title: In situ regeneration of skeletal muscle tissue through host cell recruitment.
abstract: Standard reconstructive procedures for restoring normal function after skeletal muscle defects involve the use of existing host tissues such as muscular flaps. In many instances, this approach is not feasible and delays the rehabilitation process and restoration of tissue function. Currently, cell-based tissue engineering strategies have been used for reconstruction; however, donor tissue biopsy and ex vivo cell manipulation are required prior to implantation. The present study aimed to overcome these limitations by demonstrating mobilization of muscle cells into a target-specific site for in situ muscle regeneration. First, we investigated whether host muscle cells could be mobilized into an implanted scaffold. Poly(l-lactic acid) (PLLA) scaffolds were implanted in the tibialis anterior (TA) muscle of rats, and the retrieved scaffolds were characterized by examining host cell infiltration in the scaffolds. The host cell infiltrates, including Pax7+ cells, gradually increased with time. Second, we demonstrated that host muscle cells could be enriched by a myogenic factor released from the scaffolds. Gelatin-based scaffolds containing a myogenic factor were implanted in the TA muscle of rats, and the Pax7+ cell infiltration and newly formed muscle fibers were examined. By the second week after implantation, the Pax7+ cell infiltrates and muscle formation were significantly accelerated within the scaffolds containing insulin-like growth factor 1 (IGF-1). Our data suggest an ability of host stem cells to be recruited into the scaffolds with the capability of differentiating to muscle cells. In addition, the myogenic factor effectively promoted host cell recruitment, which resulted in accelerating muscle regeneration in situ.
authors: Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
authors: Young Min
authors: YM
authors: Ju
authors: Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
authors: Anthony
authors: A
authors: Atala
authors: Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
authors: James J
authors: JJ
authors: Yoo
authors: Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA. Electronic address: sjlee@wakehealth.edu.
authors: Sang Jin
authors: SJ
authors: Lee
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D018914:Cells, Immobilized / Q000166:cytology / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D019344:Lactic Acid / Q000494:pharmacology*; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D051763:PAX7 Transcription Factor / Q000378:metabolism; D011091:Polyesters; D011108:Polymers / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012038:Regeneration; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology / Q000378:metabolism*; D054457:Tissue Scaffolds
chemical_list: D051763:PAX7 Transcription Factor; C497322:Pax7 protein, mouse; D011091:Polyesters; D011108:Polymers; C548904:insulin-like growth factor-1, rat; D019344:Lactic Acid; C033616:poly(lactide); D007334:Insulin-Like Growth Factor I
keywords: Biomaterials; Reconstruction; Skeletal muscle; Stem cells; Tissue engineering