Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).

Polymers synthesized by living organisms. They play a role in the formation of macromolecular structures and are synthesized via the covalent linkage of biological molecules, especially AMINO ACIDS; NUCLEOTIDES; and CARBOHYDRATES.

Synthetic or natural materials, other than DRUGS, that are used to replace or repair any body TISSUES or bodily function.

A methodology for chemically synthesizing polymer molds of specific molecules or recognition sites of specific molecules. Applications for molecularly imprinted polymers (MIPs) include separations, assays and biosensors, and catalysis.

Implants constructed of materials designed to be absorbed by the body without producing an immune response. They are usually composed of plastics and are frequently used in orthopedics and orthodontics.

Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.

Forms to which substances are incorporated to improve the delivery and the effectiveness of drugs. Drug carriers are used in drug-delivery systems such as the controlled-release technology to prolong in vivo drug actions, decrease drug metabolism, and reduce drug toxicity. Carriers are also used in designs to increase the effectiveness of drug delivery to the target sites of pharmacological actions. Liposomes, albumin microspheres, soluble synthetic polymers, DNA complexes, protein-drug conjugates, and carrier erythrocytes among others have been employed as biodegradable drug carriers.

Polymers of organic acids and alcohols, with ester linkages--usually polyethylene terephthalate; can be cured into hard plastic, films or tapes, or fibers which can be woven into fabrics, meshes or velours.

The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.

Characteristics or attributes of the outer boundaries of objects, including molecules.

Methylester of cellulose. Methylcellulose is used as an emulsifying and suspending agent in cosmetics, pharmaceutics and the chemical industry. It is used therapeutically as a bulk laxative.

Chemical reaction in which monomeric components are combined to form POLYMERS (e.g., POLYMETHYLMETHACRYLATE).

A biocompatible polymer used as a surgical suture material.

Dosage forms of a drug that act over a period of time by controlled-release processes or technology.

Colorless, odorless crystals that are used extensively in research laboratories for the preparation of polyacrylamide gels for electrophoresis and in organic synthesis, and polymerization. Some of its polymers are used in sewage and wastewater treatment, permanent press fabrics, and as soil conditioning agents.

Polymerized forms of styrene used as a biocompatible material, especially in dentistry. They are thermoplastic and are used as insulators, for injection molding and casting, as sheets, plates, rods, rigid forms and beads.

Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.

Relating to the size of solids.

Strongly cationic polymer that binds to certain proteins; used as a marker in immunology, to precipitate and purify enzymes and lipids. Synonyms: aziridine polymer; Epamine; Epomine; ethylenimine polymer; Montrek; PEI; Polymin(e).

Acrylic acids or acrylates which are substituted in the C-2 position with a methyl group.

The preparation, mixing, and assembling of a drug. (From Remington, The Science and Practice of Pharmacy, 19th ed, p1814)

Systems for the delivery of drugs to target sites of pharmacological actions. Technologies employed include those concerning drug preparation, route of administration, site targeting, metabolism, and toxicity.

Chemistry dealing with the composition and preparation of agents having PHARMACOLOGIC ACTIONS or diagnostic use.

Condition of having pores or open spaces. This often refers to bones, bone implants, or bone cements, but can refer to the porous state of any solid substance.

The resistance that a gaseous or liquid system offers to flow when it is subjected to shear stress. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

Deacetylated CHITIN, a linear polysaccharide of deacetylated beta-1,4-D-glucosamine. It is used in HYDROGEL and to treat WOUNDS.

Usually inert substances added to a prescription in order to provide suitable consistency to the dosage form. These include binders, matrix, base or diluent in pills, tablets, creams, salves, etc.

Biocompatible materials usually used in dental and bone implants that enhance biologic fixation, thereby increasing the bond strength between the coated material and bone, and minimize possible biological effects that may result from the implant itself.

The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.

The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.

Materials fabricated by BIOMIMETICS techniques, i.e., based on natural processes found in biological systems.

A polymer prepared from polyvinyl acetates by replacement of the acetate groups with hydroxyl groups. It is used as a pharmaceutic aid and ophthalmic lubricant as well as in the manufacture of surface coatings artificial sponges, cosmetics, and other products.

A peptide which is a homopolymer of lysine.

Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.

