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Current Research Projects
The primary focus of my research is in the area of tissue engineering. Tissue engineering is the application of engineering principles with the life sciences to develop system to repair or replace living tissue that has been lost due to injury or disease. Several projects are in development for our lab. Click on the links to learn more details about the various projects or contact Dr. Gregory Rutkowski for additional information.
The goal of this project is to create bioreactor system to for growing long segments of nerve tissue. The nerve tissue can be used in the surgical repair of nervous tissue. This reactor can also be used to study the regenerative process in vitro.
The goal of this project is to develop a tissue dense bioreactor for production of a pharmaceutical product. The system is based on a melanoma cell line with unique properties that help with the distribution of nutrients to the tissue.
Future Research Projects
Below are some project ideas that are just that...ideas. They are in no particular order. If you want to discuss them in more detail, feel free to contact me.
Microencapsulation of Single Cells
Encapsulation of cells and tissue with a synthetic coating is an important issue when using cells that can elicit a strong immune response. To date, most work has dealt with the encapsulation of large cell populations (>300 microns). This project proposes a method for encapsulating single cells (5-10 microns) using a novel biodegradable polymer. The goal is too use this mthos to encapsulate cells for microenvironmental control of tissue formation as well as cell therapy.
Neural network formation
Building on the work for the nerve tissue bioreactor, microfabrication techniques will be used to encourage neurons form synaptic connections. By combining, inhibitory and excitatory neurons, we can build living neural networks that may have computational ability. Computer modeling will also be used to describe the communication within a small network. The research will also aid in studies involved with the introduction of neurons to already established neural networks.
Multiple lumen conduit production for nerve regeneration
A bioartificial nerve consists primarily of a cylindrical tube that guides the extension of the axons through the center lumen. Though the growth is restricted to the lumen, individual axons may still meander within the confined space. Artificial nerve grafts, containing up to seven lumens restrict the space for growth and further direct the axon extension in the axial direction. A BNG containing hundreds of tiny lumens would further restrict the space and ensure axons stay aligned with target. An extruder die can be fabricated using microfabrication techniques to create polymer tubes consisting of hundreds of micron scale lumens. Such a tube would be used as part of a bioartificial nerve graft. Research would involve the development of the die and the optimization of parameters to ensure a tube with intact lumens can be formed. A kinetic diffusion model will also be developed to describe cell growth and nutrient and growth factor concentrations in three dimensions and unsteady state within the graft.
Bioartificial nerve graft mass transfer model
The regeneration of nerve tissue is a very complex process involving the timing of several different growth factors. With the bioartificial nerve graft, these factors are synthesized by Schwann cells. I have developed a simple mass transfer model (steady state, radial direction only) but would like to expand this to include axial diffusion as well as the extension of the axon bundle over time.
Endothelial alignment for blood vessel engineering
The inner surface of arterial blood vessels is comprised of endothelial cells aligned in the circumferential direction. This alignment contributes to the ability of the blood vessel to withstand higher blood pressures. Reactive ion etching can be used to create micron scale grooves in a surface. These grooves encourage the cells to align in the same direction. This technique will be used to develop a support structure for blood vessel engineering that encourages the endothelial cells to align in the appropriate direction.
Surface chemistry for stem cell differentiation
Stem cells are cells that can differentiate into a variety of cells depending on the origin. Embryonic stem cells have potential to differentiate into all the cells of the body while adult stems cells are limited. Whether working with adult or embryonic stem cells, most of the of the research in controlling differentiation has dealt with diffusible factors in solution. Since cells also receive cues from contact, I would like to evaluate the ability of surface bound molecules to encourage differentiation. Eventually, I would like to use microfabrication technique to create patterns of different molecules that would then lead to corresponding patterns of different cells that originate from the same stem cell line.
3-Dimensional biodegradable polymer scaffolds based on swelling characteristics
When placed in contact with water, polymers will adsorb the water to some extent and swell. This characteristic is dependent on the type of polymer used. By combining various polymers and other biocompatible materials with differing water adsorption characteristic, unique structures can be formed that can have applications for tissue engineering and drug delivery.
Cyclic Biodegradable Polymers
Recently, researchers have synthesized high molecular weight cyclic polyethylene. The characteristics of this cyclic polymer differ from the straight chain polymer. Cyclic polymers synthesized from biodegradable polymer, such as poly-glycolic acid, would have unique properties with respect to the degradation rate. For example, initial breaks in the polymer chain would just convert the cyclic polymer to a straight chain polymer without effecting the molecular weight. Such a characteristic may have interesting applications to tissue engineering and drug delivery.
Removal of Blood Born Pathogens
Many blood born pathogens such as viruses and certain bacteria attack the cells within the human body by attaching to proteins found on the surface of cells. Cells that express these specific surface receptors can be placed in the shell side of a hollow fiber membrane system. These cells can act as an attractant to remove the pathogens before they attack the body's own cells. Preliminary work would involve the removal of animal virus from liquid media and than blood. Eventual applications include reduction of HIV from patients with end stage AIDS to enhance the ability of traditional treatments drug treatments as well as remove or reduce fast acting viruses for which there are no current treatments (i.e. Ebola).
Generation of Electricity using a Convection Cell
I know. What does this have to do with tissue engineering? Well, nothing really, but this idea popped into my head after teaching heat and mass transfer. Basically, in a convection cell, a fluid circulates via free convection between two plates. One plat has a high temperature and the other is low. I would like to model a system in which solar radiation heats up one panel, the heat forces the fluid to circulate as the heat is then removed from the cold side away from the sun. Theoretically, a turbine can be placed within the circulating fluid to generate electricity. Properties of materials (thermal conductivity, heat capacity, radiation adsorptivity, etc) as well as the physical dimensions may make this a viable option for solar power. I would like to develop a model of the heat transfer and fluid dynamics of this system to examine the feasibility.