Self-assembled Materials Form Mini Stem Cell Lab

The article discussed how a research team from Northwestern University’s Institute for BioNanotechnology in Medicine was able to create instantly assembling sacs in which human stem cells can be grown. The sacs have been found to survive for weeks in culture and their membranes are permeable to proteins.

The sacs, made of peptide amphiphile(PA), small synthetic molecules, and the biopolymer hyaluronic acid(HA), readily found in places like joints and cartilage in the human body. When the HA solution was poured into a vial with the PA solution, the heavier HA molecules sank and were engulfed by the smaller PA molecules creating a closed sac with the HA solution trapped inside the membrane. In addition, these two molecules can be used to make many different structures including sacs, with a solid membrane on the outside and liquid in the inside, and flat membranes of any shape. Furthermore the structures, which can vary in size, can be stretched with tweezers and easily repaired through self-assembly should the material have a defect or tear.

In this study the human stem cells were then engulfed by the self-assembly process inside the sacs that they placed in the culture. The researchers found that the cells remained viable for up to four weeks, the large protein growth factor important in signaling the stem cells could cross the membrane, and the stem cells were able to differentiate.

This method could be not only be used in cell therapy and other biological applications but could also be used in the design of electronic devices by self-assembly, such as solar cells as well as the design of new materials.

I found this article interesting because of all the potential this discovery holds. In the article they discussed how these sacs could be used to cloak stem cells from the immune system, confine cancer cells for study and even architect new solar cells or nanoscale columns of catalytic nanostructures that would extend over macroscopic dimensions. There seems to be thousands of applications of these sacs.

http://www.sciencedaily.com/releases/2008/03/080327172303.htm