Premium
Genipin‐induced changes in collagen gels: Correlation of mechanical properties to fluorescence
Author(s) -
Sundararaghavan Harini G.,
Monteiro Gary A.,
Lapin Norman A.,
Chabal Yves J.,
Miksan Jennifer R.,
Shreiber David I.
Publication year - 2008
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.31715
Subject(s) - genipin , materials science , fluorescence , dynamic mechanical analysis , elastic modulus , fourier transform infrared spectroscopy , tissue engineering , biophysics , fluorescence microscope , biomedical engineering , composite material , chemical engineering , polymer , chemistry , biochemistry , optics , chitosan , medicine , physics , biology , engineering
Controlled crosslinking of collagen gels has important applications in cell and tissue mechanics as well as tissue engineering. Genipin is a natural plant extract that has been shown to crosslink biological tissues and to produce color and fluorescence changes upon crosslinking. We have characterized the effects of genipin concentration and incubation duration on the mechanical and fluorigenic properties of type I collagen gels. Gels were exposed to genipin (0, 1, 5, or 10 m M ) for a defined duration (2, 4, 6, or 12 h). Mechanical properties were characterized using parallel plate rheometry, while fluorigenic properties were examined with a spectrofluorimetric plate reader and with a standard, inverted epifluorescent microscope. Additionally, Fourier transform infrared spectroscopy was used to characterize and track the crosslinking reaction in real‐time. Genipin produced significant concentration‐ and incubation‐dependent increases in the storage modulus, loss modulus, and fluorescence intensity. Storage modulus was strongly correlated to fluorescence exponentially. Minimal cytotoxicity was observed for exposure of L929 fibroblasts cultured within collagen gels to 1 m M genipin for 24 h, but significant cell death occurred for 5 and 10 m M genipin. We conclude that genipin can be used to stiffen collagen gels in a relatively short time frame, that low concentrations of genipin can be used to crosslink cell‐populated collagen gels to affect cell behavior that is influenced by the mechanical properties of the tissue scaffold, and that the degree of crosslinking can be reliably assayed optically via simple fluorescence measurements. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008