Phospholipid reinforced P(AAm-co-AAc)/Fe3+ hydrogel with ultrahigh strength and superior tribological performance

With a similar structure as natural cartilage, hydrogels show great potential in repairing cartilage defect. However, achieving high strength and excellent lubrication is still a significant challenge for hydrogels. Herein, we synthesized a series of P(AAm-co-AAc)/Fe 3+ /hydrogenated soy phosphatidylcholine (HSPC) composite hydrogels with high strength and low friction coefficient. By tuning the concentration of Fe 3+ and HSPC, the compressive strength of the composite hydrogels can reach 59.09 MPa, which is higher than that of most current existing hydrogels. Owing to the boundary lubrication and strengthening effect of HSPC, the friction coefficient of the composite hydrogel can be reduced from 0.48 to 0.06. The combination of high compressive strength and low friction under high load makes the hydrogels promising candidates for cartilage defect treatment. • Strong covalent bonds between hydrogenated soy phosphatidylcholine (HSPC) and hydrogel matrix can strengthen the hydrogel. • The hydration lubrication ability from HSPC can lubricate the hydrogel. • HSPC vesicles with a diameter of 300 nm show a better lubrication effect than vesicles with other diameters.