The human umbilical vein: a novel scaffold for musculoskeletal soft tissue regeneration

The umbilical cord is a biological tissue that is readily available and is usually discarded. In this study, we investigate the potential of making use of part of the human umbilical cord, in particular the umbilical vein, as a functional tissue engineering scaffold. Previous studies suggested the use of the human umbilical vein (HUV) as an acellular vascular grafting material. We propose taking advantage of the longitudinal mechanical properties of the HUV to use it as a scaffold material for musculoskeletal soft tissue regeneration. HUVs were mechanically dissected from 8.5-cm sections of fresh human umbilical cords. The sections were inverted such that the luminal side formed the exterior surface. HUVs were then decellularized, and filled with mesenchymal stem cells (MSCs) suspended in a type I collagen hydrogel. Seeded HUVs were cultured for periods of up to 2 weeks. After 2 weeks of culture, results showed a significant increase in cell number reaching almost three times the original inoculation density. Histological analysis revealed cell integration and migration into the HUV scaffold and extensive remodeling of extracellular matrix. Mechanically, the ultimate tensile stress doubled, and elastic modulus values were almost 2.7-fold higher. Given the differentiation capacity of the MSCs, along with the appropriate biochemical and biomechanical environment, the seeded HUV has a potential for ligament or tendon regeneration.