|
Magnetic Drug Delivery
Magnetic nanoparticle-based drug delivery is a means in which magnetic particles such as iron oxide nanoparticles are a component of a delivery vehicle for magnetic drug delivery, due to the simplicity with which the particles can be drawn to (external) magnetopuissant targets. Magnetic nanoparticles can impart imaging and controlled release capabilities to drug delivery materials such as micelles, liposomes, and polymers. Synopsis Molecular magnets (single-molecule magnets) are a platform that incorporates insoluble (toxic) drugs into biocompatible carrier materials, without adding magnetic iron oxide nanoparticles which might adversely affect patients susceptible to iron overdose. The drawbacks in conventional magnetic drug delivery methods can be overcome by switching from typical iron oxide nanoparticles to ones based on molecular magnets, such as Fe(salen)-based "anticancer nanomagnet" with proven cancer-fighting ability. However, insoluble drugs including Fe(salen) also h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Oxide Nanoparticles
Iron oxide nanoparticles are iron oxide particles with diameters between about 1 and 100 nanometers. The two main forms are magnetite () and its oxidized form maghemite (γ-). They have attracted extensive interest due to their superparamagnetic properties and their potential applications in many fields (although cobalt and nickel are also highly magnetic materials, they are toxic and easily oxidized). Applications of iron oxide nanoparticles include terabit magnetic storage devices, catalysis, sensors, superparamagnetic relaxometry, high-sensitivity biomolecular magnetic resonance imaging, magnetic particle imaging, magnetic fluid hyperthermia, separation of biomolecules, and targeted drug and gene delivery for medical diagnosis and therapeutics. These applications require coating of the nanoparticles by agents such as long-chain fatty acids, alkyl-substituted amines, and diols. They have been used in formulations for supplementation. Structure Magnetite has an inv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug Delivery
Drug delivery refers to approaches, formulations, manufacturing techniques, storage systems, and technologies involved in transporting a pharmaceutical compound to its target site to achieve a desired therapeutic effect. Principles related to drug preparation, route of administration, site-specific targeting, metabolism, and toxicity are used to optimize efficacy and safety, and to improve patient convenience and compliance. Drug delivery is aimed at altering a drug's pharmacokinetics and specificity by formulating it with different excipients, drug carriers, and medical devices. There is additional emphasis on increasing the bioavailability and duration of action of a drug to improve therapeutic outcomes. Some research has also been focused on improving safety for the person administering the medication. For example, several types of microneedle patches have been developed for administering vaccines and other medications to reduce the risk of needlestick injury. Drug deliv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Separation
Magnetic separation is the process of separating components of mixtures by using a magnet to attract magnetic substances. The process that is used for magnetic separation separates non-magnetic substances from those which are magnetic. This technique is useful for the select few minerals which are ferromagnetic (iron-, nickel-, and cobalt-containing minerals) and paramagnetic. Most metals, including gold, silver and aluminum, are nonmagnetic. A large diversity of mechanical means are used to separate magnetic materials. During magnetic separation, magnets are situated inside two separator drums which bear liquids. Due to the magnets, magnetic particles are being drifted by the movement of the drums. This can create a magnetic concentrate (e.g. an ore concentrate). History Michael Faraday discovered that when a substance is put in a magnetic environment, the intensity of the environment is modified by it. With this information, he discovered that different materials can be separa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Controlled Release
Modified-release dosage is a mechanism that (in contrast to immediate-release dosage) delivers a drug with a delay after its administration (delayed-release dosage) or for a prolonged period of time (extended-release R, XR, XLdosage) or to a specific target in the body (targeted-release dosage).Pharmaceutics: Drug Delivery and Targeting p. 7-13 Sustained-release dosage forms are s designed to release (liberate) a drug at a predetermined rate in order to maintain a constant drug concentratio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micelle
A micelle () or micella () (plural micelles or micellae, respectively) is an aggregate (or supramolecular assembly) of surfactant amphipathic lipid molecules dispersed in a liquid, forming a colloidal suspension (also known as associated colloidal system). A typical micelle in water forms an aggregate with the hydrophilic "head" regions in contact with surrounding solvent, sequestering the hydrophobic single-tail regions in the micelle centre. This phase is caused by the packing behavior of single-tail lipids in a bilayer. The difficulty filling all the volume of the interior of a bilayer, while accommodating the area per head group forced on the molecule by the hydration of the lipid head group, leads to the formation of the micelle. This type of micelle is known as a normal-phase micelle (oil-in-water micelle). Inverse micelles have the head groups at the centre with the tails extending out (water-in-oil micelle). Micelles are approximately spherical in shape. Other phases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liposome
