Stem Cells Grow in Plastic Bags (Bilione Young @ OTW)
Researchers working in Germany have come up with a solution to a perplexing stem cell problem—how to keep the cell mixtures from becoming contaminated. While doctors have been increasingly using live cells in their treatments of patients—those cells have to be kept, cultivated, reproduced or even modified in a patient-specific manner.
The problem lies in the storability of the cell solutions used. As they can easily become infected by germs, they can only be stored for a few days in the containers conventionally used today.
Investigators from five research institutions, coordinated by the Helmholz Centre for Infection Research in Braunschweig, Germany, together with partners in the industry, have developed innovative plastic surfaces for efficiently producing human cells for diagnostic and therapeutic applications. Their idea was to cultivate the cells in sealed, sterile plastic bags. The inner surface of the bags was modified to provide the cells with good conditions for survival. A team led by Dr Michael Thomas at the Fraunhofer Institute for Surface Engineering and Thin Films IST in Braunschweig, Germany, has developed a plasma technology process for use at atmospheric pressure.
”We fill the bags with a specific gas mixture and apply an electrical voltage” explains Dr. Kristina Lachmann in the November 3 press release. ”Inside them, for a brief period, plasma is created, which chemically alters the plastic surface”. During this process the bag remains sterile as plasmas, he said, also have a disinfecting action. ”The advantage of the process is that it operates at atmospheric pressure and is therefore cost-effective, fast and flexible,” said Thomas.
The new bags facilitate the sterile handling of cell cultures. Previously, researchers and clinicians had to use open Petri dishes, bottles or bioreactors. As these systems need to be opened, at least for filling, contamination can easily occur. By contrast, Thomas notes that when using the new technology with its sealed bag system, the cells migrate directly into the bag via an injection needle or connected tube systems without coming into contact with their surroundings.
The sterile interior of the bags contains a nutrient medium, germ-free air or a suitable gas, which has been added beforehand. Even during the cultivation period the containers do not have to be opened, and at the end the cells can be removed by injection needle, said Thomas.
The researchers believe that they could use the systems for growing artificial organs. If the bags are provided with a three-dimensional structure, cells could attach themselves to it and create artificial skin, nerves, cartilage or bone which could be used prosthetically in the patient.
In collaboration with the University of Tübingen, Braunschweig City Hospital plans to isolate certain stem cells from tissue samples and investigate on which of the new plastic surfaces they could develop into bone or cartilage. For this development by the group led by Thomas, the IST was awarded ”Selected Location 2011” as part of the ”Land of Ideas” initiative. The prize will be awarded in Braunschweig on December 8, 2011.