CAREER: Biomimetic Engineering of Responsive Biomaterials

生物世界中最强大和最快的运动之一可以在单细胞纤毛原生动物Vorticella convallaria中找到。在其生活史的一个阶段，Vorticella由大小约50m的细胞体和长2~3 mm、宽4m的柄组成。Vorticella茎能够以每秒1000倍于其身体大小的速度收缩。据观察，Vorticella茎的收缩是人类骨骼肌平均功率的500倍。Vorticella茎内的收缩细胞器是一种被膜包裹的蛋白质纤维结构，称为痉挛。生物响应材料比任何合成材料都更有效率和效果。Vorticella spasmoneme是一种高效响应性生物材料的极好例子。痉挛蛋白在与钙离子浓度结合的简单物理化学条件下起作用。一旦钙被排出，触发的收缩是非常迅速和完全可逆的。该项目的研究目标是通过研究钙离子浓度变化等生物信号来仿生设计基于聚合物的生物材料，用于设计钙敏感生物材料。这项研究将对仿生工程和生物材料科学产生重大的社会影响。该项目的教育部分将为不同层次的学生提供服务。外展将包括代表性不足的本科生和K-12学生。外展活动将是为霍华德大学的本科生举办的关于仿生响应材料的讲习班，以及为明尼苏达州科学博物馆提供的仿生材料的图解博物馆实验。

Chun0547613One of the most powerful and the fastest motions in the biological world can be found in a single-cell ciliated protozoan, Vorticella convallaria. At one stage of its life cycle, the Vorticella consists of a cell body of approximately 50 m'm in size and a stalk of 2~3 mm long, 4 m'm wide. The Vorticella stalk is capable of contracting at a speed almost 1000 times its body size per second. The Vorticella stalk contraction is observed to be 500 times the average power of human skeletal muscle. The contractile organelle within the Vorticella stalk is a membrane-surrounded protein-based fiber structure called 'spasmoneme'.The biological responsive materials are more efficient and effective than any synthetic materials ever made. The Vorticella spasmoneme represents an excellent example of a highly efficient responsive biomaterial. The spasmoneme functions on simple physical chemical terms of binding to calcium ion concentration. The triggered contraction is very fast and fully reversible upon removal of calcium. The research goal of the project is to biomimetically design polymer-based biomaterials that are responsive to biological signals such as changes in calcium ion concentration by studying the spasmin protein for the design of calcium sensitive biomaterials. The research would have great societal impact in biomemetic engineering and biomaterial science. The educational component of the project will serve students at different levels. The outreach will include underrepresented undergraduate students and K-12 students. The outreach activities will be a workshop on biomimetically responsive materials for the undergraduate students at Howard University and also illustrative museum experiments of biomimetic biomaterials for the Science Museum of Minnesota.