivation, in which the effect of therapeutic gene over-expression on MSC survival was investigated. RESULTS: The second generation lentiviral vector rHIV-pWPT-EF1-alpha-GFP-W, was the most efficient and provided the most durable transgene expression of the vectors tested. Transduction with this vector did not adversely affect MSC morphology, viability or differentiation potential, and transgene expression levels were unaffected by cryopreservation of transduced cells. Over-expression of HSP70 resulted in enhanced MSC survival and increased resistance to apoptosis in conditions of hypoxia and ischaemia. MSC differentiation capacity was significantly reduced after oxygen deprivation, but was preserved with HSP70 over-expression. CONCLUSIONS: Collectively, these data validate the use of lentiviral vectors for efficient in vitro gene delivery to MSCs and suggest that lentiviral vector transduction can facilitate

Lentiviral vector mediated modification of mesenchymal stem cells & enhanced survival in an in vitro model of ischaemia

LENUS (Irish Health Repository)

McGinley, Lisa

2011-03-07

Abstract Introduction A combination of gene and cell therapies has the potential to significantly enhance the therapeutic value of mesenchymal stem cells (MSCs). The development of efficient gene delivery methods is essential if MSCs are to be of benefit using such an approach. Achieving high levels of transgene expression for the required period of time, without adversely affecting cell viability and differentiation capacity, is crucial. In the present study, we investigate lentiviral vector-mediated genetic modification of rat bone-marrow derived MSCs and examine any functional effect of such genetic modification in an in vitro model of ischaemia. Methods Transduction efficiency and transgene persistence of second and third generation rHIV-1 based lentiviral vectors were tested using reporter gene constructs. Use of the rHIV-pWPT-EF1-α-GFP-W vector was optimised in terms of dose, toxicity, cell species, and storage. The in vivo condition of ischaemia was modelled in vitro by separation into its associated constituent parts i.e. hypoxia, serum and glucose deprivation, in which the effect of therapeutic gene over-expression on MSC survival was investigated. Results The second generation lentiviral vector rHIV-pWPT-EF1-α-GFP-W, was the most efficient and provided the most durable transgene expression of the vectors tested. Transduction with this vector did not adversely affect MSC morphology, viability or differentiation potential, and transgene expression levels were unaffected by cryopreservation of transduced cells. Over-expression of HSP70 resulted in enhanced MSC survival and increased resistance to apoptosis in conditions of hypoxia and ischaemia. MSC differentiation capacity was significantly reduced after oxygen deprivation, but was preserved with HSP70 over-expression. Conclusions Collectively, these data validate the use of lentiviral vectors for efficient in vitro gene delivery to MSCs and suggest that lentiviral vector transduction can facilitate

The Identification of Hunger Behaviour of Lates Calcarifer through the Integration of Image Processing Technique and Support Vector Machine

Science.gov (United States)

Taha, Z.; Razman, M. A. M.; Adnan, F. A.; Ghani, A. S. Abdul; Majeed, A. P. P. Abdul; Musa, R. M.; Sallehudin, M. F.; Mukai, Y.

2018-03-01

Fish Hunger behaviour is one of the important element in determining the fish feeding routine, especially for farmed fishes. Inaccurate feeding routines (under-feeding or over-feeding) lead the fishes to die and thus, reduces the total production of fishes. The excessive food which is not eaten by fish will be dissolved in the water and thus, reduce the water quality (oxygen quantity in the water will be reduced). The reduction of oxygen (water quality) leads the fish to die and in some cases, may lead to fish diseases. This study correlates Barramundi fish-school behaviour with hunger condition through the hybrid data integration of image processing technique. The behaviour is clustered with respect to the position of the centre of gravity of the school of fish prior feeding, during feeding and after feeding. The clustered fish behaviour is then classified by means of a machine learning technique namely Support vector machine (SVM). It has been shown from the study that the Fine Gaussian variation of SVM is able to provide a reasonably accurate classification of fish feeding behaviour with a classification accuracy of 79.7%. The proposed integration technique may increase the usefulness of the captured data and thus better differentiates the various behaviour of farmed fishes.

Disabled infectious single cycle-herpes simplex virus (DISC-HSV) as a vector for immunogene therapy of cancer.

Science.gov (United States)

Rees, Robert C; McArdle, Stephanie; Mian, Shahid; Li, Geng; Ahmad, Murrium; Parkinson, Richard; Ali, Selman A

2002-02-01

Disabled infectious single cycle-herpes simplex viruses (DISC-HSV) have been shown to be safe for use in humans and may be considered efficacious as vectors for immunogene therapy in cancer. Preclinical studies show that DISC-HSV is an efficient delivery system for cytokine genes and antigens. DISC-HSV infects a high proportion of cells, resulting in rapid gene expression for at least 72 h. The DISC-HSV-mGM-CSF vector, when inoculated into tumors, induces tumor regression in a high percentage of animals, concomitant with establishing a cytotoxic T-cell response, which is MHC class I restricted and directed against peptides of known tumor antigens. The inherent properties of DISC-HSV makes it a suitable vector for consideration in human immunogene therapy trials.

Application of a support vector machine algorithm to the safety precaution technique of medium-low pressure gas regulators

Science.gov (United States)

Hao, Xuejun; An, Xaioran; Wu, Bo; He, Shaoping

2018-02-01

In the gas pipeline system, safe operation of a gas regulator determines the stability of the fuel gas supply, and the medium-low pressure gas regulator of the safety precaution system is not perfect at the present stage in the Beijing Gas Group; therefore, safety precaution technique optimization has important social and economic significance. In this paper, according to the running status of the medium-low pressure gas regulator in the SCADA system, a new method for gas regulator safety precaution based on the support vector machine (SVM) is presented. This method takes the gas regulator outlet pressure data as input variables of the SVM model, the fault categories and degree as output variables, which will effectively enhance the precaution accuracy as well as save significant manpower and material resources.

Low molecular weight chitosan conjugated with folate for siRNA delivery in vitro: optimization studies

Science.gov (United States)

Fernandes, Julio C; Qiu, Xingping; Winnik, Francoise M; Benderdour, Mohamed; Zhang, Xiaoling; Dai, Kerong; Shi, Qin

2012-01-01

The low transfection efficiency of chitosan is one of its drawbacks as a gene delivery carrier. Low molecular weight chitosan may help to form small-sized polymer-DNA or small interfering RNA (siRNA) complexes. Folate conjugation may improve gene transfection efficiency because of the promoted uptake of folate receptor-bearing cells. In the present study, chitosan was conjugated with folate and investigated for its efficacy as a delivery vector for siRNA in vitro. We demonstrate that the molecular weight of chitosan has a major influence on its biological and physicochemical properties, and very low molecular weight chitosan (below 10 kDa) has difficulty in forming stable complexes with siRNA. In this study, chitosan 25 kDa and 50 kDa completely absorbed siRNA and formed nanoparticles (≤220 nm) at a chitosan to siRNA weight ratio of 50:1. The introduction of a folate ligand onto chitosan decreased nanoparticle toxicity. Compared with chitosan-siRNA, folate-chitosan-siRNA nanoparticles improved gene silencing transfection efficiency. Therefore, folate-chitosan shows potential as a viable candidate vector for safe and efficient siRNA delivery. PMID:23209368

Polyethyleneimine grafted short halloysite nanotubes for gene delivery.

