 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
|
||||
 |
 |
 |
 |
 |
|
||||||||||
 |
 |
 |
 |
 |
 |
 |
 |
 |
|
||||||
 |
 |
 |
 |
 |
|
||||||||||
|
|
CTEC Projects :::: Bioreactors and Mass Transport Regulation of mass transport (MT) of nutrients such as oxygen (O2), and glucose, signaling molecules such as TGF-ß1, and waste products such as CO2, or lactate is critical for the success of all cell based therapies. This is particularly true for the therapeutic strategies involving cell implantation into 3D matrices, and in vitro fabrication of 3D tissue constructs which lack an internal capillary exchange network. In such Cases, MT must occur by diffusion, and is severely limited by the inability of these molecules to diffuse through more than a few layers of cells. As a result, MT optimization using external convection and/or supplemental convection through mechanically induced deformation or fluid pressure gradients is essential for efficient growth of thick tissue constructs. Bioreactors for therapeutic cell culture must be designed to provide such optimized environments. Oxygen tension is of particular importance. Changes in O2 tension and particularly hypoxia (low oxygen conditions, such as those found in most living tissues) have profound effects on the activation, proliferation, migration, differentiation, and survival of stem cells. Furthermore, acute hypoxia is an inevitable feature of both transplantation and wound healing environments that must be considered in the design of tissue engineering strategies. Despite this fact, the vast majority of in vitro experiments are currently performed at O2 concentration well above physiological conditions (21% FiO2, pO2=152 mmHg). This is four times the pO2 in a normal capillary bed, and perhaps 20-fold higher than conditions 1 mm deep in a 3D cellular implant. This practice persists primarily due to the challenge of reducing the FiO2 in conventional incubators, during media changes and other manipulations. To enable CTEC investigators to effectively address both MT and O2 tension in their experiments we have established two core facilities, a Bioreactor Core and an Oxygen Tension/Hypoxia Core. Project #14. Bioreactor Core. Investigators: J. Welter, H. Baskaran, L. Solchaga
Project #15. Oxygen Tension (Hypoxia) Core. Investigators: G. Muschler, C. Boehm, C Nakamoto, S Villarruel
Project #16. Molecular Surface Design of Polymers
Scaffold for Tissue Engineering. Investigators: H.A.von Recum, G. Zimmerli
|
|
|