A Study On Two Sericin Hydrogels Prepared By Different Crosslinking Methods

With good bioactivity and excellent biocompatibility,sericin has broad application prospects in tissue engineering and medical regeneration.However,there are still some problems including cross-linking toxicity,poor mechanical properties,poor transparency,and further sterilization after gelation that existing sericin hydrogels have,which limited their application.In this study,sericin of bombyx mori were extracted by different methords.Two newly sericin hydrogels were fabricated based on different cross-linking methods and their physicochemical properties and cell compatibility were systematically studies.The purpose of this subject was to explore the potential application value of sericin hydrogel in tissue engineering and medical regeneration.1.Preparation and application of a sterile self-assembled hydrogel extracted by high temperature and high pressureA two-step method to fabricate self-assembled sterile sericin hydrogel was developed in this project.For the first time,the silk fibroin-deficient silkworm cocoons were ground into powder.Since the increased contact area between the powder and water,sterile sericin solution with the highest concentration about 15w/v%could be obtained by a high extraction rate of 95%.Sericin hydrogel prepared by self-assembly with sericin solution in a sterile environment.Firstly,the hydrogel has a mild gelation condition and a simple preparation process.The gelation time is controllable ranging from a few minutes to several hours,and it is could be controlled by adjusting concentration,pH,temperature.The hydrogel contains no toxic substances especially cross-linking agents and it could be used to culture cells or fabricate tissue engineering material directly without additional sterilization.At the same time,the sericin hydrogel has good biocompatibility and cell adhesion.Sericin hydrogels scaffolds frozen at different temperature have various pore size ranging from 3 to 100?m which can be widely applied to repair various types of tissues.The sericin hydrogel has excellent swelling behavior and the maximum swelling rate reaches to 1250%.The sericin hydrogel has degradability,the degradation rate is 67%in 28 days.The hydrogel is hard,and the maximum compression modulus can reach to 2279 KPa.As a model drug,HRP can be controlled to maintain slow release for more than 22 days.Thus,the sericin self-assembled sterile hydrogel can be used as a multifunctional platform for drug,bioactive factor and cell delivery vehicles.2.Preparation and application of sericin-polyacrylamide interpenetrating double network?IPN?hydrogelIn this study,in order to prepare a polyacrylamide hydrogel with good mechanical properties,high transparency,degradability and cell adhesion,the design concept of interpenetrating double network was introduced in this study.The sericin-polyacrylamide interpenetrating double network?IPN?hydrogel was fabricated with the crosslinking agent H₂O₂.The IPN hydrogel had the following characteristics:?1?The IPN hydrogel was highly transparent.?2?With the addition of sericin,the compressive modulus of the IPN hydrogel was greatly improved from 10KPa to 23 KPa.?3?The pore size and porosity of IPN hydrogel were adjustable and increased with the increase of sericin proportion.?4?The hydrogel had controllable swelling properties and good degradation properties.The highest equilibrium water content of the sample was 86.7%,and the water absorption and degradability were adjusted by controlling the ratio of sericin to acrylamide.?5?IPN hydrogel has good cell adhesion,it can support cell growth and proliferation effectively.In summary,the IPN hydrogel can be used as a 3D biological scaffold in the field of tissue engineering and regenerative medicine.