Names | |
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Preferred IUPAC name N,N,N-Trimethylhexadecan-1-aminium bromide | |
Other names
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Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.000.283 |
KEGG | |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C19H42BrN | |
Molar mass | 364.45 g/mol |
Appearance | white powder |
Melting point | 237 to 243 °C (459 to 469 °F; 510 to 516 K) (decomposes) |
Pharmacology | |
D08AJ02 ( WHO ) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Cetrimonium bromide, also known with the abbreviation CTAB, is a quaternary ammonium surfactant with a condensed structural formula [(C16H33)N(CH3)3]Br.
It is one of the components of the topical antiseptic cetrimide. [1] The cetrimonium (hexadecyltrimethylammonium) cation is an effective antiseptic agent against bacteria and fungi. It is also one of the main components of some buffers for the extraction of DNA. [2] It has been widely used in synthesis of gold nanoparticles (e.g., spheres, rods, bipyramids), mesoporous silica nanoparticles (e.g., MCM-41), and hair conditioning products. The closely related compounds cetrimonium chloride and cetrimonium stearate are also used as topical antiseptics and may be found in many household products such as shampoos and cosmetics. CTAB, due to its relatively high cost, is typically only used in select cosmetics.
As with most surfactants, CTAB forms micelles in aqueous solutions. At 303 K (30 °C) it forms micelles with aggregation number 75–120 (depending on method of determination; average ~95) and degree of ionization, α = 0.2–0.1 (fractional charge; from low to high concentration). [3] The binding constant (K°) of Br− counterion to a CTA+ micelle at 303 K (30 °C) is c. 400 M-1. This value is calculated from Br− and CTA+ ion selective electrode measurements and conductometry data by using literature data for micelle size (r = ~3 nm)[ citation needed ], extrapolated to the critical micelle concentration of 1 mM[ citation needed ]. However, K° varies with total surfactant concentration so it is extrapolated to the point at which micelle concentration is zero.[ citation needed ]
Cell lysis is a convenient tool to isolate certain macromolecules that exist primarily inside of the cell. Cell membranes consist of hydrophilic and lipophilic endgroups. Therefore, detergents are often used to dissolve these membranes since they interact with both polar and nonpolar endgroups. CTAB has emerged as the preferred choice for biological use because it maintains the integrity of precipitated DNA during its isolation. [4] Cells typically have high concentrations of macromolecules, such as glycoproteins and polysaccharides, that co-precipitate with DNA during the extraction process, causing the extracted DNA to lose purity. The positive charge of the CTAB molecule allows it to denature these molecules that would interfere with this isolation. [5]
CTAB has been shown to have potential use as an apoptosis-promoting anticancer agent for head and neck cancer (HNC). [6] In vitro, CTAB interacted additively with γ radiation and cisplatin, two standard HNC therapeutic agents. CTAB exhibited anticancer cytotoxicity against several HNC cell lines with minimal effects on normal fibroblasts, a selectivity that exploits cancer-specific metabolic aberrations. In vivo, CTAB ablated tumor-forming capacity of FaDu cells and delayed growth of established tumors. Thus, using this approach, CTAB was identified as a potential apoptogenic quaternary ammonium compound possessing in vitro and in vivo efficacy against HNC models. CTAB is also recommended by the World Health Organisation (WHO) as a purification agent in the downstream vaccine processing of polysaccharide vaccines. [7]
Glycoproteins form broad, fuzzy bands in SDS-PAGE (Laemmli-electrophoresis) because of their broad distribution of negative charges. Using positively charged detergents such as CTAB will avoid issues associated with glycoproteins. Proteins can be blotted from CTAB-gels in analogy to western blots ("eastern blot"), and Myelin-associated high hydrophobic protein can be analyzed using CTAB 2-DE.[ citation needed ]
CTAB serves as an important surfactant in the DNA extraction buffer system to remove membrane lipids and promote cell lysis. Separation is also successful when the tissue contains high amounts of polysaccharides. [2] CTAB binds to the polysaccharides when the salt concentration is high, thus removing polysaccharides from solution. A typical recipe can be to combine 100 mL of 1 M Tris HCl (pH 8.0), 280 mL 5 M NaCl, 40 mL of 0.5 M EDTA, and 20 g of CTAB then add double distilled water (ddH2O) to bring total volume to 1 L.
