Description of a novel approach for intraperitoneal drug delivery and the related device.

BACKGROUND: Two significant limitations of intraperitoneal drug therapy are limited drug distribution and poor penetration into peritoneal nodules. A possible solution is the application of the so-called "therapeutic pneumoperitoneum," taking advantage of the gaseous nature and the pressure of capnoperitoneum during laparoscopy. Our objective was to develop a device able to apply such therapeutic pneumoperitoneum. METHODS: The technology presented here is a spraying device and can be introduced through a trocar. It is driven by mechanical pressure and consists of an injector, a line, and a nozzle. An in vivo experimental study was performed in five pigs. A transvaginal cholecystectomy was performed. At the end of the procedure, a standard dose of methylene blue was sprayed/infused into the abdominal cavity for 30 min (4 test animals w/therapeutic pneumoperitoneum (12 mmHg CO(2)) and 1 control animal w/conventional lavage (2 l intra-abdominal volume with extracorporeal circulation)). At the end of the procedure, all animals were autopsied and the peritoneum was analyzed. Outcome criteria were: (1) drug distribution (as assessed by the stained peritoneal surface at autopsy), and (2) diffusion into the peritoneum (presence or not of macroscopic staining of the outer aspect of the peritoneum immediately after surgery). RESULTS: Stained peritoneal surface was larger after aerosol application compared with peritoneal lavage, and staining more intense. Hidden peritoneal surfaces and the anterior abdominal wall were stained only in the aerosol group. In contrast to peritoneal lavage, the outer aspect of peritoneal membrane was immediately stained after pressurized spraying. CONCLUSIONS: This device and the related approach significantly improve both distribution and penetration of a test substance into the peritoneal cavity in a large animal model. This might be a significant progress in treating intraperitoneal disease, in particular peritoneal carcinomatosis.

Therapeutic approach of human peritoneal carcinomatosis with Dbait in combination with capnoperitoneum: proof of concept.

BACKGROUND: Peritoneal carcinomatosis is an unmet medical need. Laparoscopy offers a unique opportunity to control and to steer the operating environment during surgery by loading carbon dioxide with a therapeutic substance and creating the so-called therapeutic capnoperitoneum. We have treated a human sample of peritoneal carcinomatosis from an endometrial adenocarcinoma ex vivo just after surgery. METHODS: A nontoxic therapeutic agent (Dbait) was aerosolized into a box containing diseased human peritoneum under a pressure of 12 mmHg CO(2). Dbait (noncoding DNA fragments) acts through jamming DNA damage sensing and signaling, ultimately inhibiting DNA repair system of cancer cells. Dbait were coupled to cholesterol molecules to facilitate intracellular uptake, and to Cyanine (Cy5) to allow detection by fluorescence. In a control experiment, the same solution was applied to the other half of the sample using conventional lavage. RESULTS: Physical results revealed fluorescence within the tumor up to 1 mm depth in the therapeutic capnoperitoneum sample and no uptake in the lavage sample. Biological results showed intranuclear phosphorylation of H2AX in the nebulized sample and no activity in the lavage sample. Importantly, tumor nodules showed more activity than the neighbor, normal peritoneum. Detection of histone gamma-H2AX (phosphorylated H2AX) reveals activation of DNA-dependent protein kinase (DNA-PK) by Dbait, which has been shown to be the key step for sensitization to genotoxic therapy. CONCLUSIONS: Dbait are taken up by cancer cells and have a biological activity up to 1 mm depth. Nebulization of the molecule is significantly more effective than conventional lavage. This proof of principle supports the need for clinical studies applying therapeutic capnoperitoneum together with Dbait for treating peritoneal carcinomatosis.