title: Thermal denaturation behavior of collagen fibrils in wet and dry environment.
abstract: We have developed a new minimally invasive technique--integrated low-level energy adhesion technique (ILEAT)--which uses heat, pressure, and low-frequency vibrations for binding living tissues. Because the adhesion mechanism of the living tissues is not fully understood, we investigated the effect of thermal energy on the collagen structure in living tissues using ILEAT. To study the effect of thermal energy and heating time on the structure of the collagen fibril, samples were divided in two categories-wet and dry. Further, atomic force microscopy was used to analyze the collagen fibril structure before and after heating. Results showed that collagen fibrils in water denatured after 1 minute at temperatures higher than 80 °C, while partial denaturation was observed at temperatures of 80 °C and a heating time of 1 min. Furthermore, complete denaturation was achieved after 90 min, suggesting that the denaturation rate is temperature and time dependent. Moreover, the collagen fibrils in dry condition maintained their native structure even after being heated to 120 °C for 90 min in the absence of water, which specifically suppressed denaturation. However, partial denaturation of collagen fibrils could not be prevented, because this determines the adhesion between the collagen molecules, and stabilizes tissue bonding.
authors.affiliation: Department of Mechanical Engineering, College of Engineering, Ibaraki University, 1-12-1 Nakanarusawa, Hitachi, Ibaraki, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Suwa
authors.affiliation: Department of Material-based Medical Engineering, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-0062, Japan.
authors.forename: Kwangwoo
authors.initials: K
authors.lastname: Nam
authors.affiliation: Department of Mechanical Engineering, College of Engineering, Ibaraki University, 1-12-1 Nakanarusawa, Hitachi, Ibaraki, Japan.
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Ozeki
authors.affiliation: Department of Material-based Medical Engineering, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-0062, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kimura
authors.affiliation: Department of Material-based Medical Engineering, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-0062, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Kishida
authors.affiliation: Department of Mechanical Engineering, College of Engineering, Ibaraki University, 1-12-1 Nakanarusawa, Hitachi, Ibaraki, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Masuzawa
mesh_terms: D000818:Animals; D002417:Cattle; D003094:Collagen / Q000737:chemistry*; D006358:Hot Temperature; D006813:Humidity; D011489:Protein Denaturation
chemical_list: D003094:Collagen
keywords: atomic force microscopy; collagen fibril; fibrillogenesis; thermal denaturation; tissue adhesion