In vitro and in vivo investigation of a zonal microstructured scaffold for osteochondral defect repair
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Published version
Author(s)
Type
Journal Article
Abstract
Articular cartilage is comprised of zones that vary in architecture, extracellular matrix composition, and mechanical properties. Here, we designed and engineered a porous zonal microstructured scaffold from a single biocompatible polymer (poly [ϵ-caprolactone]) using multiple fabrication strategies: electrospinning, spherical porogen leaching, directional freezing, and melt electrowriting. With this approach we mimicked the zonal structure of articular cartilage and produced a stiffness gradient through the scaffold which aligns with the mechanics of the native tissue. Chondrocyte-seeded scaffolds accumulated extracellular matrix including glycosaminoglycans and collagen II over four weeks in vitro. This prompted us to further study the repair efficacy in a skeletally mature porcine model. Two osteochondral lesions were produced in the trochlear groove of 12 animals and repaired using four treatment conditions: (1) microstructured scaffold, (2) chondrocyte seeded microstructured scaffold, (3) MaioRegen™, and (4) empty defect. After 6 months the defect sites were harvested and analyzed using histology, micro computed tomography, and Raman microspectroscopy mapping. Overall, the scaffolds were retained in the defect space, repair quality was repeatable, and there was clear evidence of osteointegration. The repair quality of the microstructured scaffolds was not superior to the control based on histological scoring; however, the lower score was biased by the lack of histological staining due to the limited degradation of the implant at 6 months. Longer follow up studies (e.g., 1 yr) will be required to fully evaluate the efficacy of the microstructured scaffold. In conclusion, we found consistent scaffold retention, osteointegration, and prolonged degradation of the microstructured scaffold, which we propose may have beneficial effects for the long-term repair of osteochondral defects.
Date Issued
2022-07
Date Acceptance
2022-04-23
Citation
Biomaterials, 2022, 286, pp.1-13
ISSN
0142-9612
Publisher
Elsevier
Start Page
1
End Page
13
Journal / Book Title
Biomaterials
Volume
286
Copyright Statement
© 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
License URL
Sponsor
Medical Research Council (MRC)
Wellcome Trust
Wellcome Trust
Commission of the European Communities
Identifier
https://www.sciencedirect.com/science/article/pii/S0142961222001880
Grant Number
MR/R015651/1
088844/Z/09/A
208858/Z/17/Z
676137
Subjects
Biomedical Engineering
Publication Status
Published
Date Publish Online
2022-05-02