M. Rajeev1, K. Lampe1, J. Hawes2, C. Lin2, M. Oria1, J. Peiro1 1Cincinnati Children’s Hospital Medical Center, Pediatric Surgery, Cincinnati, OH, USA 2University Of Cincinnati, Orthopaedic Surgery, Cincinnati, OH, USA
Introduction: Current therapeutic strategies for spina bifida repair with dural patches showed a limited number of options in the market and any of them have all the requirements as the perfect dural substitute. The novel PLA/PCL “smart” patch we designed for fetoscopic Myelomeningocele (MMC) repair has been tested to be easily applicable via endoscopes, durable, and biodegradable in studies thus far. It has not yet been compared to a commercial patch, such as a collagen based patch.
Methods: Blend films of poly (L-lactic acid) (PLA) and poly (ε-caprolactone) (PCL) were fabricated by solvent casting the blend consisted of 83% PLA and 17% PCL in chloroform as solvent. A total of 12 pregnant sheep were used in this project. Fetal sheep underwent spina bifida surgically created at E85, repaired with either Durepair™ or PLA/PCL patches at E105, or non-repaired. Twin sheep were used as non-spina bifida controls. C-section and harvest of the spinal cords were performed at term (E140) for analysis. Immunofluorescence and western blot were used to compare astrocytes, neurons, and microglia cells in the spina bifida compared to controls
Results: We found more structure maintenance for both patch samples in comparison to no-repair model in H&E staining. Qualitative decrease in GFAP and fibronectin expression within spinal cord tissue in patch models in comparison to no-repair model via immunofluorescence. Similar NeuN expression via immunofluorescence between patch models. Increased Iba1+ expression in smart PLA/PCL patch vs. Durepair™ but also increased P2Y12+ homeostatic microglia.
Conclusion: Preliminary findings indicate the novel PLA/PCL patch alike in biocompatibility to the Durepair™ patch in terms of astrogenesis, neural loss, fibrogenesis and maintenance of spinal cord structure. The Iba1+ population in both patches should be further quantified as activated or homeostatic to determine if an inflammatory response is occurring.