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Precision And Accuracy Of Thermal Calibration Of Atomic Force Microscopy Cantilevers, Nancy Burnham, G Matei, E Thoreson, J Pratt, D Newell

Nancy A. Burnham

To have confidence in force measurements made with atomic force microscopes(AFMs), the spring constant of the AFM cantilevers should be known with good precision and accuracy, a topic not yet thoroughly treated in the literature. In this study, we compared the stiffnesses of uncoated tipless uniform rectangular silicon cantilevers among thermal, loading, and geometric calibration methods; loading was done against an artifact from the National Institute of Standards and Technology (NIST). The artifact was calibrated at NIST using forces that were traceable to the International System of units. The precision and accuracy of the thermal method were found to be …

Substrate Rigidity Regulates The Formation And Maintenance Of Tissues, Nancy Burnham, Wei-Hui Guo, Margo Frey, Yu-Li Wang

Nancy A. Burnham

The ability of cells to form tissues represents one of the most fundamental issues in biology. However, it is unclear what triggers cells to adhere to one another in tissues and to migrate once a piece of tissue is planted on culture surfaces. Using substrates of identical chemical composition but different flexibility, we show that this process is controlled by substrate rigidity: on stiff substrates, cells migrate away from one another and spread on surfaces, whereas on soft substrates they merge to form tissue-like structures. Similar behavior was observed not only with fibroblastic and epithelial cell lines but also explants …

Application Of Inkjet Printing To Tissue Engineering, Thomas Boland, Tao Xu, Brook Damon, Xiaofeng Cui

Thomas Boland

ecent advances in organ printing technology for applications relating to medical interventions and organ replacement are described. Organ printing refers to the placement of various cell types into a soft scaffold fabricated according to a computer-aided design template using a single device. Computer aided scaffold topology design has recently gained attention as a viable option to achieve function and mass transport requirements within tissue engineering scaffolds. An exciting advance pioneered in our laboratory is that of simultaneous printing of cells and biomaterials, which allows precise placement of cells and proteins within 3-D hydrogel structures. This advance raises the possibility of …

The Use Of Extracellular Matrix As An Inductive Scaffold For The Partial Replacement Of Functional Myocardium., Glenn Gaudette, S Badylak, P Kochupura, I Cohen, S Doronin, A Saltman, T Gilbert, D Kelly, R Ignotz

Glenn R. Gaudette

Regenerative medicine approaches for the treatment of damaged or missing myocardial tissue include cell-based therapies, scaffold-based therapies, and/or the use of specific growth factors and cytokines. The present study evaluated the ability of extracellular matrix (ECM) derived from porcine urinary bladder to serve as an inductive scaffold for myocardial repair. ECM scaffolds have been shown to support constructive remodeling of other tissue types including the lower urinary tract, the dermis, the esophagus, and dura mater by mechanisms that include the recruitment of bone marrow-derived progenitor cells, angiogenesis, and the generation of bioactive molecules that result from degradation of the ECM. …

Viability And Electrophysiology Of Neural Cell Structures Generated By The Inkjet Printing Method, Tao Xu, Cassie Gregory, Peter Molnar, S Jalota, Sarit Bhaduri, Thomas Boland

Thomas Boland

Complex cellular patterns and structures were created by automated and direct inkjet printing of primary embryonic hippocampal and cortical neurons. Immunostaining analysis and whole-cell patch-clamp recordings showed that embryonic hippocampal and cortical neurons maintained basic cellular properties and functions, including normal, healthy neuronal phenotypes and electrophysiological characteristics, after being printed through thermal inkjet nozzles. In addition, in this study a new method was developed to create 3D cellular structures: sheets of neural cells were layered on each other (layer-by-layer process) by alternate inkjet printing of NT2 cells and fibrin gels. These results and findings, taken together, show that inkjet printing …

Prospective Energy Densities In The Forisome, A New Smart Material, William Pickard, Michael Knoblauch, Winfried Peters, Amy Shen

Winfried S. Peters