Biodegradation study in FBS media of polycaprolactone patch as a potential prenatal treatment for myelomeningocele

Myelomeningocele (MMC) is a congenital defect of the spine characterized by meningeal and spinal cord protrusion through open vertebral archs, and its exposure to the amniotic fluid. Given that the progression of neuronal loss begins early in fetal life, an early coverage of the defect is required to improve the neurological outcomes. Several studies have proposed patches as an alternative to full surgical repair, to achieve an early protection of the spine and possibly reduce the rate of complications of current prenatal surgical procedures. In our previous work, we developed a biocompatible, watertight and biodegradable patch to improve in utero MMC repair. This patch offers an anti-adhesive internal surface to prevent adhesion to spinal cord tissue, and a bioactive external surface to promote tissue coverage. The aim of this study is to assess the patch's in vitro degradation in an amniotic-fluid-like medium and investigate the surface functionalization effect, to understand its mechanism and predict the patch's behavior over time. The study was carried out for 24 weeks in FBS medium and after each period the samples were characterized by differential scanning calorimetry, scanning electron microscopy, steric exclusion chromatography, toluidine blue assay and contact angle measurement. The results revealed a progression of PCL hydrolysis over time, characterized by a decrease in molar mass and evidence of erosion as observed by SEM. Furthermore, this process appears to be accelerated by ozonation, compared to surface functionalization without ozonation. The latter can be considered as the most suitable technique to preserve the patch structure over time, while benefiting from the grafting polymers properties during the first weeks of implantation.