title: Quantitative mapping of matrix content and distribution across the ligament-to-bone insertion.
abstract: The interface between bone and connective tissues such as the Anterior Cruciate Ligament (ACL) constitutes a complex transition traversing multiple tissue regions, including non-calcified and calcified fibrocartilage, which integrates and enables load transfer between otherwise structurally and functionally distinct tissue types. The objective of this study was to investigate region-dependent changes in collagen, proteoglycan and mineral distribution, as well as collagen orientation, across the ligament-to-bone insertion site using Fourier transform infrared spectroscopic imaging (FTIR-I). Insertion site-related differences in matrix content were also evaluated by comparing tibial and femoral entheses. Both region- and site-related changes were observed. Collagen content was higher in the ligament and bone regions, while decreasing across the fibrocartilage interface. Moreover, interfacial collagen fibrils were aligned parallel to the ligament-bone interface near the ligament region, assuming a more random orientation through the bulk of the interface. Proteoglycan content was uniform on average across the insertion, while its distribution was relatively less variable at the tibial compared to the femoral insertion. Mineral was only detected in the calcified interface region, and its content increased exponentially across the mineralized fibrocartilage region toward bone. In addition to new insights into matrix composition and organization across the complex multi-tissue junction, findings from this study provide critical benchmarks for the regeneration of soft tissue-to-bone interfaces and integrative soft tissue repair.
authors.affiliation: Biomaterials and Interface Tissue Engineering Laboratory, Department of Biomedical Engineering, Columbia University, New York, New York, United States of America.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Spalazzi
authors.forename: Adele L
authors.initials: AL
authors.lastname: Boskey
authors.forename: Nancy
authors.initials: N
authors.lastname: Pleshko
authors.forename: Helen H
authors.initials: HH
authors.lastname: Lu
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000033:anatomy & histology* / Q000378:metabolism; D002417:Cattle; D003094:Collagen / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D008022:Ligaments / Q000033:anatomy & histology* / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D003094:Collagen
references.citation: J Bone Joint Surg Am. 1970 Jan;52(1):1-20
references.pmid: 4189231
references.citation: Am J Sports Med. 1987 May-Jun;15(3):225-9
references.pmid: 3303979
references.citation: Biochim Biophys Acta. 2006 Jul;1758(7):934-41
references.pmid: 16815242
references.citation: Tissue Eng. 2006 Dec;12(12):3497-508
references.pmid: 17518686
references.citation: Clin Orthop Relat Res. 1975 Jan-Feb;(106):216-31
references.pmid: 1126079
references.citation: J Bone Joint Surg Am. 1993 Dec;75(12):1795-803
references.pmid: 8258550
references.citation: J Orthop Res. 2006 Oct;24(10):2001-10
references.pmid: 16900541
references.citation: Am J Sports Med. 1986 Sep-Oct;14(5):398-403
references.pmid: 3535550
references.citation: Clin Orthop Relat Res. 1985 Jun;(196):9-14
references.pmid: 3888475
references.citation: J Bone Miner Res. 2004 Dec;19(12):2000-4
references.pmid: 15537443
references.citation: Biomaterials. 2007 May;28(15):2465-78
references.pmid: 17175021
references.citation: Connect Tissue Res. 1996;34(3):203-11
references.pmid: 9023049
references.citation: Biopolymers. 2001;62(1):1-8
references.pmid: 11135186
references.citation: Arch Biochem Biophys. 1996 Apr 1;328(1):135-42
references.pmid: 8638922
references.citation: J Histochem Cytochem. 1997 Feb;45(2):307-13
references.pmid: 9016319
references.citation: Tissue Eng. 2006 Dec;12(12):3307-39
references.pmid: 17518671
references.citation: Tissue Eng Part C Methods. 2010 Jun;16(3):355-64
references.pmid: 19586313
references.citation: J Orthop Surg Res. 2006 Sep 25;1:2
references.pmid: 17150122
references.citation: J Orthop Res. 2006 Aug;24(8):1745-55
references.pmid: 16779829
references.citation: Microsc Res Tech. 2010 May;73(5):503-12
references.pmid: 19839035
references.citation: Cells Tissues Organs. 2005;181(3-4):144-53
references.pmid: 16612080
references.citation: J Orthop Res. 1988;6(6):907-31
references.pmid: 3171771
references.citation: PLoS One. 2012;7(11):e48630
references.pmid: 23152788
references.citation: J Bone Miner Res. 2009 Sep;24(9):1565-71
references.pmid: 19419303
references.citation: Calcif Tissue Int. 2002 May;70(5):422-9
references.pmid: 12055658
references.citation: Anal Chem. 1995 Oct 1;67(19):3377-81
references.pmid: 8686889
references.citation: Adv Biochem Eng Biotechnol. 2006;102:91-111
references.pmid: 17089787
references.citation: Acta Anat (Basel). 1997;160(4):261-8
references.pmid: 9732127
references.citation: Ann Biomed Eng. 2008 Jan;36(1):123-31
references.pmid: 17999192
references.citation: Histochem J. 1991 Nov-Dec;23(11-12):534-40
references.pmid: 1724236
references.citation: Anat Embryol (Berl). 1999 Sep;200(3):325-34
references.pmid: 10463347
references.citation: J Cell Biol. 1991 Aug;114(3):597-604
references.pmid: 1860888
references.citation: J Orthop Res. 2003 May;21(3):413-9
references.pmid: 12706013
references.citation: J Orthop Res. 2007 Dec;25(12):1609-20
references.pmid: 17676622
references.citation: J Biomech. 1995 Feb;28(2):147-57
references.pmid: 7896857
references.citation: J Anat. 1986 Dec;149:89-100
references.pmid: 3693113
references.citation: Appl Spectrosc. 2008 Dec;62(12):1285-94
references.pmid: 19094386
references.citation: J Bone Miner Res. 2003 Jun;18(6):1005-11
references.pmid: 12817752
references.citation: J Biomed Opt. 2005 May-Jun;10(3):031105
references.pmid: 16229630
references.citation: Spine (Phila Pa 1976). 2007 Jun 15;32(14):1493-7
references.pmid: 17572617
references.citation: Annu Rev Biomed Eng. 2013;15:201-26
references.pmid: 23642244
references.citation: J Bone Miner Res. 1997 Nov;12(11):1936-43
references.pmid: 9383698
references.citation: Osteoarthritis Cartilage. 2005 Dec;13(12):1050-8
references.pmid: 16154778
references.citation: Proc Natl Acad Sci U S A. 2008 Jun 10;105(23):7947-52
references.pmid: 18541916
references.citation: J Orthop Res. 1993 Jan;11(1):68-77
references.pmid: 8423522