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Phototrexate
Phototrexate is a photochromic antifolate drug developed at the Institute for Bioengineering of Catalonia (IBEC, The Barcelona Institute of Science and Technology). In particular, it is a photopharmacological agent that behaves as light-regulated inhibitor of the dihydrofolate reductase (DHFR) enzyme. Phototrexate is a photoisomerizable structural analogue of the chemotherapy agent methotrexate. It is also an example of "azologization". Pharmacological effects of phototrexate can be switched on and off by UVA and visible light, respectively. Phototrexate is almost inactive in its ''trans'' configuration while it behaves as a potent antifolate in its ''cis'' configuration. It can also spontaneously self-deactivate in the dark. See also * Cancer * Psoriasis * Psoriatic arthritis Psoriatic arthritis (PsA) is a long-term inflammatory arthritis that may occur in some people affected by the autoimmune disease psoriasis. The classic features of psoriatic arthritis inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photopharmacology
Photopharmacology is an emerging multidisciplinary field that combines photochemistry and pharmacology. Built upon the ability of light to change the pharmacokinetics and pharmacodynamics of bioactive molecules, it aims at regulating the activity of drugs in vivo by using light. The light-based modulation is achieved by incorporating molecular photoswitches such as azobenzene and diarylethenes or photocages such as o-nitrobenzyl, coumarin, and BODIPY compounds into the pharmacophore. This selective activation of the biomolecules helps prevent or minimize off-target activity and systemic side effects. Moreover, light being the regulatory element offers additional advantages such as the ability to be delivered with high spatiotemporal precision, low to negligible toxicity, and the ability to be controlled both qualitatively and quantitatively by tuning its wavelength and intensity. History Though photopharmacology is a relatively new field, the concept of using light in therapeutic a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photochromism
Photochromism is the reversible change of color upon exposure to light. It is a transformation of a chemical species (photoswitch) between two forms through the absorption of electromagnetic radiation (photoisomerization), where each form has a different absorption spectrum. This reversible structural or geometric change in photochromic molecules affects their electronic configuration, molecular strain energy, and other properties. History In 1867, Carl Julius Fritzsche reported the concept of photochromism, indicating that orange tetracene solution lost its color in daylight but regained it in darkness. Later, similar behavior was observed by both Edmund ter Meer and Phipson. Ter Meer documented the color change of the potassium salt of dinitroethane, which appeared red in daylight and yellow in the dark. Phipson also recorded that a painted gatepost appeared black during the day and white at night due to a zinc pigment, likely lithopone. In 1899, Willy Markwald, who studied th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Institute For Bioengineering Of Catalonia
The Institute for Bioengineering of Catalonia (IBEC) is an institution engaged in basic and applied research in bioengineering and nanomedicine, with experts working on tissue regeneration, biomechanics, molecular dynamics, biomimetics, drug delivery, organs ‘on-a-chip’, cell migration, stem cells, artificial olfaction and microbial biotechnology. The institute was created by the Government of Catalonia, the University of Barcelona and the Polytechnic University of Catalonia in December 2005 and is located at the Barcelona Science Park (Parc Científic de Barcelona – PCB). The director of the institute is Prof. Josep Samitier, who took over from founding director Josep A. Planell i Estany in 2013. In 2014 IBEC was named a "Severo Ochoa Centre of Excellence" by the Spanish Ministry of Economy and Competitiveness. Mission The institute aims to pursue interdisciplinary research in bioengineering and nanomedicine which is combined with specific transfer targets to produce new a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydrofolate Reductase
Dihydrofolate reductase, or DHFR, is an enzyme that reduces dihydrofolic acid to tetrahydrofolic acid, using NADPH as an electron donor, which can be converted to the kinds of tetrahydrofolate cofactors used in one-carbon transfer chemistry. In humans, the DHFR enzyme is encoded by the ''DHFR'' gene. It is found in the q14.1 region of chromosome 5. There are two structural classes of DHFR, evolutionarily unrelated to each other. The former is usually just called DHFR and is found in bacterial chromosomes and animals. In bacteria, however, antibiotic pressure has caused this class to evolve different patterns of binding diaminoheterocyclic molecules, leading to many "types" named under this class, while mammalian ones remain highly similar. The latter (type II), represented by the plastid-encoded R67, is a tiny enzyme that works by forming a homotetramer. Function Dihydrofolate reductase converts dihydrofolate into tetrahydrofolate, a proton shuttle required for the de no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoisomerization
In chemistry, photoisomerization is a form of isomerization induced by photoexcitation. Both reversible and irreversible photoisomerizations are known for photoswitchable compounds. The term "photoisomerization" usually, however, refers to a reversible process. Applications Photoisomerization of the compound retinal in the eye allows for vision. Photoisomerizable substrates have been put to practical use, for instance, in pigments for rewritable CDs, DVDs, and 3D optical data storage solutions. In addition, interest in photoisomerizable molecules has been aimed at molecular devices, such as molecular switches, molecular motors, and molecular electronics. Another class of device that uses the photoisomerization process is as an additive in liquid crystals to change their linear and nonlinear properties. Due to the photoisomerization is possible to induce a molecular reorientation in the liquid crystal bulk, which is used in holography, as spatial filter or optical switching. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemotherapy
Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) in a standard chemotherapy regimen, regimen. Chemotherapy may be given with a cure, curative intent (which almost always involves combinations of drugs), or it may aim only to prolong life or to Palliative care, reduce symptoms (Palliative care, palliative chemotherapy). Chemotherapy is one of the major categories of the medical discipline specifically devoted to pharmacotherapy for cancer, which is called ''oncology#Specialties, medical oncology''. The term ''chemotherapy'' now means the non-specific use of intracellular poisons to inhibit mitosis (cell division) or to induce DNA damage (naturally occurring), DNA damage (so that DNA repair can augment chemotherapy). This meaning excludes the more-selective agents that block extracellular signals (signal transduction) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methotrexate
Methotrexate, formerly known as amethopterin, is a chemotherapy agent and immunosuppressive drug, immune-system suppressant. It is used to treat cancer, autoimmune diseases, and ectopic pregnancy, ectopic pregnancies. Types of cancers it is used for include breast cancer, leukemia, lung cancer, lymphoma, gestational trophoblastic disease, and osteosarcoma. Types of autoimmune diseases it is used for include psoriasis, rheumatoid arthritis, and Crohn's disease. It can be given Oral administration, by mouth or by injection. Common side effects include nausea, feeling tired, fever, increased risk of infection, leukopenia, low white blood cell counts, and ulcerative stomatitis, breakdown of the skin inside the mouth. Other side effects may include liver disease, lung disease, lymphoma, and severe skin rashes. People on long-term treatment should be regularly checked for side effects. It is not safe during breastfeeding. In those with kidney problems, lower doses may be needed. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. The photons of ultraviolet have greater energy than those of visible light, from about 3.1 to 12 electron volts, around the minimum energy required to ionize atoms. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack sufficient energy, it can induce chemical reactions and cause many substances to glow or fluoresce. Many practical applications, including chemical and biological effects, are derived from the way that UV radiation can interact with organic molecules. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light
Light, visible light, or visible radiation is electromagnetic radiation that can be visual perception, perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequency, frequencies of 750–420 terahertz (unit), terahertz. The visible band sits adjacent to the infrared (with longer wavelengths and lower frequencies) and the ultraviolet (with shorter wavelengths and higher frequencies), called collectively ''optical radiation''. In physics, the term "light" may refer more broadly to electromagnetic radiation of any wavelength, whether visible or not. In this sense, gamma rays, X-rays, microwaves and radio waves are also light. The primary properties of light are intensity (physics), intensity, propagation direction, frequency or wavelength spectrum, and polarization (waves), polarization. Its speed of light, speed in vacuum, , is one of the fundamental physi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cis–trans Isomerism
''Cis''–''trans'' isomerism, also known as geometric isomerism, describes certain arrangements of atoms within molecules. The prefixes "''cis''" and "''trans''" are from Latin: "this side of" and "the other side of", respectively. In the context of chemistry, ''cis'' indicates that the functional groups (substituents) are on the same side of some plane, while ''trans'' conveys that they are on opposing (transverse) sides. ''Cis''–''trans'' isomers are stereoisomers, that is, pairs of molecules which have the same formula but whose functional groups are in different orientations in three-dimensional space. ''Cis'' and ''trans'' isomers occur both in organic molecules and in inorganic coordination complexes. ''Cis'' and ''trans'' descriptors are not used for cases of conformational isomerism where the two geometric forms easily interconvert, such as most open-chain single-bonded structures; instead, the terms "''syn''" and "''anti''" are used. According to IUPAC, "geome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antifolate
Antifolates are a class of antimetabolite medications that antagonise (that is, block) the actions of folic acid (vitamin B9). Folic acid's primary function in the body is as a cofactor to various methyltransferases involved in serine, methionine, thymidine and purine biosynthesis. Consequently, antifolates inhibit cell division, DNA/RNA synthesis and repair and protein synthesis. Some such as proguanil, pyrimethamine and trimethoprim selectively inhibit folate's actions in microbial organisms such as bacteria, protozoa and fungi. The majority of antifolates work by inhibiting dihydrofolate reductase (DHFR). Comparison of available agents Image:Methotrexate skeletal.svg, Methotrexate Image:Pemetrexed.svg, Pemetrexed Image:Raltitrexed.svg, Raltitrexed Image:Pralatrexate.png, Pralatrexate Mechanism Many are primarily DHFR inhibitors, but raltitrexed is an inhibitor of thymidylate synthase, and pemetrexed inhibits both and a third enzyme. Antifolates act specificall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
