Muscle reconstruction and regeneration using biodegradable scaffolds

The complete loss or weakening of anatomically defined muscular structures may be determined by many pathological states and may lead to high morbidity and clinical expense. Attempts to functionally correct them have encountered limited success. On the account of more demanding requirements of materials for the myofascial repair, we evaluated a bioabsorbable polymer mimicking, at the structural level, the characteristics of the native extracellular matrix (ECM). A described model of muscle injury was used, consisting in the generation of a large abdominal wall defect in 20 Wistar rats. Ablated rectus abdominis was repaired with electrospun poly-L-lactide (PLLA) acellullar patch. Evaluation of the newly developed ECM showed a more delicate fibrillar and organized collagen network in the PLLA group in comparison to control indicating a more advanced process of wound remodeling and a more controlled and modulated tissutal reaction. Scaffold elicited a potent angiogenic response with the appearance of CD31 positive vessels. Additionally, the graft hosted CD34 positive cells, reliable sign of organism response to muscle injury. The biomimesis principle inspiring the structure of this scaffold guided a reparative processes and modulated the microenvironment of the damaged tissue, favoring the regenerative drive over the inflammatory reaction.