Biotechnological Applications Of Lipid Microstructures

In the twenty years since Bangham first described the model membrane system which he named "liposomes", a generation of scientists have explored the properties of lipid-based microstructures. Liposomes of all sizes, tubular and helical structures, and self-assembled lipid films have been prepared and studied in detail. Many of the advances· in the basic research have led to significant technological applications. Lipid microstructure research has begun to mature and it is an appropriate time for an in-depth look at the biotechnological applications, both achieved and potential. As a forum for active discussions within this growipg field, two Workshops were organized: "Technological Applications of Phospholipid Bilayers, Vesicles and Thin Films", held in Puerto de la Cruz, Tenerife, Canary Islands; and "Biotechnological Applications of Membrane Studies", held in Donostia-San Sabastian, Basque Country, Spain. The organizers of these Workshops believe that development of lipid self-assembly into a technological discipline requires significant interaction across traditional scientific boundaries. Thus the Workshops gathered an eclectic group of colleagues whose interests ranged from basic research into structure, interactions and stabilization of biomembranes to applications of lipid microstructures such as artificial cells, diagnostic reagents, energy transfer systems, and biosensors.

The Third International Conference on Synthetic Microstructures in Biological Research (SMIBR) was held in Williamsburg, Virginia, September 9-12, 1991. This book represents the compilation of many of the papers and posters presented at the meeting. Publications resulting from previous SMIBR meetings held at Airlie House, Airlie, Virginia (March 24-26, 1986 and March 20-23, 1988) can be obtained from the Institute of Electrical and Electronic Engineers, Inc. (IEEE) Service Center (908 562-5418). The purpose of these conferences is to provide an interface between the engineering community and those at the cutting edge of biological and related material science. The overriding motive for assembling representatives from these diverse disciplines is clear. Engineers, even in 1986, could manipulate materials over dimensional scales on the order of those critical to biological systems. The devices that emerge from these manipulations could then be tailored to monitor system function more directly with significantly more localization than ever before. Thus, one important goal of the meetings is to provide the detailed specifications required for effective interfacing of devices with biological systems under investiga tion.

Some have predicted that the coming several decades will be the decades of "biotechnology," wherein cancer, birth defects, life span increases, cosmetics, biodegradation, oil spills and exploration, solid waste disposal, and almost every aspect of our material life will be affected by this new area of science. There will also be an extension of emphasis on giant molecules: DNA, enzymes, polysaccharides, lignins, proteins, hemoglobin, and many others. Biotechnology has been defined in various ways. In one sense, this field is older than human history and references to the human use of biotechnology-derived materials can be found in the oldest human writings, such as the Bible. In this book, biotechnology refers to the direct usage of naturally occurring materials or their uses as a feedstock, including the associated biological activities and applications of these materials. Bioactive polymers, on the other hand, are polymers which exert some type of activity on living organisms. These polymers are used in agriculture, controlled release systems, medicine and many other areas. The papers in this book describe polymers which essentially combine features of biotechnology and bioactivity.

This text presents the latest advances in supercritical fluid technology, biocatalysis, bioprocess engineering, and crop breeding. It offers an in-depth review of the most recent principles and approaches utilized in the development and design of lipids for cosmetic, industrial and pharmaceutical, and food products. Discussing a variety of lipid-active enzymes from animal, plant, fungal, and microbial sources, "Lipid Biotechnology" covers modern techniques in genetic engineering for the modification of conventional oilseed crops and biosynthetic pathways for cutin polymers, flavor volatiles, oxylipins, and terpenoid compounds. It chronicles the use of lipases and phospholipases in the creation of structured lipids and fats, including cocoa butter, low-calorie fats, and Betapol, and emerging methods using supercritical carbon dioxide as a benign solvent for lipid analysis, fractionation, and enzymatic reaction. It also covers reaction conditions, reactor design, solvent selection, immobilization technology, and enzyme sources for optiml large-scale manufacturing, and describes the formation of oxylipins through the lipoxygenase pathway, as well as other unusual fatty acids. The authors provide in-depth analyses of the structure, metabolic and enzymatic functions and mechanisms, defensive and catalytic properties, industrial uses, and other applications of oxilipins and lipases.

Employing a multidisciplinary approach to phospholipid research, this work catalogues the current knowledge of this class of molecules and details the general, chemical, physical and structural properties of phospholipid monolayers and bilayers. Phospholipid applications are also covered.