|
Bioadhesives are natural polymeric materials that act as adhesives. The term is sometimes used more loosely to describe a glue formed synthetically from biological monomers such as sugars, or to mean a synthetic material designed to adhere to biological tissue. Bioadhesives may consist of a variety of substances, but proteins and carbohydrates feature prominently. Proteins such as gelatin and carbohydrates such as starch have been used as general-purpose glues by man for many years, but typically their performance shortcomings have seen them replaced by synthetic alternatives. Highly effective adhesives found in the natural world are currently under investigation but not yet in widespread commercial use. For example, bioadhesives secreted by microbes and by marine molluscs and crustaceans are being researched with a view to biomimicry.〔Smith, A.M. & Callow, J.A., eds. (2006) ''Biological Adhesives.'' Springer, Berlin. ISBN 978-3-540-31048-8〕 Bioadhesives are of commercial interest because they tend to be biocompatible, i.e. useful for biomedical applications involving skin or other body tissue. Some work in wet environments and under water, while others can stick to low surface energy – non-polar surfaces like plastic. In recent years, the synthetic adhesives industry has been impacted by environmental concerns and health and safety issues relating to hazardous ingredients, volatile organic compound emissions, and difficulties in recycling or re mediating adhesives derived from petrochemical feedstocks. Rising oil prices may also stimulate commercial interest in biological alternatives to synthetic adhesives. == Examples of bioadhesives in nature == Organisms may secrete bioadhesives for use in attachment, construction and obstruction, as well as in predation and defense. Examples〔Graham, L.D. (2008) Biological adhesives from nature. In: ''Encyclopedia of Biomaterials and Biomedical Engineering'', 2nd ed., Eds. Wnek, G. & Bowlin, G., Informa Healthcare, New York & London, vol. 1, p.236-253. (Online abstract )〕 include their use for * colonization of surfaces (e.g. bacteria, algae, fungi, mussels, barnacles) * mussels increase amount of byssal threads enabling mussels to more firmly attach to substrates induced by waterborne cues such as predator proximity and broken conspecifics * tube building by polychaete worms, which live in underwater mounds * insect egg, larval or pupal attachment〔Li, D., Huson, M.G. & Graham, L.D. (2008) Proteinaceous adhesive secretions from insects, and in particular the egg attachment glue of ''Opodiphthera'' sp. moths. ''Arch. Insect Biochem. Physiol.'' 69, 85-105. DOI: 10.1002/arch.20267〕 to surfaces (vegetation, rocks), and insect mating plugs * host attachment by blood-feeding ticks * nest-building by some insects, and also by some fish (e.g. the three-spined stickleback) * defense by ''Notaden'' frogs and by sea cucumbers * prey capture in spider webs and by velvet worms Some bioadhesives are very strong. For example, adult barnacles achieve pull-off forces as high as 2 MPa (2 N/mm2). Silk dope can also be used as a glue by arachnids and insects. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「bioadhesive」の詳細全文を読む スポンサード リンク
|