Correlating Cellular Response To Nanoscale Morphology And Mechanical Properties Utilizing Atomic Force Microscopy And Optical Microscopy.

 

Tighe A. Spurlin1, Koo-Hyun Chung2, Kiran Bhadriraju3, Anne L. Plant1.
1Biochemical Science Division

2 Manufacturing Metrology Division

3SAIC, Arlington, VA, USA.

 

Cell behavior is known to be affected by the mechanical properties of the extracellular matrix. Cellular response to mechanical stimuli has been achieved previously using the tailored bulk properties of a variety of biological and non-biological materials, but less has been reported about response to nanoscale mechanical features. We have used Atomic Force Microscopy (AFM) and optical microscopy to correlate cell response to the nanoscale mechanical properties of Type 1 collagen fibrils. Dehydrating films of collagen fibrils causes fibrils to become stiffer, and results in greater spreading and proliferation of vascular smooth muscle cells. Here we provide additional insight into how matrix properties on the nanometer scale influence cell behavior using quantitative AFM techniques. Collagen films that have been subjected to dehydration display reduced surface roughness, suggesting a decrease in fibril-fibril interspacing, likely due to the removal of water. In addition, force-distance curves obtained at varying loading rates before and after dehydration show that the viscoelastic behavior of the collagen fibril network is significantly diminished after dehydration. We observe that in addition to a higher rate of proliferation and greater spreading, the quantified changes in the nanoscale properties due to dehydration of the thin collagen fibril films lead, to a more highly organized actin cytoskeleton in cells and greater focal adhesion maturation. We suggest that these effects result as a direct response to the mechanical characteristics of the fibrils. Comparisons of dehydrated collagen with enzymatically cross-linked collagen suggest similar effects.

 

 

Additional Information:

 

Presenter:     Tighe A. Spurlin

Mentor:        Anne L. Plant

Division:      Biochemical Science Division (831)

Office:         Advanced Chemical Science Laboratory (227), Room A263

Mail Stop:    8313

Phone:          (301) 975-5088
Fax:               (301)-975-4845
E-mail:           tighe.spurlin@nist.gov
 
Tighe A. Spurlin is a member of Sigma Xi.