Small uniformly-sized spherical particles, of micrometer dimensions, frequently labeled with radioisotopes or various reagents acting as tags or markers.

Materials which have structured components with at least one dimension in the range of 1 to 100 nanometers. These include NANOCOMPOSITES; NANOPARTICLES; NANOTUBES; and NANOWIRES.

A cellulose derivative which is a beta-(1,4)-D-glucopyranose polymer. It is used as a bulk laxative and as an emulsifier and thickener in cosmetics and pharmaceuticals and as a stabilizer for reagents.

The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.

Colloids with a solid continuous phase and liquid as the dispersed phase; gels may be unstable when, due to temperature or other cause, the solid phase liquefies; the resulting colloid is called a sol.

The application of scientific knowledge or technology to pharmacy and the pharmaceutical industry. It includes methods, techniques, and instrumentation in the manufacture, preparation, compounding, dispensing, packaging, and storing of drugs and other preparations used in diagnostic and determinative procedures, and in the treatment of patients.

A polyvinyl polymer of variable molecular weight; used as suspending and dispersing agent and vehicle for pharmaceuticals; also used as blood volume expander.

A group of thermoplastic or thermosetting polymers containing polyisocyanate. They are used as ELASTOMERS, as coatings, as fibers and as foams.

A group of glucose polymers made by certain bacteria. Dextrans are used therapeutically as plasma volume expanders and anticoagulants. They are also commonly used in biological experimentation and in industry for a wide variety of purposes.

Acids derived from monosaccharides by the oxidation of the terminal (-CH2OH) group farthest removed from the carbonyl group to a (-COOH) group. (From Stedmans, 26th ed)

Water swollen, rigid, 3-dimensional network of cross-linked, hydrophilic macromolecules, 20-95% water. They are used in paints, printing inks, foodstuffs, pharmaceuticals, and cosmetics. (Grant & Hackh's Chemical Dictionary, 5th ed)

Term used to designate tetrahydroxy aldehydic acids obtained by oxidation of hexose sugars, i.e. glucuronic acid, galacturonic acid, etc. Historically, the name hexuronic acid was originally given to ascorbic acid.

A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A nonionic polyoxyethylene-polyoxypropylene block co-polymer with the general formula HO(C2H4O)a(-C3H6O)b(C2H4O)aH. It is available in different grades which vary from liquids to solids. It is used as an emulsifying agent, solubilizing agent, surfactant, and wetting agent for antibiotics. Poloxamer is also used in ointment and suppository bases and as a tablet binder or coater. (Martindale The Extra Pharmacopoeia, 31st ed)

The development and use of techniques to study physical phenomena and construct structures in the nanoscale size range or smaller.

Materials that have a limited and usually variable electrical conductivity. They are particularly useful for the production of solid-state electronic devices.

Polymers where the main polymer chain comprises recurring amide groups. These compounds are generally formed from combinations of diamines, diacids, and amino acids and yield fibers, sheeting, or extruded forms used in textiles, gels, filters, sutures, contact lenses, and other biomaterials.

Polysaccharides found in bacteria and in capsules thereof.

The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.

A generic term for all substances having the properties of stretching under tension, high tensile strength, retracting rapidly, and recovering their original dimensions fully. They are generally POLYMERS.

A polynucleotide formed from the ADP-RIBOSE moiety of nicotinamide-adenine dinucleotide (NAD) by POLY(ADP-RIBOSE) POLYMERASES.

A polysaccharide with glucose units linked as in CELLOBIOSE. It is the chief constituent of plant fibers, cotton being the purest natural form of the substance. As a raw material, it forms the basis for many derivatives used in chromatography, ion exchange materials, explosives manufacturing, and pharmaceutical preparations.

Solid dosage forms, of varying weight, size, and shape, which may be molded or compressed, and which contain a medicinal substance in pure or diluted form. (Dorland, 28th ed)

Polysaccharides composed of repeating glucose units. They can consist of branched or unbranched chains in any linkages.

A normal intermediate in the fermentation (oxidation, metabolism) of sugar. The concentrated form is used internally to prevent gastrointestinal fermentation. (From Stedman, 26th ed)

A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.

The rate dynamics in chemical or physical systems.