Science.gov (United States)

Long, Zheru; Zhang, Jun; Shen, Yan; Zhou, Changren; Liu, Mingxian

2017-12-01

Inorganic nanoparticles have attracted much attentions in gene delivery because of their desirable characteristics including low toxicity, well-controlled characteristics, high gene delivery efficiency, and multi-functionalities. Here, natural occurred halloysite nanotubes (HNTs) were developed as a novel non-viral gene vector. To increase the efficiency of endocytosis, HNTs were firstly shortened into an appropriate size (~200nm). Then polyethyleneimine (PEI) was grafted onto HNTs to bind green fluorescence protein (GFP) labeled pDNA. The structure and physical-chemical properties of PEI grafted HNTs (PEI-g-HNTs) were characterized by various methods. PEI-g-HNTs show lower cytotoxicity than PEI. PEI-g-HNTs are positively charged and can bind DNA tightly at designed N/P ratio from 5:1 to 40:1. PEI-g-HNTs/pDNA complexes show much higher transfection efficiency towards both 293T and HeLa cells compared with PEI/pDNA complexes at the equivalent N/P ratio. The transfection efficiencies of PEI-g-HNTs/pDNA complex towards HeLa cell can reach to 44.4% at N/P ratio of 20. PEI-g-HNTs/pDNA complexes possess a higher GFP protein expression than PEI/pDNA from simple western immunoblots. So, PEI-g-HNTs are potential gene vectors with good biocompatibility and high transfection efficiency, which have promising applications in cancer gene therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

Lipopolyplex for therapeutic gene delivery and its application for the treatment of Parkinson’s disease

Directory of Open Access Journals (Sweden)

Wei eChen

2016-04-01

Full Text Available Abstract: Lipopolyplex is a core-shell structure composed of nucleic acid, polycation and lipid. As a non-viral gene delivery vector, lipopolyplex combining the advantages of polyplex and lipoplex has shown superior colloidal stability, reduced cytotoxicity, extremely high gene transfection efficiency. Following intravenous administration, there are many strategies based on lipopolyplex to overcome the complex biological barriers in systemic gene delivery including condensation of nucleic acids into nanoparticles, long circulation, cell targeting, endosomal escape, release to cytoplasm and entry into cell nucleus. Parkinson’s disease is the second most common neurodegenerative disorder and severely influences the patients’ life quality. Current gene therapy clinical trials for Parkinson’s disease employing viral vectors didn’t achieve satisfactory efficacy. However, lipopolyplex may become a promising alternative approach owing to its stability in blood, ability to cross the blood-brain barrier and specific targeting to diseased brain cells.

[French residents' training in instrumental deliveries: A national survey].

Science.gov (United States)

Saunier, C; Raimond, E; Dupont, A; Pelissier, A; Bonneau, S; Gabriel, R; Graesslin, O

2016-11-01

To evaluate French residents in Obstetrics and Gynaecology's training in instrumental deliveries in 2015. We conducted a national descriptive survey among 758 residents between December 2014 and January 2015. Respondents were invited by email to specify their University Hospital, their current university term, the number of instrumental deliveries performed by vacuum extractor, forceps or spatulas, and whether they made systematic ultrasound exams before performing the extraction. Response rate was 34.7 % (n=263). There were important differences between regions in terms of type of instruments used. Vacuum extractor was the most commonly used instrument for instrumental deliveries by French residents (56.9 %), more than forceps (25.2 %) and spatulas (17.9 %). At the end of the residency, all the residents had been trained in instrumental deliveries with at least two instruments. The training of difficult techniques as well as their perfect control is required for instrumental deliveries. Yet, we are forced to note that there are substantial differences in the French residents' training in instrumental deliveries depending on their region. So, teaching at least two techniques seems essential as well as improving the training capacities and standardizing practices. A greater systematization of the teaching of the mechanics and obstetric techniques might be a solution to be considered too. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Genetic manipulation of endosymbionts to control vector and vector borne diseases

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Jay Prakash Gupta

Full Text Available Vector borne diseases (VBD are on the rise because of failure of the existing methods of control of vector and vector borne diseases and the climate change. A steep rise of VBDs are due to several factors like selection of insecticide resistant vector population, drug resistant parasite population and lack of effective vaccines against the VBDs. Environmental pollution, public health hazard and insecticide resistant vector population indicate that the insecticides are no longer a sustainable control method of vector and vector-borne diseases. Amongst the various alternative control strategies, symbiont based approach utilizing endosymbionts of arthropod vectors could be explored to control the vector and vector borne diseases. The endosymbiont population of arthropod vectors could be exploited in different ways viz., as a chemotherapeutic target, vaccine target for the control of vectors. Expression of molecules with antiparasitic activity by genetically transformed symbiotic bacteria of disease-transmitting arthropods may serve as a powerful approach to control certain arthropod-borne diseases. Genetic transformation of symbiotic bacteria of the arthropod vector to alter the vector’s ability to transmit pathogen is an alternative means of blocking the transmission of VBDs. In Indian scenario, where dengue, chikungunya, malaria and filariosis are prevalent, paratransgenic based approach can be used effectively. [Vet World 2012; 5(9.000: 571-576

A New Multistage Lattice Vector Quantization with Adaptive Subband Thresholding for Image Compression

Directory of Open Access Journals (Sweden)

J. Soraghan

2007-01-01

Full Text Available Lattice vector quantization (LVQ reduces coding complexity and computation due to its regular structure. A new multistage LVQ (MLVQ using an adaptive subband thresholding technique is presented and applied to image compression. The technique concentrates on reducing the quantization error of the quantized vectors by “blowing out” the residual quantization errors with an LVQ scale factor. The significant coefficients of each subband are identified using an optimum adaptive thresholding scheme for each subband. A variable length coding procedure using Golomb codes is used to compress the codebook index which produces a very efficient and fast technique for entropy coding. Experimental results using the MLVQ are shown to be significantly better than JPEG 2000 and the recent VQ techniques for various test images.

