Mechanically Tunable Thin Films of Photosensitive Artificial Proteins: Preparation and Characterization by Nanoindentation
Abstract
Thin films of controlled elastic modulus were made by photo-cross-linking artificial extracellular matrix (aECM) proteins containing the photosensitive amino acid p-azidophenylalanine (pN_3Phe). The elastic moduli of the films were calculated from nanoindentation data collected by atomic force microscopy (AFM) using a thin-film Hertz model. The modulus was shown to be tunable in the range 0.3−1.0 MPa either by controlling the irradiation time or by varying the level of pN_3Phe in the protein. Tensile measurements on bulk films of the same proteins and finite-element simulation of the indentation process agreed with the thin-film modulus measurements from AFM. Substrates characterized by spatial variation in elastic modulus were created by local control of the irradiation time.
Additional Information
© 2008 American Chemical Society. Received July 31, 2007. Revised Manuscript Received December 12, 2007. Published on Web 02/15/2008. Published In Issue March 11, 2008. We gratefully acknowledge support of this research by the Center for the Science and Engineering of Materials at Caltech (NSF DMR-0520565) and by NIH grant EB1971. S.A.M. is supported by a pre-doctoral fellowship from the NIH. We thank Marissa Mock for NMR characterization and Doron Shilo for help with AFM measurements.Additional details
- Eprint ID
- 53575
- DOI
- 10.1021/ma071717a
- Resolver ID
- CaltechAUTHORS:20150112-113738681
- NSF
- DMR-0520565
- NIH
- EB1971
- NIH Predoctoral Fellowship
- GM007616
- Created
-
2015-01-12Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- GALCIT