Tumor therapy: drug delivery pump instead of injection

Drugs always have undesired side effects. Cytostatics are powerful drugs used to treat cancer. They reach almost all cells in the body, killing healthy cells as well as cancer cells in the process. A targeted delivery to the specific cellular site would be a gentler treatment. Implants are extremely valuable tools in this setting since they can automatically or with the push of a button deliver drugs.

In this MEDICA-tradefair.com interview, Dr. Sebastian Kibler explains how a micropump and an implantable system help deliver drugs with precision.

Dr. Kibler, we are talking about the implantable TUDOS micropump developed by Fraunhofer EMFT. What kind of system is this?

Dr. Sebastian Kibler: It is a silicon micromembrane pump powered by piezoelectricity. We developed the pump to combat liver cancers about ten years ago as part of the TUDOS project. The overall project aimed at developing a system that facilitates the control and dosage monitoring of the miniaturized pump.

We focused on the features this micropump would need to be applicable in implantable drug delivery systems that can stay permanently in the body and must be refilled at regular intervals.

How can a micropump help effectively treat cancer?

Kibler: Cytotoxic drugs or cytostatics are the classic cancer treatment. Unfortunately, many patients suffer from the side effects of these powerful drugs since they not only attack cancer cells but affect the whole body. Another approach is to deliver high doses of cytostatics directly to the tumor which targets the treatment at the affected site and reduces the side effects.

What does the overall system look like?

Kibler: Our TUDOS project system featured an integrated matchbox-sized device. At the time, we designed it for animal testing.

We are now incorporating this prior experience in the "μP Brain Test" project, in which a client wants to implement the system to treat brain tumors. Aside from our pump, this will also include electronic components, sensor technology that controls the drug dosing, and an integrated drug reservoir for refill via a port.

This type of system could then be implanted under the skin in the upper chest or lower abdominal area. From there, a catheter can be placed to the delivery site, usually into the tumor tissue or the distributing blood vessels.

Could this type of implant be fully autonomous, or would it still require external monitoring?

Kibler: Both are conceivable options. One option is an approach with a preset constant dosage, but clients usually prefer control via a wireless interface as is also the case with "μP Brain Test". The idea here is for the physician to adjust the bolus dose via an external device using Bluetooth communication and monitor optimal functioning of the system.

How long can this type of device be used?

Kibler: The project focuses on brain tumors and is aimed at prolongation of life since there is otherwise no cure at this point. As a result, life expectancy may be extended by several months or even years. That is why this application entails a temporary implant.

Having said that, there is another conceivable application for this type of system. It can also work as an implantable insulin pump for diabetics. In this case, the minimum life expectancy of the implant is ten years.

What is the current status of the "μP Brain Test" project?

Kibler: As far as the micropump is concerned, we are now ready to transfer from development to production. We are in close contact with potential medical equipment manufacturing partners who are equipped for large-scale production.

Our client is in animal experiments with functional demonstrators of the complete system. This is a first critical step toward clinical trials, providing the basis for the needed certification before starting component production. My guess is it will be another two years before the first clinical trial.