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April 21, 2009

Genetic modification of cells for transplantation

Filed under: Pharmacology, Toxicology and Pharmaceutical Science — Tags: , — medical insurance @ 6:01 am

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Progress in gene therapy has produced promising results that translate experimental research into clinical treatment. Gene modification has been extensively employed in cell transplantation. The main barrier is an effective gene delivery system. Several viral vectors were utilized in end-stage differentiated cells. Recently, successful applications were described with adenovirus-associated vectors. As an alternative, embryonic stem cell- and stem cell-like systems were established for generation of tissue-specified gene-modified cells. Owing to the feasibility for genetic manipulations and the self-renewing potency of these cells they can be used in a way enabling large-scale in vitro production. This approach offers the establishment of in vitro cell culture systems that will deliver sufficient amounts of highly purified, immunoautologous cells suitable for application in regenerative medicine. In this review, the current technology of gene delivery systems to cells is recapitulated and the latest developments for cell transplantation are discussed.

Yi Laia Irina Drobinskayab Eugen Kolossovc Chunguang Chend Thomas LinndEmail:Thomas.linn@innere.med.uni-giessen.de
[a]Department of Molecular Microbiology & Immunology, University of Missouri-Columbia, USA;[b]Institute for Neurophysiology, University of Cologne, Germany;[c]Axiogenesis AG, Cologne, Germany;[d]Medical Clinic and Policlinic 3, Justus Liebig University, Rodthohl 6, 35392 Giessen, Germany

April 20, 2009

Beta-cell replacement for insulin-dependent diabetes mellitus

Filed under: Pharmacology, Toxicology and Pharmaceutical Science — Tags: — medical insurance @ 8:31 pm

Beta-cell replacement is considered the optimal treatment for type 1 diabetes, however, it is hindered by a shortage of human organ donors. Given the difficulty of expanding adult beta cells in vitro, stem/progenitor cells, which can be expanded in tissue culture and induced to differentiate into multiple cell types, represent an attractive source for generation of cells with beta-cell properties. In the absence of well-characterized human pancreas progenitor cells, investigators are exploring the use of embryonic stem cells and stem/progenitor cells from other tissues. Once abundant surrogate beta cells are available, the challenge will be to protect them from recurring autoimmunity.

Shimon EfrataEmail:sefrat@post.tau.ac.il
[a]Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978

Advancements in immune tolerance

Filed under: Pharmacology, Toxicology and Pharmaceutical Science — Tags: , — medical insurance @ 12:50 pm

In recent years, considerable attention has been given to immune tolerance and its potential clinical applications for the treatment of cancers and autoimmune diseases, and the prevention of allo-graft rejection and graft-versus-host diseases. Advances in our understanding of the underlying mechanisms of establishment and maintenance of immune tolerance in various experimental settings and animal models, and in our ability to manipulate the development of various immune tolerogenic cells in vitro and in vivo, have generated significant momentum for the field of cell-based tolerogenic therapy. This review briefly summarizes the major tolerogenic cell populations and their mechanisms of action, while focusing mainly on potential exploitation of their tolerogenic mechanisms for clinical applications.

Ping-Ying PanaEmail:ping-ying.pan@mssm.edu Junko Ozaoa Zuping Zhoua Shu-Hsia ChenaEmail:shu-hsia.chen@mssm.edu
[a]Department of Gene and Cell Medicine, Box 1946, Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, NY, 10029, USA

Particle design of poorly water-soluble drug substances using supercritical fluid technologies

Filed under: Pharmacology, Toxicology and Pharmaceutical Science — Tags: , — medical insurance @ 12:35 pm

In order to improve the dissolution properties of poorly water-soluble drugs, some drugs were subjected to micronization or prepared as composite particles using supercritical fluid (SCF) technology with carbon dioxide (CO2). Solubility in CO2 is the key when using this method. Solubility affects the supersaturation of the materials in the solvent as well as the mass transfer of that solvent, which are both critical to the micronization of the materials and the formation of the composite particles. Some useful techniques that can be used to avoid the problems posed by the characteristics of the drug itself are combining SC-CO2 with other technologies, such as the formation of coacervates or emulsions, and other equipment types, such as milling or ultrasound fields. Another advantage of SCF technology is that it is considered to be green chemistry. SC-CO2 can improve the solubility of poorly water-soluble drug substances using few or no organic solvents and with little or no heating.

