Altered swelling and ion fluxes in articular cartilage as a biomarker in osteoarthritis and joint immobilization: a computational analysis.
In healthy cartilage, mechano-electrochemical phenomena act together to maintain tissue homeostasis. Osteoarthritis (OA) and degenerative diseases disrupt this biological equilibrium by causing structural deterioration and subsequent dysfunction of the tissue. Swelling and ion flux alteration as well as abnormal ion distribution are proposed as primary indicators of tissue degradation. In this paper, we present an extension of a previous three-dimensional computational model of the cartilage behaviour developed by the authors to simulate the contribution of the main tissue components in its behaviour. The model considers the mechano-electrochemical events as concurrent phenomena in a three-dimensional environment. This model has been extended here to include the effect of repulsion of negative charges attached to proteoglycans. Moreover, we have studied the fluctuation of these charges owning to proteoglycan variations in healthy and pathological articular cartilage. In this sense, standard patterns of healthy and degraded tissue behaviour can be obtained which could be a helpful diagnostic tool. By introducing measured properties of unhealthy cartilage into the computational model, the severity of tissue degeneration can be predicted avoiding complex tissue extraction and subsequent in vitro analysis. In this work, the model has been applied to monitor and analyse cartilage behaviour at different stages of OA and in both short (four, six and eight weeks) and long-term (11 weeks) fully immobilized joints. Simulation results showed marked differences in the corresponding swelling phenomena, in outgoing cation fluxes and in cation distributions. Furthermore, long-term immobilized patients display similar swelling as well as fluxes and distribution of cations to patients in the early stages of OA, thus, preventive treatments are highly recommended to avoid tissue deterioration.
Group of Structural Mechanics and Materials Modelling (GEMM), Aragón Institute of Engineering Research (I3A), University of Zaragoza, Spain Mechanical Engineering Department, School of Engineering and Architecture (EINA), University of Zaragoza, Spain Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Spain.
Sara
S
Manzano
LAGENBIO-I3A, Veterinary School, University of Zaragoza, Spain.
Raquel
R
Manzano
Group of Structural Mechanics and Materials Modelling (GEMM), Aragón Institute of Engineering Research (I3A), University of Zaragoza, Spain Mechanical Engineering Department, School of Engineering and Architecture (EINA), University of Zaragoza, Spain Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Spain.
Manuel
M
Doblaré
Group of Structural Mechanics and Materials Modelling (GEMM), Aragón Institute of Engineering Research (I3A), University of Zaragoza, Spain Mechanical Engineering Department, School of Engineering and Architecture (EINA), University of Zaragoza, Spain Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Spain mohamed@unizar.es.
Mohamed Hamdy
http://orcid.org/0000-0003-0088-7222
MH
Doweidar
D053674:Aggrecans / Q000737:chemistry; D015415:Biomarkers / Q000737:chemistry*; D002358:Cartilage, Articular / Q000502:physiology*; D002412:Cations; D003094:Collagen / Q000737:chemistry; D003198:Computer Simulation; D004548:Elasticity; D006706:Homeostasis; D006801:Humans; D007477:Ions; D007596:Joints / Q000502:physiology*; D008962:Models, Theoretical; D010003:Osteoarthritis / Q000503:physiopathology*; D016062:Porosity; D011509:Proteoglycans / Q000737:chemistry; D012149:Restraint, Physical; D013499:Surface Properties
D053674:Aggrecans; D015415:Biomarkers; D002412:Cations; D007477:Ions; D011509:Proteoglycans; D003094:Collagen
cartilage degradation; immobilized joints; osteoarthritis; swelling process; three-dimensional mechano-electrochemical model