据3月7日的《科学》（Science）杂志报道，研究人员已经研发出了一种新型材料，该材料就像海参一样可以在僵硬与松软状态之间转换。这样的材料也许某一天可用于生物医学移植上，如作为围绕脑中微电极的保护鞘。该保护鞘在植入的时候应该是呈刚性的，但可以在以后变成柔软状态，以减轻对周围组织的冲击。（微电极现在被用于巴金森氏病、中风及脊髓损伤的治疗，但这种治疗随着机体在坚硬的移植物周围生成疤痕组织而降低了疗效。）
Jeffrey Capadona及其同僚在某橡胶状共聚混合物中加入了纤维素纳米纤维，或称“晶须”。 当研究人员加入一种引起氢键结合的溶剂后，该溶剂打断了纤维之间的键合，因而使该材料变软。当该溶剂挥发之后，在晶需之间的网络结构会重新形成，因此而使该材料变硬。研究人员所用的是来自被囊动物（一种固着海洋动物）套膜中的纤维素晶须。不过他们表示，可再生性物质如木材和棉花也可作为类似纳米纤维的来源。（来源：EurekAlert!中文版）
生物谷推荐原始出处:
（Science），Vol. 319. no. 5868, pp. 1370 - 1374，Jeffrey R. Capadona，Christoph Weder
Stimuli-Responsive Polymer Nanocomposites Inspired by the Sea Cucumber Dermis
Jeffrey R. Capadona, Kadhiravan Shanmuganathan, Dustin J. Tyler, Stuart J. Rowan, Christoph Weder
Sea cucumbers, like other echinoderms, have the ability to rapidly and reversibly alter the stiffness of their inner dermis. It has been proposed that the modulus of this tissue is controlled by regulating the interactions among collagen fibrils, which reinforce a low-modulus matrix. We report on a family of polymer nanocomposites, which mimic this architecture and display similar chemoresponsive mechanic adaptability. Materials based on a rubbery host polymer and rigid cellulose nanofibers exhibit a reversible reduction by a factor of 40 of the tensile modulus, for example, from 800 to 20 megapascals (MPa), upon exposure to a chemical regulator that mediates nanofiber interactions. Using a host polymer with a thermal transition in the regime of interest, we demonstrated even larger modulus changes (4200 to 1.6 MPa) upon exposure to emulated physiological conditions.
