Imaging systems vesicular

Complexes of oxalic, citric or tartaric acids with FeI I can be used as the light-sensitive and gas-bubble-producing components in vesicular imaging systems. In the vesicular process, an image... 

It should be noted that, whilst TEM and AFM may not be suited to the imaging of vesicular structures in drug-delivery systems, SEM may offer an excellent solution to the problem. In fact, environmental scanning electron microscopy (ESEM) provides an elegant approach to imaging the structures of biomedical materials at high resolution, and occasionally also under the physiological conditions encountered in body tissues [10]. 

A different vesicular photoimaging material consists of an assembly of lipid vesicles sensitized with rhodopsin. In one system the vesicles can be filled with a solution containing Co2+, and the solution outside the vesicles can be free of metal ions but contain a chelating indicator dye such as xylenol orange (101). The whole assembly can be coated, and when exposed to actinic radiation the vesicles are disrupted in exposed areas and release Co2+ ions, which are complexed by the dye indicator, thereby forming an image.253... 

In another system, catalase or peroxidase enzymes can be used to produce an image in minute 02 bubbles (vesicular image) or an image in dye produced by the catalyzed reaction of a peroxy compound and a leuco dye, or a color developer in the presence of a dye-forming coupler. The enzymes are inactivated in areas exposed to light. In one system the metalloenzymes are poisoned by CN photodissociated by exposure of cyanotriphenylmethane compounds255 such as (123). 

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