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Alptekin Aksan
Assistant Professor,
McKnight Land-Grant Professor
e-mail: aaksan@me.umn.edu
telephone: 612/626-6618

Ph.D., 2002, Mechanical Engineering, Michigan State University, E. Lansing, MI

M.S., 1995, Mechanical Engineering, Middle East Technical University, Ankara, Turkey

B.S., 1992, Mechanical Engineering, Middle East Technical University, Ankara, Turkey

Research

Biopreservation/Biothermodynamics
Stabilization of Proteins and Membranes, Anhydrobiosis, & Reversible Membrane Permeabilization

With the advances in medicine and biotechnology, especially in cell-based therapies, tissue engineering, regenerative medicine, gene therapy, cell transplantation and biopharmaceutical research, the demand for successful stabilization of proteins, cells and organs during storage is increasing. We believe that in order for the protein and cell-based therapies to be widely available, economical, efficient and safe, we need to devise ways to process, store, transport, and distribute these products without the requirement for cryogenic temperatures. We are interested in developing methods to stabilize and preserve proteins, cells, tissues and ultimately, organs in a desiccated/vitrified state.

Desiccation/Vitrification Phenomena:
Desiccation/Vitrification Kinetics of Sugar Glasses, Molecular Mobility

Due to their unique glass-forming tendency, carbohydrate-based solutions introduce certain challenges during desiccation. Depending on various factors such as their chemical properties, the glass transition temperature and the surface interactions nonhomogeneities within the drying solution arise. These effects range from the formation of very sharp concentration gradients within the processed product (the biopreservation solution containing the macromolecules, cells, etc. to be preserved) to cracking, which physically destroys the product. We are interested in engineering carbohydrate solutions to decrease the molecular mobility around proteins, membranes and in biological systems for preservation purposes.

Applications of MEMS in Bioengineering

Microelectromechanical systems have unique properties that make them very valuable for bioengineering applications. We are utilizing MEMS devices to measure intracellular mobility, viability and function of live mammalian cells during cryopreservation, desiccation and osmotic stress.

Bioheat and Mass Transfer:
Collagenous Tissue Thermomechanics/Sub-Ablative Thermal Therapies

There are numerous applications of thermal energy in medicine such as in tissue welding, thermokeratoplasty, skin resurfacing, elimination of discogenic pain in the spine and treatment of joint instability. We are interested in developing computer models to simulate the thermomechanical responses of collagenous tissues to help the physician with pre-operational planning.

Publications

Posters

Effects of Kinetic and Thermodynamic Transitions of Confined Water
on the Structures of Isolated and Cytoplasmic Proteins (PDF)

Quantification of Heterogeneity in Desiccating Droplets (PDF)

Preservation of Geobacter Sulfurreducens at Room Temperature (PDF)

Shortcourse: Preservation of Cells, Tissues, and Gametes, May 21-23, 2008: website - poster(pdf)

Laboratories

Biostabilization Laboratory

Biotransport Center