Computational study on electromechanics of electroactive hydrogels for cartilage-tissue repair

Abdul Razzaq Farooqi; Julius Zimmermann; Rainer Bader; Ursula van Rienen

doi:10.1016/j.cmpb.2020.105739

Computational study on electromechanics of electroactive hydrogels for cartilage-tissue repair

Comput Methods Programs Biomed. 2020 Dec:197:105739. doi: 10.1016/j.cmpb.2020.105739. Epub 2020 Sep 12.

Authors

Abdul Razzaq Farooqi¹, Julius Zimmermann², Rainer Bader³, Ursula van Rienen⁴

Affiliations

¹ Institute of General Electrical Engineering, Faculty of Computer Science and Electrical Engineering, University of Rostock, Albert Einstein Str. 2, Rostock 18059, Germany; Department of Electronic Engineering, Faculty of Engineering, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan. Electronic address: abdul.farooqi@uni-rostock.de.
² Institute of General Electrical Engineering, Faculty of Computer Science and Electrical Engineering, University of Rostock, Albert Einstein Str. 2, Rostock 18059, Germany.
³ Department of Orthopaedics, University Medical Center Rostock, Rostock 18057, Germany; Department Life, Light & Matter, University of Rostock, Rostock 18051, Germany.
⁴ Institute of General Electrical Engineering, Faculty of Computer Science and Electrical Engineering, University of Rostock, Albert Einstein Str. 2, Rostock 18059, Germany; Department Life, Light & Matter, University of Rostock, Rostock 18051, Germany.

PMID: 32950923
DOI: 10.1016/j.cmpb.2020.105739

Abstract

Background and objective: The self-repair capability of articular cartilage is limited because of non-vascularization and low turnover of its extracellular matrix. Regenerating hyaline cartilage remains a significant clinical challenge as most non-surgical and surgical treatments provide only mid-term relief. Eventually, further pain and mobility loss occur for many patients in the long run due to further joint deterioration. Repair of articular cartilage tissue using electroactive scaffolds and biophysical stimuli like electrical and osmotic stimulation may have the potential to heal cartilage defects occurring due to trauma, osteoarthritis, or sport-related injuries. Therefore, the focus of the current study is to present a computational model of electroactive hydrogels for the cartilage-tissue repair as a first step towards an optimized experimental design.

Methods: The multiphysics transport model that mainly includes the Poisson-Nernst-Planck equations and the mechanical equation is used to find the electrical stimulation response of the polyelectrolyte hydrogels. Based upon this, a numerical model on electromechanics of electroactive hydrogels seeded with chondrocytes is presented employing the open-source software FEniCS, which is a Python library for finite-element analysis.

Results: We analyzed the ionic concentrations and electric potential in a hydrogel sample and the cell culture medium, the osmotic pressure created due to ionic concentration variations and the resulting hydrogel displacement. The proposed mathematical model was validated with examples from literature.

Conclusions: The presented model for the electrical and osmotic stimulation of a hydrogel sample can serve as a useful tool for the development and analysis of a cartilaginous scaffold employing electrical stimulation. By analyzing various parameters, we pave the way for future research on a finer scale using open-source software.

Keywords: Articular cartilage; Electrical stimulation; Electroactive hydrogels; Finite-element simulation; Multiphysics model; Scaffolds.

MeSH terms

Cartilage, Articular*
Chondrocytes
Extracellular Matrix
Humans
Hydrogels*
Tissue Engineering

Substances

Hydrogels