Surfactants play a key role in nanoparticle synthesis by adsorbing to the surface of the forming nanoparticle and lowering its surface energy. [8] [9] Surfactants also help to prevent aggregation (e.g. via DLVO mechanisms).
Gold (Au) nanoparticles are interesting to researchers because of their unique properties that can be used in applications such as catalysis, optics, electronics, sensing, and medicine. [10] Control of nanoparticle size and shape is important in order to tune its properties. CTAB has been a widely used reagent to both impart stability to these nanoparticles as well as control their morphologies. CTAB may play a role in controlling nanoparticle size and shape by selectively or more strongly binding to various emerging crystal facets.
Some of this control originates from the reaction of CTAB with other reagents in the gold nanoparticle synthesis. For example, in aqueous gold nanoparticle syntheses, chlorauric acid (HAuCl4) may react with CTAB to create a CTA+-AuCl−
4 complex. [11] [12] The gold complex is then reacted with ascorbic acid to produce hydrochloric acid, an ascorbic acid radical, and CTA-AuCl3. The ascorbic acid radical and CTA-AuCl3 react spontaneously to create metallic Au0 nanoparticles and other byproducts. An alternative or simultaneous reaction is the substitution of Cl− with Br− about the Au(III) center. Both complexation with the ammonium cation and/or speciation of the Au(III) precursor influence the kinetics of the nanoparticle formation reaction and therefore influence the size, shape, and (size and shape) distributions of the resulting particles.
However, CTA+-AuCl−
4 should not be called a complex, electrostatic interaction of quaternary ammonium cation with AuCl−
4 results in formation of an ion pair at best. CTA+ does not have any donating centers which can form a coordination complex with Au(III) metal centers.
CTAB is used as the template for the first report of ordered mesoporous materials. [13] Microporous and mesoporous inorganic solids (with pore diameters of ≤20 Å and ~20–500 Å respectively) have found great utility as catalysts and sorption media because of their large internal surface area. Typical microporous materials are crystalline framework solids, such as zeolites, but the largest pore dimensions are still below 2 nm which greatly limit application. Examples of mesoporous solids include silicas and modified layered materials, but these are invariably amorphous or paracrystalline, with pores that are irregularly spaced and broadly distributed in size. There is a need to prepare highly ordered mesoporous material with good mesoscale crystallinity. The synthesis of mesoporous solids from the calcination of aluminosilicate gels in the presence of surfactants was reported. The material possesses regular arrays of uniform channels, the dimensions of which can be tailored (in the range of 16 Å to >100 Å) through the choice of surfactant, auxiliary chemicals, and reaction conditions. It was proposed that the formation of these materials takes place by means of a liquid-crystal 'templating' mechanism, in which the silicate material forms inorganic walls between ordered surfactant micelles. CTAB formed micelles in the solution and these micelles further formed a two dimensional hexagonal mesostructure. The silicon precursor began to hydrolyze between the micelles and finally filled the gap with silicon dioxide. The template could be further removed by calcination and left a pore structure behind. These pores mimicked exactly the structure of mesoscale soft template and led to highly ordered mesoporous silica materials.
