Fibroblast remodeling activity at two- and three-dimensional collagen-glycosaminoglycan interfaces

Previously we demonstrated that high throughput gene expression experiments can yield novel information about how cells respond to a collagen-glycosaminoglycan (GAG) three-dimensional culture environment. The goal of the current study was to determine which of these differences result from culture in a three-dimensional construct versus those caused simply by the presence of the collagen-GAG biomaterial. To make this distinction, cells were cultured both in collagen-GAG scaffolds fabricated using a phase separation method and on thin two-dimensional coatings of the same material. Control cells were grown on standard tissue culture polystyrene (TCPS). Cell response was measured using histology and microarray analysis and select results were verified with real time polymerase chain reaction (RT-PCR) assays. Genes involved in matrix remodeling (matrix components, matrix metalloproteinases and growth factors) and angiogenesis (VEGF, HGF and HMOX) were shown to be differentially expressed between the treatment conditions. Several matrix metalloproteinases (MMPs) were up regulated in mesh grown cell while some of their inhibitors (TIMPs) were down regulated. These results suggest that the three-dimensional presentation of the collagen-GAG material to the cells is required to stimulate the observed increase in fibroblast remodeling behavior.