A Structurally and Functionally Biomimetic Biphasic Scaffold for Intervertebral Disc Tissue Engineering

PLoS One. 2015 Jun 26;10(6):e0131827. doi: 10.1371/journal.pone.0131827. eCollection 2015.

Abstract

Tissue engineering offers high hopes for the treatment of intervertebral disc (IVD) degeneration. Whereas scaffolds of the disc nucleus and annulus have been extensively studied, a truly biomimetic and mechanically functional biphasic scaffold using naturally occurring extracellular matrix is yet to be developed. Here, a biphasic scaffold was fabricated with collagen and glycosaminoglycans (GAGs), two of the most abundant extracellular matrix components in the IVD. Following fabrication, the scaffold was characterized and benchmarked against native disc. The biphasic scaffold was composed of a collagen-GAG co-precipitate making up the nucleus pulposus-like core, and this was encapsulated in multiple lamellae of photochemically crosslinked collagen membranes comprising the annulus fibrosus-like lamellae. On mechanical testing, the height of our engineered disc recovered by ~82-89% in an annulus-independent manner, when compared with the 99% recovery exhibited by native disc. The annulus-independent nature of disc height recovery suggests that the fluid replacement function of the engineered nucleus pulposus core might mimic this hitherto unique feature of native disc. Biphasic scaffolds comprised of 10 annulus fibrosus-like lamellae had the best overall mechanical performance among the various designs owing to their similarity to native disc in most aspects, including elastic compliance during creep and recovery, and viscous compliance during recovery. However, the dynamic mechanical performance (including dynamic stiffness and damping factor) of all the biphasic scaffolds was similar to that of the native discs. This study contributes to the rationalized design and development of a biomimetic and mechanically viable biphasic scaffold for IVD tissue engineering.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomechanical Phenomena
  • Biomimetic Materials* / chemical synthesis
  • Biomimetic Materials* / chemistry
  • Bone Substitutes / chemistry
  • Bone Substitutes / therapeutic use
  • Cells, Cultured
  • Compressive Strength
  • Intervertebral Disc / cytology*
  • Intervertebral Disc / physiology*
  • Intervertebral Disc Degeneration / therapy
  • Materials Testing
  • Rabbits
  • Tissue Engineering / instrumentation
  • Tissue Engineering / methods*
  • Tissue Scaffolds / chemistry*

Substances

  • Bone Substitutes

Grants and funding

This work was supported by AO Spine (AOSPN) (grant number: SRN_2011_14). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.