Control of drug accessibility on functional polyelectrolyte multilayer films.

A surface coating based on polylysine/hyaluronic acid multilayers was designed and acted as a reservoir for an antiproliferative agent, paclitaxel (Taxol). Absolutely no chemical modification of polyelectrolytes or of the drug was needed and the final architecture was obtained in an extremely simple way using the layer-by-layer method. The paclitaxel dose available for human colonic adenocarcinoma cells HT29 seeded on the films could be finely tuned. Moreover, the accessibility of the drugs was controlled by adding on the top of the drug reservoir a capping made of synthetic polyelectrolyte multilayers. This capping was also required to allow adhesion of HT29 cells. Paclitaxel activity was maintained after embedding in the polyelectrolyte multilayers and cellular viability could be reduced by about 80% 96 h after seeding. The strategy described in this paper could be valuable for various other drug/cell systems.