Cationic detergents, toxicity

ODNs directed to a point mutation in codon 12 of the HA-ras mRNA adsorbed to such nanoparticles were injected into tumor tissue, and suppressed oncogene-mediated tumor proliferation at concentrations 100 times lower than the free oligonucleotides [435], Because of the negative surface potential ( -potential) of polycyanoacrylate particles, a cationic copolymer such as DEAE-dextran (known as a transfection enhancer), or a hydrophobic cationic detergent such as CTAB, are usually used. In the meantime, base-modified nanoparticles of the methacrylate type have also been described [399-401, 404, 405, 407]. They have shown to increase plasma stability of ODNs and increase cellular uptake. Effects of toxicity were observed depending on the type of modification. As they are also used as car-... 

The various types of surfactants available have been described in Chapter 1. Just as their properties in aqueous solution vary with each individual compound so does their ability to solubilize. The chemical properties of certain surfactants may obviate their use in given circumstances. Fatty acid soaps of the monovalent alkaline-earth elements are precipitated by divalent cations and are only suitable at an alkaline pH. Paraffin chain salts of the strong acid sulphates are not so readily precipitated cationic detergents are often more toxic than the other types. 

The widespread use of cationic surfactants as detergents and disinfectants in many different home- and industrial-cleaning products suggests its likely presence in the aquatic environment, such as in surface water from WWTP. Environmental detections of cationic surfactants have been reported at the submicrogram-per-htre level in water and sediment matrices. The presence of surfactants in surface water also suggests potential toxicity for organisms, such as fish... 

II. Toxic dose. Mortality and serious morbidity are rare, but the nature of the toxic effect varies with the ingredients and concentration of the product. Cationic and dishwasher detergents are more dangerous than anionic and nonionic products. For benzalkonium chloride solutions, ingestion of 100-400 mg/kg has been fatal. 

Attempts are being made to find agents that will rupture the membranes of cancer cells selectively. For example amines, stich as 4-dodecylpyridine 14.20), with a pX a value between 5 and 9, are selectively accumulated by lysosomes because these have an acidic sap, as have cancer cells (p. 151). The amines enter the cells freely, being non-ionized and lipophilic, but are trapped as cations by the acidic sap and cannot escape. Because the cations (but not the neutral species) are detergents, the lysosomal membranes become ruptured, and it is hoped to adapt this phenomenon to anti-cancer therapy. 4-Dodecylpyridine is non-toxic to mice after intraperitoneal injection of 0.5 g/kg (Firestone, Pisano and Bonney, 1979). 

Although naturally occurring phosphorus compounds are almost invariably non-toxic, known synthetic products show a very wide range of toxicity. Most inorganic phosphates based on pentavalent phosphorus are among the safest of all substances known to man (unless, of course, toxic cations are present). They are essential to nutrition and are consumed in food and soft drinks and are taken in tonics and medicines (Chapter 12). The varieties employed in toothpastes and detergents are completely harmless. No deaths or illnesses have resulted from these phosphates being present in water, foods or other commodities (Tables 2.5 and 2.13). 

In contrast to alkyl-based cationics, esterquats contain ester groups in the molecule. Owing to this hydrolytically unstable function in the molecule, esterquats are much better biodegradable than alkyl-based cationics. In the European detergent industry, this fact and its lower toxicity to water organisms [21] led to a nearly complete replacement of DSDMAC by esterquats in household rinse cycle softeners since 1991. 

Thousands of surfactants are produced commercially worldwide, with applications ranging from pharmaceuticals and food additives to soaps and detergents. Surfactants are typically classified as either anionic, cationic, nonionic or anq>hoteric depending upon the nature of their hydrophilic head group. Nonionic surfactants are widely used in agricultural applications because of their relatively low cost, generally low toxicity, and tolerance to varying solution conditions (e.g., electrolyte concentration). The most common nonionic... 

Chlorhexidine is another cationic agent which is used extensively in periodontal therapy to suppress Gram-negative plaque organisms since it is non-toxic, readily retained and is very effective at low concentrations even though it has a poor detergent capability. Structurally it is a substituted 1,6-bisguanidohexane which contains both hydrophilic and hydrophobic components. 

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