Determining equilibrium osmolarity in poly(ethylene glycol)/chondrotin sulfate gels mimicking articular cartilage

JOURNAL OF THEORETICAL BIOLOGY

卷:364

Article

Sircar, S.¹  Aisenbrey, E.²  Bryant, S. J.^2,3,4  Bortz, D. M.⁵ 

[1] Univ Adelaide, Sch Math Sci, Adelaide, SA 5000, Australia

[2] Univ Colorado, Dept Chem & Biol Engn, Boulder, CO 80309 USA

[3] Univ Colorado, BioFrontiers Inst, Boulder, CO 80309 USA

[4] Univ Colorado, Mat Sci & Engn Program, Boulder, CO 80309 USA

[5] Univ Colorado, Dept Appl Math, Boulder, CO 80309 USA

关键词: Polyelectrolyte gel;    Multi-phase mixture;    Donnan potential;    Cross-links;    Hydrogel;   

DOI  :  10.1016/j.jtbi.2014.09.037

来源: Elsevier

【 摘 要 】

We present an experimentally guided, multi-phase, multi-species polyelectrolyte gel model to make qualitative predictions on the equilibrium electro-chemical properties of articular cartilage. The mixture theory consists of two different types of polymers: poly(ethylene gylcol) (PEG), chondrotin sulfate (ChS), water (acting as solvent) and several different ions: H+, Na+, Cl-. The polymer chains have covalent cross-links whose effect on the swelling kinetics is modeled via Doi rubber elasticity theory. Numerical studies on equilibrium polymer volume fraction and net osmolarity (difference in the solute concentration across the gel) show a complex interplay between ionic bath concentrations, pH, cross-link fraction and the average charge per monomer. Generally speaking, swelling is aided due to a higher average charge per monomer (or a higher particle fraction of ChS, the charged component of the polymer), low solute concentration in the bath, a high pH or a low cross-link fraction. A peculiar case arises at higher values of cross-link fraction, where it is observed that increasing the average charge per monomer leads to gel deswelling. (C) 2014 Elsevier Ltd. All rights reserved.

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