%0 Journal Article
%T Intravital Microscopic Research of Microembolization with Degradable Starch Microspheres
%A Micaela Ebert
%A Juergen Ebert
%A Gerd Berger
%J Journal of Drug Delivery
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/242060
%X Treatment efficacy in cancer patients using systemically applied cytostatic drugs is decreased by cytotoxic side effects, which limits the use of efficient dosages. Degradable starch microspheres (DSM) are used to apply drugs into blood vessels which supply the target organ leading to drug accumulation in the target organ by reduction of the blood flow. The present investigations show that DSM is a very effective embolization material leading to effective and enhanced accumulation of 5-FU within the liver tumor tissue of experimental induced liver cancer in rats. By using intravital microscopy, a rapid deceleration of the blood flow into the target organ is observed immediately after application of DSM. The microspheres are stepwise degraded in the direction of the systemic blood flow and are totally dissolved after 25 minutes. These stepwise processes leave the degraded material during the degradation process within the vessels leading to temporally reciprocal blood flow via some of the side-arms of the major blood vessels. By using DMS in transarterial chemoembolization (TACE), severe adverse side effects like postembolization syndrome are rarely observed when compared to other embolization materials. The complete degradation of DSM causes only a short-lasting temporary vascular occlusion, which allows a repeat application of DSM in TACE. 1. Introduction Systemic chemotherapy in cancer patients with liver tumors or liver metastases shows up to now especially with respect to the prolongation of overall survival insufficient results probably due to not high enough local tumor drug dosages [1]. Collins and coworkers could show that the response rates can be doubled when the drug concentration is increased by a factor of 10 [2]. However, systemic applied cytostatic drugs may worsen the quality of life of patients by sometimes very severe adverse side effects especially when used in high dosages. Those cytotoxic side effects limit the use of efficient dosages. Thus, since several years various techniques were investigated and used for intra-arterial administration of certain cytostatic drugs, which allows higher drug concentrations [3]. It could be shown, for example, that regional infusion of 5-fluorouracil (5-FU) increases liver exposure to the drug by a factor of 100 when compared to intravenous application route [4]. In fact, meanwhile, several randomized clinical trials in colon cancer patients suffering from liver metastases have shown that the intra-arterial application of 5-FU or floxuridine leads to increased response rates with a tendency to
%U http://www.hindawi.com/journals/jdd/2013/242060/