Preparation Of Sericin Hydrogel And Scaffold For Biomedical Applications

Part one Sericin/Dextran Hydrogel as a Drug Delivery System for Malignant Melanoma TreatmentObjective:To explore the sericin/dextran injectable hydrogel as an optically trackable drug delivery system for oncotherapy.Methods:At beginning, we used heat and alkaline degumming method to extract the sericin from cocoons (Bombyx mori, Baiyu). Next, the sericin was modified by adipodihydrazide (sericin-ADH). Meanwhile, we synthesized different oxidation degree of dextran dialdehyde (DEX-AL). We prepared the sericin/dextran composite hydrogels by mixed with the different concentration of sericin-ADH and DEX-AL. Furthermore, the physical, chemical and biological properties of sericin/dextran composite hydrogels were tested. Moreover, the release behavior of sericin/dextran composite hydrogels was detected. Finally, we treated the malignant melanoma by the hydrogels loaded Doxorubicin.Results:(1) We successfully extracted sericin by heat and alkaline degumming method from cocoons (Bombyx mori, Baiyu) and modified by adipodihydrazide; (2) We prepared the different concentration of DEX-AL; (3) We prepared the sericin/ dextran injectable hydrogel; (4) The hydrogels have better biodegradation and biocompatible property; (5) The hydrogels, which loaded large and small molecule drugs, could be implanted into the body by injection; (6) The hydrogels were monitored degradation and release behavior by the photoluminescence of hydrogels; (7) The hydrogels could inhibit the growth of tumor by loaded Doxorubicin.Conclusion:The sericin/dextran injectable hydrogel is a photoluminescence drug delivery system, which could monitor the degradation and release behavior by photoluminescence in vivo. Meanwhile, sericin/dextran injectable hydrogel loaded doxorubicin could inhibit growth of tumor.Part two The Preparation of Sericin Hydrogel Cross-linked by UV Light and its Application as a 3D ScaffoldObjective:To explore the sericin-MA hydrogels, which prepared by UV light, used as three dimensional scaffolds in biomedicine.Methods:Firstly, we used heat and alkaline degumming method to extract the sericin from fibroin-deficient mutant silkworm (Bombyx mori,140 Nd-s) and modified by methacrylic anhydride.Meanwhile, the sericin-MA hydrogels were prepared by mixed with the sericin-MA and Irgacure 2959 and exposured in UV light. We used'H-NMR to detect the grafting degree of double bond. Moreover, the FTIR analysis revealed the change of protein secondary structure of sericin-MA. Furthermore, the physical, chemical and biological properties of hydrogels were tested. In addition, we selected HRP as pattern drug to evaluate the release behavior. Finally, we detected the biocompatible property and 3D cell culture of hydrogels.Result:(1) We successfully extracted sericin by heat and alkaline degumming method from fibroin-deficient mutant silkworm (Bombyx mori,140 Nd-s) and modified by methacrylic anhydride; (2) This sericin could sterilize by filtration and retained by freeze-dried; (3) We successfully prepared the sericin hydrogels by UV light; (4) The hydrogels have better biodegradation and biocompatible properties; (5) The hydrogels could be used as drug delivery system to carry large and small molecule drugs; (6) The hydrogels were monitored in vivo by the photoluminescence; (7) The hydrogels have better cell adhesion property, which could promote cell proliferation and support cell survival in a long period of time; (8) The hydrogels could support three dimensional cell culture.Conclusion:The sericin-MA hydrogels could promote the cell adheresion and proliferation, which could be used as three dimensional scaffolds and applied in tissue engineering and regenerative medicine.Part three The Study of Sericin Hydrogel Applied in Wound RepairObjective:To explore the sericin-MA hydrogels used as tissue engineering materials applied in wound repair.Methods:Firstly, we established mouse model of lack whole skin. Moreover, we selected sericin-MA hydrogels as skin regenerating materials applied in mouse model of lack whole skin and PELNAC as controls. At each time point, the areas of wound site were monitored. Furthermore, the skin of wound site was removed and stained by H&E, Masson, CD68, MPO, VEGF, CD31 and a-SMA. In addition, we extracted the RNA from the skin tissue and NIH 3T3 cells and detected the relative mRNA level of VEGF and EGF of each groups.Results:(1) The wound recovery rate of sericin-MA groups was quickly than controls. (2) The wound recovery degree of sericin-MA groups was better than controls. (3) Inflammatory response of sericin-MA groups was better than controls. (4) The angiogenesis of sericin-MA groups was better than controls; (5) The relative mRNA level of VEGF of sericin-MA groups was higher than controls; (6) The relative mRNA level of EGF of sericin-MA groups was higher than controls; (7) The relative mRNA level of VEGF of sericin-MA co-culture with NIH3T3 was higher than controls; (8) The relative mRNA level of EGF of sericin-MA co-culture with NIH3T3 was higher than controls.Conclusion:The sericin-MA hydrogels could be used as artificial skin applied in wound repair.