In Patterning of Bone Regeneration via Ultrasound Activation of Heat Shock-responsive Gene Switches, investigators Mario Fabiilli, PhD, and Renny Franceschi, PhD, developed stable cell lines containing heat-activated and ligand-dependent gene switches, incorporated them into a hydroxyapatite/fibrin composite scaffold, and used focused ultrasound to spatiotemporally control transgene expression of several growth factors in these cells at various time points.
After conducting experiments to determine the optimal physical parameters, the research team was able to observe significant, pattern-specific transgene activation in the composite scaffolds following exposure to two minutes of continuous focused ultrasound at 200 watts per square centimeter.
Although conventional tissue engineering approaches rely on scaffold-based delivery of exogenous proteins, genes, or cells to stimulate regeneration via growth factor signaling, these approaches currently do not allow active control of crucial factors such as the dose, timing, or spatial localization of the delivered growth factor.
This novel approach provides the needed control that could translate in new therapies for patients with bone loss due to trauma, neoplasia, or congenital defects.
The study was recently published in the journal Biomaterials, and the research team used the data from this study to successfully obtain an NIH grant to continue the work (National Institutes of Health R21 AR072336).