Exogenous Lysyl Oxidase‐Like 2 and Perfusion Culture Induce Collagen Crosslink Formation in Osteogenic Grafts. Issue 3 (16th August 2018)

• Record Type: Journal Article
• Authors: Mitra, Debika; Yasui, Osamu W.; Harvestine, Jenna N.; Link, Jarrett M.; Hu, Jerry C.; Athanasiou, Kyriacos A.; Leach, J. Kent
• Is Part Of: Biotechnology journal. Volume 14:Issue 3(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-08-16
• Subjects: bone engineering -- collagen crosslinks -- mesenchymal stem cells -- perfusion cultures -- pyridinoline; Biotechnology -- Periodicals; 660.605
• DOI: 10.1002/biot.201700763
• Languages: English
• ISSNs: 1860-6768

Abstract

Abstract : Lysyl oxidase (LOX)‐mediated collagen crosslinking can regulate osteoblastic phenotype and enhance mechanical properties of tissues, both areas of interest in bone tissue engineering. The objective of this study is to investigate the effect of lysyl oxidase‐like 2 (LOXL2) on osteogenic differentiation of mesenchymal stem cells (MSCs) cultured in perfusion bioreactors, enzymatic collagen crosslink formation in the extracellular matrix (ECM), and mechanical properties of engineered bone grafts. Exogenous LOXL2 to MSCs seeded in composite scaffolds under perfusion culture for up to 28 days is administered. Constructs treated with LOXL2 appear brown in color and possess greater DNA content and osteogenic potential measured by a twofold increase in bone sialoprotein gene expression. Collagen expression of LOXL2‐treated scaffolds is lower than untreated controls. Functional outputs such as calcium deposition, osteocalcin expression, and compressive modulus are unaffected by LOXL2 supplementation. Excitingly, LOXL2‐treated constructs contain 1.8‐ and 1.4‐times more pyridinoline (PYD) crosslinks per mole of collagen and per wet weight, respectively, than untreated constructs. Despite these increases, compressive moduli of LOXL2‐treated constructs are similar to untreated constructs over the 28‐day culture duration. This is the first report of LOXL2 application to engineered, three‐dimensional bony constructs. The results suggest a potentially new strategy for engineering osteogenic grafts with a mature ECM by modulating crosslink formation. Abstract : Lysyl oxidase‐like 2 (LOXL2) administration to mesenchymal stem cell‐laden engineered bony constructs increases enzymatic collagen crosslinking, DNA content, and osteogenic gene expression. Exogenous application of LOXL2 to osteogenic grafts cultured under perfusion represents an exciting new approach for tailoring the functional properties of engineered tissues.