{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T06:10:56Z","timestamp":1790662256919,"version":"4.1.0"},"reference-count":37,"publisher":"Public Library of Science (PLoS)","issue":"6","license":[{"start":{"date-parts":[[2021,6,3]],"date-time":"2021-06-03T00:00:00Z","timestamp":1622678400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"\n Background<\/jats:title>\n Collagen cross-links contribute to the mechanical resilience of the intervertebral disc (IVD). UVA-light-activated riboflavin-induced collagen crosslinking (UVA-CXL) is a well-established and effective ophthalmological intervention that increases the mechanical rigidity of the collagen-rich corneal matrix in Keratoconus. This study explores the feasibility, safety and efficacy of translating this intervention in reinforcing the IVD.<\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n \n Annulus fibrosus (AF) cells were isolated from bovine IVDs and treated with different combinations of riboflavin (RF) concentrations (0.05\u20138 mM) and UVA light intensities (0.3\u20134 mW\/cm\n 2<\/jats:sup>\n ). Metabolic activity (resazurin assay), cell viability (TUNEL assay), and gene expression of apoptosis regulators\n C-FOS<\/jats:italic>\n and\n PT5<\/jats:italic>\n were assessed immediately and 24 hours after treatment. Biomechanical effects of UVA-CXL on IVDs were measured by indentation analysis of changes in the instantaneous modulus and by peel-force delamination strength analysis of the AF prior and after treatment.\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n Different intensities of UVA did not impair the metabolic activity of AF cells. However, RF affected metabolic activity (p < 0.001).\n PT53<\/jats:italic>\n expression was similar in all RF conditions tested while\n C-FOS<\/jats:italic>\n expression decreased 24 hours after treatment. Twenty-four hours after treatment, no apoptotic cells were observed in any condition tested. Biomechanical characterizations showed a significant increase in the annular peel strength of the UVA-CXL group, when compared to controls of UVA and RF alone (p < 0.05). UVA-CXL treated IVDs showed up to 152% higher (p < 0.001) instantaneous modulus values compared to the untreated control.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n This is the first study on UVA-CXL treatment of IVD. It induced significantly increased delamination strength and instantaneous modulus indentation values in intact IVD samples in a structure\u2013function relationship. RF concentrations and UVA intensities utilized in ophthalmological clinical protocols were well tolerated by the AF cells. Our findings suggest that UVA-CXL may be a promising tool to reinforce the IVD matrix.<\/jats:p>\n <\/jats:sec>","DOI":"10.1371\/journal.pone.0252672","type":"journal-article","created":{"date-parts":[[2021,6,3]],"date-time":"2021-06-03T14:03:00Z","timestamp":1622728980000},"page":"e0252672","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":6,"title":["Can UVA-light-activated riboflavin-induced collagen crosslinking be transferred from ophthalmology to spine surgery? A feasibility study on bovine intervertebral disc"],"prefix":"10.1371","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5820-1110","authenticated-orcid":true,"given":"Ioannis","family":"Vasilikos","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4206-6326","authenticated-orcid":true,"given":"Graciosa Q.","family":"Teixeira","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andreas","family":"Seitz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Julia","family":"Nothelfer","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Julian","family":"Haas","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hans-Joachim","family":"Wilke","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Boris","family":"Mizaikoff","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J\u00fcrgen","family":"Beck","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ulrich","family":"Hubbe","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cornelia","family":"Neidlinger-Wilke","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2021,6,3]]},"reference":[{"key":"pone.0252672.ref001","doi-asserted-by":"crossref","first-page":"743","DOI":"10.1016\/S0140-6736(15)60692-4","article-title":"Global, regional, and