A Peritoneal Implant Combines Treatment and Sampling: Ovarian Cancer Research Takes a First Step in Mice

Once ovarian cancer enters the abdominal cavity, treatment involves more than determining how to kill the tumor. It also requires delivering drugs to the disease site and continuously observing changes within the peritoneum. An international research team has designed a replenishable flexible implant intended to integrate local treatment and fluid sampling through a single channel, reducing the burden of having to re-enter the abdominal cavity for each treatment or monitoring procedure.

The device is made of thermoplastic polyurethane and consists of a porous reservoir, a catheter, and a self-sealing access port that passes through the skin. Therapeutic materials can be introduced through the external access port and enter the peritoneal cavity through pores in the reservoir; when negative pressure is applied in the opposite direction, peritoneal fluid can be withdrawn. Unlike preloaded implants that cease functioning once their contents have been released, this device allows researchers to adjust the treatment regimen and dosing frequency after implantation.

In a mouse model of ovarian cancer, researchers used the device to deliver ex vivo-expanded natural killer cells once a week and interleukin-15, which can support the activity of these immune cells, three times a week. Compared with mice given the same regimen through standard intraperitoneal injections, mice in the implant group had a lower tumor burden, suggesting that concentrating delivery of the cells and cytokine into the peritoneal cavity may improve the treatment’s local effect. However, the study did not demonstrate that this difference could translate into a survival benefit in humans.

Another function of the device is to turn peritoneal fluid into a continuously accessible window on the disease. Researchers detected ovarian cancer cells and natural killer cells in fluid collected through the access port, indicating that repeated sampling might eventually be used to track whether immune cells reach the disease site, whether the tumor rebounds, and how the microenvironment changes during treatment, without requiring another surgical procedure.

Durability testing also provided preliminary engineering evidence: ex vivo experiments showed that peripheral blood mononuclear cells could still pass through the porous membrane after as long as 70 days. The research team also noted that the platform could, in principle, carry chemotherapy drugs, cytokines, monoclonal antibodies, and other protein therapies. However, these applications largely represent the platform’s potential and should not be regarded as evidence that the efficacy and compatibility of every type of treatment have been validated.

The findings were published in the peer-reviewed journal *Device* and resulted from collaboration among teams at the National University of Ireland Galway, the University of Minnesota, the Massachusetts Institute of Technology, and other institutions. The researchers envision placing the device during ovarian cancer debulking surgery, but no human testing data are currently available. Infection, long-term care of the access port, foreign-body reactions caused by the material, catheter blockage, and the stability of different drugs and cells within the device must all be clarified in animal studies that more closely reflect clinical conditions before human trials can be considered.