Adult bone marrow stromal cell-based tissue-engineered aggrecan exhibits ultrastructure and nanomechanical properties superior to native cartilage
Objective: To quantify the structural characteristics and nanomechanical properties of aggrecan produced by adult bone marrow stromal cells (BMSCs) in peptide hydrogel scaffolds and compare to aggrecan from adult articular cartilage. Design: Adult equine BMSCs were encapsulated in 3D-peptide...
| Հիմնական հեղինակներ: | , , , , , , , |
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| Այլ հեղինակներ: | |
| Ձևաչափ: | Հոդված |
| Լեզու: | en_US |
| Հրապարակվել է: |
Elsevier Ltd.
2011
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| Առցանց հասանելիություն: | http://hdl.handle.net/1721.1/67287 https://orcid.org/0000-0003-3511-5679 https://orcid.org/0000-0003-0026-6215 https://orcid.org/0000-0002-4942-3456 |
| Ամփոփում: | Objective:
To quantify the structural characteristics and nanomechanical properties of aggrecan produced by adult bone marrow stromal cells (BMSCs) in peptide hydrogel scaffolds and compare to aggrecan from adult articular cartilage.
Design:
Adult equine BMSCs were encapsulated in 3D-peptide hydrogels and cultured for 21 days with TGF-β1 to induce chondrogenic differentiation. BMSC-aggrecan was extracted and compared with aggrecan from age-matched adult equine articular cartilage. Single molecules of aggrecan were visualized by atomic force microcopy-based imaging and aggrecan nanomechanical stiffness was quantified by high resolution force microscopy. Population-averaged measures of aggrecan hydrodynamic size, core protein structures and CS sulfation compositions were determined by size-exclusion chromatography, Western analysis, and fluorescence-assisted carbohydrate electrophoresis (FACE).
Results:
BMSC-aggrecan was primarily full-length while cartilage-aggrecan had many fragments. Single molecule measurements showed that core protein and GAG chains of BMSC-aggrecan were markedly longer than those of cartilage-aggrecan. Comparing full-length aggrecan of both species, BMSC-aggrecan had longer GAG chains, while the core protein trace lengths were similar. FACE analysis detected a ∼1:1 ratio of chondroitin-4-sulfate to chondroitin-6-sulfate in BMSC-GAG, a phenotype consistent with aggrecan from skeletally-immature cartilage. The nanomechanical stiffness of BMSC-aggrecan was demonstrably greater than that of cartilage-aggrecan at the same total sGAG (fixed charge) density.
Conclusions:
The higher proportion of full-length monomers, longer GAG chains and greater stiffness of the BMSC-aggrecan makes it biomechanically superior to adult cartilage-aggrecan. Aggrecan stiffness was not solely dependent on fixed charge density, but also on GAG molecular ultrastructure. These results support the use of adult BMSCs for cell-based cartilage repair. |
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