Bioinspired Hydroxyapatite Coating Infiltrated with a Graphene Oxide Hybrid Supramolecular Hydrogel Orchestrates Antibacterial and Self-Lubricating Performance

Abstract

Hydroxyapatite (HA) bioceramic coating has been extensively applied for the modification of metallic implants to improve their biocompatibility and service life after implantation. Unfortunately, HA coating often suffers from high friction, severe wear, and bacterial invasion, which restrict its application in artificial joints. According to a bioinspired soft/hard combination strategy, a novel HA composite coating that is infiltrated with a vancomycin-loaded graphene oxide (GO) hybrid supramolecular hydrogel is developed via vacuum infiltration and a subsequent host−guest interactioninduced self-assembly process. The holes of textured HA ceramic coating act just like a "magic pocket", offering a stable container to form and store GO hybrid hydrogels and even to recycle wear debris as well. The drug-loaded hybrid hydrogels stored in textured HA coating possess a unique shear force and/or frictional heat triggered gel−sol transition and sustained drug release behavior, acting like the extrusion of synovial fluid during articular cartilage movement, leading to a remarkable self-lubrication, anti-wear performance, and promising antibacterial property against Staphylococcus aureus. The friction coefficient and wear rate of composite coating reduced by nearly five times and three orders of magnitude compared with textured HA coating, respectively, which benefited from the synergistic lubricate effect of cyclodextrin-based pseudopolyrotaxane supramolecular hydrogel and GO lubricants.

Synergistic Effects of Ultrasonic Rolling Textures and PTFE‐PPS/SiO2 Coatings on Dry Friction and Wear Properties of GCr15 Steel Surfaces

“…The main mechanisms of synergetic performance improvement were as follows: 1) Texture grooves could store lubricating materials and continuously supply them to the interface of the friction pair, so that the lubricating transfer film could maintain for a longer time. [ 39 ] 2) Textures could improve the adhesion between the lubricant coating and substrate. [ 40 ] However, the results showed that only the L2 texture and solid lubricant coating synergistically improved the tribological properties of the substrate.…”

Tribological Behavior of Bioinspired Surfaces

“…In a 15% texture ratio, the T-shaped network texture’s friction coefficient drops to 0.077, a 38% reduction from the original surface [ 250 ]. Self-lubricating artificial joints benefit from this strategy for friction reduction [ 254 , 255 , 256 , 257 ]. Therefore, the Y-shaped network has been recommended to improve friction/tribological performance.…”

Adhesive Gel System Growable by Reversible Addition–Fragmentation Chain Transfer (RAFT) Polymerization

“…6−8 Many gel materials have good and interesting elastic properties and can deform their shapes smoothly without disrupting their chemical structures. 9 Thus, these materials are expected to be used in various applications such as coating reagents, 10,11 soft actuators, 12,13 soft robotics, 14,15 soft sensors, 16 and artificial biomaterials. 17,18 To date, researchers have attempted to create various functional gel materials to use in the above applications.…”

“…Gel materials , consist of solvents and three-dimensional polymeric networks formed from low-molecular-weight molecules − or polymers. − Many gel materials have good and interesting elastic properties and can deform their shapes smoothly without disrupting their chemical structures . Thus, these materials are expected to be used in various applications such as coating reagents, , soft actuators, , soft robotics, , soft sensors, and artificial biomaterials. , To date, researchers have attempted to create various functional gel materials to use in the above applications. For example, gel materials that shrink and expand depending on time based on the Belousov–Zhabotinsky (BZ) reaction have been reported. , These gel materials oscillate like a heartbeat.…”