CTAB has been used for applications from nanoparticle synthesis to cosmetics. Due to its use in human products, along with other applications, it is essential to be made aware of the hazards this agent contains. The Santa Cruz Biotechnology, Inc. [14] offers a comprehensive MSDS for CTAB and should be referred to for additional questions or concerns. [15] Animal testing has shown ingestion of less than 150 g of the agent can lead to adverse health effects or possibly death by CTAB causing chemical burns throughout the esophagus and gastrointestinal tract that can be followed by nausea and vomiting. [15] If the substance continues through the gastrointestinal tract, it will be poorly absorbed in the intestines followed by excretion in feces. [16] Toxicity has also been tested on aquatic life including Brachydanio rerio (zebra fish) and Daphnia magna (water flea). Zebra fish showed CTAB toxicity when exposed to 0.3 mg/L for 96 hours, and water fleas showed CTAB toxicity when exposed to 0.03 mg/L for 48 hours. [17]
CTAB along with other quaternary ammonium salts have frequently been used in cosmetics at concentrations up to 10%. Cosmetics at that concentration must only be used as rinse-off types such as shampoos. Other leave-on cosmetics are considered only safe at or below 0.25% concentrations. Injections into the body cavity of pregnant mice showed embryotoxic and teratogenic effects. Only teratogenic effects were seen with 10 mg/kg doses, while both effects were seen at 35 mg/kg doses. Oral doses of 50 mg/kg/day showed embryotoxic effects as well. [16] Similar tests were completed by giving rats 10, 20, and 45 mg/kg/day of CTAB in their drinking water for one year. At the 10 and 20 mg/kg/day doses, the rats did not have any toxic symptoms. At the highest dose, the rats began experiencing weight loss. The weight loss in the male rats was attributed to less efficient food conversion. The tests showed no microscopic alterations to the gastrointestinal tract of the rats. [18]
Other toxicity tests have been conducted using incubated human skin HaCaT keratinocyte cells. These human cells were incubated with gold nanorods that were synthesized using seed-mediated, surfactant-assisted growth of gold nanoparticles. Gold nanoparticles are shown to be nontoxic, however once the nanoparticles are put through the growth solutions, the newly formed nanorods are highly toxic. This large increase in toxicity is attributed to the CTAB that is used in the growth solutions to cause anisotropic growth. [19] Experiments also showed the toxicity of bulk CTAB and the synthesized gold nanorods to be equivalent. Toxicity tests showed CTAB remaining toxic with concentrations as low as 10 μM. The human cells show CTAB being nontoxic at concentrations less than 1 μM. Without the use of CTAB in this synthesis, the gold nanorods are not stable; they break into nanoparticles or undergo aggregation. [19]
The mechanism for cytotoxicity has not been extensively studied, but there has been possible mechanisms proposed. One proposal showed two methods that led to the cytotoxicity in U87 and A172 glioblastoma cells. The first method showed CTAB exchanging with phospholipids causing rearrangement of the membrane allowing β-galactoside to enter into the cell by way of cavities. At low concentrations, there are not enough cavities to cause death to the cells, but with increasing the CTAB concentration, more phospholipids are displaced causing more cavities in the membrane leading to cell death. The second proposed method is based on the dissociation of CTAB into CTA+ and Br− within the mitochondrial membrane. The positively charged CTA+ binds to the ATP synthase not allowing H+ to bind stopping the synthesis of ATP and resulting in cell death. [20]
A bactericide or bacteriocide, sometimes abbreviated Bcidal, is a substance which kills bacteria. Bactericides are disinfectants, antiseptics, or antibiotics. However, material surfaces can also have bactericidal properties based solely on their physical surface structure, as for example biomaterials like insect wings.
Sodium dodecyl sulfate (SDS) or sodium lauryl sulfate (SLS), sometimes written sodium laurilsulfate, is an organic compound with the formula CH3(CH2)11OSO3Na and structure H3C−(CH2)11−O−S(=O)2−O−Na+. It is an anionic surfactant used in many cleaning and hygiene products. This compound is the sodium salt of the 12-carbon organosulfate. Its hydrocarbon tail combined with a polar "headgroup" give the compound amphiphilic properties that make it useful as a detergent. SDS is also component of mixtures produced from inexpensive coconut and palm oils. SDS is a common component of many domestic cleaning, personal hygiene and cosmetic, pharmaceutical, and food products, as well as of industrial and commercial cleaning and product formulations.
