Solvent biocompatibility

As a basic in B LMs for the wastewater treatment the author presents two-phase partitioning bioreactors. He presents the main criteria which must be considered in the selection of the LM solvent biocompatibility (toxicity of the solvent to the microorganism), bioavailabihty (resistance of the solvent to biodegradation by the microorganism used), immiscibility in the aqueous phase, high solubility of pollutant in the solvent, favorable mass-transfer characteristics, etc. Biodegradation mechanisms and kinetics are discussed. Apphcations of bioreactors in wastewater treatment in laboratory, phot, and industrial scale are reviewed. Potential applications are considered also. 

Poly(iV-vinyl caprolactam) (PVCa) Soluble in water and organic solvents, biocompatible, high absorption ability and LCSTof33°C. 

The presence of polymer, solvent, and ionic components in conducting polymers reminds one of the composition of the materials chosen by nature to produce muscles, neurons, and skin in living creatures. We will describe here some devices ready for commercial applications, such as artificial muscles, smart windows, or smart membranes other industrial products such as polymeric batteries or smart mirrors and processes and devices under development, such as biocompatible nervous system interfaces, smart membranes, and electron-ion transducers, all of them based on the electrochemical behavior of electrodes that are three dimensional at the molecular level. During the discussion we will emphasize the analogies between these electrochemical systems and analogous biological systems. Our aim is to introduce an electrochemistry for conducting polymers, and by extension, for any electrodic process where the structure of the electrode is taken into account. 

In order to test the tissue compatibility of tyrosine-derived poly-(iminocarbonates), solvent cast films of poIy(CTTH) were subcutaneously implanted into the back of outbread mice. In this study, conventional poly(L-tyrosine) served as a control (42). With only small variations, the experimental protocol described for the biocompatibility testing of poly(N-palmitoylhydroxyproline ester) (Sec. III. 

C2-C4 w-alkanes [42,43], and in supercritical carbon dioxide when employing novel surfactants with fluorocarbon tails [38,44], There is also interest in the further employment of lipids (triglycerides and wax esters, such as isopropyl myristate) as solvent to improve biocompatibility [45],... 

One of the main obstacles for whole-cell microbial transformation in an organic solvent is its biocompatibility, which has led to screening for organic-solvent-tolerant microorganisms. Numerous organic-solvent-tolerant microorganisms have been found and their tolerance mechanisms have been reviewed [14,33,34]. Two-phase biotransformation systems have been successfully implemented for the production of pharmaceutically relevant metabolites. 

The main advantage is that the entrapment conditions are dictated by the entrapped enzymes, but not the process. This includes such important denaturing factors as the solution pH, the temperature and the organic solvent released in the course of precursor hydrolysis. The immobilization by THEOS is performed at a pH and temperature that are optimal for encapsulated biomaterial [55,56]. The jellification processes are accomplished by the separation of ethylene glycol that possesses improved biocompatibility in comparison with alcohols. 

Nanoparticle surface modification is of tremendous importance to prevent nanoparticle aggregation prior to injection, decrease the toxicity, and increase the solubility and the biocompatibility in a living system [20]. Imaging studies in mice clearly show that QD surface coatings alter the disposition and pharmacokinetic properties of the nanoparticles. The key factors in surface modifications include the use of proper solvents and chemicals or biomolecules used for the attachment of the drug, targeting ligands, proteins, peptides, nucleic acids etc. for their site-specific biomedical applications. The functionalized or capped nanoparticles should be preferably dispersible in aqueous media. 

The second aspect of biocompatibility is a leaching problem. Ion-selective electrode materials, especially components of solvent polymeric membranes, are subject to leaching upon prolonged contact with physiological media. Membrane components such as plasticizers, ion exchangers and ionophores may activate the clotting cascade or stimulate an immune response. Moreover, they can be potentially toxic when released to the blood stream in significant concentrations. 

As carriers for proteins and enzymes biocompatible reactive microgels must be synthesized which are soluble in the serum at 37 °C. Moreover they should be hydrophilic enough that no ionic monomers are needed but they should not be soluble in water. An inert comonomer should serve as a spacer as well as a reactive solvent that may dissolve solid comonomers. The coupling reaction should be possible under mild reaction conditions. 

The investigation of macromolecules has just begun to unfold its potential in our lives. Polymer modification is a major frontier introducing needed subtle or gross changes that allow biocompatability, enhanced thermal stability, increased solvent stability, etc. to the modified polymer. 

Concerning utilisation of CNTs for the delivery of nucleic acids, CNTs have already been shown to be versatile platforms for nucleic acid delivery in vitro and in vivo because of their high surface area, facile functionalisation of their surface and their ability to cross the cell membranes. To our knowledge, it is crucial to functionalise the surface of CNTs, in order to transform nonfunctionalised CNTs (insoluble in most solvents) into water-soluble and biocompatible CNTs. On the other hand, with a growing number of functionalisation routes, many important questions remain unanswered. Each functionalisation method is probably producing... 

Braun T, Mark L, Ohmacht R, Sharma U (2007) Olive oil as biocompatible solvent for pristine C60. Fullerenes Nanotechnol. Carbon Nanostruct. 15 311-314. 

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