Study On Sericin Gel With Thixtropy

Sericin is a natural high molecular polymer with a wide range of sources as a by-product of silk industry.Many studies have shown that sericin has good biocompatibility,hydrophilicity,etc.,it can be prepared into gel,film,foam,fiber composite materials which are widely used in tissue engineering.Due to the complexity of structure and the properties,so far,for the study of sericin is still very limited.In this paper,three aspects including hydrogen bond,charge and molecular agglomeration had been investigated to studied the formation mechanism of sericin gel systematically.Results show that the hydrogen bond interaction and charge between molecules,and molecular agglomeration affect the gelation of sericin solution.The strength of hydrogen bond and charge is positively correlated with gelation,while molecular agglomeration hinders gelation.This paper also describes the thixotropy of sericin gel,that is,the continuous decrease of viscosity with time when flow is applied to a sample that has been previously at rest and the subsequent recovery of viscosity in time when the flow is discontinued.The thixotropy and regelation is an isothermal reversible conversion process.In this paper,with combination of the formation mechanism and thixotropy,the change of structure,cross-sectional morphology,viscosity and gel time had also been investigated to study sol-gel system.The shear action on sericin only destroys the cross-linking of network due to hydrogen bonding and charge action,but does not cause the change of secondary structure.When sericin dissolved in 0.9% saline,then form gel as a injectable scafford for tissue engineering.The feasibility of the injectable scaffolds was further explored.Put sericin gel whose solvent is saline into percoll after 7 days,and its mass was 83% left.Sercin is injectable resulted from the decrease of viscosity after shear action.It just took within 1-40 min to accomplish regelation from the sol-gel state to regelation state,and the greater the solid content,and then the shorter the time of geation.Sericin dissolved in saline,gel with different solid content had been prepared for fibroblasts culture.The results indicated that HS-865 fibroblasts grew well in the 3D scaffords in all groups,especially,when fibroblast was seeded in sercin gel whose solid content is less than 2%,their proliferation activities are much better than those solid content is higher than 2%.In summary,the sericin gel whose solvent is saline meets the need for injectable hydrogels and has great potential in the development of intelligent injectable tissue engineering hydrogel materials.