@article {18839,
	title = {Anti-cancer drug-eluting biodegradable stent - Aerogel approach toward the preparation of new therapies for urothelial cancer},
	booktitle = {3rd International Semiar on Aerogels},
	year = {2016},
	month = {2016-09-22 00:00:00},
	address = {Sophia Antipolis (France)},
	abstract = {<p>In this work we explore the drug-eluting ability of biodegradable ureteral stent and the possibility to use it as a support to address other, more relevant clinical scenarios in urology. In particular, we focused the work on tumors of the upper urinary tract. These are nowadays difficult to treat due the low contact time of the anti-cancer drugs with the cancer cells owing to the peristalsis of the ureter and hence poor bioavailability. To overcome the problems of conventional therapies, such as the need for frequent drug instillation and poor tolerance we developed a biodegradable ureteral stent using an aerogel approach impregnated by supercritical fluid CO<sub>2</sub>(SCF) with the most commonly used anti-cancer drugs, namely epirubicin, doxorubicin, paclitaxel and gemcitabine. We hypothesized that this type of delivery device increases the time of contact as the drugs are released closer to the site of action leading to a local delivery system. The impregnation was carried out at 40{\textordmasculine}C and 100bar for 1.5h. The release kinetics of developed anti-cancer drug-eluting stents was measured in artificial urine solution (AUS) for 9 days. The in vitro release study in AUS showed a higher release in the first 72h for the four anti-cancer drugs impregnated after this time a plateau was achieved and the stent degraded after 9 days. Regarding the amount of impregnated drugs by SCF the gemcitabine showed higher amount (109 {\textmu}g) and the lower amount was obtained for paclitaxel (67ng). The anti-tumoral effect of the developed stents in transitional cell carcinoma (TCC) - T24 cell lines was evaluated. The direct and indirect contact of the anti-cancer biodegradable stents with the T24 and a non-cancerigenous (HUVEC) cell lines confirm the anti-tumoral effect of the stents impregnated with for all the four anti-cancer drugs, reducing around 75\% of the viability of the T24 cell line after 72h and no killing effect in the HUVEC cells. This study has proven the viability of preparing an efficient system using supercritical fluids impregnation.</p>},
	keywords = {anti-cancer, biodegradable stent, urology},
	author = {Barros, A. A. and Browne, S. and Oliveira, C. and Lima, E. and Healy, K. E. and Reis, R. L. and Duarte, A. R. C.}
}
