Tribological Rehydration and Its Role on Frictional Behavior of PVA/GO Hydrogels for Cartilage Replacement Under Migrating and Stationary Contact Conditions

Abstract

Graphene oxide (GO) was incorporated into polyvinyl alcohol (PVA) hydrogel to improve its mechanical and tribological performances for potential articular cartilage replacement application. The compressive mechanical properties, creep resistance, and dynamic mechanical properties of PVA/GO hydrogels with varied GO content were studied. The frictional behavior of PVA/GO hydrogels under stationary and migrating contact configurations during reciprocal and unidirectional sliding movements were investigated. The effects of load, sliding speed, diameter of counterface, and counterface materials on the frictional coefficient of PVA/GO hydrogels were discussed. PVA/0.10wt%GO hydrogel show higher compressive modulus and creep resistance, but moderate friction coefficient. The friction coefficient of PVA/GO hydrogel under stationary and migratory contact configurations greatly depends on interstitial fluid pressurization and tribological rehydration. The friction behavior of PVA/GO hydrogels shows load, speed, and counterface diameter dependence similar to those observed in natural articular cartilage. A low friction coefficient (~ 0.03) was obtained from PVA/0.10wt%GO hydrogel natural cartilage counter pair. Graphical Abstract

Low-Friction Hybrid Hydrogel with Excellent Mechanical Properties for Simulating Articular Cartilage Movement

“…Gan et al found that the existence of nano-hydroxyapatite makes (PVA-HA/HACC) DN hydrogels have a low friction coefficient (0.026), excellent wear resistance, and good cytocompatibility, which offers a potential application for DN hydrogels in cartilage repair . The research on the tribological properties of hydrogels mostly focuses on the reciprocation of hydrogels and hard materials (such as stainless steel and Titanium alloy) as friction pairs, leading to the obtained friction coefficient with great fluctuation. − Few literature studies involve in the soft–soft contact mode between hydrogels, which is closer to simulate the actual working conditions of human articular cartilage.…”

PVA-Based Hydrogels Loaded with Diclofenac for Cartilage Replacement

“…As both moduli were practically independent of the studied frequency range, this also reveals a stable gel-like behavior of the materials. Although values of the same order of magnitude have been found for G’ and G’’ by other authors for PVA hydrogel [ 55 ], they are quite different depending on the hydrogel composition, the preparation protocols, and measurement methodology [ 56 ]. It must be stressed that the values found in the literature for natural cartilage are about one order of magnitude superior for G’ and two orders for G’’ [ 57 , 58 ].…”

Electrospun fibrous membrane reinforced hydrogels with preferable mechanical and tribological performance as cartilage substitutes

“…In the PPG-4 hydrogel, the multilayer ordered fibrous membrane mimic the ordered collagen fiber of articular cartilage to endow excellent mechanical properties on the PPG-4 hydrogel that much higher than that of the pure PPG hydrogel. The tribological properties of hydrogels are usually improved by adding a lubricating medium (liposome 50 or lamellar lubricating particles [51][52][53] ) or grafting molecular brush. 10 Studies have shown that GO can significantly reduce the coefficient of friction of hydrogels, resulting in PPG hydrogels showed a low coefficient of friction (Table S1, ESI †).…”