Stem cells have been touted as the potential key to treating ailments ranging from Parkinson’s disease and multiple sclerosis to spinal cord injuries, to name just a few. That’s because they can be made into any type of cell that’s needed – they’re essentially the plasticine of the cell world. The problem that scientists have encountered is the difficulty in growing them. For one thing, it’s hard to grow enough of them to perform large-scale experiments. For another, most of the materials upon which the stem cells are grown contain cells or proteins from mouse embryos, which stimulate cell growth but would probably also cause an immune reaction if injected into a human recipient. Researchers from MIT, however, have just announced the creation of a new growing surface that does away with both of these limitations.
The new surface is synthetic, contains no foreign animal material, and lets stem cells stay alive and reproduce themselves into the millions, for at least three months. It’s also the first such material that allows single cells to form colonies of identical cells, which is necessary for identifying cells with desired traits, and has been difficult to achieve with traditional materials.
Currently, stem cells are grown in plastic dishes coated with a layer of gelatin and then a layer of mouse cells or proteins. According to MIT team member Krishanu Saha, this medium is notoriously inefficient for growing the amount of cells needed, over the extended time period necessary. “For therapeutics, you need millions and millions of cells,” he stated. “If we can make it easier for the cells to divide and grow, that will really help to get the number of cells you need to do all of the disease studies that people are excited about.”
To create their growing surface, the scientists tried out about 500 polymers with varying degrees of roughness, stiffness, and surface hydrophobicity (water-repelling behavior). While the first two variables seemed to make little difference, they discovered that there was indeed an optimal range of hydrophobicity that the cells liked best. They also found that the best polymers contained a high percentage of acrylates, a common ingredient in plastics. They coated these polymers with a protein called vitronectin, which encourages cells to attach to surfaces.
The scientists now hope to develop other growing surfaces tailored to other types of cells.
The research was recently published in the journal Nature Materials.