ResearchActivities

Superlubricity of synovial joint and cartilage substitutes

Abstract:
This research aims at revealing the mechanisms behind the superlubricity of joint cartilage and develop advanced cartilage substitutes. The study emphasizes the role of individual components of synovial fluid, aiming to replicate superlubricity in ex vivo conditions using both biological and synthetic materials.

Main objectives:

  • To elucidate the superlubricity mechanisms and assess the efficiency of joint cartilage viscosupplementation.

  • To investigate the role of individual synovial fluid constituents.

  • To develop hydrogel-based synthetic cartilage substitutes.

Research content:
The research focuses on developing a tribological model of natural synovial joints to better understand and describe the superlubricity mechanisms of joint cartilage. This involves detailed examination of the roles of individual synovial fluid components by monitoring friction coefficients and observing lubricant film thickness. Experiments have been conducted using both biological samples, such as animal cartilage, and hydrogel-based synthetic materials. A significant innovation in this study is the development of a unique simulator that allows for simultaneous friction measurement and film thickness evaluation through fluorescent microscopy.

The research also examines viscosupplements based on hyaluronic acid (HA), which have the potential to significantly alleviate symptoms in patients with joint osteoarthritis. Comprehensive experimental investigations have clarified the interaction mechanisms between proteins and HA, as well as the impact of HA's molecular weight and concentration on friction and lubrication. Moreover, in collaboration with an international partner, a new PVA hydrogel-based material designed to mimic natural cartilage was developed and tested. This material has demonstrated a friction reduction of up to 98% compared to conventional joint replacements indicating its promising potential as a substitute for damaged joint cartilage.

Publications:
REBENDA, D.; VRBKA, M.; ČÍPEK, P.; TOROPITSYN, E.; NEČAS, D.; PRAVDA, M.; HARTL, M. On the Dependence of Rheology of Hyaluronic Acid Solutions and Frictional Behavior of Articular Cartilage. Materials, 2020, vol. 13, no. 11, p. 1-14. ISSN: 1996-1944.
https://doi.org/10.3390/ma13112659

NEČAS, D.; YARIMITSU, S.; REBENDA, D.; SHINMORI, H.; VRBKA, M.; SAWAE, Y.; MURAKAMI, T.; KŘUPKA, I. On the Replacement of Articular Cartilage: The Friction of PVA Hydrogel Layer in Hip Simulator Test. Tribology International, 2023, vol. 178, no. Part B, p. 108100-108100. ISSN: 0301-679X. https://doi.org/10.1016/j.triboint.2022.108100

REBENDA, D.; VRBKA, M.; NEČAS, D.; TOROPITSYN, E.; YARIMITSU, S.; ČÍPEK, P.; PRAVDA, M.; HARTL, M. Rheological and frictional analysis of viscosupplements towards improved lubrication of human joints. Tribology International, 2021, vol. 160, no. 1, p. 107030-107030. ISSN: 0301-679X. https://doi.org/10.1016/j.triboint.2021.107030

Partners and Collaboration:
Kyushu University, Faculty of Engineering, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.

Contipro, a.s., Dolní Dobrouč 401, 561 02 Dolní Dobrouč, Czech Republic.

Czech Technical University in Prague, Faculty of Mechanical Engineering, Technická 4, 160 00 Praha 6, Czech Republic.

Projects:
MEBioSys – Mechanical engineering of biological and bio-inspired systems, Johannes Amos Comenius programme, CZ.02.01.01/00/22_008/0004634, 2023-2028.

An investigation of synovial fluid viscosupplementation and its impact on friction and lubrication, Czech Science Foundation – Standard grant projects, 20-00483S, 2020-2022.

Contact person:
prof. Ing. Martin Vrbka, Ph.D.