The Research On Controlling Lubrication And Mechanical Property Of The Responsive Hydrogel

Intelligent response hydrogels that use external stimuli as triggering conditions have unique responsiveness and broad application prospects in the field of biomedicine.Biomimetic smart hydrogels close to the requirements of the human environment have received great attention in the fields of drug release,tissue engineering,and biochips.The pH of synovial fluid is slightly acidic compared to normal body fluids and friction of joint increase when joint is affected.Therefore,designing mild pH-responsive high-strength lubricating hydrogels as alternative material for artificial joints is important.First,a pH-responsive high-strength composite hydrogel composed of pH-responsive chitosan supramolecular hydrogel and high-strength poly-2-acrylamide-2-methylpropanesulfonic acid / polyacrylamide double network hydrogel was prepared.When the composite hydrogel in neutral environment of pH=7.4,assembly of chitosan supramolecular network cause composite gel in a "non-lubricating" state.When the composite hydrogel is placed in a weakly acidic environment,the chitosan supramolecular network undergo gel-sol conversion,the disassembled chitosan sol form lubricant layer on composite hydrogel surface to control surface lubrication performance of hydrogel.At the same time,the material has high mechanical strength and reversibility,which provide a new idea for preparation of artificial joints.Biomechanical stimulation causes hepatic stellate cells changes between static and activated phenotypes.Therefore,from the perspective of external mechanical performance regulation,combined with biochemical factors;designing and preparing composite hydrogels with ionic response and mechanical properties adjustable have great significance for regulating biological functions of hepatic stellate cells.The composite hydrogel is supported by covalently crosslinked chitosan network,and fibronectin-functionalized chitosan supramolecular network with ionic response is introduced therein.The supramolecular network is assembled under the action of zinc ions,the mechanical strength of composite hydrogel is consistent with mechanical strength of activated hepatic stellate cells.Disassembly occurs under the action of iron ions,and mechanical strength of hydrogel is consistent with corresponding strength of hepatic stellate cells in static phenotype.Therefore,the hydrogel with ionic response mechanical properties adjustable can be used as a model for vitro study of hepatic stellate cell activation.In summary,this paper designs and prepares biomimetic smart hydrogels by introducing pH or ionic response factors.The pH-responsive hydrogel that responds in mild pH range realizes the regulation of hydrogel surface lubrication performance,which provide a new method for artificial joint preparation.Ionic response hydrogels have corresponding changes in mechanical properties when the ionic species change,and the mechanical properties before and after response are consistent with the mechanical strength of hepatic stellate cells activated or static phenotypes,it provides a feasible approach for the design of hepatic stellate cells activation studies.