An abnormal hemoglobin resulting from the substitution of valine for glutamic acid at position 6 of the beta chain of the globin moiety. The heterozygous state results in sickle cell trait, the homozygous in sickle cell anemia.

The thermodynamic interaction between a substance and WATER.

Organic polymeric materials which can be broken down by naturally occurring processes. This includes plastics created from bio-based or petrochemical-based materials.

Polymerized methyl methacrylate monomers which are used as sheets, moulding, extrusion powders, surface coating resins, emulsion polymers, fibers, inks, and films (From International Labor Organization, 1983). This material is also used in tooth implants, bone cements, and hard corneal contact lenses.

Tree-like, highly branched, polymeric compounds. They grow three-dimensionally by the addition of shells of branched molecules to a central core. The overall globular shape and presence of cavities gives potential as drug carriers and CONTRAST AGENTS.

Synthetic thermoplastics that are tough, flexible, inert, and resistant to chemicals and electrical current. They are often used as biocompatible materials for prostheses and implants.

The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

Nanometer-scale composite structures composed of organic molecules intimately incorporated with inorganic molecules. (Glossary of Biotechnology and Nanobiotechology Terms, 4th ed)

Salts of alginic acid that are extracted from marine kelp and used to make dental impressions and as absorbent material for surgical dressings.

Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.

Polymers of silicone that are formed by crosslinking and treatment with amorphous silica to increase strength. They have properties similar to vulcanized natural rubber, in that they stretch under tension, retract rapidly, and fully recover to their original dimensions upon release. They are used in the encapsulation of surgical membranes and implants.

The sum of the weight of all the atoms in a molecule.

A group of 13 or more deoxyribonucleotides in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.

Generating tissue in vitro for clinical applications, such as replacing wounded tissues or impaired organs. The use of TISSUE SCAFFOLDING enables the generation of complex multi-layered tissues and tissue structures.

A polyester used for absorbable sutures & surgical mesh, especially in ophthalmic surgery. 2-Hydroxy-propanoic acid polymer with polymerized hydroxyacetic acid, which forms 3,6-dimethyl-1,4-dioxane-dione polymer with 1,4-dioxane-2,5-dione copolymer of molecular weight about 80,000 daltons.

The study of the deformation and flow of matter, usually liquids or fluids, and of the plastic flow of solids. The concept covers consistency, dilatancy, liquefaction, resistance to flow, shearing, thixotrophy, and VISCOSITY.

Bacterial polysaccharides that are rich in phosphodiester linkages. They are the major components of the cell walls and membranes of many bacteria.

Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.

Cell growth support structures composed of BIOCOMPATIBLE MATERIALS. They are specially designed solid support matrices for cell attachment in TISSUE ENGINEERING and GUIDED TISSUE REGENERATION uses.

A type of scanning probe microscopy in which a probe systematically rides across the surface of a sample being scanned in a raster pattern. The vertical position is recorded as a spring attached to the probe rises and falls in response to peaks and valleys on the surface. These deflections produce a topographic map of the sample.

Artificially produced membranes, such as semipermeable membranes used in artificial kidney dialysis (RENAL DIALYSIS), monomolecular and bimolecular membranes used as models to simulate biological CELL MEMBRANES. These membranes are also used in the process of GUIDED TISSUE REGENERATION.

Substances that cause the adherence of two surfaces. They include glues (properly collagen-derived adhesives), mucilages, sticky pastes, gums, resins, or latex.

A property of the surface of an object that makes it stick to another surface.

The characteristic three-dimensional shape of a molecule.

The properties and processes of materials that affect their behavior under force.

The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)

Linear polymers in which orthophosphate residues are linked with energy-rich phosphoanhydride bonds. They are found in plants, animals, and microorganisms.

The chemical and physical integrity of a pharmaceutical product.

An interdisciplinary field in materials science, ENGINEERING, and BIOLOGY, studying the use of biological principles for synthesis or fabrication of BIOMIMETIC MATERIALS.

A polyvinyl resin used extensively in the manufacture of plastics, including medical devices, tubing, and other packaging. It is also used as a rubber substitute.

Differential thermal analysis in which the sample compartment of the apparatus is a differential calorimeter, allowing an exact measure of the heat of transition independent of the specific heat, thermal conductivity, and other variables of the sample.

