M. Oria1, R. Tatu2, C. Lin2, J. Peiro1 1Cincinnati Children’s Hospital Medical Center,Pediatric Surgery,Cincinnati, OH, USA 2University Of Cincinnati,Department Of Biomedical Engineering,Cincinnati, OH, USA
Introduction:
Current therapeutic strategies for spina bifida repair showed a limited number of options in the market and any of them have all the requirements as the perfect patch. In fact, sometimes the surgical procedures become really challenge using different patches to fully cover the spina bifida lesion. For this purpose, the blend films of poly (lactic acid) and poly (ε-caprolactone) was designed and validated in vitro to cover all these requirements but was never tested in vivo.
Methods:
Blend films of poly (L-lactic acid) (PLA) and poly (ε-caprolactone) (PCL) were fabricated by solvent casting the blend consisted 83% PLA and 17% PCL in chloroform as solvent. The blend solution poured in Teflon mold and dried for 24h to attain films. A total of 26 adult Sprague-Dawley rats weighing 200-250 gwere used in this project. 2 sets of experiments were performed A) Subcutaneous implantation of the patch: 1 cm x 1 cm blend patch was surgically implanted under the skin the back of the animals during 2 weeks till tissue and patch were harvested for histological analysis and B) Dural implantation of the patch: A rat laminectomy model was used to determine the effects of PLA-PLC as a dural substitute. Once a week after surgery and during for 4 weeks an electrophysiological test was assessed using six needle subcutaneous electrodes to assess the motor function in the rats. For the recording of the evoked potentials to assess the function of the motor tract we recorded motor evoked potentials (MEP) and compound motor action potential (CMAP) as a control. After 4 weeks tissue was harvested for histological analysis.
Results:
The blend patch was analyzed in terms of rejection from the animal, inflammation reaction and functional interaction with spinal cord tissue in rat animal models. No evidence of adverse or inflammatory reactions was observed in both models of subcutaneous implantation, neither as a dural substitute. No signs of astrogliosis in the neural tissue was observed and no functional alteration of the motor evoked potentials after 4 weeks of implantation as dural substitute in the rat spinal cord.
Conclusion:
The results of the present study suggest that PLA-PLCpatch are the ideal form factor for a minimally-invasive application such as fetoscopy and will serve as our SB repair patch. Blended patches when are in contact with the spinal cord as a dural substitute will not induce any adverse effect such as scar formation or tethering cord and functions of the spinal cord. These findings encourage further investigation of this patch with the possibility for future design of cellular or/and pharmacological treatment bipolar combination.