betadex and Peritoneal-Neoplasms

To evaluate the tumour growth delay of a peritoneal carcinomatosis (PC) of colorectal origin after intraperitoneal chemotherapy with paclitaxel/randomly-methylated-β-cyclodextrin (Pac/RAME-β-CD) versus Taxol® at normo- and hyperthermic conditions in rats.. Hyperthermic intraperitoneal chemotherapy (HIPEC) was performed 7 days post implantation of the tumour with both formulations at a Pac concentration of 0.24 mg/ml. Tumour evaluation was performed via positron emission tomography (PET) and magnetic resonance imaging (MRI) imaging, measuring tumour activity and tumour volume, respectively. Scans were taken at 2 and 7 days post treatment.. PET and MRI data showed a significant reduction in tumour activity and tumour volume for rats treated with Pac/RAME-β-CD (at normo- and hyperthermic conditions), compared to the control group. Treatment with Taxol® did not result in a significant reduction of tumour activity and tumour volume. No significant differences between the normo- and hyperthermic conditions were observed for both formulations, indicating that hyperthermia and paclitaxel were not synergistic despite the direct cytotoxic effect of hyperthermia.. Monitoring tumour growth via PET and MRI indicated that Pac/RAME-β-CD inclusion complexes had a significantly higher efficacy compared to Taxol® in a rat model for peritoneal carcinomatosis.

Topics: Animals; Antineoplastic Agents; beta-Cyclodextrins; Cell Line, Tumor; Colorectal Neoplasms; Combined Modality Therapy; Disease Models, Animal; Hyperthermia, Induced; Injections, Intraperitoneal; Magnetic Resonance Imaging; Paclitaxel; Peritoneal Neoplasms; Positron-Emission Tomography; Rats; Time Factors; Tumor Burden

Hyperthermic intraperitoneal chemotherapy (HIPEC) is a promising strategy in the treatment of peritoneal carcinomatosis. To perform HIPEC, a tensioactive- and solvent-free paclitaxel formulation consisting of water-soluble paclitaxel/randomly methylated-beta-cyclodextrin (Pac/RAMEB) complexes was developed previously. Using MTT and SRB assays the cytotoxic activity of this formulation versus Taxol, was evaluated as well as the cytotoxicity of the different formulation excipients (RAMEB and Cremophor EL. The possible synergistic effect of heat and paclitaxel-based chemotherapy during HIPEC was also evaluated in vitro. The cytotoxicity assays revealed differences in viability between Cremophor EL and RAMEB treated cells of 40 and 50% for the CaCo-2 human and the CC531s rat colon cancer line, respectively, in favour of RAMEB. Despite the higher cytotoxicity of Cremophor EL, Pac/RAMEB complexes and Taxol were equipotent. Using the MTT and SRB assays the average difference in viability between both cell lines was below 10% and IC50 values showed no significant difference. Hyperthermia after drug administration (41 degrees C during 1h) had no effect on cell viability. These results indicated that it was possible to reformulate paclitaxel with a less cytotoxic vehicle while maintaining the cytotoxic activity of the formulation and that there is no synergism between paclitaxel and heat for in vitro cytotoxicity.

Topics: Animals; Antineoplastic Agents, Phytogenic; beta-Cyclodextrins; Caco-2 Cells; Cell Culture Techniques; Cell Survival; Combined Modality Therapy; Drug Carriers; Excipients; Hot Temperature; Humans; Hyperthermia, Induced; Paclitaxel; Peritoneal Neoplasms; Rats