Devices and Method for Rapid Extraction of Stem cell - Collagen Patches from a Human Umbilical Cord

Introduction: The human umbilical cord is composed of umbilical blood vessels surrounded by a support tissue called Wharton's Jelly (WJ). WJ comprises a strong collagen matrix that is rich in hyaluronic acid and chondroitin sulfate. In addition, WJ contains large numbers of mesenchymal stem cells (MSCs). Patches of WJ would therefore offer unique properties as a matrix for tissue regeneration in wound management. Due to its widely perceived nature as a gelatinous material, the mechanical manipulation of WJ into solid products for clinical application has never been fully explored.

Methods: Donated cords were collected under the approved IRB #HSC-MS-11-1601 at UTHealth. Cords were washed, segmented (5-10cms long), and rinsed in DPBS with 100µM gentamycin. A first novel device was developed to rapidly strip the umbilical vein from the cord. A second new device slices the remaining cord to yield the WJ patch. Use of the these devices reduce the harvesting time from >30mins (manually) to under 10mins. SEM and trichrome stain images indicate that WJ Patch is composed primarily of collagen fibers that are aligned parallel to each other.

Results: Mechanical testing of the patches showed Young's Modulus of 10.4 +- 2.7 MPa, making WJ Patch significantly stronger than AlloDerm (0.125MPa), Vicryl (0.091MPa) or Surgisis (0.142MPa)[2]. Using resazurin based assay, we found the viable cell count in a cryopreserved WJ tissue to be 68.9% (4.16e5 cells/gm of tissue) compared to a fresh tissue.

Conclusion: Combination of superior physical and biologic properties makes WJ Patch a highly attractive option for burn and wound covering.