Light-Activated Hydrogel Formation via the Triggered Folding and Self-Assembly of a Designed Peptide
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- 作者：Lisa A. Haines ; Karthikan Rajagopal ; Bulent Ozbas ; Daphne A. Salick ; Darrin J. Pochan ; and Joel P. Schneider
- 刊名：Journal of the American Chemical Society
- 出版年：2005
- 出版时间：December 7, 2005
- 年：2005
- 卷：127
- 期：48
- 页码：17025 - 17029
- 全文大小：249K
- 年卷期：v.127,no.48(December 7, 2005)
- ISSN：1520-5126
文摘
Photopolymerization can be used to construct materials with precise temporal and spatialresolution. Applications such as tissue engineering, drug delivery, the fabrication of microfluidic devicesand the preparation of high-density cell arrays employ hydrogel materials that are often prepared by thistechnique. Current photopolymerization strategies used to prepare hydrogels employ photoinitiators, manyof which are cytotoxic and require large macromolecular precursors that need to be functionalized withmoieties capable of undergoing radical cross-linking reactions. We have developed a simple light-activatedhydrogelation system that employs a designed peptide whose ability to self-assemble into hydrogel materialis dependent on its intramolecular folded conformational state. An iterative design strategy affordedMAX7CNB, a photocaged peptide that, when dissolved in aqueous medium, remains unfolded and unableto self-assemble; a 2 wt % solution of freely soluble unfolded peptide is stable to ambient light and has theviscosity of water. Irradiation of the solution (260 < 
rs/lambda.gif" BORDER=0 > < 360 nm) releases the photocage and triggerspeptide folding to produce amphiphilic rs/beta2.gif" BORDER=0 ALIGN="middle">-hairpins that self-assemble into viscoelastic hydrogel material.Circular dichroic (CD) spectroscopy supports this folding and self-assembly mechanism, and oscillatoryrheology shows that the resulting hydrogel is mechanically rigid (G' = 1000 Pa). Laser scanning confocalmicroscopy imaging of NIH 3T3 fibroblasts seeded onto the gel indicates that the gel surface is noncytotoxic,conducive to cell adhesion, and allows cell migration. Lastly, thymidine incorporation assays show thatcells seeded onto decaged hydrogel proliferate at a rate equivalent to cells seeded onto a tissue culture-treated polystyrene control surface.
rs/lambda.gif" BORDER=0 > < 360 nm) releases the photocage and triggerspeptide folding to produce amphiphilic rs/beta2.gif" BORDER=0 ALIGN="middle">-hairpins that self-assemble into viscoelastic hydrogel material.Circular dichroic (CD) spectroscopy supports this folding and self-assembly mechanism, and oscillatoryrheology shows that the resulting hydrogel is mechanically rigid (G' = 1000 Pa). Laser scanning confocalmicroscopy imaging of NIH 3T3 fibroblasts seeded onto the gel indicates that the gel surface is noncytotoxic,conducive to cell adhesion, and allows cell migration. Lastly, thymidine incorporation assays show thatcells seeded onto decaged hydrogel proliferate at a rate equivalent to cells seeded onto a tissue culture-treated polystyrene control surface.