A New Multistage Lattice Vector Quantization with Adaptive Subband Thresholding for Image Compression

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Salleh MFM

2007-01-01

Full Text Available Lattice vector quantization (LVQ reduces coding complexity and computation due to its regular structure. A new multistage LVQ (MLVQ using an adaptive subband thresholding technique is presented and applied to image compression. The technique concentrates on reducing the quantization error of the quantized vectors by "blowing out" the residual quantization errors with an LVQ scale factor. The significant coefficients of each subband are identified using an optimum adaptive thresholding scheme for each subband. A variable length coding procedure using Golomb codes is used to compress the codebook index which produces a very efficient and fast technique for entropy coding. Experimental results using the MLVQ are shown to be significantly better than JPEG 2000 and the recent VQ techniques for various test images.

Emerging vector borne diseases – incidence through vectors

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Sara eSavic

2014-12-01

Full Text Available Vector borne diseases use to be a major public health concern only in tropical and subtropical areas, but today they are an emerging threat for the continental and developed countries also. Nowdays, in intercontinetal countries, there is a struggle with emerging diseases which have found their way to appear through vectors. Vector borne zoonotic diseases occur when vectors, animal hosts, climate conditions, pathogens and susceptible human population exist at the same time, at the same place. Global climate change is predicted to lead to an increase in vector borne infectious diseases and disease outbreaks. It could affect the range and popultion of pathogens, host and vectors, transmission season, etc. Reliable surveilance for diseases that are most likely to emerge is required. Canine vector borne diseases represent a complex group of diseases including anaplasmosis, babesiosis, bartonellosis, borreliosis, dirofilariosis, erlichiosis, leishmaniosis. Some of these diseases cause serious clinical symptoms in dogs and some of them have a zoonotic potential with an effect to public health. It is expected from veterinarians in coordination with medical doctors to play a fudamental role at primeraly prevention and then treatment of vector borne diseases in dogs. The One Health concept has to be integrated into the struggle against emerging diseases.During a four year period, from 2009-2013, a total number of 551 dog samples were analysed for vector borne diseases (borreliosis, babesiosis, erlichiosis, anaplasmosis, dirofilariosis and leishmaniasis in routine laboratory work. The analysis were done by serological tests – ELISA for borreliosis, dirofilariosis and leishmaniasis, modified Knott test for dirofilariosis and blood smear for babesiosis, erlichiosis and anaplasmosis. This number of samples represented 75% of total number of samples that were sent for analysis for different diseases in dogs. Annually, on avarege more then half of the samples

Support Vector Machines as tools for mortality graduation

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Alberto Olivares

2011-01-01

Full Text Available A topic of interest in demographic and biostatistical analysis as well as in actuarial practice,is the graduation of the age-specific mortality pattern. A classical graduation technique is to fit parametric models. Recently, particular emphasis has been given to graduation using nonparametric techniques. Support Vector Machines (SVM is an innovative methodology that could be utilized for mortality graduation purposes. This paper evaluates SVM techniques as tools for graduating mortality rates. We apply SVM to empirical death rates from a variety of populations and time periods. For comparison, we also apply standard graduation techniques to the same data.

Image superresolution using support vector regression.

Science.gov (United States)

Ni, Karl S; Nguyen, Truong Q

2007-06-01

A thorough investigation of the application of support vector regression (SVR) to the superresolution problem is conducted through various frameworks. Prior to the study, the SVR problem is enhanced by finding the optimal kernel. This is done by formulating the kernel learning problem in SVR form as a convex optimization problem, specifically a semi-definite programming (SDP) problem. An additional constraint is added to reduce the SDP to a quadratically constrained quadratic programming (QCQP) problem. After this optimization, investigation of the relevancy of SVR to superresolution proceeds with the possibility of using a single and general support vector regression for all image content, and the results are impressive for small training sets. This idea is improved upon by observing structural properties in the discrete cosine transform (DCT) domain to aid in learning the regression. Further improvement involves a combination of classification and SVR-based techniques, extending works in resolution synthesis. This method, termed kernel resolution synthesis, uses specific regressors for isolated image content to describe the domain through a partitioned look of the vector space, thereby yielding good results.

Long-circulating DNA lipid nanocapsules as new vector for passive tumor targeting.

OpenAIRE

Morille , Marie; Montier , Tristan; Legras , Pierre; Carmoy , Nathalie; Brodin , Priscille; Pitard , Bruno; Benoît , Jean-Pierre; Passirani , Catherine

2010-01-01

International audience; Systemic gene delivery systems are needed for therapeutic application to organs that are inaccessible by percutaneous injection. Currently, the main objective is the development of a stable and non-toxic vector that can encapsulate and deliver foreign genetic material to target cells. To this end, DNA, complexed with cationic lipids i.e. DOTAP/DOPE, was encapsulated into lipid nanocapsules (LNCs) leading to the formation of stable nanocarriers (DNA LNCs) with a size in...

A novel prokaryotic vector for identification and selection of recombinants: Direct use of the vector for expression studies in E. coli

Directory of Open Access Journals (Sweden)

Apte-Deshpande Anjali

2010-05-01

Full Text Available Abstract Background The selection of bacterial recombinants that harbour a desired insert, has been a key factor in molecular cloning and a series of screening procedures need to be performed for selection of clones carrying the genes of interest. The conventional cloning techniques are reported to have problems such as screening high number of colonies, generation of false positives, setting up of control ligation mix with vector alone etc. Results We describe the development of a novel dual cloning/expression vector, which enables to screen the recombinants directly and expression of the gene of interest. The vector contains Green fluorescence protein (GFP as the reporter gene and is constructed in such a way that the E. coli cells upon transformation with this vector does not show any fluorescence, but readily fluoresce upon insertion of a foreign gene of interest. The same construct could be easily used for screening of the clones and expression studies by mere switching to specific hosts. Conclusions This is the first vector reported that takes the property of colour or fluorescence to be achieved only upon cloning while all the other vectors available commercially show loss of colour or loss of fluorescence upon cloning. As the fluorescence of GFP depends on the solubility of the protein, the intensity of the fluorescence would also indicate the extent of solubility of the expressed target protein.

Integrating principal component analysis and vector quantization with support vector regression for sulfur content prediction in HDS process

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Shokri Saeid

2015-01-01

Full Text Available An accurate prediction of sulfur content is very important for the proper operation and product quality control in hydrodesulfurization (HDS process. For this purpose, a reliable data- driven soft sensors utilizing Support Vector Regression (SVR was developed and the effects of integrating Vector Quantization (VQ with Principle Component Analysis (PCA were studied on the assessment of this soft sensor. First, in pre-processing step the PCA and VQ techniques were used to reduce dimensions of the original input datasets. Then, the compressed datasets were used as input variables for the SVR model. Experimental data from the HDS setup were employed to validate the proposed integrated model. The integration of VQ/PCA techniques with SVR model was able to increase the prediction accuracy of SVR. The obtained results show that integrated technique (VQ-SVR was better than (PCA-SVR in prediction accuracy. Also, VQ decreased the sum of the training and test time of SVR model in comparison with PCA. For further evaluation, the performance of VQ-SVR model was also compared to that of SVR. The obtained results indicated that VQ-SVR model delivered the best satisfactory predicting performance (AARE= 0.0668 and R2= 0.995 in comparison with investigated models.