national incidence, prevalence, and years lived with disability for 301 acute and chronic diseases and injuries in 188 countries, 1990\u20132013: a systematic analysis for the Global Burden of Disease Study 2013","volume":"386","author":"T Vos","year":"2015","journal-title":"The Lancet"},{"key":"pone.0252672.ref002","doi-asserted-by":"crossref","first-page":"2356","DOI":"10.1016\/S0140-6736(18)30480-X","article-title":"What low back pain is and why we need to pay attention","volume":"391","author":"J Hartvigsen","year":"2018","journal-title":"Lancet"},{"key":"pone.0252672.ref003","doi-asserted-by":"crossref","first-page":"2394","DOI":"10.3174\/ajnr.A4498","article-title":"MRI Findings of Disc Degeneration are More Prevalent in Adults with Low Back Pain than in Asymptomatic Controls: A Systematic Review and Meta-Analysis","volume":"36","author":"W Brinjikji","year":"2015","journal-title":"AJNR Am J Neuroradiol"},{"key":"pone.0252672.ref004","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1111\/j.1533-2500.2007.00171.x","article-title":"Intervertebral disc: anatomy-physiology-pathophysiology-treatment","volume":"8","author":"PP Raj","year":"2008","journal-title":"Pain practice: the official journal of World Institute of Pain"},{"key":"pone.0252672.ref005","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1186\/ar629","article-title":"Degeneration of the intervertebral disc","volume":"5","author":"JPG Urban","year":"2003","journal-title":"Arthritis Res Ther. BioMed Central"},{"key":"pone.0252672.ref006","doi-asserted-by":"crossref","first-page":"2545","DOI":"10.1097\/00007632-199812010-00009","article-title":"Changes in collagen cross-linking in degenerative disc disease and scoliosis","volume":"23","author":"VC Duance","year":"1998","journal-title":"Spine"},{"key":"pone.0252672.ref007","doi-asserted-by":"crossref","first-page":"1645","DOI":"10.1097\/00007632-199808010-00005","article-title":"Collagen crosslinks in human lumbar intervertebral disc aging","volume":"23","author":"HK Pokharna","year":"1998","journal-title":"Spine"},{"key":"pone.0252672.ref008","doi-asserted-by":"crossref","first-page":"2151","DOI":"10.1097\/01.brs.0000231761.73859.2c","article-title":"What is intervertebral disc degeneration, and what causes it?","volume":"31","author":"MA Adams","year":"2006","journal-title":"Spine"},{"key":"pone.0252672.ref009","doi-asserted-by":"crossref","first-page":"94","DOI":"10.1007\/s40846-016-0207-z","article-title":"Effects of Collagen Crosslink Augmentation on Mechanism of Compressive Load Sharing in Intervertebral Discs","volume":"37","author":"TP Hedman","year":"2017","journal-title":"Journal of Medical and Biological Engineering. Springer Berlin Heidelberg"},{"key":"pone.0252672.ref010","doi-asserted-by":"crossref","first-page":"1572","DOI":"10.1097\/BRS.0000000000001089","article-title":"Exogenous Crosslinking Restores Intradiscal Pressure of Injured Porcine Intervertebral Discs","volume":"40","author":"H-J Lin","year":"2015","journal-title":"Spine"},{"key":"pone.0252672.ref011","doi-asserted-by":"crossref","first-page":"560","DOI":"10.1097\/ICO.0000000000001505","article-title":"Corneal Collagen Cross-Linking With Riboflavin and Ultraviolet A Light for Pediatric Keratoconus: Ten-Year Results","volume":"37","author":"C Mazzotta","year":"2018","journal-title":"Cornea"},{"key":"pone.0252672.ref012","doi-asserted-by":"crossref","first-page":"1259","DOI":"10.1016\/j.ophtha.2017.03.052","article-title":"United States Crosslinking Study Group. United States Multicenter Clinical Trial of Corneal Collagen Crosslinking for Keratoconus Treatment","volume":"124","author":"PS Hersh","year":"2017","journal-title":"Ophthalmology"},{"key":"pone.0252672.ref013","doi-asserted-by":"crossref","first-page":"1475","DOI":"10.1016\/j.ophtha.2017.05.036","article-title":"U.S. Crosslinking Study Group. U.S. Multicenter Clinical Trial of Corneal Collagen Crosslinking for