Takehiko Yasujia Hirofumi TakeuchibEmail:takeuchi@gifu-pu.ac.jp Yoshiaki Kawashimac
[a]Pharmaceutical Research and Technology Labs, Astellas Pharma Inc., 180 Ozumi, Yaizu, Shizuoka 425-0072, Japan;[b]Pharmaceutical Engineering, Department of Manufacturing Pharmacy, Gifu Pharmaceutical University, 5-6-1, Mitahora-higashi, Gifu, Gifu 502-8585, Japan;[c]Pharmaceutical Engineering, School of Pharmaceutical science, Aichi Gukuin University, 1-100 Kusumoto, Chikusaku, Nagoya, Aichi 464-8650, Japan

Applications of supercritical CO2 in the fabrication of polymer systems for drug delivery and tissue engineering

Supercritical CO2 has the potential to be an excellent environment within which controlled release polymers and dry composites may be formed. The low temperature and dry conditions within the fluid offer obvious advantages in the processing of water, solvent or heat labile molecules. The low viscosity and high diffusivity of scCO2 offer the possibility of novel processing routes for polymer drug composites, but there are still technical challenges to overcome. Moreover, the low solubility of most drug molecules in scCO2 presents both challenges and advantages. This review explores the current methods that use high pressure and scCO2 for the production of drug delivery systems and the more specialized application of the fluid in the formation of highly porous tissue engineering scaffolds.

Owen R. Daviesa Andrew L. Lewisa Martin J. Whitakera Hongyun Taib Kevin M. Shakesheffb Steven M. HowdleaEmail:steve.howdle@nottingham.ac.uk
[a]Critical Pharmaceuticals Ltd BioCity Pennyfoot St., Nottingham, NG1 1GF, United Kingdom;[b]School of Pharmacy, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom;[c]School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom

Separation processes for organic molecules using SCF Technologies

Supercritical fluids have been applied for many years for the separation of solutes from solids or solute mixtures in both exploratory and industrial applications. In the pharmaceutical industry the generation of pure solid states without impurities is important as the presence of impurities can result in a change in chemical properties or lead to physical instability. The literature on the separation and purification of solutes from solid matrices and solute mixtures using supercritical fluids, with the main emphasis on pharmaceutically important molecules, is reviewed in this article. Also discussed is the application of supercritical fluids in the control of process impurities such as chemical intermediates and residual solvent and in polymorphic control and chiral resolution.As the generation of organic molecules of pharmaceutical interest with high purity is important in pharmaceuticals this review additionally provides a brief overview of highly selective chemical reactions in supercritical fluids.

L.S. DaintreeaEmail:L.Daintree@leeds.ac.uk A. Kordikowskib P. Yorkc
[a]ParticlesCIC, University of Leeds, Houldsworth Building, Leeds LS2 9JT, United Kingdom;[b]Activery Biotech SL, Edificio MATGAS, Campus de la Universitat Autónoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain;[c]Institute of Pharmaceutical Innovation, University of Bradford, Bradford BD7 1DP, United Kingdom

Micronization processes with supercritical fluids: Fundamentals and mechanisms

Filed under: Pharmacology, Toxicology and Pharmaceutical Science — Tags: , — medical insurance @ 10:55 am

Supercritical fluid techniques for materials precipitation have been proposed as an alternative to conventional precipitation processes as they allow to improve the performance of these processes in terms of reduction of particle size and control of morphology and particle size distribution, without degradation or contamination of the product. These techniques have received much attention during the last years, and their feasibility and performance have been experimentally demonstrated for many substances. One of the main pending tasks is the development of a systematic procedure for the design and scale-up of these processes. This requires not only empirical knowledge, but also information about the fundamentals of the process. This work aims to review the published literature dealing with a fundamental investigation or modeling of supercritical fluid precipitation processes.