The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.

A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).

A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from SPERM FLAGELLUM; CILIA; and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120,000 and a sedimentation coefficient of 5.8S. It binds to COLCHICINE; VINCRISTINE; and VINBLASTINE.

The maximum stress a material subjected to a stretching load can withstand without tearing. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed, p2001)

Manufacturing technology for making microscopic devices in the micrometer range (typically 1-100 micrometers), such as integrated circuits or MEMS. The process usually involves replication and parallel fabrication of hundreds or millions of identical structures using various thin film deposition techniques and carried out in environmentally-controlled clean rooms.

Nanometer-sized, hollow, spherically-shaped objects that can be utilized to encapsulate small amounts of pharmaceuticals, enzymes, or other catalysts (Glossary of Biotechnology and Nanobiotechnology, 4th ed).

The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.

Organic compounds that contain silicon as an integral part of the molecule.

Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.

A highly miniaturized version of ELECTROPHORESIS performed in a microfluidic device.

Particles consisting of aggregates of molecules held loosely together by secondary bonds. The surface of micelles are usually comprised of amphiphatic compounds that are oriented in a way that minimizes the energy of interaction between the micelle and its environment. Liquids that contain large numbers of suspended micelles are referred to as EMULSIONS.

The diversion of RADIATION (thermal, electromagnetic, or nuclear) from its original path as a result of interactions or collisions with atoms, molecules, or larger particles in the atmosphere or other media. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

Process by which unwanted microbial, plant or animal materials or organisms accumulate on man-made surfaces.

Completed forms of the pharmaceutical preparation in which prescribed doses of medication are included. They are designed to resist action by gastric fluids, prevent vomiting and nausea, reduce or alleviate the undesirable taste and smells associated with oral administration, achieve a high concentration of drug at target site, or produce a delayed or long-acting drug effect.

The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.

Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)

Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.

Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.

Agents that modify interfacial tension of water; usually substances that have one lipophilic and one hydrophilic group in the molecule; includes soaps, detergents, emulsifiers, dispersing and wetting agents, and several groups of antiseptics.

Any of a variety of procedures which use biomolecular probes to measure the presence or concentration of biological molecules, biological structures, microorganisms, etc., by translating a biochemical interaction at the probe surface into a quantifiable physical signal.

Submicron-sized fibers with diameters typically between 50 and 500 nanometers. The very small dimension of these fibers can generate a high surface area to volume ratio, which makes them potential candidates for various biomedical and other applications.

Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.

A network of cross-linked hydrophilic macromolecules used in biomedical applications.

The methyl esters of methacrylic acid that polymerize easily and are used as tissue cements, dental materials, and absorbent for biological substances.

Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.

Polymeric materials (usually organic) of large molecular weight which can be shaped by flow. Plastic usually refers to the final product with fillers, plasticizers, pigments, and stabilizers included (versus the resin, the homogeneous polymeric starting material). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Small containers or pellets of a solid drug implanted in the body to achieve sustained release of the drug.

Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.

The introduction of functional (usually cloned) GENES into cells. A variety of techniques and naturally occurring processes are used for the gene transfer such as cell hybridization, LIPOSOMES or microcell-mediated gene transfer, ELECTROPORATION, chromosome-mediated gene transfer, TRANSFECTION, and GENETIC TRANSDUCTION. Gene transfer may result in genetically transformed cells and individual organisms.

Resistance and recovery from distortion of shape.

Technique whereby the weight of a sample can be followed over a period of time while its temperature is being changed (usually increased at a constant rate).

Nanometer-sized tubes composed of various substances including carbon (CARBON NANOTUBES), boron nitride, or nickel vanadate.

Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.

Silicone polymers which consist of silicon atoms substituted with methyl groups and linked by oxygen atoms. They comprise a series of biocompatible materials used as liquids, gels or solids; as film for artificial membranes, gels for implants, and liquids for drug vehicles; and as antifoaming agents.

Artificial substitutes for body parts and materials inserted into organisms during experimental studies.

A trace element that constitutes about 27.6% of the earth's crust in the form of SILICON DIOXIDE. It does not occur free in nature. Silicon has the atomic symbol Si, atomic number 14, and atomic weight [28.084; 28.086].