Project Summary
Osteopenic fragility fractures are a devastating result of poor bone quality secondary to high mortality and long-
term patient disability. Currently there is limited understanding on the mechanistic level reflected in the relatively
few available treatment and diagnostic options. Dual-energy x-ray absorptiometry (DEXA) is utilized in
combination with established patient standards for diagnosis and management of osteoporosis, however its use
is limited in patients. There is a clear need to improve technologies that enable bone quality measurements,
especially to avoid refracture.
In the proposed work we will develop technology that enables chronic insight into bone health for rodent animal
models to enable real-time high-fidelity readout enabling advanced insight for the study of mechanisms and to
evaluate the efficacy of new treatments. Specifically, we will build on our recently introduced device class,
osseosurface electronics, which are battery free and fully implantable bone strain monitors.
In aim 1 we will evaluate permanent interfacing and sensing capabilities of the platform that is grown to the bone
via calcium phosphate ceramic particles on month long timescales. Data captured from daily exercise on a
treadmill will enable insight in sensing fidelity and will be compared against gait parameters automatically
captured by deep neural net image analysis. In aim 2 we will develop a new sensing modality, thermal
conductivity measurements, that will be validated by the attachment of the biointerface to the bone, a mechanism
we already characterized with strain sensors. This platform will then be used to compare the sensitivity of serial
DEXA, µCT, in vivo strain and thermal conductivity measurement in detecting bone changes following
administration of an anabolic medication used to treat osteoporosis in aim 3. Ovariectomy animal models with
and without treatment will be evaluated by osseosurface electronics against DEXA and µCT.
Successful expansion of our osseosurface electronic platform will enable new real time and high-fidelity
measurement of bone health in freely moving small animal models. This capability is instrumental to explore
mechanisms of chronic and acute changes attributed to fracture or disease in models that have the full genetic
toolset and enable rapid test of hypothesis with little cost. The experiments will also inform the utility of the
devices towards the use in patients for chronic treatment of osteoporosis.
