Biocompatible surfactants

Fatty acid esters of sugars are also very important biodegradable and biocompatible surfactants that are prepared either by transesterification of methyl ester with sugar on basic catalysts or by esterification of fatty acids with sugar on acidic catalysts. Liquid acids and bases have been replaced by enzymatic catalysis with lipase, giving a higher yield of monoester [43, 44], but solid catalysts have not been used extensively so far. 

In order to overcome toxicity issues with some PTCs, new bio-sourced and biocompatible surfactants are being developed. ... 

A number of batch and column studies have sought to enhance the solubilization and desorption of PAHs from soil. Surfactants are commonly used to remediate PAH-contaminated soil. Two methods are employed micellar solubilization and PAH mobilization by reduction of interfacial tension (West and Harwell, 1992). As surfactant toxicity became a significant issue, biodegradable and biocompatible surfactants have been more widely examined. For example, food-grade surfactants such as Tergitol 15-S-X (X = 7,9, and 12) (Li and Chen, 2002) and other surfactants with indirect food additive status, such as alkyl diphenyl disulfonate (DOWFAX) (Deshpande et /., 2000), have been investigated for use in solubilization/desorption of single PAHs or PAHs mixtures from contaminated soils. 

Although siloxane surfactants and especially silicone polyethers are known and produced for some decades, they continue to incite the interest of the scientific world. New structures are emerging, new methods are used for their investigation and new applications are discovered. In particular, biocompatible surfactants are of great importance nowadays, as well as those obtained from renewable sources. Nano-materials may be prepared with siloxane-containing surfactants, which are active both in water and in organie media. 

Holtze C, Rowat AC, Agresti JJ, Hutcbisrai JB, Angile FE, Schmitz CHJ, Koster S, Duan H, Humphry KJ, Scanga RA, Johnson JS, Pisignano D, Weitz DA (2008) Biocompatible surfactants for water-in-lluorocarbon emulsions. Lab Chip 8 1632-1639... 

The physicochemical properties (surface tension, cmc) of these surfactants in binary mixtures with water are comparable to other nonionic surface-active agents. They have no hemolytic activity toward red blood cells. As to the cellular viability of hybridoma cell cultures, compounds 36 and 37 show a behavior strictly identical to that of commercial biocompatible surfactants [85]. 

The stability of the particles can be enhanced by coating with biocompatible surfactants (Ma et al., 2003) capable of interactions with hydroxyl groups on the magnetite surface and ensuring the ferrofluid stability. The coating agent should have sjjedfic functional groups for further functionalization for specific applications. 

In 1988, Walde and coworkers studied the kinetic and structural properties of another serine protease, namely trypsin, in two reverse micellar systems, AOT/ isooctane and CTAB/chloroform/isooctane, employing three different model substrates, an amide and two esters [71], The main aim of this work was to compare the behavior of trypsin in reverse micelles with that of a-chymotrypsin. In the case of trypsin, superactivity was not observed and in general no obvious similarities between the two enzymes were recorded. Some years later, reverse micelles formulated with biocompatible surfactants such as lecithin of variable chain lengths in isooctane/alcohol were studied in relation to their capacity to solubilize a-chymotrypsin and trypsin [72]. The hydrolytic behavior of the same serine proteases, namely a-chymotrypsin and trypsin, in both AOT and CTAB microemulsions was studied and related to the polarity of the reaction medium as expressed by the logP value and measured by the hydrophilic probe 1-methyl-8-oxyquinolinium betaine [39], In this study a remarkable superactivity of trypsin in reverse micelles formed with the cationic surfactant CTAB was reported. 

Various kinds of self-organizing structures are formed in polyoxyethylene-type nonionic surfactant/water systems depending on temperature, surfactant concentration, surfactant structures, etc. [1,2], In previous studies on the basic phase behavior of nonionic surfactants, dodecyl chain surfactants have been mainly used. In longer chain nonionic surfactant systems, more phases appear and they are more important for practical applications, although the phase behavior have not been extensively studied. Polyoxyethylene oleyl ethers are biocompatible surfactants used for cosmetics, medicines, etc. The purity of commercially available oleic acid (cis-9-octadecenoic acid) is usually around 60% and the rest contains more than 50 kinds of other fatty acids [3]. Since conventional commercial polyoxyethylene oleyl ethers are synthesized from the low-purity oleic acid, it is difficult to figure out the basic phase behavior of the nonionic surfactants in water. 

Infante MR, Perez L, Moran MC, et al. 2009b. Biocompatible surfactants from renewable hydrophiles. European Journal of Lipid Science and Technology 112(1) 110-121. 

Amino Acids, Lactic Acid and Ascorbic Acid as Raw Materials for Biocompatible Surfactants... 

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