Surfactants are chemical compounds that decrease the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. The word "surfactant" is a blend of surface-active agent, coined c. 1950. As they consist of a water-repellent and a water-attracting part, they enable water and oil to mix; they can form foam and facilitate the detachment of dirt.
A micelle or micella is an aggregate of surfactant amphipathic lipid molecules dispersed in a liquid, forming a colloidal suspension. 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.
Ethidium bromide is an intercalating agent commonly used as a fluorescent tag in molecular biology laboratories for techniques such as agarose gel electrophoresis. It is commonly abbreviated as EtBr, which is also an abbreviation for bromoethane. To avoid confusion, some laboratories have used the abbreviation EthBr for this salt. When exposed to ultraviolet light, it will fluoresce with an orange colour, intensifying almost 20-fold after binding to DNA. Under the name homidium, it has been commonly used since the 1950s in veterinary medicine to treat trypanosomiasis in cattle. The high incidence of antimicrobial resistance makes this treatment impractical in some areas, where the related isometamidium chloride is used instead. Despite its reputation as a mutagen, tests have shown it to have low mutagenicity without metabolic activation.
Colloidal gold is a sol or colloidal suspension of nanoparticles of gold in a fluid, usually water. The colloid is coloured usually either wine red or blue-purple . Due to their optical, electronic, and molecular-recognition properties, gold nanoparticles are the subject of substantial research, with many potential or promised applications in a wide variety of areas, including electron microscopy, electronics, nanotechnology, materials science, and biomedicine.
Tetraethylammonium (TEA) is a quaternary ammonium cation with the chemical formula [Et4N]+, consisting of four ethyl groups attached to a central nitrogen atom. It is a counterion used in the research laboratory to prepare lipophilic salts of inorganic anions. It is used similarly to tetrabutylammonium, the difference being that its salts are less lipophilic, more easily crystallized and more toxic.
Ammonium lauryl sulfate (ALS) is the common name for ammonium dodecyl sulfate (CH3(CH2)10CH2OSO3NH4). The anion consists of a nonpolar hydrocarbon chain and a polar sulfate end group. The combination of nonpolar and polar groups confers surfactant properties to the anion: it facilitates dissolution of both polar and non-polar materials. This salt is classified as a sulfate ester. It is made from coconut or palm kernel oil for use primarily in shampoos and body-wash as a foaming agent. Lauryl sulfates are very high-foam surfactants that disrupt the surface tension of water in part by forming micelles at the surface-air interface.
In organic chemistry, quaternary ammonium cations, also known as quats, are positively-charged polyatomic ions of the structure [NR4]+, where R is an alkyl group, an aryl group or organyl group. Unlike the ammonium ion and the primary, secondary, or tertiary ammonium cations, the quaternary ammonium cations are permanently charged, independent of the pH of their solution. Quaternary ammonium salts or quaternary ammonium compounds are salts of quaternary ammonium cations. Polyquats are a variety of engineered polymer forms which provide multiple quat molecules within a larger molecule.
Behentrimonium chloride, also known as docosyltrimethylammonium chloride or BTAC-228, is a yellow waxlike organic compound with chemical formula CH3(CH2)21N(Cl)(CH3)3, used as an antistatic agent and, sometimes, a disinfectant. It is commonly found in cosmetics such as conditioners, hair dye, and mousse, and also in detergents. Laboratory tests have indicated that it does readily biodegrade.
In nanotechnology, nanorods are one morphology of nanoscale objects. Each of their dimensions range from 1–100 nm. They may be synthesized from metals or semiconducting materials. Standard aspect ratios are 3-5. Nanorods are produced by direct chemical synthesis. A combination of ligands act as shape control agents and bond to different facets of the nanorod with different strengths. This allows different faces of the nanorod to grow at different rates, producing an elongated object.
