生物医学工程系学术报告1.8(报告人:刘海峰 副教授)
发布时间: 2010-01-05 02:55:00
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北京大学工学院 生物医学工程系学术报告 |
题目：Silk-based scaffolds for ligament tissue engineering
报告人 刘海峰 副教授
北京航空航天大学生物与医学工程学院
主持人：葛子钢 特聘研究员
时 间：1月8日（周五）上午9:30
地 点：廖凯原楼2-102会议室
报告内容摘要：
Silk from the silkworm, Bombyx mori, has been used as surgical suture material for centuries. In recent years, silk has been increasingly studied as the scaffold for ligament tissue engineering due to the biocompatibility, slow degradability, and remarkable mechanical properties. Braided silk scaffold modified with short polypeptide also significantly increases collagen synthesis on it. To increase cell attachment and tissue infiltration, the braided scaffold can be incorporated with silk-gelatin microsponges. A novel silk cable-reinforced gelatin/silk fibroin hybrid scaffold was fabricated, which, apart from providing proper mechanical strength and enlarged surface area, also supported the proliferation and differentiation of BMSCs on it. The knitted silk mesh is another important silk-based scaffold for its excellent mechanical properties and good nutrients transport. To prevent cells from leaking out of scaffold after seeding, electrospun nanofibers or freeze-dried silk microsponges were incorporated into the macro pores of knitted scaffold. While the knitted structure held the micro pores or nanofibers together and provided the structural strength, the microporous or nanofibers structure could mimic the ligament extracellular matrix to promote cell proliferation, function, and differentiation. In vitro culture demonstrated that BMSCs on scaffolds proliferated vigorously and produced abundant collagen. The transcription levels of ligament-specific genes (collagen I, collagen III, and tenascin-C) also increased significantly with time. The comparison of BMSCs and fibroblasts as cell sources for ligament tissue engineering demonstrated that BMSC was the most suitable candidate for its vigorous proliferation and ECM production. The BMSCs/knitted scaffolds were implanted into rabbits to regenerate ACL in vivo. After 24 weeks, histology observation showed that BMSCs were distributed throughout the regenerated ligament and exhibited fibroblast morphology. The key ligament ECM components including collagen I, collagen III, and tenascin-C were produced prominently. Furthermore, direct ligament-bone insertion with typical four zones (bone, mineralized fibrocartilage, fibrocartilage, ligament) was reconstructed, which resembled the native structures of ACL-bone insertion. The tensile strength of regenerated ligament also met the mechanical requirements of daily activities. In conclusion, the results imply that silk scaffold has great potentials in future clinical applications.
报告人简介：
主要从事组织工程生物材料的研究工作。在新加坡国立大学工作期间，主要从事肌腱、韧带组织工程的研究，利用骨髓基质干细胞和蚕丝生物支架对受损的肌腱、韧带进行修复重建。为《Biomaterials》、《Biomacromolecules》、《Journal of Biomedical Materials Research》、《Cell Biology International》、《Tissue Engineering》等杂志的特约审稿人，国际组织工程与康复医学协会（TERMIS）会员。
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