Treatment of Corneal Ectasia after Refractive Surgery","volume":"124","author":"PS Hersh","year":"2017","journal-title":"Ophthalmology"},{"key":"pone.0252672.ref014","doi-asserted-by":"crossref","first-page":"935","DOI":"10.1016\/j.ophtha.2019.02.029","article-title":"Keratoconus Natural Progression: A Systematic Review and Meta-analysis of 11\u2009529 Eyes","volume":"126","author":"AC Ferdi","year":"2019","journal-title":"Ophthalmology"},{"key":"pone.0252672.ref015","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1167\/iovs.09-3738","article-title":"Mechanisms of Corneal Tissue Cross-linking in Response to Treatment with Topical Riboflavin and Long-Wavelength Ultraviolet Radiation (UVA)","volume":"51","author":"AS McCall","year":"2010","journal-title":"Invest Ophthalmol Vis Sci"},{"key":"pone.0252672.ref016","doi-asserted-by":"crossref","first-page":"581","DOI":"10.2147\/OPTH.S188517","article-title":"Management of progressive keratoconus with partial topography-guided PRK combined with refractive, customized CXL\u2014a novel technique: the enhanced Athens protocol","volume":"13","author":"AJ Kanellopoulos","year":"2019","journal-title":"Clin Ophthalmol"},{"key":"pone.0252672.ref017","first-page":"1120672119872375","article-title":"Efficacy of pulsed-light accelerated crosslinking in the treatment of progressive keratoconus: Two-year results","author":"S Belviranli","year":"2019","journal-title":"Eur J Ophthalmol"},{"key":"pone.0252672.ref018","doi-asserted-by":"crossref","first-page":"922","DOI":"10.1007\/s00586-019-05901-w","article-title":"GEORG SCHMORL PRIZE OF THE GERMAN SPINE SOCIETY (DWG) 2018: combined inflammatory and mechanical stress weakens the annulus fibrosus: evidences from a loaded bovine AF organ culture","volume":"28","author":"T Saggese","year":"2019","journal-title":"Eur Spine J"},{"key":"pone.0252672.ref019","doi-asserted-by":"crossref","first-page":"611","DOI":"10.1373\/clinchem.2008.112797","article-title":"The MIQE guidelines: minimum information for publication of quantitative real-time PCR experiments","author":"SA Bustin","year":"2009","journal-title":"Clin Chem"},{"key":"pone.0252672.ref020","doi-asserted-by":"crossref","first-page":"1716","DOI":"10.1007\/s00586-012-2308-x","article-title":"Anular delamination strength of human lumbar intervertebral disc","volume":"21","author":"DE Gregory","year":"2012","journal-title":"Eur Spine J"},{"key":"pone.0252672.ref021","doi-asserted-by":"crossref","first-page":"858","DOI":"10.1002\/jor.23330","article-title":"Electromechanical probe and automated indentation maps are sensitive techniques in assessing early degenerated human articular cartilage","volume":"35","author":"S Sim","year":"2017","journal-title":"J Orthop Res"},{"key":"pone.0252672.ref022","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1016\/0021-9290(94)00060-H","article-title":"Comparison of optical, needle probe and ultrasonic techniques for the measurement of articular cartilage thickness","volume":"28","author":"JS Jurvelin","year":"1995","journal-title":"Journal of Biomechanics"},{"key":"pone.0252672.ref023","doi-asserted-by":"crossref","first-page":"541","DOI":"10.1016\/0021-9290(72)90010-3","article-title":"A mathematical analysis for indentation tests of articular cartilage","volume":"5","author":"WC Hayes","year":"1972","journal-title":"Journal of Biomechanics"},{"key":"pone.0252672.ref024","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.clinbiomech.2006.08.001","article-title":"Effects of exogenous crosslinking on in vitro tensile and compressive moduli of lumbar intervertebral discs","volume":"22","author":"S-Y Chuang","year":"2007","journal-title":"Clin Biomech (Bristol, Avon)"},{"key":"pone.0252672.ref025","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1163\/156856299X00289","article-title":"In vitro evaluation of cytotoxicity of a naturally occurring cross-linking reagent for biological tissue fixation","volume":"10","author":"HW Sung","year":"1999","journal-title":"J Biomater Sci Polym Ed"},{"key":"pone.0252672.ref026","doi-asserted-by":"crossref","first-page":"e202000110","DOI":"10.1002\/jbio.202000110","article-title":"Infrared