Cartilage-bone inspired the construction of soft-hard composite material with excellent interfacial binding performance and low friction for artificial joints

Inspired by the cartilage-bone structure in natural joints, soft-hard integrated materials have received extensive attention, which are the most promising candidates for artificial joints due to their combination of excellent load-bearing properties and lubricating properties. The latest progress showed that the combination of hydrogel and titanium alloy can realize a bionic natural joint lubrication system on the surface of titanium alloy. However, obtaining a tough interface between the hydrogel (soft and wet) and the titanium substrate (hard and dry) is still a great challenge. Here, we designed a soft (hydrogel)-hard (Ti6Al4V) integrated material with outstanding combination, which simulates the structure and function of cartilage-bone in the natural joint. The load-bearing properties, binding performance, and tribological behaviors for different forms of the soft-hard integrated materials were investigated. The results showed that the hydrogel layer and Ti6Al4V substrate possess ultra-high interfacial toughness (3,900 J/m(2)). In addition, the combination of the hydrogel layer and Ti6Al4V substrate provided a good lubrication system to endow the soft (hydrogel)-hard (Ti6Al4V) integrated material with high load-bearing and excellent tribological properties. Therefore, this study provided an effective strategy for prolonging the service life of Ti6Al4V in the biomedical field.

Automated summary

Inspired by natural joint structure, researchers designed a soft-hard integrated material that simulates the structure of cartilage and bone. The combination of hydrogel layer and titanium substrate provides high load-bearing and excellent tribological properties.