Exploring Bioethics - NIH Office of Science Education - National ...

Ear MiceThe scarcity of organs for tissue transplantationhas created a serious medical problem. However,the ability of scientists to grow an ear on theback of a mouse may lead to viable alternatives toorgan donation as a source of organs and otherbody parts (such as corneas) for transplantation.In this instance, scientists molded sterile, biodegradablemesh into the shape of a human earand placed cartilage from a cow knee onto themesh. The mesh was then implanted into theMouse with ear scaffolding surgically implanted on its back.back of the mouse. The mouse provided energyand nutrients needed for cartilage to grow over the scaffolding through extra blood vessels grown bythe mouse. The strain of mouse used in this experiment was modified to have little or no immunesystem and, therefore, the mouse did not reject the foreign material. The goal of the research was todetermine whether this approach would be a viable method for growing organs, such as human livers,for transplantation in larger animals, such as pigs. Scientists used to think that they could grow onlysimple human tissues in culture in the laboratory, but this research shows that growing more complexstructures is possible.Photo: Courtesy Charles A. VacantiCopyright © 2009 Education Development Center, Inc. Exploring Bioethics.Permission granted for classroom use.The risks to the mouse include the surgery to implant the scaffolding and living with an ear on itsback. How many people this might benefit and how soon are not known, nor is the ultimate numberof mice to be used in this research.There are as yet no equivalent alternatives for doing this type of research. To date, organs (includingskin) and body parts can only be obtained from living human donors and cadavers.Is it ethically acceptable to use mice to research the growing of body parts? Why or why not?Master 6.2 (Page 3 of 12)