Migration pattern, morphology and viability of cells suspended in or sealed with fibrin glue: a histomorphologic study

INTRODUCTION: We studied the migration pattern, morphology and viability of cells suspended in five different fibrin glues. Besides this, the behaviour of chondrocytes seeded on porous matrices comprising different collagen types sealed with fibrin glue was investigated. MATERIAL AND METHODS: In an experiment A, cell suspension (0.5x10(6) cells) was incubated with different fibrin glues. Experiment B was set up to evaluate chondrocytes migration either through a collagen I/III (Chondro-Gide, Geistlich Biomaterials, Switzerland) or collagen II matrix sealed with different fibrin glues in a perfusion chamber system. Analysis were performed by lightmicroscopy (Mayer's hematoxylin-eosin; Masson-Goldner; TUNEL test) and by transmission and scanning electron microscopy. All fibrin glues were measured for TGF-beta 1 and 2 with a specific ELISA. RESULTS: After incubation of cell suspension in autologous fibrin glue, the morphology of cells is chondrocyte-like. Spindly, process-bearing cells were seen in commercial fibrin glue. Cells suspended in commercial fibrin glue revealed a significant higher percentage of TUNEL positive cells compared to fibrin tissue adhesives mixed with autologous serum (p=0.006). The TGF-beta 1 and 2 concentration was significantly higher in partial autologous fibrin sealant (PAF) compared to their commercial counterparts (p=0.001). Cells seeded on the collagen I/III matrix retained their chondrocytic morphology, while in the type II collagen matrix the chondrocytes displayed a fibroblastic phenotype. The ratio of TUNEL positive cells for the collagen I/III matrix was significantly surpassed by the values, when a collagen II matrix was used (p=0.008). No ingrowth of cells was seen in any of the experimental conditions. CONCLUSION: Partial autologous fibrin glue and collagen I/III matrices are favourable in respect to migration pattern, morphology and viability, but definitive conclusions can only be drawn after in vivo studies. This will be addressed in future animal studies.