EVANSTON, Ill. --- Imagine having one polymer and one small molecule that instantly assemble into a flexible but strong sac in which you can grow human stem cells, creating a sort of miniature laboratory. And that sac, if used for cell therapy, could cloak the stem cells from the human bodys immune system and biodegrade upon arriving at its destination, releasing the stem cells to do their work.
Futuristic" Only in part. A research team from Northwestern Universitys Institute for BioNanotechnology in Medicine has created such sacs and demonstrated that human stem cells will grow in them. The researchers also report that the sacs can survive for weeks in culture and that their membranes are permeable to proteins. Proteins, even large ones, can travel freely across the membrane.
This new and unexpected mode of self-assembly, to be published March 28 in the journal Science, also can produce thin films whose size and shape can be tailored. The method holds promise for use in cell therapy and other biological applications as well as in the design of electronic devices by self-assembly, such as solar cells, and the design of new materials.
We started with two molecules of interest, dissolved in water, and brought the two solutions together, said Samuel I. Stupp, Board of Trustees Professor of Materials Science and Engineering, Chemistry and Medicine, who led the research.
We expected them to mix, but, much to our surprise, they formed a solid membrane instantly on contact. This was an exciting discovery, and we then proceeded to investigate why it happened. Understanding the surprising molecular mechanism was even more exciting.
One of the molecules is a peptide amphiphile (PA), small synthetic molecules that Stupp first developed seven years ago, which have been essential in his work on regenerative medicine. The other molecule is the biopolymer hyaluronic acid (HA), which is readily found in the human body, in places l
|Contact: Megan Fellman|