Muscle fragments on a scaffold in rats: a potential regenerative strategy in urogynecology

The use of permanent synthetic meshes to improve the outcome of pelvic organ prolapse (POP) repair causes frequent and serious complications. The use of the synthetic, biodegradable scaffold methoxypolyethyleneglycol-polylactic-co-glycolic acid (MPEG-PLGA) seeded with autologous muscle fiber fragments (MFF), as an adjunct to native tissue POP repair, is a potential new alternative.

A rat abdominal wall model of native repair was used with six animals in each of three groups: native repair, native repair + MPEG-PLGA, and native repair + MPEG-PLGA + MFF. MFF were labeled with PKH26-fluorescence dye. After 8 weeks labeled cells were identified in tissue samples and histopathological and immunohistochemical analyses of connective tissue organization and desmin reactivity of muscle cells were performed. Fresh tissue samples were subjected to uniaxial biomechanical testing. Statistical analyses were performed using one-way analysis of variance (ANOVA).

MPEG-PLGA was fully degraded after 8 weeks. Desmin-immunopositive (6/6) and PKH26-positive cells (6/6) were found only after native repair + MPEG-PLGA + MFF, indicating survival, proliferation, and integration of cells originating from the MFF. This group also showed significantly increased stiffness in the high stiffness zone compared with native repair + MPEG-PLGA (p = 0.032) and borderline significantly higher stiffness compared to native repair (p = 0.054).

In this pilot study, MPEG-PLGA scaffolds seeded with autologous MFF affected some histological and biomechanical properties of native tissue repair in an abdominal wall defect model in rats. The method thus appears to be a simple tissue engineering concept with potential relevance for native tissue repair of POP.