Preparation And Medical Application Of Chitosan Based Self-healing Hydrogel

Hydrogels are widely used in biomedical fields due to its dynamic self-healing property.In this paper,a self-healing chitosan hydrogel(CPH)was constructed based on dynamic Schiff base.The basic properties such as mechanical strength,injectability,self-healing,shape adaptation,and biocompatibility were evaluated.The potential applications of CP hydrogel in clinical tumor thermal ablation and 3D stem cell culture were further investigated.Thermal ablation has the merits of minimally invasive,rapid and accurate,low pain and high efficiency.Normal saline is used as a thermal ablation insulator to protect adjacent tissues from local high temperature burns.However,due to its leachability,poorly thermal shielding performance,and frequency injection,saline can easily lead to complications such as secondary injury.The self-healing hydrogel was used as a protective medium to challenge the clinical formulation(saline、non self-healing hydrogel F127)and injected around the ablation zone to isolate and protect the adjacent tissue owing to its “flowing solid”properties.The results showed that CPH exhibited superior thermal shielding performance in thermal ablation of thyroid nodules in a Beagle dog model compared to saline and non-self-healing hydrogel F127.The thermal physical properties of the hydrogel were measured using the transient planar source(TPS)method.The results showed that CPH has lower thermal diffusivity and higher heat capacity compared to F127.The mechanism of thermal shielding was further revealed to be related to the form of water molecules present in the gel and the thermal stability of the cross-linking agent PEG.Three-dimensional stem cell culture has created new technologies for studying stem cell biological behavior.CPH can be used for 3D stem cell culture.NCTC clone 929(L929)were set as the control group and bone marrow mesenchymal stem cells(BMSC)as the experimental group.The selectivity of BMSC for hydrogel scaffold matrix stiffness,and their growth and proliferation behavior within the scaffold were investigated.The cell proliferation data showed that both BMSC and L929 were proliferated;the cell live/dead staining results demonstrated that the cells were capable of growing and proliferating normally in the hydrogel.In conclusion,the excellent properties of CPH endow it with excellent thermal shielding ability,rapid clearance in vivo and potential of three-dimensional cell culture,which will provide a theoretical basis and direction for clinical application of hydrogels.