Complex gradient systems, stable

CONJECTURES CONCERNING THE STABLE EQUILIBRIUM CONFIGURATIONS OF COMPLEX GRADIENT SYSTEMS... 

Encapsulation of enzymes in LMs offers further improvements for immobilization of complex enzyme systems, as the enzymes / cofactors, etc. are situated in aqueous droplets surrounded by a stable liquid hydrocarbon film (Figure 1). Instead of the physical pores present in microcapsules, the HC barrier, which has a diffusion thickness of about 0.1-1.0 p, effectively blocks all molecules except those which are oil-soluble or transportable by the selected carriers. Encapsulation of enzymes in LMs is accomplished simply by emulsifying aqueous enzyme solutions. Hence, LMs offer many advantages over other systems used for separation and eirzyme immobilization they are inexpensive and easy to prepare they promote rapid mass transport they are selective for various chemical species they can be disrupted (demulsified) for recovery of internal aqueous solutions gradients of pH and concentration (even of small molecules) can be maintained across the HC barrier multiple enzyme / cofactor systems can be coencapsulated and enzymatic reaction and separation can be combined. Some of the potential disadvantages of LMs for enzyme encapsulation have been discussed earlier. 

Because of the use of various electrolyte systems, pH gradients, and not least an electric field, some complexes would not survive the separation. It is therefore necessary that the species to be separated are both thermodynamically and kineti-cally stable. Recently, Bocek and Foret have reviewed the application of isotachophoresis to the separation of inorganic species. This technique appears to be well-suited for the study of the distribution of metabolites of metal-containing drugs in body fluids. A survey of the application of electrophoretic techniques to biological materials can be found in the book edited by Deyl... 

Biological systems seem to contradict the notion that disorder is the most natural state of things. Biological systems, after all, are stable and sustaining. They concentrate material species against density gradients, they separate random external environments from ordered and complex interiors, and they act in complex, but mostly predictable, manners. And these patterns have been sustained for eons. 

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