Gene expression in tissue associated with extracellular matrix modified ePTFE

Previous studies have established that surface modification of ePTFE with extracellular matrix molecules promotes vascularization within and around the implanted material. To understand the molecular basis of this tissue response to modified ePTFE, we analyzed large-scale gene expression in nonmodified and extracellular matrix-modified ePTFE-associated healing. Using a microarray containing 15,000 unique mouse cDNAs and an ANOVA-based analysis, we identified 789 genes related to cell signaling, inflammation, matrix remodeling, and proliferation that were differentially expressed across time, between modifications, or both. Genes were clustered based upon similarity in gene expression, producing 7 unique temporal super-patterns of expression. The clustered data revealed 3 general expression patterns unique to tissue surrounding the nonmodified ePTFE, while 6 unique expression patterns were associated with extracellular matrix-modified ePTFE. The more diverse expression patterns associated with extracellular matrix-modified ePTFE suggests that the tissue surrounding the extracellular matrix-modified ePTFE is more dynamic in terms of transcriptional activity. Taken together, these clusters serve as a "genetic fingerprint" for tissue healing in response to a specific material or material modification. Use of these genetic profiles will aid in the pursuit of improved device biocompatibility and enhanced material function.