A liposome is a small artificial vesicle, spherical in shape, having at least one lipid bilayer. Due to their hydrophobicity and/or hydrophilicity, biocompatibility, particle size and many other properties, liposomes can be used as drug delivery vehicles for administration of pharmaceutical drugs and nutrients, such as lipid nanoparticles in mRNA vaccines, and DNA vaccines. Liposomes can be prepared by disrupting biological membranes (such as by sonication). Liposomes are most often composed of phospholipids, especially phosphatidylcholine and cholesterol, but may also include other lipids, such as egg, phosphatidylethanolamine, as long as they are compatible with lipid bilayer structure. A liposome design may employ surface ligands for attaching to unhealthy tissue. The major types of liposomes are the multilamellar vesicle (MLV, with several lamellar phase lipid bilayers), the small unilamellar liposome vesicle (SUV, with one lipid bilayer), the large unilamellar vesicle ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-molecule Magnet
A single-molecule magnet (SMM) is a metal-organic compound that has superparamagnetic behavior below a certain blocking temperature at the molecular scale. In this temperature range, a SMM exhibits magnetic hysteresis of purely molecular origin.Introduction to Molecular Magnetism by Dr. Joris van Slageren. In contrast to conventional bulk s and molecule-based magnets, collective long-range magnetic ordering of s is not necessary. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Overdose
Iron poisoning typically occurs from ingestion of excess iron that results in acute toxicity. Mild symptoms which occur within hours include vomiting, diarrhea, abdominal pain, and drowsiness. In more severe cases, symptoms can include tachypnea, low blood pressure, seizures, or coma. If left untreated, iron poisoning can lead to multi-organ failure resulting in permanent organ damage or death. Iron is available over the counter as a single entity supplement in an iron salt form or in combination with vitamin supplements and is commonly used in the treatment of anemias. Overdoses on iron can be categorized as unintentional ingestion which is predominantly associated with children or intentional ingestion involving suicide attempts in adults. Unintentional ingestion of iron containing drug products are a major cause of mortality in children under the age of 6 years old in the United States. As a response, in 1997 the US Food and Drug Administration (FDA) implemented a regulation req ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anticancer Nanomagnet
An anticarcinogen (also known as a carcinopreventive agent) is a substance that counteracts the effects of a carcinogen or inhibits the development of cancer. Anticarcinogens are different from anticarcinoma agents (also known as anticancer or anti-neoplastic agents) in that anticarcinoma agents are used to selectively destroy or inhibit cancer cells ''after'' cancer has developed. Interest in anticarcinogens is motivated primarily by the principle that it is preferable to prevent disease (preventive medicine) than to have to treat it ( rescue medicine). In theory, anticarcinogens may act via different mechanisms including enhancement of natural defences against cancer, deactivation of carcinogens, and blocking the mechanisms by which carcinogens act (such as free radical damage to DNA). Confirmation that a substance possesses anticarcinogenic activity requires extensive ''in vitro'', ''in vivo'', and clinical investigation. Health claims for anticarcinogens are regulated by v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-assembly
Self-assembly is a process in which a disordered system of pre-existing components forms an organized structure or pattern as a consequence of specific, local interactions among the components themselves, without external direction. When the constitutive components are molecules, the process is termed molecular self-assembly. Self-assembly can be classified as either static or dynamic. In ''static'' self-assembly, the ordered state forms as a system approaches equilibrium, reducing its free energy. However, in ''dynamic'' self-assembly, patterns of pre-existing components organized by specific local interactions are not commonly described as "self-assembled" by scientists in the associated disciplines. These structures are better described as "self-organized", although these terms are often used interchangeably. Self-assembly in chemistry and materials science Self-assembly in the classic sense can be defined as ''the spontaneous and reversible organization of molec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smart Polymer
Smart polymers, stimuli-responsive polymers or functional polymers are high-performance polymers that change according to the environment they are in. Such materials can be sensitive to a number of factors, such as temperature, humidity, pH, chemical compounds, the wavelength or intensity of light or an electrical or magnetic field and can respond in various ways, like altering color or transparency, becoming conductive or permeable to water or changing shape ( shape memory polymers). Usually, slight changes in the environment are sufficient to induce large changes in the polymer's properties. Applications Smart polymers appear in highly specialized applications and everyday products alike. They are used for sensors and actuators such as artificial muscles , the production of hydrogels, biodegradable packaging, and to a great extent in biomedical engineering . One example is a polymer that undergoes conformational change in response to pH change, which can be used in drug deliver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