Efficient delivery of anticancer drug MTX through MTX-LDH nanohybrid system

Science.gov (United States)

Oh, Jae-Min; Park, Man; Kim, Sang-Tae; Jung, Jin-Young; Kang, Yong-Gu; Choy, Jin-Ho

2006-05-01

We have been successful to intercalate anticancer drug, methotrexate (MTX), into layered double hydroxides (LDHs), Mg2Al(OH)6(NO3)·0.1H2O, through conventional co-precipitation method. Layered double hydroxides (LDHs) are endowed with great potential for delivery vector, since their cationic layers lead to safe reservation of biofunctional molecules such as drug molecules or genes. And their ion exchangeability and solubility in acidic media (pHosteosarcoma cell culture lines (Saos-2 and MG-63) and the normal one (human fibroblast) were used for in vitro test. The anticancer efficacy of MTX intercalated LDHs (MTX-LDH nanohybrids) was also estimated in vitro by the bioassay such as MTT and BrdU (5-bromo-2-deoxyuridine) with the bone cancer cell culture lines (Saos-2 and MG-63). According to the toxicity test results, LDHs do not harm to both the normal and cancer cells upto the concentration of 500 ug/mL. The anticancer efficacy test for the MTX-LDH nanohybrids turn out to be much more effective in cell suppression compared to the MTX itself. According to the cell-line tests, the MTX-LDH shows same drug efficacy to the MTX itself in spite of the low concentration by ˜5000 times. Such a high cancer suppression effect of MTX-LDH hybrid is surely due to the excellent delivery efficiency of inorganic delivery vector, LDHs.

Vector-vector production in photon-photon interactions

International Nuclear Information System (INIS)

Ronan, M.T.

1988-01-01

Measurements of exclusive untagged /rho/ 0 /rho/ 0 , /rho//phi/, K/sup *//bar K//sup */, and /rho/ω production and tagged /rho/ 0 /rho/ 0 production in photon-photon interactions by the TPC/Two-Gamma experiment are reviewed. Comparisons to the results of other experiments and to models of vector-vector production are made. Fits to the data following a four quark model prescription for vector meson pair production are also presented. 10 refs., 9 figs

Oncolytic Adenovirus: Strategies and Insights for Vector Design and Immuno-Oncolytic Applications

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Hanni Uusi-Kerttula

2015-11-01

Full Text Available Adenoviruses (Ad are commonly used both experimentally and clinically, including oncolytic virotherapy applications. In the clinical area, efficacy is frequently hampered by the high rates of neutralizing immunity, estimated as high as 90% in some populations that promote vector clearance and limit bioavailability for tumor targeting following systemic delivery. Active tumor targeting is also hampered by the ubiquitous nature of the Ad5 receptor, hCAR, as well as the lack of highly tumor-selective targeting ligands and suitable targeting strategies. Furthermore, significant off-target interactions between the viral vector and cellular and proteinaceous components of the bloodstream have been documented that promote uptake into non-target cells and determine dose-limiting toxicities. Novel strategies are therefore needed to overcome the obstacles that prevent efficacious Ad deployment for wider clinical applications. The use of less seroprevalent Ad serotypes, non-human serotypes, capsid pseudotyping, chemical shielding and genetic masking by heterologous peptide incorporation are all potential strategies to achieve efficient vector escape from humoral immune recognition. Conversely, selective vector arming with immunostimulatory agents can be utilized to enhance their oncolytic potential by activation of cancer-specific immune responses against the malignant tissues. This review presents recent advantages and pitfalls occurring in the field of adenoviral oncolytic therapies.

An Update on in Vivo Imaging of Extracellular Vesicles as Drug Delivery Vehicles

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Prakash Gangadaran

2018-02-01

Full Text Available Extracellular vesicles (EVs are currently being considered as promising drug delivery vehicles. EVs are naturally occurring vesicles that exhibit many characteristics favorable to serve as drug delivery vehicles. In addition, EVs have inherent properties for treatment of cancers and other diseases. For research and clinical translation of use of EVs as drug delivery vehicles, in vivo tracking of EVs is essential. The latest molecular imaging techniques enable the tracking of EVs in living animals. However, each molecular imaging technique has its certain advantages and limitations for the in vivo imaging of EVs; therefore, understanding the molecular imaging techniques is essential to select the most appropriate imaging technology to achieve the desired imaging goal. In this review, we summarize the characteristics of EVs as drug delivery vehicles and the molecular imaging techniques used in visualizing and monitoring EVs in in vivo environments. Furthermore, we provide a perceptual vision of EVs as drug delivery vehicles and in vivo monitoring of EVs using molecular imaging technologies.

Animal vectors of eastern dwarf mistletoe of black spruce.

Science.gov (United States)

Michael E. Ostry; Thomas H. Nicholls; D.W. French

1983-01-01

Describes a study to determine the importance of animals in the spread of eastern dwarf mistletoe of black spruce. Radio telemetry, banding, and color-marking techniques were used to study vectors of this forest pathogen.

Innovations in gene and growth factor delivery systems for diabetic wound healing

Science.gov (United States)

Laiva, Ashang Luwang; O'Brien, Fergal J.

2017-01-01

Abstract The rise in lower extremity amputations due to nonhealing of foot ulcers in diabetic patients calls for rapid improvement in effective treatment regimens. Administration of growth factors (GFs) are thought to offer an off‐the‐shelf treatment; however, the dose‐ and time‐dependent efficacy of the GFs together with the hostile environment of diabetic wound beds impose a major hindrance in the selection of an ideal route for GF delivery. As an alternative, the delivery of therapeutic genes using viral and nonviral vectors, capable of transiently expressing the genes until the recovery of the wounded tissue offers promise. The development of implantable biomaterial dressings capable of modulating the release of either single or combinatorial GFs/genes may offer solutions to this overgrowing problem. This article reviews the state of the art on gene and protein delivery and the strategic optimization of clinically adopted delivery strategies for the healing of diabetic wounds. PMID:28482114

Pseudo-stokes vector from complex signal representation of a speckle pattern and its applications to micro-displacement measurement

DEFF Research Database (Denmark)

Wang, W.; Ishijima, R.; Matsuda, A.

