Functional Assessment Core

The overall long term goal of the Functional Assessment Core is to bring together the animal and organ level phenotyping resources currently used within individual laboratories and departmental cores at the University of Michigan into a cohesive and easily accessible Core service that can be used by the entire musculoskeletal research community. This core will provide access to state of the art whole animal phenotyping, muscle function and mechanical testing from fibers to whole muscles in situ, tendon and ligament mechanical testing, whole bone mechanical testing, and tissue-level bone mechanical testing. This core will enable center investigators to establish the functional context of animal models to targeted genetic or pharmacological perturbations. Further, the broad technology base and solid communication plan and expert guidance will allow center investigators to expand on their tissue of interest to also include assays on adjacent tissues to test for effects across tissues.

The Core brings together the leadership and technical proficiency in the physiology and biomechanics of the musculoskeletal system along with specialized laboratory approaches to musculoskeletal biology including state-of-the-art measurements in the following areas:

bone composition and mechanics muscle function and mechanics tendon and soft tissue mechanics neuromuscular function at the whole animal level the adaptations and regeneration of these tissues in response to injury and disease.

Contact: Contact Dan Michele, PhD (whole animal testing, micro-surgery models), Ken Kozloff, PhD (bone testing, fracture healing/surgical models, in vivo microCT imaging), Ellen Arruda, PhD (tendon testing), or Susan Brooks, PhD (muscle mechanics) when beginning a project. Contact either Dr. Michele, Dr. Kozloff, or Dr. Arruda if you are uncertain about who to contact. They will provide guidance on experimental design and the appropriate Faculty and/or Core expert to contact next.

Existing Core Websites:

Physiology Phenotyping Core: https://sites.google.com/a/umich.edu/mippc/

Core Leadership

Services Offered and Prices

The supported services will use the NIH P30 support to offset the staffing costs for the services below. The maximum amount of NIH P30 support available to each investigator may be capped, and therefore the number of recharged procedures that will be available at the discounted rate may be limited. Please contact the appropriate director or faculty expert for an estimate of the amount of P30 discount that you will be able to apply to your study. “Fees” include supplies and equipment maintenance and are charged either per sample, per experiment, or per hour as indicated. All rates are rounded to the nearest dollar.

1. WHOLE ANIMAL TESTING

Contact: Daniel Michele, PhD (dmichele@umich.edu)

2. MICROSURGEY MODELS

Contact: Daniel Michele, PhD (dmichele@umich.edu)

**Additional animal phenotyping services are available through the Physiology Phenotyping Core but are not receiving support from the P30. Please see the PPC website for the list of available services and contact Dr. Michele if you have any questions (https://sites.google.com/a/umich.edu/mippc/).

3. MUSCLE MECHANICS

Contact:

Susan Brooks, PhD (svbrooks@umich.edu)

Dennis Claflin, PhD (claflin@umich.edu)

4. TENDON TESTING

Contact: Andy Poli, MS, MEng (polia@umich.edu)

Support for the mechanical testing of soft tissues like tendon, ligament, and cartilage can be conducted by contacting Andy Poli who manages operations in Dr. Arruda's Lab.

Many resources focus on ovine biomechanical testing including bone-to-bone testing of knee ligaments as well as scapula-to-humerus fixtures for investigation of tissues in the rotator cuff group. Imaging can be performed up to 5,400 frames per second and testing combined with digital image correlation has been used recently to examine the biomechanics of native anterior cruciate ligament (ACL), native patellar tendon (PT), and various types of ACL replacement grafts. A transparent saline bath can be used in some tests. Ramped and oscillatory excitations can be applied to soft tissues at speeds of 0-100 mm/s with forces from about 10 mN to 10 kN. A high-speed electric linear actuator is available for speeds near 1000 mm/s. For even higher strain-rate testing, multiple split Hopkinson pressure bars (SHPB) are available.

Hourly support for staff is provided by the P30 so that some biomechanical testing services can be provided free of charge. Standard fixturing for test protocols are available for routine testing, however if custom holders are required, users will be asked to contribute to fabrication or purchasing costs.

5. BONE TESTING

Contact: Ken Kozloff, PhD (kenkoz@umich.edu)

Support for the mechanical testing of bone tissues can be conducted by contacting Dr. Kozloff. Resources focus on rodent biomechanical testing and tests are typically performed in tandem with samples that have been imaged by microCT or nanoCT cores to provide a fully comprehensive functional phenotype. We encourage users to consider both CT imaging and biomechanical testing on the same samples.

Hourly support for staff is provided directly by the P30, and standard biomechanical testing services are provided free of charge. Standard fixturing for test protocols are available for routine testing, however if custom holders are required, users will be asked to contribute to fabrication or purchasing costs. Nanoindentation is permitted for trained users following discussion with the core directors.


6. IN VIVO MICROCT

Contact: Ken Kozloff, PhD (kenkoz@umich.edu)

In collaboration with the Structural and Compositional Assessment Core, we support in vivo microCT imaging on a Bruker/Skyscan 1176 system. In vivo imaging may be useful for longitudinal assessment of skeletal changes in the same animal to monitor growth, healing, or other adaptations. Cost structure for users is as follows:

7. FRACTURE HEALING / SURGICAL MODELS

Contact: Ken Kozloff, PhD (kenkoz@umich.edu)

A fully operational small animal surgical suite is housed within the Orthopaedic Research Laboratories and located within the BSRB animal housing unit. The role of this facility will be to provide services to P30 members seeking metabolic challenge to the skeleton, specifically in the form of bone repair. Surgical models include mouse tibial fracture, drill hole defects, and rat critical defect models. Please contact Dr. Kozloff for support of surgical models.

Referencing Core services in manuscripts

When referencing the use of the MiMHC Core services in your manuscripts, please use the following text:

"Research reported in this publication was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under Award Number P30 AR069620. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.”