Abstract
Open spina bifida or myelomeningocele (MMC) is a devastating neurologic congenital defect characterized by primary failure of neural tube closure of the spinal column during the embryologic period. Cerebrospinal fluid leak caused by the MMC spinal defect in the developing fetus can result in a constellation of encephalic anomalies that include hindbrain herniation and hydrocephalus. The exposure of extruded spinal cord to amniotic fluid also poses a significant risk for inducing partial or complete paralysis of the body parts beneath the spinal aperture by progressive spinal cord damage in-utero. A randomized trial demonstrated that prenatal repair by fetal surgery, sometimes using patches, to cover the exposed spinal cord with a watertight barrier is effective in reducing the postnatal neurologic morbidity as evidenced by decreased incidence and severity of postnatal hydrocephalus and the reduced need for ventricular-peritoneal shunting. Currently, the use of inert or collagen-based patches are associated with high costs and inadequate structural properties. Specifically, the inert patches do not degrade after implantation, causing the need for a post-natal removal surgery associated with trauma for the newborn. Our present study is aimed towards in-vitro degradation studies of a newly designed patch, which potentially can serve as a superior alternative to existing patches for MMC repair. This novel patch was fabricated by blending poly(l-lactic acid) and poly(ε-caprolactone). The 16-week degradation study in amniotic fluid was focused on tracking changes in crystallinity and mechanical properties. An additional set of designed patches was exposed to phosphate-buffered saline (PBS), as a time-paired control. Crystallinity studies indicate the progress of hydrolytic degradation of the patch in both media, with a preference to bulk erosion in phosphate buffered saline and surface erosion in amniotic fluid. Mechanical testing results establish that patch integrity is not compromised up to 16 weeks of exposure either to body fluids analog (PBS) or to amniotic fluid.
Highlights
Abbreviations phosphate-buffered saline (PBS) Phosphate-buffered saline Amniotic Fluid (AF) Amniotic fluid poly(l-lactic acid) (PLA) Poly(lactic acid) PCL Poly(ε-caprolactone) X-ray diffractometer (XRD) X-ray diffraction FTIR-ATR Fourier transform infrared spectroscopy-attenuated total reflectance
A recent randomized trial demonstrated that prenatal MMC repair by fetal surgery is effective in reducing the postnatal neurologic morbidity, as evidenced by preserving motor function, reverting the hindbrain herniation, decreased incidence and severity of postnatal hydrocephalus, and reduced need for postnatal ventricular-peritoneal shunting[4]
From the analysis of X-ray diffraction (XRD) data, peaks for PLA were observed at 2θ = 17.41°, and for PCL at 21.51° and 23.92° (Figs. 1 and 2), which are similar to values reported in literature[19]
Summary
Abbreviations PBS Phosphate-buffered saline AF Amniotic fluid PLA Poly(lactic acid) PCL Poly(ε-caprolactone) XRD X-ray diffraction FTIR-ATR Fourier transform infrared spectroscopy-attenuated total reflectance. Incumbent patches adopted in fetoscopic MMC repair are primarily commercial surgical patches. These patches are typically naturally derived (e.g. dermal, pericardium, collagen, or bio-cellulose based) that can be absorbed over time[8]. The additional procedure inevitably causes economic and psychological burdens for the patients. This scenario makes it necessary to develop a biodegradable patch fit for prenatal or postnatal MMC repair that can retain mechanical integrity up to 16 weeks of implantation, and eventually degrade inside the body in the long term. The current study focuses on the in-vitro degradation of the designed patch in a simulated fetal environment by using body fluid analog (PBS) and human amniotic fluid
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
