AN IN-VITRO BIOCOMPATIBILITY EVALUATION OF DOUBLE-J STENTS

Objectives. For several years, studies performed to estimate in vitro biocompatibility of urinary catheters have been carried out using perm anent cell lines. However, for a rational design of the testing proced ure, the cell culture model should depend on the material application. We assess the biocompatibility of 13 double-J stents using an in vitr o model of normal human urothelial cells (HUC). This article aims to m imic in vitro, on HUC monolayers, the close contact existing in vivo b etween the urothelium and double-J stents and to evaluate the subseque nt effect on these cells. Methods. Fragments of each stent were deposi ted into the wells containing confluent HUC, with close contact mainta ined between the material and the cells. The same procedure with eithe r no material or fragments of latex catheter was undertaken to provide the negative and positive controls, respectively. The contact was mai ntained for 1, 3, and 8 days. At the end of the incubation period, fra gments of stent were removed and cell activity tests were performed (n eutral red assay, MTT assay, and cell proliferation). Results, One of the silicone stents is significantly deleterious on HUC as determined by three tests after 8 days of contact. For two copolymers, a tendency to increase cell proliferation was noted. Concerning polyurethanes, w e observed significant decreases in HUC viability and cell metabolic a ctivity for five stents after 8 days of contact. All seven polyurethan e stents significantly inhibited cell proliferation. Conclusions. The HUC culture model may be of relevance for the screening of materials i ntended for use as double-J stents. UROLOGY 52: 524-530, 1998. (C) 199 8, Elsevier Science Inc. All rights reserved.