Evaluation of diaphragmatic hernia repair using PLGA mesh-collagen sponge hybrid scaffold: an experimental study in a rat model.

Patch closure is necessary to achieve tension-free repair in large congenital diaphragmatic hernia. However, the use of prosthetic material may lead to granulation, allergic reaction, infection, recurrence of hernia, and thoracic deformity. Tissue engineering may become an alternative treatment strategy for diaphragmatic hernia repair, since the regenerated autologous tissue is expected to grow potentially without rejection or infection. We evaluated the efficacy of diaphragmatic hernia repair in a rat model using a poly-lactic-co-glycolic acid (PLGA) mesh-collagen sponge hybrid scaffold, designed for in situ tissue engineering. Twenty-four F344 female rats were used. Oval-shaped defects were surgically created in the left diaphragm and repaired with three different grafts, including PLGA mesh in group 1 (n = 7), PLGA mesh-collagen sponge hybrid scaffold in group 2 (n = 7), and PLGA mesh-collagen sponge hybrid scaffold seeded with bone marrow-derived mesenchymal stem cells (MSCs) in group 3 (n = 10). The animals were killed at 1, 2, and 3 months after operation. The specimens were examined macroscopically and microscopically. No recurrence or eventration was observed. In all animals, autologous fibrous tissue with vascularization was generated at the graft site. Although no muscular tissue was detected, scattered desmin-positive cells were observed in groups 2 and 3. The 'neodiaphragm' in groups 2 and 3 was significantly thicker compared with that in group 1. There was no significant difference in the 'neodiaphragm' between groups 2 and 3. The PLGA mesh-collagen sponge hybrid scaffold provided better promotion of autologous in situ tissue regeneration in the diaphragm, suggesting its potential application to diaphragmatic repair in place of other prosthetic patches.