Application of multiphysics models to efficient design of experiments of solute transport across articular cartilage.
Transport of solutes helps to regulate normal physiology and proper function of cartilage in diarthrodial joints. Multiple studies have shown the effects of characteristic parameters such as concentration of proteoglycans and collagens and the orientation of collagen fibrils on the diffusion process. However, not much quantitative information and accurate models are available to help understand how the characteristics of the fluid surrounding articular cartilage influence the diffusion process. In this study, we used a combination of micro-computed tomography experiments and biphasic-solute finite element models to study the effects of three parameters of the overlying bath on the diffusion of neutral solutes across cartilage zones. Those parameters include bath size, degree of stirring of the bath, and the size and concentration of the stagnant layer that forms at the interface of cartilage and bath. Parametric studies determined the minimum of the finite bath size for which the diffusion behavior reduces to that of an infinite bath. Stirring of the bath proved to remarkably influence neutral solute transport across cartilage zones. The well-stirred condition was achieved only when the ratio of the diffusivity of bath to that of cartilage was greater than ≈1000. While the thickness of the stagnant layer at the cartilage-bath interface did not significantly influence the diffusion behavior, increase in its concentration substantially elevated solute concentration in cartilage. Sufficient stirring attenuated the effects of the stagnant layer. Our findings could be used for efficient design of experimental protocols aimed at understanding the transport of molecules across articular cartilage.
Department of Orthopedics, UMC Utrecht, Heidelberglaan100, 3584CX Utrecht, The Netherlands; Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628CD Delft, The Netherlands. Electronic address: b.pouran-2@umcutrecht.nl.
Behdad
B
Pouran
Department of Orthopedics, UMC Utrecht, Heidelberglaan100, 3584CX Utrecht, The Netherlands; Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628CD Delft, The Netherlands; Department of Mechanical Engineering, University of Birjand, 61597175 Birjand, Iran.
Vahid
V
Arbabi
Department of Orthopedics, UMC Utrecht, Heidelberglaan100, 3584CX Utrecht, The Netherlands; Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628CD Delft, The Netherlands; Department of Rheumatology, UMC Utrecht, Heidelberglaan100, 3584CX Utrecht, The Netherlands.
Harrie
H
Weinans
Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628CD Delft, The Netherlands.
Amir A
AA
Zadpoor
D000818:Animals; D001692:Biological Transport / Q000502:physiology*; D002358:Cartilage, Articular / Q000737:chemistry* / Q000378:metabolism*; D004058:Diffusion; D005269:Femur / Q000737:chemistry; D020342:Finite Element Analysis; D006736:Horses; D008954:Models, Biological; D014283:Triiodobenzoic Acids / Q000737:chemistry; D055114:X-Ray Microtomography
D014283:Triiodobenzoic Acids; C044834:iodixanol
Articular cartilage; Bath stirring; Biphasic-solute finite element model; Iodixanol bath; Micro-CT; Neutral solute diffusion; Stagnant layer