Ph.D. Dissertation Defense: Natalie Chernets
Friday, January 31, 2014
1:00 PM-3:00 PM
Title: Enhancement of Skeletal Cell Differentiation by Microsecond Pulsed Dielectric Barrier Discharged Plasma
Advisor: Dr. Gary Friedman
Date: Friday, January 31, 2014
Time: 1:00 p.m.
Location: ECE Conference Room 302, 3rd Floor, Bossone Research Enterprise Center
Plasma medicine has yet to successfully demonstrate that utilization of non-thermal plasma (NT-plasma) technology has clinical potential in medicine and biology. Current concepts being tested in the laboratory range from wound healing to cancer suppression and even dental applications. To date clinical trials testing NT-plasma effects have mainly focused on its bacteriostatic and bacteriocidal properties in patients possessing chronic and acute wounds, or diverse skin and itching diseases. Further development of NT-plasma as a clinical tool depends on gaining a better understanding of the mechanisms underlying NT-plasma interactions with living organisms. Several strategies have been employed including; characterizing NT-plasmas, determining cellular response to specific NT-plasmas and identification of NT-plasma modifications to the environment surrounding cells and tissues. The successful accomplishment of these goals and to prove plasma medicine has true clinical potential requires a multiple disciplinary approach where physicists, chemists, biologists, and electrical, mechanical and biomedical engineers work together with clinicians to meet the needs of the medical community.
The best characterized mechanism underlying NT-plasma activity on both eukaryotic and prokaryotic cells is the generation of ROS and RNS at the cell/environment interface which elicits an immediate intracellular oxidative response. This thesis tests the hypothesis that NT-plasma promotes redox dependent changes to enhance differentiation and developmental signaling Using murine limb autopod development and mesenchymal cell differentiation, this study elucidates the mechanisms of how NT-plasma generated intracellular ROS and extra- and intracellular calcium flux determine the effectiveness of NT-plasma treatment. Additionally, NT-plasma parameters including electrode size, plasma dose, filament formation and energy density were compared to determine both cellular response and treatment effectiveness.
Results of this study indicate that NT-plasma stimulation increases intracellular ROS production to activate oxidative-stress responsive proteins and gene expression. If applied under the appropriate conditions NT-plasma can induce chondrocyte differentiation, osteoblast differentiation and mouse limb autopod development. The enhancement of limb autopod elongation by NT-plasma requires increases in intracellular calcium. Intracellular calcium is increased by NT-plasma treatment through the activation of voltage gated calcium channels on the plasma membrane. Tolerable NT-plasma dose was governed by both biological model and electrode geometry and size. Energy density was not effective enough to predict cellular response to NT-plasma or to characterize the filament pattern which strongly depended on electrode size in frequencies higher than 50Hz.
The potential uses of this technology, both translational and clinical, include improved healing after skeletal injury, tissue engineering and regenerative medicine applications.