Scientists create new 3-D scaffold for growing stem cells
Scientists at MIT's Centre for Biomedical Engineering have created a new three-dimensional scaffold that may one day replace the ubiquitous Petri dish for growing stem cells.
Shuguang Zhang, associate director of MIT's Centre for Biomedical Engineering, and his Italian colleagues created the designer scaffold from a network of protein nanofibers, and it is more like a living body than any other cell culture system.
Each protein nanofiber used for making the scaffold was 5,000 times thinner than a human hair, and contained pores up to 20,000 times smaller than the eye of a needle.
They say that they were able to grow a healthy colony of adult mouse stem cells on the new scaffold, and that too without the drawbacks of 2-D systems.
Besides helping researchers get a more accurate picture of how cells grow and behave in the body, the new synthetic structure can provide a more conducive microenvironment for tissue cell cultures and tissues used in regenerative medicine, such as neurons to replace brain cells lost to injury or disease.
The scaffold can be transplanted directly into the body without any ill effects.
"The time has come to move on from two-dimensional dishes to culture systems that better represent the natural context of cells in tissues and organs," said Zhang, whose coauthors on the paper, in addition to Gelain, are from institutes and medical schools in Milan, Italy.
Zhang's nanofiber scaffold is around 1,000 times smaller than the existing systems of coated, 2-D Petri dishes and glass slides, which have many limitations.
With the addition of defined amino acid fragments called active motifs, the scaffold can be fashioned to coax stem cells to behave in certain desirable ways, such as differentiating into needed body tissues or migrating toward bone marrow and other natural destinations.
"What makes these designer scaffolds particularly interesting is that cells survive longer and differentiate better without additional soluble growth factors. This suggests that extracellular microenvironments may play a more important role for cell survival and for carrying out cell functions than previously thought," Zhang said.
The active motif method could be readily adapted to studying cell-to-cell interaction, cell migrations, tumor and cancer cell interaction with normal cells, cell-based drug testing and other diverse applications.
"I believe that in the next 20 years all cell cultures will be in 3D with the designer scaffolds, and most textbooks about cell biology will have to be revised when people obtain results from 3D cell culture studies," Zhang said.
The study has been published in the PLoS ONE.
