Implantation of In Vitro Tissue Engineered Muscle Repair Constructs and Bladder Acellular Matrices Partially Restore In Vivo Skeletal Muscle Function in a Rat Model of Volumetric Muscle Loss Injury
ARMY INST OF SURGICAL RESEARCH FORT SAM HOUSTON TX
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The frank loss of a large volume of skeletal muscle i.e., volumetric muscle loss VML can lead to functional debilitation and presents a significant problem to civilian and military medicine. Current clinical treatment for VML involves the use of free muscle flaps and physical rehabilitation however, neither are effective in promoting regeneration of skeletal muscle to replace the tissue that was lost. Toward this end, skeletal muscle tissue engineering therapies have recently shown great promise in offering an unprecedented treatment option for VML. In the current study, we further extend our recent progress Machingal et al., 2011, Tissue Eng Corona et al., 2012, Tissue Eng in the development of tissue engineered muscle repair TEMR constructs i.e., muscle-derived cells MDCs seeded on a bladder acellular matrix BAM preconditioned with uniaxial mechanical strain for the treatment of VML. TEMR constructs were implanted into a VML defect in a tibialis anterior TA muscle of Lewis rats and observed up to 12 weeks post injury. The salient findings of the study were 1 TEMR constructs exhibited a highly variable capacity to restore in vivo function of injured TA muscles, wherein TEMR-positive responders n 6 promoted an 61 improvement, but negative responders n 7 resulted in no improvement compared to nonrepaired controls, 2 TEMR-positive and -negative responders exhibited differential immune responses that may underlie these variant responses, 3 BAM scaffolds n 7 without cells promoted an 26 functional improvement compared to uninjured muscles, 4 TEMR-positive responders promoted muscle fiber regeneration within the initial defect area, while BAM scaffolds did so only sparingly. These findings indicate that TEMR constructs can improve the in vivo functional capacity of the injured musculature at least, in part, by promoting generation of functional skeletal muscle fibers.
- Anatomy and Physiology
- Medicine and Medical Research
- Biomedical Instrumentation and Bioengineering