Regenerative medicine focuses on the repair or replacement of tissue lost to injury, disease, or age, primarily via the enhancement of endogenous stem cell function or the transplantation of exogenous stem cells. The focus of rehabilitation science is on the use of mechanical and other stimuli to promote functional recovery. The field of Regenerative Rehabilitation integrates these two approaches, with the ultimate goal of optimizing outcomes. It is where applied biophysics meets tissue engineering and cellular therapies.
McGowan Institute for Regenerative Medicine faculty member Fabrisia Ambrosio, PhD, MPT, is the Director of Rehabilitation for UPMC International and an Associate Professor in the Department of Physical Medicine & Rehabilitation at the University of Pittsburgh. Dr. Ambrosio’s research has the long-term goal of developing Regenerative Rehabilitation approaches to enhance skeletal muscle function with increasing age and in the setting of disease. She is a co-author of the chapter on cell therapies/transplantation in Goodman and Fuller’s Pathology, 5th Edition, by Catherine C. Goodman, MBA, PT, CBP and Kenda S. Fuller, PT, NCS. The authors and associate editor Rolando Lazaro, PT, PhD, DPT, recently shared their insights on the landscape of physical therapy and important topics covered in their new title. Their response to a question re Regenerative Rehabilitation during that conversation follows:
How does regenerative medicine translate to physical rehabilitation management?
Regenerative Rehabilitation has been defined as “the application of rehabilitation protocols and principles together with regenerative medicine therapeutics toward the goal of optimizing functional recovery through tissue regeneration, remodeling, or repair.” The rationale for Regenerative Rehabilitation includes three main areas, including:
For functional tissue regeneration to occur, resident stem cells are dependent upon supporting cues from the microenvironment, or niche. These microenvironmental cues include vascularity, growth factor secretion, and neural signals, for example, all of which serve to direct stem cell fate.
Stem cells “sense” static and dynamic physical aspects of their surroundings. Through a process known as “mechanotransduction,” or the conversion of physical stimuli into chemical responses, extrinsic signals may directly affect stem cell responses, such as gene expression and differentiation into a specific tissue lineage.
Differentiation of stem cells into the tissue target is often a goal of stem cell therapeutics, and physical therapy may serve as an important adjunct therapy to promote functionality of the newly formed tissue. Future studies are needed to investigate the ability of physical therapy protocols to promote hypertrophy of the newly formed myofibers so as to maximize functional outcomes.
Clearly, physical therapists will play a major role in the success of regenerative medicine and tissue engineering approaches in the clinic, much in the same way that successful outcomes following an orthopedic procedure relies on well-defined post-surgical rehabilitation protocols.
Illustration: Ambrosio, et al. 2010.