SUMMARY
The research of Mimi C. Sammarco, Ph.D., focuses on limb regeneration after traumatic injury. Although complete regeneration of a limb isn't possible, regenerative approaches that extend limbs or improve the integration of prosthetics can vastly improve quality of life for people with limb loss or limb differences.
Understanding the mechanisms that drive tissue replacement and patterning and delineating the timeline that drives this regenerative event are key steps in moving toward translational and clinical approaches to replace bone and soft tissue.
While whole limbs don't regenerate, amputation of the digit tip provides an ideal regenerating model for the limb and results in high-fidelity replacement of bone and soft tissue. Limb amputation and digit amputation closer to the palm result in callus formation, fibrotic scarring and failure to regenerate. Dr. Sammarco and her team in the Limb and Musculoskeletal Regenerative Research Laboratory use a mouse model to understand the complex interactions of a multitissue regenerative system and identify the mechanisms that drive cell differentiation and patterning during the regenerative process.
Focus areas
- Modulation of cell metabolism by gene expression and conversely modulation of gene expression by cell metabolism. Understanding the synergy between these mechanisms will aid regenerative approaches and help clarify the relationship between cell metabolism and gene expression.
- The role of sensory nerves in regeneration. Dr. Sammarco's team uses a mouse model and cell culture techniques to study the role of sensory nerves on proliferation, differentiation and cell patency.
- Predictive finite element model. Dr. Sammarco collaborates with Kevin F. Hoffseth, Ph.D., at the LSU AgCenter in Baton Rouge, Louisiana, to develop a predictive finite element model. Using the predictive features of this model, they hope to create a platform that will computationally anticipate where bone regeneration will spatially mineralize on the bone stump.
- Bone and soft tissue patterning. Dr. Sammarco collaborates with Robert Tower, Ph.D., at UT Southwestern Medical Center in Dallas, Texas, and Anyonya Guntur, Ph.D., at MaineHealth Institute for Research in Scarborough, Maine. They're investigating how cell metabolism drives bone and soft tissue patterning by modulating signals such as reactive oxygen species. They aim to uncover how cell metabolism modulates both cell function and energy requirements.
- Inflammation and metabolism. Dr. Sammarco collaborates with Jennifer Simkin, Ph.D., at LSU Health New Orleans School of Medicine in Louisiana. They study amputation of the second phalangeal element to investigate the role of inflammation and metabolism in regeneration versus scarring.
Significance to patient care
Dr. Sammarco's research uses digit tip amputation as a model to explore how to restore bone and tissue after larger amputation injuries, such as the loss of a leg. Limb regeneration is limited in humans, and injury usually results in thickening and scarring, a process called fibrotic response. Understanding the mechanisms behind regenerative and fibrotic healing in the limb is important to promoting translational studies and better treatments. Dr. Sammarco hopes to identify treatments using genetics and medicine to help regeneration and healing.
Professional highlights
- National Institute of Child Health and Human Development:
- Principal investigator, R03HD112824, A computational model for prediction of morphology, patterning, and strength in bone regeneration, 2023-present.
- Principal investigator, R01HD107034, Cellular metabolism at the crossroads of skeletal regeneration, 2022-present.
- Principal investigator, R21HD106162, Spatiotemporal regulation of digit regeneration by sensory nerves, 2022-present.
- Associate editor, Frontiers in Cell and Developmental Biology, 2023-present.