Effects of intraperitoneal mitomycin C adsorbed on activated carbon on adhesion formation and mesothelial cells in vitro

Gemcitabine adsorbed onto carbon particles increases drug concentrations at the injection site and in the regional lymph nodes in an animal experiment and a clinical study

This study investigated whether gemcitabine, adsorbed onto activated carbon particles (GEM-AC), increased the concentration of gemcitabine at the injection site and in the regional lymph nodes in an experimental animal model and a clinical study. The adsorption isotherm for GEM-AC was defined, and the concentration and distribution of gemcitabine in rats (n = 50) and in patients with pancreatic cancer (n = 8) was investigated. Drug concentrations in plasma, tumour samples, lymph nodes and at the injection site were measured after GEM-AC or gemcitabine solution (GEM-Sol) were subcutaneously injected into the left hind foot pad in rats, or into pancreatic tumours in patients. These experiments showed that GEM-AC was selectively delivered to the regional lymph nodes and the injection site, from which it slowly released greater amounts of gemcitabine to maintain the free concentration of gemcitabine at a relatively high level for a long period of time. The administration of GEM-AC might enhance the anticancer effects of gemcitabine.

The optimal starting time of postoperative intraperitoneal mitomycin-C therapy with preserved intestinal wound healing

Background

There is controversy about the effect of the timing of intraperitoneal administration of chemotherapeutic agents on the healing of intestinal anastomosis. We have investigated the effect on intestinal wound healing of mitomycin-C administered at different times post-operatively.

Methods

Eighty-four Wistar-Albino female rats underwent ileal resection and end-to-end anastomosis. The rats were randomly selected for intraperitoneal administration of mitomycin-C or saline as follows: mitomycin-C group (n = 65), 2 mg/kg mitomycin-C; control group (n = 13), 10 ml saline. The former was sub-divided into 5 equal groups (A 1–5) and mitomycin-C was administered postoperatively as follows: day 0 (A1), day 3 (A2), day 5 (A3), day 7 (A4) and day 10 (A5). All the rats were sacrificed on the 14th postoperative day and anastomotic bursting pressures and tissue hydroxyproline levels were determined.

Results

Five of the animals died postoperatively: 2 (15.4%) in group A1, 2 (15.4%) in group A2 and 1(7.7%) in group A3. Non-lethal anastomotic leakage was observed in a further five animals: 1 in group A1, 2 in group A2, 1 in group A5 and 1 in the control group. Groups A1 and A2 had significantly lower anastomotic bursting pressures than the other groups (P was <0.05 for each comparison). The anastomotic bursting pressures of group A3, A4 and A5 were comparable with those of the controls (P was >0.05 for each comparison). Tissue hydroxyproline levels in group A1 and A2 were significantly lower than in the controls (P values were <0.05 for each comparison) or the other mitomycin-C sub-groups (P was <0.05 for each comparison).

Conclusions

Intraperitoneal chemotherapy impairs intestinal wound healing when applied before the 5th postoperative day. Additional therapeutic approaches are needed to prevent this potentially lethal side effect of early intraperitoneal mitomycin-C administration.