ABSTRACT
Although intravenous administration of high levels of cisplatin (CDDP) are limited due to its severe side effects, efficient delivery of CDDP directly to the tumor should improve the therapeutic response while potentially by-passing significant side effects. High loading of CDDP into liposomes is one technique that could be used as a potential drug delivery system. Since cis-diamminedinitratoplatinum (CDDP3) is highly soluble in water and converts to CDDP in the presence of chloride ions, we encapsulated CDDP3 into liposomes in the absence of chloride ions and supplemented chloride ions to prepare CDDP-encapsulated liposomes (CDDP-Lip) resulting in a significantly improved loading efficiency of CDDP. We further conjugated the CDDP-Lip with Sialyl Lewis(X) (CDDP-SLX-Lip) because we previously demonstrated Sialyl Lewis(X) enhanced efficient accumulation of liposomes into tumors in vivo. CDDP-SLX-Lip treated mice showed a survival rate of 75% at 14 days even if a lethal level of CDDP was injected into mice. Loss of body weight was negligible and no histological abnormality was found in a variety of normal tissues. Accumulation of CDDP-SLX-Lip was about 6 times more than that of CDDP-Lip or CDDP. As the result, there was better antitumor activity of CDDP-SLX-Lip than that of CDDP-Lip with significantly less toxic effects in normal tissues.
Subject(s)
Antineoplastic Agents/administration & dosage , Cisplatin/administration & dosage , Drug Delivery Systems/methods , Liposomes , Oligosaccharides/administration & dosage , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Cell Line, Tumor , Cells, Cultured , Cisplatin/chemistry , Cisplatin/pharmacokinetics , Drug Delivery Systems/adverse effects , E-Selectin/metabolism , Female , Mice , Mice, Inbred BALB C , Oligosaccharides/chemistry , Sialyl Lewis X Antigen , Survival Rate , Xenograft Model Antitumor AssaysABSTRACT
BACKGROUND AND AIM: As a tool for examining the small intestine, double-balloon enteroscopy (DBE) has been used routinely. However, there remain a few issues relating to the handling of DBE, such as attaching a balloon to the tip of the scope, and inflating/deflating the two balloon systems. Recently, we developed a novel single-balloon enteroscopy (SBE) system for the examination of the small intestine. The aim of the present study was to evaluate the insertion technique, the safety, and the clinical impact of the SBE system. PATIENTS AND METHODS: Between January 2006 and June 2007, all patients undergoing enteroscopy with the Olympus SBE system (length 200 cm, outer diameter 9.2 mm) were studied. Instead of a balloon attached to the distal scope end, the distal scope end was hook-shaped, and manipulating the up-angle or down-angle of the scope end enabled exploration of the small intestine. RESULTS: A total of 78 procedures were performed in 41 patients (24 men, 17 women; mean age 48.9 years, range 23 - 85 years). The indications for the examination were suspected mid-gastrointestinal bleeding (n = 12), Crohn's disease (n = 17), abdominal pain (n = 8), and abdominal tumor (n = 4). The mean procedure time was 62.8 +/- 20.2 minutes and 70.4 +/- 19.3 minutes for the oral and anal routes, respectively. Among 24 patients in whom total enteroscopy was attempted, the entire small intestine was explored in 6. CONCLUSION: SBE is not only easy to perform, due to the single balloon, but it can also safely examine the deep small intestine. Therefore, SBE may be a useful diagnostic and therapeutic tool in addition to DBE for investigating suspected small bowel disease.
