Nanofibrous biologic laminates replicate the form and function of the annulus fibrosus.
Successful engineering of load-bearing tissues requires recapitulation of their complex mechanical functions. Given the intimate relationship between function and form, biomimetic materials that replicate anatomic form are of great interest for tissue engineering applications. However, for complex tissues such as the annulus fibrosus, scaffolds have failed to capture their multi-scale structural hierarchy. Consequently, engineered tissues have yet to reach functional equivalence with their native counterparts. Here, we present a novel strategy for annulus fibrosus tissue engineering that replicates this hierarchy with anisotropic nanofibrous laminates seeded with mesenchymal stem cells. These scaffolds directed the deposition of an organized, collagen-rich extracellular matrix that mimicked the angle-ply, multi-lamellar architecture and achieved mechanical parity with native tissue after 10 weeks of in vitro culture. Furthermore, we identified a novel role for inter-lamellar shearing in reinforcing the tensile response of biologic laminates, a mechanism that has not previously been considered for these tissues.
Nerurkar
Nandan L
NL
McKay Orthopaedic Research Laboratory, University of Pennsylvania, 424 Stemmler Hall, 36th Street and Hamilton Walk, Philadelphia, Pennsylvania 19104-6081, USA.
Baker
Brendon M
BM
Sen
Sounok
S
Wible
Emily E
EE
Elliott
Dawn M
DM
Mauck
Robert L
RL
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002417:Cattle; D003094:Collagen / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D007403:Intervertebral Disc / Q000502:physiology*; D059630:Mesenchymal Stem Cells / Q000166:cytology; D049329:Nanostructures / Q000737:chemistry*; D023822:Tissue Engineering
D001672:Biocompatible Materials; D003094:Collagen