2010-01-01

As an improvement of the intensity correlation used widely in conventional electronic speckle photography, we propose a new technique for displacement measurement based on correlating Stokes-like parameters derivatives for transformed speckle patterns. The method is based on a Riesz transform of ...... are presented that demonstrate the validity and advantage of the proposed pseudo-Stokes vector correlation technique over conventional intensity correlation technique....... of the intensity speckle pattern, which converts the original real-valued signal into a complex signal. In closest analogy to the polarisation of a vector wave, the Stokes-like vector constructed from the spatial derivative of the generated complex signal has been applied for correlation. Experimental results...

Molecular Epidemiology for Vector Research on Leishmaniasis

Science.gov (United States)

Kato, Hirotomo; Gomez, Eduardo A; Cáceres, Abraham G; Uezato, Hiroshi; Mimori, Tatsuyuki; Hashiguchi, Yoshihisa

2010-01-01

Leishmaniasis is a protozoan disease caused by the genus Leishmania transmitted by female phlebotomine sand flies. Surveillance of the prevalence of Leishmania and responsive vector species in endemic and surrounding areas is important for predicting the risk and expansion of the disease. Molecular biological methods are now widely applied to epidemiological studies of infectious diseases including leishmaniasis. These techniques are used to detect natural infections of sand fly vectors with Leishmania protozoa and are becoming powerful tools due to their sensitivity and specificity. Recently, genetic analyses have been performed on sand fly species and genotyping using PCR-RFLP has been applied to the sand fly taxonomy. In addition, a molecular mass screening method has been established that enables both sand fly species and natural leishmanial infections to be identified simultaneously in hundreds of sand flies with limited effort. This paper reviews recent advances in the study of sand flies, vectors of leishmaniasis, using molecular biological approaches. PMID:20617005

Molecular Epidemiology for Vector Research on Leishmaniasis

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Hirotomo Kato

2010-03-01

Full Text Available Leishmaniasis is a protozoan disease caused by the genus Leishmania transmitted by female phlebotomine sand flies. Surveillance of the prevalence of Leishmania and responsive vector species in endemic and surrounding areas is important for predicting the risk and expansion of the disease. Molecular biological methods are now widely applied to epidemiological studies of infectious diseases including leishmaniasis. These techniques are used to detect natural infections of sand fly vectors with Leishmania protozoa and are becoming powerful tools due to their sensitivity and specificity. Recently, genetic analyses have been performed on sand fly species and genotyping using PCR-RFLP has been applied to the sand fly taxonomy. In addition, a molecular mass screening method has been established that enables both sand fly species and natural leishmanial infections to be identified simultaneously in hundreds of sand flies with limited effort. This paper reviews recent advances in the study of sand flies, vectors of leishmaniasis, using molecular biological approaches.

Molecular epidemiology for vector research on leishmaniasis.

Science.gov (United States)

Kato, Hirotomo; Gomez, Eduardo A; Cáceres, Abraham G; Uezato, Hiroshi; Mimori, Tatsuyuki; Hashiguchi, Yoshihisa

2010-03-01

Leishmaniasis is a protozoan disease caused by the genus Leishmania transmitted by female phlebotomine sand flies. Surveillance of the prevalence of Leishmania and responsive vector species in endemic and surrounding areas is important for predicting the risk and expansion of the disease. Molecular biological methods are now widely applied to epidemiological studies of infectious diseases including leishmaniasis. These techniques are used to detect natural infections of sand fly vectors with Leishmania protozoa and are becoming powerful tools due to their sensitivity and specificity. Recently, genetic analyses have been performed on sand fly species and genotyping using PCR-RFLP has been applied to the sand fly taxonomy. In addition, a molecular mass screening method has been established that enables both sand fly species and natural leishmanial infections to be identified simultaneously in hundreds of sand flies with limited effort. This paper reviews recent advances in the study of sand flies, vectors of leishmaniasis, using molecular biological approaches.

Telomerase-mediated life-span extension of human primary fibroblasts by human artificial chromosome (HAC) vector

International Nuclear Information System (INIS)

Shitara, Shingo; Kakeda, Minoru; Nagata, Keiko; Hiratsuka, Masaharu; Sano, Akiko; Osawa, Kanako; Okazaki, Akiyo; Katoh, Motonobu; Kazuki, Yasuhiro; Oshimura, Mitsuo; Tomizuka, Kazuma

2008-01-01

Telomerase-mediated life-span extension enables the expansion of normal cells without malignant transformation, and thus has been thought to be useful in cell therapies. Currently, integrating vectors including the retrovirus are used for human telomerase reverse transcriptase (hTERT)-mediated expansion of normal cells; however, the use of these vectors potentially causes unexpected insertional mutagenesis and/or activation of oncogenes. Here, we established normal human fibroblast (hPF) clones retaining non-integrating human artificial chromosome (HAC) vectors harboring the hTERT expression cassette. In hTERT-HAC/hPF clones, we observed the telomerase activity and the suppression of senescent-associated SA-β-galactosidase activity. Furthermore, the hTERT-HAC/hPF clones continued growing beyond 120 days after cloning, whereas the hPF clones retaining the silent hTERT-HAC senesced within 70 days. Thus, hTERT-HAC-mediated episomal expression of hTERT allows the extension of the life-span of human primary cells, implying that gene delivery by non-integrating HAC vectors can be used to control cellular proliferative capacity of primary cultured cells

RNA Interference: A Promising Tool in the Control of Important Vector Born Diseases Zika, Dengue Fever, and Malaria

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Jalil Nejati

2017-05-01

Full Text Available Background and Objectives: RNA interference is a process, in which a molecule of double-stranded RNA prevents the expression of a particular gene and leads to its silencing. Application of this technology in the control of disease-carrying insects is rising in agriculture and medical sciences. Also, its application in control of insect-borne diseases could be considered as a new, important, and effective approach. In this article, it was attempted to study the mechanisms of RNA interference, routs of its delivery to insects, as well as its application in genetic control of disease vector insects. Methods: In this study, 71 indexed articles in databases, such as Pubmed, SID, Scopus, Science direct, and Google scholar, were used. Results: dsRNA could be delivered to insect body through three routes of oral, injection, and Impregnation. The mechanism of dsRNA entrance into the cells has considerable effect on the success and applicability of this technique. Identification of host-parasite relationship in the insect body is one of the important applications of RNAi in medical entomology. Conclusion: Although, there is a considerable number of researches on RNAi in the agricultural pests field, studies on insect vectors of human diseases have been mostly in-vivo. However, application of RNAi is suggested as a new, safe and applicable approach, alone or along with other methods. Certainly, further researches in this field can pave the way for enforcement measures in the control of disease vectors, especially Zika, dengue fever, and malaria in the not so distant future.

