Chapter 1
Polymer Biocatalysis and Biomaterials: Current Trends and Developments 1
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Downloaded by UNIV OF UTAH on November 30, 2014 | http://pubs.acs.org Publication Date: September 19, 2008 | doi: 10.1021/bk-2008-0999.ch001
H. N. Cheng and Richard A. Gross 1
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Hercules Incorporated Research Center, 500 Hercules Road, Wilmington, DE 19808-1599 NSF, Center for Biocatalysis and Bioprocessing of Macromolecules, Polytechnic University, Six Metrotech Center, Brooklyn, NY 11201
This paper reviews current trends and developments in polymer biocatalysis and biomaterials. Developments in biocatalysis and biomaterials are largely fueled by demands for sustainable chemical technologies, a desire to decrease our dependence on foreign petroleum, and real commercial oppor tunities to develop 'green' products. Commercial activities continue to increase as is evident from a review of the patent literature. The following topics are covered in this review: 1) novel biomaterials, 2) new and improved biocatalysis, 3) new biocatalytic methodologies, 4) polyesters and polyurethanes, 5) polyamides and polypeptides, 6) polysaccharides, 7) silicon-containing materials, 8) biocatalytic redox poly merizations forming C-C bonds, 9) enzymatic hydrolysis and degradation of natural polymers, 10) biocatalytic routes to monomers. Examples featured are mostly taken from contri butions to the Symposium on Biocatalysis in Polymer Science held during the A C S National Meeting in San Francisco in September 2006.
© 2008 American Chemical Society In Polymer Biocatalysis and Biomaterials II; Cheng, H., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.
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Downloaded by UNIV OF UTAH on November 30, 2014 | http://pubs.acs.org Publication Date: September 19, 2008 | doi: 10.1021/bk-2008-0999.ch001
2 Biocatalysis involves the use of enzymes, microbes, and higher organisms to carry out chemical reactions. Because the reaction conditions are often mild, water-compatible, and environmentally friendly, they offer excellent examples of "green chemistry". In view of the wealth of enzymes and whole-cell approaches available and the quality of researchers, this field continues to be very dynamic and productive. Biocatalysis in polymeric materials has been reviewed periodically (1-2). It is clear from the reviews that there is no shortage of activity and creativity in this field. Biomaterials constitute an equally exciting field of research that finds numerous applications in medical and industrial areas (3,4). In fact, much commonality is found in biomaterial and biocatalytic research. For example, many researchers in biomaterials work with enzymes, and, often, investigators in biocatalysis are producing natural polymers or polymers that are closely related but are are modified by chemical or enzymatic methods to improve their physical properties. This paper does not attempt to provide a comprehensive review of research in biocatalysis or biomaterials. Instead, it highlights major themes and developments in these fields, using selected literature and emphasizing research presented during the A C S National Meeting in San Francisco in September 2006 as published in ACS Polymer Preprints (31-57), and papers published in expanded form in this book (5-30). This paper has been divided into the following ten sections: 1) novel biomaterials, 2) new and improved biocatalysts, 3) new biocatalytic methodologies, 4) polyesters and polyurethanes, 5) polyamides and polypeptides, 6) polysaccharides, 7) silicon-containing materials, 8) biocatalytic redox polymerizations forming C-C bonds, 9) enzymatic hydrolysis and degradation of natural polymers, and 10) biocatalytic routes to monomers.
1. Novel Biomaterials As noted earlier, biomaterials (and other bio-related materials) comprise one of most active research areas today. Major research themes in biomaterials include tissue engineering (58), molecular imprinting strategies (59), biosensors (60), stimuli responsive materials (61), biodegradable polymers (62), and smart biomaterials (63). In this book, a large number of biomaterials are reported. These include polypeptides/proteins, carbohydrates, lipids/triglycerides and synthetic polymers. In addition, it is understood that many of the polymeric materials involved in all the chapters can potentially be used as biomaterials although they may not be specified as such.
In Polymer Biocatalysis and Biomaterials II; Cheng, H., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.
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Downloaded by UNIV OF UTAH on November 30, 2014 | http://pubs.acs.org Publication Date: September 19, 2008 | doi: 10.1021/bk-2008-0999.ch001
Polypeptîdes/proteins. A major research trend is to tailor the structure of proteins and polypeptides so they can function for a wide range of advanced material applications. In their paper, Kiick et al (5) described their work in using biosynthetic routes to produce polypeptides with non-natural amino acids that have desired conformation and side-chain placement. Montclare et al (6) described novel research on elastins where the aim is to generate new biomaterials that have the desired biological activity, optimal function in delivery of therapeutics, and more applications. Ito et al (16) used combinatorial bioengineering methods to produce new biomaterials based on amino acids, nucleic acid, and non-natural components. In a different way, Silvestri et al (7) produced biomaterials by combining enzymes with synthetic polymers; some examples were combinations of
