Preparation And Characterization Of Ion And PH Response Lubricating Hydrogel

The supramolecular monomer forms a crosslinked network through specific,directed,dynamic,non-covalent interactions.Supramolecular hydrogels exhibit many excellent properties such as stimuli responsiveness and self-healing properties.Its main applications are artificial cartilage substitutes,superabsorbent materials,storage media,and drug release in biomedical applications.Because of its good biocompatibility and the ability to selectively mimic the viscoelasticity of human tissues,supramolecular hydrogels have wide application prospects in biomedicine,especially in the preparation of biomimetic artificial cartilage.Articular cartilage is capable of achieving ultra-low surface friction characteristics under high contact pressure.However,as the age increases or the lesion occurs,the liquid environment in the joint will change,especially the ionic strength or pH of the synovial fluid.These changes cause weaken of the physicochemical properties of the cartilage tissue(such as lubrication ability and Anti-wear ability).Therefore,it is particularly important to design the material to maintain the lubrication characteristics under the condition of ionic strength or type change.In this paper,we designed a synergistic system combine a high-intensity hydrogel and a ion-responsive supramolecular hydrogel,in order to control the surface lubrication of hydrogel by regulating the ion species and charged state of hydrogel materials.First,we designed a composite hydrogel combining high-strength double network hydrogel polyacrylamide-polyvinyl alcohol and ion/pH-responsive chitosan-zinc ion supramolecular network.On the one hand,the double-network high-strength hydrogel polyacrylamide-polyvinyl alcohol can provide good mechanical support to the composite hydrogel.On the other hand,the ion/pH-responsive chitosan-zinc ion system could occur sol-gel conversion when the external pH or ion species changes.The sol-gel conversion allows the hydrogel to self-lubricate when subjected to friction.This process have good reversibilityMoreover,by introducing metal ions with different valence states,the chitosan-zinc ion system in the composite hydrogel undergoes sol-gel conversion to achieve the purpose of reversible regulation of hydrogel surface lubrication.This high-intensity ion-response lubrication Hydrogel greatly enhances the stability and environmental adaptability of bionic cartilage and has a widely medical prospect.In summary,combine a high-strength hydrogel with ion/pH response self-lubricating supramolecular system,we designed and prepared a high-strength hydrogel with ion/pH-response ability.This work provides a new thought for preparation of the bionic cartilage with self-lubricating ability.