| Autor: |
Rafat A. Siddiqui, Kevin Harvey, Philipp Rauch, Joseph Kás, Guilherme Sprowl, Simon J. Atkinson, Johannes Stelzer, Amanda P. Siegel, Christoph A. Naumann, Daniel E. Minner |
| Rok vydání: |
2009 |
| Předmět: |
|
| Zdroj: |
Biophysical Journal. 96(3) |
| ISSN: |
0006-3495 |
| DOI: |
10.1016/j.bpj.2008.12.2684 |
| Popis: |
An important aspect of mechanobiology is that tissue cells are anchorage-dependent and respond to viscoelastic changes in their environments. The mechanosensitivity of cells is believed to play an important role in processes such as cancer cell migration and stem cell differentiation. Previously, cellular mechano-response has been mainly studied using μm-thick polymeric films of adjustable viscoelasticity. Here we report on the design and characterization of alternative cell substrates based on 8-40nm thick polymer-tethered phospholipid membranes where cellular mechano-response can be regulated by tuning bilayer fluidity. Two complementary membrane systems are employed to span a wide range from low to high bilayer fluidity. Low to medium bilayer fluidity is achieved by using a single polymer-tethered lipid bilayer of adjustable tethering concentration. Medium to high bilayer fluidity is obtained through the regulation of the number of bilayers in a stack of polymer-tethered lipid bilayers. Changes in bilayer fluidity in these substrates have been confirmed through wide-field single molecule tracking of fluorescently labeled lipids. To facilitate the adsorption and migration of cells, these biomembrane-mimicking substrates contain bilayer-cell linkages of well-defined concentrations. Phase contrast microscopy experiments on PC12 neurons show that dendritic growth can be tuned by modifying the tethering concentration in a single polymer-tethered lipid bilayer. Comparing phase contrast and epifluorescence microscopy experiments on 3T3 fibroblasts containing GFP-actin, which were plated on multi-bilayer stacks, revealed profound changes in cellular phenotype, projected cell area, cell migration, and cytoskeletal organization with the number of bilayers in the stack. For example, on very fluid substrates, neuron-like, dendritic fibroblasts were observed. The described substrates are particularly significant because, unlike in the case of polymeric films, substrate-cell linkages are free to move and matrix remodulation caused by adsorbed cells is largely suppressed. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
