Onyi Irrechukwu1, Ping-Chang Lin1, David Reiter1, Ligaya Roque1, Steve Doty2, Richard Spencer1, Kenneth Fisbein1, Nancy Pleshko3
1National Institute on Aging, National Institutes of Health, Baltimore, MD, USA; 2Department of Orthopaedics, Hospital for Special Surgery, New York, NY, USA; 3Exponent Inc., Philadelphia, PA, USA
The objective of this study was to use MRI as a tool to probe the effect of ultrasound stimulation of engineered cartilage. Chondrocyte-seeded collagen constructs were stimulated with ultrasound for 3 weeks while in culture. Longitudinal (T1) and transverse (T2) relaxation times and magnetization transfer rate (km) were obtained from the analysis of decay curves. T2 decreased while km increased in treated samples indicating an increase in the macromolecular content of constructs with ultrasound stimulation. These results were consistent with the greater sulphated glycosaminoglycan content measured biochemically and the more intense Alcian-blue staining visualized in treated samples.
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