Dimethyldioctadecylammonium chloride is an organic compound classified as quaternary ammonium salt. The nitrogen center substituted with two methyl groups and two stearyl groups. The combination of long-chain hydrocarbon groups and the cationic ammonium confers surfactant- or a detergent-like properties. For professional use only, it can be found in many wares-and-equipment sanitizers as well as cleaner/sanitizer combinations that are standard in the foodservice industry – it was once a major component of fabric softeners, but has been largely phased out because of its low biodegradability. In household products, it may also be found as an ingredient in cosmetics and hair conditioners in which it is added primarily for its antistatic effects. It is also used in organic synthesis as a phase transfer catalyst to increase reaction rates in a two-phase organic-water system.
Platinum nanoparticles are usually in the form of a suspension or colloid of nanoparticles of platinum in a fluid, usually water. A colloid is technically defined as a stable dispersion of particles in a fluid medium.
Silver nanoparticles are nanoparticles of silver of between 1 nm and 100 nm in size. While frequently described as being 'silver' some are composed of a large percentage of silver oxide due to their large ratio of surface to bulk silver atoms. Numerous shapes of nanoparticles can be constructed depending on the application at hand. Commonly used silver nanoparticles are spherical, but diamond, octagonal, and thin sheets are also common.
Dimethyldioctadecylammonium bromide is a double-chained quaternary ammonium surfactant that forms unilamellar vesicles (ULVs) in water. Among various preparation methods, the ‘‘hot-water” method offers a simple procedure to prepare DODAB cationic vesicles by simply dissolving the DODAB in hot water above 50 °C, i.e., chain melting (main) transition, Tm. In general, the DSC thermograms of the unsonicated DODAB dispersions are dominated by two endotherms; the pre- and main transition peaks. Moreover, in literature reported the presence of a third endotherm at 52.2 °C. The main transition (Tm) is ascribed to gel to liquid-crystalline phase transition in which the alkyl chains transform from solidlike to liquid-like state.
The behavior of quantum dots (QDs) in solution and their interaction with other surfaces is of great importance to biological and industrial applications, such as optical displays, animal tagging, anti-counterfeiting dyes and paints, chemical sensing, and fluorescent tagging. However, unmodified quantum dots tend to be hydrophobic, which precludes their use in stable, water-based colloids. Furthermore, because the ratio of surface area to volume in a quantum dot is much higher than for larger particles, the thermodynamic free energy associated with dangling bonds on the surface is sufficient to impede the quantum confinement of excitons. Once solubilized by encapsulation in either a hydrophobic interior micelle or a hydrophilic exterior micelle, the QDs can be successfully introduced into an aqueous medium, in which they form an extended hydrogel network. In this form, quantum dots can be utilized in several applications that benefit from their unique properties, such as medical imaging and thermal destruction of malignant cancers.
MCM-41 is a mesoporous material with a hierarchical structure from a family of silicate and alumosilicate solids that were first developed by researchers at Mobil Oil Corporation and that can be used as catalysts or catalyst supports.
Gold nanoparticles in chemotherapy and radiotherapy is the use of colloidal gold in therapeutic treatments, often for cancer or arthritis. Gold nanoparticle technology shows promise in the advancement of cancer treatments. Some of the properties that gold nanoparticles possess, such as small size, non-toxicity and non-immunogenicity make these molecules useful candidates for targeted drug delivery systems. With tumor-targeting delivery vectors becoming smaller, the ability to by-pass the natural barriers and obstacles of the body becomes more probable. To increase specificity and likelihood of drug delivery, tumor specific ligands may be grafted onto the particles along with the chemotherapeutic drug molecules, to allow these molecules to circulate throughout the tumor without being redistributed into the body.
A copper nanoparticle is a copper based particle 1 to 100 nm in size. Like many other forms of nanoparticles, a copper nanoparticle can be prepared by natural processes or through chemical synthesis. These nanoparticles are of particular interest due to their historical application as coloring agents and the biomedical as well as the antimicrobial ones.
Nanoparticle drug delivery systems are engineered technologies that use nanoparticles for the targeted delivery and controlled release of therapeutic agents. The modern form of a drug delivery system should minimize side-effects and reduce both dosage and dosage frequency. Recently, nanoparticles have aroused attention due to their potential application for effective drug delivery.