Culture of bovine pulmonary artery endothelial cells on Gelfoam blocks

Conventional methods of endothelial cell culture on monolayers and beads require enzymatic digestion, traumatic scraping, or centrifugation to transfer cells to other experimental systems. Gelfoam, a porous gelatin block, not only supports the growth of bovine pulmonary artery endothelial cells but also allows the rapid transfer of cell-laden blocks from one experimental system to another with minimal intervention. This property has been shown to be especially useful for the rapid fixation of endothelial cells for microscopy using standard histologic methods. Histology confirmed that the trabecular nature of the substrate allows endothelial cells to line the interstices of the sponge matrix and grow in a configuration that simulates the appearance of the endothelium in small vessels and capillaries. The inoculation of 1 × 10⁵ endothelial cells on 7.5 mg Gelfoam (24 × 8 × 2 mm blocks) was enhanced by fibroblast growth factor and resulted in cell attachment by day 2 with a cell doubling time of 1.7 days. In addition, endothelial cells completely infiltrated 1, 5 and 7.5 mg Gelfoam blocks, as verified by histology. Assays to quantify cell number and protein were easily performed. To facilitate cell counting, the Gelfoam matrix was rapidly removed by the addition of 0.05 mg/ml collagenase, a concentration that interfered minimally with the assay for cellular protein concentration. The data demonstrate that Gelfoam is a suitable support growth matrix for the in vitro culture of bovine pulmonary artery endothelial cells.