Encouraging Stem Cell Activation Through Mechanical Means

MIT Researcher Frances Liu Investigates Mechanical Factors Affecting Stem Cell Chemical Production

Frances Liu, a third-year PhD student at the Massachusetts Institute of Technology (MIT), is delving into the intricate world of bone marrow-derived stem cells. Liu, who received her bachelor of science degree in biomedical engineering from Brown University, is expected to complete her doctorate in 2017.

Previous researchers have studied the mechanical factors on these stem cells, but their work mainly focused on a mixed population of cells, not a single well-defined cell population. Liu's work, however, aims to bridge this gap by determining the correlations between the mechanical properties of the materials the cells interact with and the chemical factors they produce in response.

Bone marrow cells are known for secreting special chemicals called cytokines, which are essential for repairing bone, fat, and connective tissue like cartilage. Liu's research could provide valuable insights into how changing the material properties of the cells' environment affects the chemicals they produce.

To achieve this, Liu is employing a microfluidic device, a tool adapted from a design by MIT Professor Jongyoon Han. This device allows for a better understanding of the differences between the subpopulations of heterogeneous bone marrow cells and the cytokines each subpopulation may be secreting.

Liu sorts her stem cells into groups using an inertial microfluidic separation device that separates large diameter cells from small diameter cells. This separation process enables her to study each group individually and observe how they respond to lab-controlled changes in their environment.

The term "Heterogeneous cellular factories" is a potential title or description for the research being conducted. The research group, led by Associate Professor Krystyn J. Van Vliet, discovered three biomechanical and biophysical markers to identify desirable stem cells from bone marrow-derived cells. MIT Professor Mehmet Toner contributed to the development of the microfluidic separation devices used to sort different subgroups of bone marrow cells.

Liu is currently in the characterization phase, quantifying which and how much of different cytokines the cells secrete in response to different chemical and mechanical cues. Her ultimate goal is to manipulate these cells using cell-material interactions or synthetic materials to produce beneficial cytokines for tissue repair.

Factors such as stiffness, acidity, and roughness of the environment can directly affect the chemicals produced by the cells. By understanding these relationships, Liu hopes to create an environment that optimises the production of desirable cytokines, potentially revolutionising the field of tissue repair.