Expression of VEGF and collagen using a latex biomembrane as bladder replacement in rabbits

objective: to investigate the vegf expression and collagen deposition using a latex biomembrane as bladder replacement in rabbits. materials and methods: after partial cystectomy, a patch of a non-vulcanized latex biomembrane (2 x 2 cm) was sewn to the bladder of rabbits with 5/0 monofilament polydioxanone sulfate sutures in a watertight manner. groups of 5 animals were killed at 15, 45 and 90 days after surgery and the bladder was removed. sections of 5μm were cut and stained with picrosirius-red in order to estimate the amount of extracellular matrix in the graft. to confirm the presence of vegf in tissues, protein expression was determined by immunohistochemistry. results: no death, urinary leakage or graft extrusion occurred in any group. all bladders showed a spherical shape. a progressive reduction in the amount of collagen occurred in the graft area and was negatively and linearly correlated with time (p < 0.001). vegf expression was higher in grafted areas when compared to controls at 15 and 45 days after surgery and decreased with time (p < 0.001). conclusion: the latex biomembrane as a matrix for partial bladder replacement in rabbits promotes temporary collagen deposition and stimulates the angiogenic process.