Research

Postdoctoral Research

 

Growing bacteria in picoliter droplets.

 

 

Doctoral Research

 

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Cross-sectional view of a scaffold seeded with mouse bone marrow stromal cells. Maximum intensity z-projection of a 100 micron stack acquired by 2-photon microscopy.

The goal of my doctoral research is to safely regenerate bone in response to injuries or surgical procedures where patient bone is in limited supply. The basic approach employs marrow-derived adult stem cells loaded in a delivery scaffold capable of providing the microenvironmental cues necessary for bone regeneration. I hope to address the following questions:

  1. What is the detailed progression of bone repair in a scaffold based system?
  2. How do host and donor cells interact with a biomaterial to form new tissue?
  3. What is the ideal proto-tissue prior to implantation?
  4. What is the ideal scaffold design for bone tissue engineering?

Towards addressing these questions, I: (1)  design and test scaffolds for delivering cells to an injury site and provide a bridge between undamaged host tissue, and (2) use 2-photon live animal imaging to gain insight into the cellular dynamics of the repair.

FIG. 1| Electron micrograph of scaffolds for bone regeneration. Scaffolds are used deliver cells to a site of injury and to provide a pathway for migration of host and donor cells. This particular scaffold is primarily made of type-I collagen fibers.

FIG. 2| Visualizing cells in a live animal. 2D (left) and 3D (right) 2-photon acquired images showing osteoblast cells (bone makers, GREEN) and the surrounding collagen matrix (BLUE). This image was taken in a mouse skull. 2-photon microscopy allows our team to visualize cells in living tissue.

Master’s Thesis

Stem cell fate depends on physical and chemical cues in the cell microenvironment; which can be more accurately controlled within a perfused microfluidic system. I developed a novel microculture system for murine embryonic stem cells, the volume of which is about 6 microliters. Furthermore, I outlined the optimal nutrient perfusion conditions and seeding density for self renewal of primary mouse embryonic stem cells cultured in the device. This work provides a practical description of the fabrication and use of a microculture system that provides increased control of the stem cell microenvironment.  Villa, M.M. et al., Biomed Microdevices 12, 253, 2010.

Top row: Primary mouse fibroblasts cultured in the system during development.
Bottom row L to R: Close up of the microsystem, 2 microsystems hooked up to a syringe pump, and syringe pump providing perfusion for microsystems within a cell culture incubator.