April 14th, 2015

Sunita Ho is an interdisciplinary scientist, an Associate Professor in the Division of Biomaterials and Bioengineering, Department of Preventive & Restorative Dental Sciences, part of the University of California San Francisco's School of Dentistry. Dr Ho's research team in the Laboratory of Biomechanics and Biomineralization uses a Deben CT500 tensile stage to visualize organs under loaded conditions. Imaging for visualisation is typically done using a high resolution x-ray microscope, the Micro XCT-200, (ZEISS Xradia, Pleasanton, CA). 
Scans obtained at no load and loaded conditions are used to evaluate mechanical strains in volumes of tissues. Responses of bone and other related mineralized tissues at the entheses of bone-ligament, cementum-ligament, and dentin and enamel in various vertebrates at different loading rates are routinely investigated. Additionally, studies entail investigating changes in biomechanics as a result of adaptation due to a prolonged chewing of harder and softer food substrates and clinical interventions such as pharmacological therapies. The biomechanical data (deformations and strains in volumes of tissues) obtained from Deben system is routinely correlated with conventional histology and immunohistochemistry. 
Describing her motivation for this research, Dr Ho says "Our motivation is to perform multiscale biomechanical analyses on organs and then tissues within intact organs to visualize volumes of strains in intact tissues. This enables us to gain a holistic perspective on their role toward organ adaptation. That is to address the tenet of 'form and function.' The use of the Deben stage coupled to our x-ray microscope is optimum. Additionally, to be able to perform in situ biomechanical studies under wet conditions provides a much needed realistic perspective by allowing measurements closer to physiological conditions." 
Dr Ho selected the Deben tensile stage to fit specifically into the ZEISS Xradia microscope. This is because it provides in situ imaging under loaded conditions. The ability to couple the loading device with a microscope is a key requirement for in situ biomechanical testing and volumetric strain mapping. Having been one of the pioneers to perform in situ tensile testing, the group has been able to publish several keynote papers and have been presenting concepts related to "biomechanics and mechanobiology" at several meetings including the Materials Research Society (MRS), and International Association for Dental Research (IADR), many of which are available on the web.