Multigenic lentiviral vectors for combined and tissue-specific expression of miRNA- and protein-based antiangiogenic factors

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Anne Louise Askou

Full Text Available Lentivirus-based gene delivery vectors carrying multiple gene cassettes are powerful tools in gene transfer studies and gene therapy, allowing coexpression of multiple therapeutic factors and, if desired, fluorescent reporters. Current strategies to express transgenes and microRNA (miRNA clusters from a single vector have certain limitations that affect transgene expression levels and/or vector titers. In this study, we describe a novel vector design that facilitates combined expression of therapeutic RNA- and protein-based antiangiogenic factors as well as a fluorescent reporter from back-to-back RNApolII-driven expression cassettes. This configuration allows effective production of intron-embedded miRNAs that are released upon transduction of target cells. Exploiting such multigenic lentiviral vectors, we demonstrate robust miRNA-directed downregulation of vascular endothelial growth factor (VEGF expression, leading to reduced angiogenesis, and parallel impairment of angiogenic pathways by codelivering the gene encoding pigment epithelium-derived factor (PEDF. Notably, subretinal injections of lentiviral vectors reveal efficient retinal pigment epithelium-specific gene expression driven by the VMD2 promoter, verifying that multigenic lentiviral vectors can be produced with high titers sufficient for in vivo applications. Altogether, our results suggest the potential applicability of combined miRNA- and protein-encoding lentiviral vectors in antiangiogenic gene therapy, including new combination therapies for amelioration of age-related macular degeneration.

Rare Hadronic B Decays to Vector, Axial-Vector and Tensors

International Nuclear Information System (INIS)

Gao, Y.Y.

2011-01-01

The authors review BABAR measurements of several rare B decays, including vector-axial-vector decays B ± → φK 1 ± (1270), B ± → φ K 1 ± (1400) and B ± → b 1 # -+ρ# ± , vector-vector decays B ± → φK* ± (1410), B 0 → K* 0 (bar K)* 0 , B 0 → K*0K*0 and B 0 → K*+K*-, vector-tensor decays B ± → φK* 2 (1430) ± and φK 2 (1770)/ ± (1820), and vector-scalar decays B ± → φK* 0 (1430) ± . Understanding the observed polarization pattern requires amplitude contributions from an uncertain source.

Magnetic concentration of a retroviral vector using magnetite cationic liposomes.

Science.gov (United States)

Ito, Akira; Takahashi, Tetsuya; Kameyama, Yujiro; Kawabe, Yoshinori; Kamihira, Masamichi

2009-03-01

For tissue engineering purposes, retroviral vectors represent an efficient method of delivering exogenous genes such as growth factors to injured tissues because gene-transduced cells can produce stable and constant levels of the gene product. However, retroviral vector technology suffers from low yields. In the present study, we used magnetite nanoparticles and magnetic force to concentrate the retroviral vectors to enhance the transduction efficiency and to enable their magnetic manipulation. Magnetite nanoparticles modified with cationic liposomes were added to a solution containing a retroviral vector pseudotyped with vesicular stomatitis virus glycoprotein. The magnetic particles that captured the viral vectors were collected using a magnetic force and seeded into mouse neuroblastoma Neuro2a cells. The viral titer was up to 55 times greater (up to 3 x 10(8) infectious units/mL). Additionally, the magnetically labeled retroviral vectors can be directed to the desired regions for infection by applying magnetic fields, and micro-patterns of gene-transduced cell regions could be created on a cellular monolayer using micro-patterned magnetic concentrators. These results suggest that this technique provides a promising approach to capturing and concentrating viral vectors, thus achieving high transduction efficiency and the ability to deliver genes to a specific injured site by applying a magnetic field.

The feasibility of incorporating Vpx into lentiviral gene therapy vectors

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Samantha A McAllery

2016-01-01

Full Text Available While current antiretroviral therapy has significantly improved, challenges still remain in life-long targeting of HIV-1 reservoirs. Lentiviral gene therapy has the potential to deliver protective genes into the HIV-1 reservoir. However, inefficient reverse transcription (RT occurs in HIV-1 reservoirs during lentiviral gene delivery. The viral protein Vpx is capable of increasing lentiviral RT by antagonizing the restriction factor SAMHD1. Incorporating Vpx into lentiviral vectors could substantially increase gene delivery into the HIV-1 reservoir. The feasibility of this Vpx approach was tested in resting cell models utilizing macrophages and dendritic cells. Our results showed Vpx exposure led to increased permissiveness of cells over a period that exceeded 2 weeks. Consequently, significant lower potency of HIV-1 antiretrovirals inhibiting RT and integration was observed. When Vpx was incorporated with anti-HIV-1 genes inhibiting either pre-RT or post-RT stages of the viral life-cycle, transduction levels significantly increased. However, a stronger antiviral effect was only observed with constructs that inhibit pre-RT stages of the viral life cycle. In conclusion this study demonstrates a way to overcome the major delivery obstacle of gene delivery into HIV-1 reservoir cell types. Importantly, incorporating Vpx with pre-RT anti-HIV-1 genes, demonstrated the greatest protection against HIV-1 infection.

USING LEARNING VECTOR QUANTIZATION METHOD FOR AUTOMATED IDENTIFICATION OF MYCOBACTERIUM TUBERCULOSIS

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Endah Purwanti

2012-01-01

Full Text Available In this paper, we are developing an automated method for the detection of tubercle bacilli in clinical specimens, principally the sputum. This investigation is the first attempt to automatically identify TB bacilli in sputum using image processing and learning vector quantization (LVQ techniques. The evaluation of the learning vector quantization (LVQ was carried out on Tuberculosis dataset show that average of accuracy is 91,33%.

Vector analysis

CERN Document Server

Brand, Louis

2006-01-01

The use of vectors not only simplifies treatments of differential geometry, mechanics, hydrodynamics, and electrodynamics, but also makes mathematical and physical concepts more tangible and easy to grasp. This text for undergraduates was designed as a short introductory course to give students the tools of vector algebra and calculus, as well as a brief glimpse into these subjects' manifold applications. The applications are developed to the extent that the uses of the potential function, both scalar and vector, are fully illustrated. Moreover, the basic postulates of vector analysis are brou

Cell-penetrating DNA-binding protein as a safe and efficient naked DNA delivery carrier in vitro and in vivo

International Nuclear Information System (INIS)

Kim, Eun-Sung; Yang, Seung-Woo; Hong, Dong-Ki; Kim, Woo-Taek; Kim, Ho-Guen; Lee, Sang-Kyou