A. Martína M.J. CoceroaEmail:mjcocero@iq.uva.es
[a]Departamento de Ingeniería Química y Tecnología del Medio Ambiente, Facultad de Ciencias, Universidad de Valladolid, 47011 Valladolid, Spain

Supercritical carbon dioxide processing of active pharmaceutical ingredients for polymorphic control and for complex formation

Filed under: Pharmacology, Toxicology and Pharmaceutical Science — Tags: , — medical insurance @ 10:52 am

Supercritical fluid technique have been exploited in extraction, separation and crystallization processes. In the field of pharmaceutics, supercritical carbon dioxide (scCO2) has been used for the purpose of micronization, polymorphic control, and preparation of solid dispersion and complexes. Particle design of active pharmaceutical ingredients is important to make the solid dosage forms with suitable physicochemical properties. Control of the characteristic properties of particles, such as size, shape, crystal structure and morphology is required to optimize the formulation. For solubility enhancement of poorly water-soluble drugs, preparation of the solid dispersion or the complexation with proper drugs or excipients should be a promising approach. This review focuses on aspects of polymorphic control and complexation behavior of active pharmaceutical ingredients by scCO2 processing.

Kunikazu Moribea Yuichi Tozukab Keiji YamamotoaEmail:yamamotk@p.chiba-u.ac.jp
[a]Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan;[b]Department of Pharmaceutical Engineering, Gifu Pharmaceutical University, 5-6-1 Mitahora-Higashi, Gifu 502-8585, Japan

Nanoparticles synthesis using supercritical fluid technology – towards biomedical applications

Filed under: Pharmacology, Toxicology and Pharmaceutical Science — Tags: , — medical insurance @ 10:47 am

Supercritical fluid (SCF) technology has become an important tool of materials processing in the last two decades. Supercritical CO2 and H2O are extensively being used in the preparation of a great variety of nanomaterials. The greatest requirement in the application of nanomaterials is its size and morphology control, which determine the application potential of the nanoparticles, as their properties vary significantly with size. Although significance of SCF technology has been described earlier by various authors, the importance of this technology for the fabrication of inorganic and hybrid nanomaterials in biomedical applications has not been discussed thoroughly. This review presents the nanomaterial preparation systematically using SCF technology with reference to the processing of biomedical materials. The basic principles of each one of the processes have been described in detail giving their merits and perspectives. The actual experimental data and results have been discussed in detail with respect to the selected nanomaterials for biomedical applications. The SCF synthesis of nanoparticles like phosphors, magnetic materials, carbon nanotubes, etc. have been discussed as they have potential applications in bio-imaging, hyperthermia, cancer therapy, neutron capture therapy, targeted drug delivery systems and so on. The more recent approach towards the in situ surface modification, dispersibility, single nanocrystal formation, and morphology control of the nanoparticles has been discussed in detail.

K. ByrappabEmail:kbyrappa@gmail.com S. OharaaEmail:ohara@jwri.osaka-u.ac.jp T. AdschiriaEmail:ajiri@tagen.tohoku.ac.jp
[a]Institute of Multidisciplinary Research for Advanced Materials (IMRAM)Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan;[b]University of Mysore, P.B. No.21, Manasagangotri, Mysore 570 006, India

April 10, 2009

Homeoproteins as natural Penetratin cargoes with signaling properties

Filed under: Pharmacology, Toxicology and Pharmaceutical Science — Tags: , — medical insurance @ 10:23 am

Most of this volume is dedicated to a very important and pragmatic issue which is to design ways of internalizing active pharmacological compounds into cells. In fact, many vectors have now been developed and the improvement in the technology can be seen on two main fronts. A first one is the identification of extremely efficient cargoes, for example siRNAs, which can enter the cells once attached to the vectors. A second one is the development of chemical vectors designed after the properties of the peptides and of tags allowing in vivo addressing to specific organs, for example the brain, cell types or sub-cellular compartments.This chapter is of a different nature, as it is devoted to the physiological significance of protein transduction and to the comparative analysis of the Penetratin PTD with its parental proteins, the homeoproteins. Although very academic, these two issues are of practical interest for the rational design of new vectors and the identification of unforeseen pathological mechanisms and pharmacological targets.

Alain JoliotaEmail:joliot@biologie.ens.fr Alain ProchiantzbEmail:prochian@biologie.ens.fr
[a]Homeoprotein Cell Biology Group, UMR CNRS 8542, Ecole Normale Supérieure, 46 rue d’Ulm 75230 Paris Cedex 05, France;[b]Development and Neuropharmacology, UMR CNRS 8542, Ecole Normale Supérieure, 46 rue d’Ulm 75230 Paris Cedex 05, France

2008.60,12-4

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