A tissue engineering approach for prenatal closure of myelomeningocele with gelatin sponges incorporating basic fibroblast growth factor.

Myelomeningocele (MMC) is a common and devastating malformation. Although fetal surgical closure may improve outcome, a less invasive approach that can be applied earlier in gestation is desirable. The objective of this study was to evaluate the therapeutic feasibility of a tissue engineering approach for prenatal coverage of MMC. A gelatin hydrogel composite combining a gelatin sheet and gelatin sponge was prepared with or without basic fibroblast growth factor incorporation, and applied prenatally to retinoic-acid-induced fetal MMC in the rat model. Most of the composites were adherent to the MMC within the amniotic fluid environment with the help of cyanoacrylate adhesive. Histological examination revealed cells layered over the composites with associated extracellular matrix as well as cellular ingrowth into the sponges. The layer over the composite was composed of mixed nonepithelial and epithelial cells with the extracellular matrix consisting of collagen type I and hyaluronic acid. The tissue inside the sponge consisted of nonepithelial cells and hyaluronic acid. Epidermal ingrowth underneath the sponges and neovascularization into the sponges occurred and were significantly increased by the incorporation of basic fibroblast growth factor. Although further development is needed, this study supports the therapeutic potential of a tissue engineering approach for prenatal coverage of MMC.