2010-01-01

Non-viral gene delivery is a safe and suitable alternative to viral vector-mediated delivery to overcome the immunogenicity and tumorigenesis associated with viral vectors. Using the novel, human-origin Hph-1 protein transduction domain that can facilitate the transduction of protein into cells, we developed a new strategy to deliver naked DNA in vitro and in vivo. The new DNA delivery system contains Hph-1-GAL4 DNA-binding domain (DBD) fusion protein and enhanced green fluorescent protein (EGFP) reporter plasmid that includes the five repeats of GAL4 upstream activating sequence (UAS). Hph-1-GAL4-DBD protein formed complex with plasmid DNA through the specific interaction between GAL4-DBD and UAS, and delivered into the cells via the Hph-1-PTD. The pEGFP DNA was successfully delivered by the Hph-1-GAL4 system, and the EGFP was effectively expressed in mammalian cells such as HeLa and Jurkat, as well as in Bright Yellow-2 (BY-2) plant cells. When 10 μg of pEGFP DNA was intranasally administered to mice using Hph-1-GAL4 protein, a high level of EGFP expression was detected throughout the lung tissue for 7 days. These results suggest that an Hph-1-PTD-mediated DNA delivery strategy may be an useful non-viral DNA delivery system for gene therapy and DNA vaccines.

Cell-penetrating DNA-binding protein as a safe and efficient naked DNA delivery carrier in vitro and in vivo

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun-Sung; Yang, Seung-Woo [Department of Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Hong, Dong-Ki; Kim, Woo-Taek [Department of Biology, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, Ho-Guen [Department of Pathology, Yonsei Medical School, Seoul 120-752 (Korea, Republic of); Lee, Sang-Kyou, E-mail: sjrlee@yonsei.ac.kr [Department of Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

2010-01-29

Non-viral gene delivery is a safe and suitable alternative to viral vector-mediated delivery to overcome the immunogenicity and tumorigenesis associated with viral vectors. Using the novel, human-origin Hph-1 protein transduction domain that can facilitate the transduction of protein into cells, we developed a new strategy to deliver naked DNA in vitro and in vivo. The new DNA delivery system contains Hph-1-GAL4 DNA-binding domain (DBD) fusion protein and enhanced green fluorescent protein (EGFP) reporter plasmid that includes the five repeats of GAL4 upstream activating sequence (UAS). Hph-1-GAL4-DBD protein formed complex with plasmid DNA through the specific interaction between GAL4-DBD and UAS, and delivered into the cells via the Hph-1-PTD. The pEGFP DNA was successfully delivered by the Hph-1-GAL4 system, and the EGFP was effectively expressed in mammalian cells such as HeLa and Jurkat, as well as in Bright Yellow-2 (BY-2) plant cells. When 10 {mu}g of pEGFP DNA was intranasally administered to mice using Hph-1-GAL4 protein, a high level of EGFP expression was detected throughout the lung tissue for 7 days. These results suggest that an Hph-1-PTD-mediated DNA delivery strategy may be an useful non-viral DNA delivery system for gene therapy and DNA vaccines.

3D Model Retrieval Based on Vector Quantisation Index Histograms

International Nuclear Information System (INIS)

Lu, Z M; Luo, H; Pan, J S

2006-01-01

This paper proposes a novel technique to retrieval 3D mesh models using vector quantisation index histograms. Firstly, points are sampled uniformly on mesh surface. Secondly, to a point five features representing global and local properties are extracted. Thus feature vectors of points are obtained. Third, we select several models from each class, and employ their feature vectors as a training set. After training using LBG algorithm, a public codebook is constructed. Next, codeword index histograms of the query model and those in database are computed. The last step is to compute the distance between histograms of the query and those of the models in database. Experimental results show the effectiveness of our method

Introduction to Vector Field Visualization

Science.gov (United States)

Kao, David; Shen, Han-Wei

2010-01-01

Vector field visualization techniques are essential to help us understand the complex dynamics of flow fields. These can be found in a wide range of applications such as study of flows around an aircraft, the blood flow in our heart chambers, ocean circulation models, and severe weather predictions. The vector fields from these various applications can be visually depicted using a number of techniques such as particle traces and advecting textures. In this tutorial, we present several fundamental algorithms in flow visualization including particle integration, particle tracking in time-dependent flows, and seeding strategies. For flows near surfaces, a wide variety of synthetic texture-based algorithms have been developed to depict near-body flow features. The most common approach is based on the Line Integral Convolution (LIC) algorithm. There also exist extensions of LIC to support more flexible texture generations for 3D flow data. This tutorial reviews these algorithms. Tensor fields are found in several real-world applications and also require the aid of visualization to help users understand their data sets. Examples where one can find tensor fields include mechanics to see how material respond to external forces, civil engineering and geomechanics of roads and bridges, and the study of neural pathway via diffusion tensor imaging. This tutorial will provide an overview of the different tensor field visualization techniques, discuss basic tensor decompositions, and go into detail on glyph based methods, deformation based methods, and streamline based methods. Practical examples will be used when presenting the methods; and applications from some case studies will be used as part of the motivation.

Vector blood velocity estimation in medical ultrasound

DEFF Research Database (Denmark)

Jensen, Jørgen Arendt; Gran, Fredrik; Udesen, Jesper

2006-01-01

Two methods for making vector velocity estimation in medical ultrasound are presented. All of the techniques can find both the axial and transverse velocity in the image and can be used for displaying both the correct velocity magnitude and direction. The first method uses a transverse oscillation...... in the ultrasound field to find the transverse velocity. In-vivo examples from the carotid artery are shown, where complex turbulent flow is found in certain parts of the cardiac cycle. The second approach uses directional beam forming along the flow direction to estimate the velocity magnitude. Using a correlation...... search can also yield the direction, and the full velocity vector is thereby found. An examples from a flow rig is shown....

Development of Viral Vectors for Gene Therapy for Chronic Pain

Directory of Open Access Journals (Sweden)

Yu Huang

2011-01-01

Full Text Available Chronic pain is a major health concern that affects millions of people. There are no adequate long-term therapies for chronic pain sufferers, leading to significant cost for both society and the individual. The most commonly used therapy for chronic pain is the application of opioid analgesics and nonsteroidal anti-inflammatory drugs, but these drugs can lead to addiction and may cause side effects. Further studies of the mechanisms of chronic pain have opened the way for development of new treatment strategies, one of which is gene therapy. The key to gene therapy is selecting safe and highly efficient gene delivery systems that can deliver therapeutic genes to overexpress or suppress relevant targets in specific cell types. Here we review several promising viral vectors that could be applied in gene transfer for the treatment of chronic pain and further discuss the possible mechanisms of genes of interest that could be delivered with viral vectors for the treatment of chronic pain.