attenuated total reflection spectroscopic surface analysis of bovine-tail intervertebral discs after UV-light-activated riboflavin-induced collagen cross-linking","author":"I Vasilikos","year":"2020","journal-title":"J Biophotonics"},{"key":"pone.0252672.ref027","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1046\/j.1469-7580.2002.00080.x","article-title":"Regional variations in the cellular matrix of the annulus fibrosus of the intervertebral disc","volume":"201","author":"SB Bruehlmann","year":"2002","journal-title":"J Anat"},{"key":"pone.0252672.ref028","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1159\/000357617","article-title":"UVA-photoactivated riboflavin treatment of vaginal cells derived from pelvic organ prolapse cases","volume":"77","author":"KJ Schultz","year":"2014","journal-title":"Gynecol Obstet Invest"},{"key":"pone.0252672.ref029","doi-asserted-by":"crossref","first-page":"2594","DOI":"10.1128\/MCB.19.4.2594","article-title":"The c-fos proto-oncogene is a target for transactivation by the p53 tumor suppressor","volume":"19","author":"A Elkeles","year":"1999","journal-title":"Mol Cell Biol"},{"key":"pone.0252672.ref030","doi-asserted-by":"crossref","first-page":"961","DOI":"10.1016\/j.biocel.2004.10.013","article-title":"The signals and pathways activating cellular senescence","volume":"37","author":"I Ben-Porath","year":"2005","journal-title":"Int J Biochem Cell Biol"},{"key":"pone.0252672.ref031","first-page":"1367","article-title":"Influence of microgravity-induced intervertebral disc degeneration of rats on expression levels of p53\/p16 and proinflammatory factors","volume":"17","author":"Y Li","year":"2019","journal-title":"Exp Ther Med"},{"key":"pone.0252672.ref032","doi-asserted-by":"crossref","first-page":"103","DOI":"10.22203\/eCM.v023a08","article-title":"Inflammatory and catabolic signalling in intervertebral discs: the roles of NF-\u03baB and MAP kinases","volume":"23","author":"K Wuertz","year":"2012","journal-title":"Eur Cell Mater"},{"key":"pone.0252672.ref033","first-page":"20141191","article-title":"Inflammation in intervertebral disc degeneration and regeneration. J R Soc Interface","volume":"12","author":"M Molinos","year":"2015","journal-title":"The Royal Society"},{"key":"pone.0252672.ref034","first-page":"10","article-title":"Corneal collagen crosslinking: a systematic review","volume":"232","author":"N Sorkin","year":"2014","journal-title":"Ophthalmologica. Karger Publishers"},{"key":"pone.0252672.ref035","doi-asserted-by":"crossref","first-page":"1131","DOI":"10.1007\/s00586-008-0712-z","article-title":"Recent advances in annular pathobiology provide insights into rim-lesion mediated intervertebral disc degeneration and potential new approaches to annular repair strategies","volume":"17","author":"J Melrose","year":"2008","journal-title":"Eur Spine J"},{"key":"pone.0252672.ref036","doi-asserted-by":"crossref","first-page":"4788","DOI":"10.1364\/BOE.8.004788","article-title":"Custom built nonlinear optical crosslinking (NLO CXL) device capable of producing mechanical stiffening in ex vivo rabbit corneas","volume":"8","author":"SM Bradford","year":"2017","journal-title":"Biomedical Optics Express"},{"key":"pone.0252672.ref037","doi-asserted-by":"crossref","first-page":"1660","DOI":"10.1016\/j.jcrs.2016.06.040","article-title":"Nonlinear optical corneal collagen crosslinking of ex vivo rabbit eyes","volume":"42","author":"SM Bradford","year":"2016","journal-title":"Journal of Cataract & Refractive Surgery"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0252672","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,11,4]],"date-time":"2023-11-04T09:29:09Z","timestamp":1699090149000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0252672"}},"subtitle":[],"editor":[{"given":"Demetrios G.","family":"Vavvas","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2021,6,3]]},"references-count":37,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2021,6,3]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0252672","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,6,3]]}}}