METHODOLOGY
We strive to construct the 3-D model with normal primary (non-transformed) cell lines. The significance of the non-transformed cell is highlighted by Sexton et al, 2008:
"By utilizing normal (non-immortalized) human tissue, potential species-related differences which may compromise data evaluation lessens. The full spectrum of pathophysiological effects resulting from in vivo exposure to toxic airway particulates can only be realized in a biological model in which the cell-cell interactions can be fully transcribed and translated by the cellular genetic response to those toxins."
The 3-D cell culture models overcome the inherent problems associated with the traditional 2-D monolayer culture such as the following:
- Cellular de-differentiation
- Loss of metabolic functionality
In contrast, 3-D tissue culture technology alleviates these problems:
- Cells are cultured on beads or fiber platforms, forming tissue-like organoids
- Cells assume their native spatial conformation
- Cell-cell interactions relative to their phenotype characteristics and metabolic functionality
The 3-D model assumes the phenotype and functionality of in vivo tissue.
Model Engineering: Aliquots of frozen cells are thawed and propagated in 2-D cell culture flasks until sufficient numbers are recovered and then infused into a bioreactor. With multiple cell types, this procedure is repeated until all required cell lines have been infused. The infused cells continue to propagate and develop within the bioreactor to a predetermined time point. At certain points along the developmental timeline, aliquots of cells are removed for quality control of histology, viability and apoptosis.
Advantages of 3-D cell culture technology:
- Pathogens not currently supported by 2-D cell culture or laboratory animal models
- Detection and identification of pathogen metabolic pathways
- Definition of host cell-pathogen receptors
- Recognition of host cell innate responses
- Rapid pre-clinical screening of novel therapeutic candidates