Vectors and Rotations in 3-Dimensions: Vector Algebra for the C++ Programmer

Science.gov (United States)

2016-12-01

release; distribution is unlimited. 1. Introduction This report describes 2 C++ classes: a Vector class for performing vector algebra in 3-dimensional...ARL-TR-7894•DEC 2016 US Army Research Laboratory Vectors and Rotations in 3-Dimensions:Vector Algebra for the C++ Programmer by Richard Saucier...Army Research Laboratory Vectors and Rotations in 3-Dimensions:Vector Algebra for the C++ Programmer by Richard Saucier Survivability/Lethality

Adaptive track scheduling to optimize concurrency and vectorization in GeantV

International Nuclear Information System (INIS)

Apostolakis, J; Brun, R; Carminati, F; Gheata, A; Novak, M; Wenzel, S; Bandieramonte, M; Bitzes, G; Canal, P; Elvira, V D; Jun, S Y; Lima, G; Licht, J C De Fine; Duhem, L; Sehgal, R; Shadura, O

2015-01-01

The GeantV project is focused on the R and D of new particle transport techniques to maximize parallelism on multiple levels, profiting from the use of both SIMD instructions and co-processors for the CPU-intensive calculations specific to this type of applications. In our approach, vectors of tracks belonging to multiple events and matching different locality criteria must be gathered and dispatched to algorithms having vector signatures. While the transport propagates tracks and changes their individual states, data locality becomes harder to maintain. The scheduling policy has to be changed to maintain efficient vectors while keeping an optimal level of concurrency. The model has complex dynamics requiring tuning the thresholds to switch between the normal regime and special modes, i.e. prioritizing events to allow flushing memory, adding new events in the transport pipeline to boost locality, dynamically adjusting the particle vector size or switching between vector to single track mode when vectorization causes only overhead. This work requires a comprehensive study for optimizing these parameters to make the behaviour of the scheduler self-adapting, presenting here its initial results. (paper)

Topological vector spaces and their applications

CERN Document Server

Bogachev, V I

2017-01-01

This book gives a compact exposition of the fundamentals of the theory of locally convex topological vector spaces. Furthermore it contains a survey of the most important results of a more subtle nature, which cannot be regarded as basic, but knowledge which is useful for understanding applications. Finally, the book explores some of such applications connected with differential calculus and measure theory in infinite-dimensional spaces. These applications are a central aspect of the book, which is why it is different from the wide range of existing texts on topological vector spaces. In addition, this book develops differential and integral calculus on infinite-dimensional locally convex spaces by using methods and techniques of the theory of locally convex spaces. The target readership includes mathematicians and physicists whose research is related to infinite-dimensional analysis.

Interaction of DNA/nuclear protein/polycation and the terplexes for gene delivery

Energy Technology Data Exchange (ETDEWEB)

Shen Yuan; Pan Shirong; Feng Min; Wen Yuting; Deng Jingjing; Luo Xin; Wu Chuanbin [School of Pharmaceutical Sciences, Sun Yat-sen University, Zhongshan II Road 74, Guangzhou 510080 (China); Peng Hui, E-mail: fengmin@mail.sysu.edu.cn [School of Zhongshan Medicine, Sun Yat-sen University, 74 Zhongshan Road II, Guangzhou 510080 (China)

2010-01-29

Nuclear transport of exogenous DNA is a major barrier to nonviral gene delivery that needs to be addressed in the design of new vectors. In this study, we prepared pDNA/HMGB1/PEG-PEI terplexes to promote nuclear import. HMGB1 in the terplexes was used to assist the transportation of pDNA into the nucleus of cells, since it contained nuclear localization signal (NLS); PEG chains were introduced to stabilize pDNA/vector terplexes and reduce the cytotoxicity. HMGB1/PEG-PEI combined vectors have been investigated specifically for their structure interaction by atomic force microscopy and circular dichroic spectroscopy. The results demonstrated that the HMGB1 molecule could bind with the pDNA chains, but not condense pDNA well. The PEG-PEI further compacted pDNA/HMGB1 complexes into nanosized spherical terplexes. The pDNA delivered by HMGB1/PEG-PEI combined vectors was significantly accumulated in the nucleus of cells, as observed by confocal laser scanning microscopy. The percentage of GFP-transfected cells and VEGF protein expression level induced by HMGB1/PEG-PEI were 2.6-4.9-fold and 1.4-2.8-fold higher, respectively, than that of a common cationic polymer PEI 25 kDa. Therefore, the HMGB1/PEG-PEI combined vector could be used as a versatile vector for promoting exogenous DNA nuclear localization, thereby enhancing its expression.

Permeation enhancer strategies in transdermal drug delivery.

Science.gov (United States)

Marwah, Harneet; Garg, Tarun; Goyal, Amit K; Rath, Goutam

2016-01-01

Today, ∼74% of drugs are taken orally and are not found to be as effective as desired. To improve such characteristics, transdermal drug delivery was brought to existence. This delivery system is capable of transporting the drug or macromolecules painlessly through skin into the blood circulation at fixed rate. Topical administration of therapeutic agents offers many advantages over conventional oral and invasive techniques of drug delivery. Several important advantages of transdermal drug delivery are prevention from hepatic first pass metabolism, enhancement of therapeutic efficiency and maintenance of steady plasma level of the drug. Human skin surface, as a site of drug application for both local and systemic effects, is the most eligible candidate available. New controlled transdermal drug delivery systems (TDDS) technologies (electrically-based, structure-based and velocity-based) have been developed and commercialized for the transdermal delivery of troublesome drugs. This review article covers most of the new active transport technologies involved in enhancing the transdermal permeation via effective drug delivery system.

Interactive exploratory visualization of 2D vector fields

NARCIS (Netherlands)

Isenberg, Tobias; Everts, Maarten H.; Grubert, Jens; Carpendale, Sheelagh

In this paper we present several techniques to interactively explore representations of 2D vector fields. Through a set of simple hand postures used on large, touch-sensitive displays, our approach allows individuals to custom design glyphs (arrows, lines, etc.) that best reveal patterns of the

Transverse spin in the scattering of focused radially and azimuthally polarized vector beams

Science.gov (United States)

Singh, Ankit Kumar; Saha, Sudipta; Gupta, Subhasish Dutta; Ghosh, Nirmalya

2018-04-01

We study the effect of focusing of the radially and azimuthally polarized vector beams on the spin angular momentum (SAM) density and Poynting vector of scattered waves from a Mie particle. Remarkably, the study reveals that the SAM density of the scattered field is solely transverse in nature for radially and azimuthally polarized incident vector beams; however, the Poynting vector shows the usual longitudinal character. We also demonstrate that the transverse SAM density can further be tuned with wavelength and focusing of the incident beam by exploiting the interference of different scattering modes. These results may stimulate further experimental techniques to detect the transverse spin and Belinfante's spin-momentum densities.