A single step process forming a tiny liquid-filled, biodegradable, micro-balloons containing various drug solutions (a process called microgravity micro-encapsulation) has been shown to provide better drug delivery and new medical treatments for solid tumors and resistant infections. Recent testing in mouse models has shown that these unique microcapsules can be injected into human prostate tumors to inhibit tumor growth or can be injected following cryo-surgery (freezing) to improve the destruction of the tumors much better than freezing or local chemotherapy alone. The microcapsules also contain a contrast agent that enables C-T, x-ray or ultrasound imaging to monitor the distribution within the tissues to insure that the entire tumor is treated when the microcapsules release their drug contents.Principal Investigator(s)
National Aeronautics and Space Administration (NASA)Sponsoring Organization
Human Exploration and Operations Mission Directorate (HEOMD)Research Benefits
Information PendingISS Expedition Duration
June 2002 - December 2002Expeditions Assigned
5Previous ISS Missions
STS-95 and Increment 5
The microcapsulation electrostatic processing system (MEPS) is an automated system that is used to produce liquid-filled micro-balloons. It works through the use of microcapsules, unique capsules resembling miniature liquid-filled balloons the size of blood cells, that deliver FDA-approved anti-cancer drugs by injection into the bloodstream. The microgravity environment on ISS is vital to the development of these capsules because the station environment enables the pharmaceutical and its outer membrane to form spontaneously.
MEPS was designed with flexibility in mind. The system can process a wide range of experiments. For example, it can handle volumetric proportions of up to six chemical constituents; it can transfer liquids back and forth, at variable rates, between its six reservoirs and two main chambers; it can apply different electrical fields to the enclosed experiments; and it can be programmed to use filters or membranes of different porosity between chambers. Electrical fields charge the surface of the microcapsules, making it less recognizable as a foreign invader to the immune system.
The use of microcapsules will benefit the treatment of several diseases. For example, to eliminate daily insulin shots diabetes patients can use implanted microcapsules as treatment. A further Earth application is the microcapsules can be used as a substitution for chemotherapy. Traditional anti-cancer treatment involves large quantities of drugs that affect the entire body. The microcapsules contain a smaller dose of medication that directly targets tumors. Also, they reduce the unwanted side effects currently produced by chemotherapy.
Expanding our understanding of the use of microgravity to enable development of new drug delivery devices which can protect astronauts on long-duration space missions and provide alternative delivery routes and countermeasures to injured or sick crew members.Earth Applications
The utilization of microcapsules will benefit the treatment of several diseases here on Earth. Microcapsules can be inhaled to delivery antibiotic and immune stimulant drugs to treat inhaled bacterial infections of the lungs. These unique microcapsules can be injected directly into solid tumors to provide local, sustained release, of anti-cancer drugs. The microcapsules can be imaged with C-T scans or ultrasound to insure that the release combinations of medications slowly over 12-14 days which can be delivered directly to the target tumors. Since the drug release is local, using these microcapsules reduces the unwanted side effects of systemic (intravenous) chemotherapy, which involves large amount of drugs producing major side effects throughout the entire body.
EXPRESS Rack 1, locker 5 supplies MEPS with power, video, and computer support. MEPS requires less than 15 minutes of crew time to set up and initiate an experiment.Operational Protocols
To initiate the MEPS experiments the crew installs the pre-programmed PC-MCIA card into the front control panel. They unstow and insert a PCM (experiment), which was pre-loaded with chemical fluids before flight, into the Experiment Module, and then activate the experiment which runs automatically for approximately two hours. At the end of the run, the MEPS automatically powers down to await later removal of the PCM for stowage until it is returned to Earth. Real-time data is recorded for post-flight analysis. The crew may also monitor the fluid flows and microencapsulation process via the video display on the front panel.
While MEPS will remain on orbit past Increment 6, the Shuttle will return used PCMs and video tape to Earth and deliver new PCMs, PC-MCIA cards, and videotapes for future experiments.
MEPS experiments were conducted during Increment 5. Eight samples were processed using various methods to mix dissimilar liquids to form micro-balloons / microcapsules. The recovered micro-balloons were analyzed for size and drug content. Additionally, studies included the effects of temperature and internal pressure on the size of the micro-balloons. Ground based medical investigations revealed that when using these microcapsules, the growth of human prostate and lung tumors can be inhibited with only a few local injections. When anti-cancer microcapsules are injected following cryo-surgery the combined treatment can completely destroy 1-2 cm. size tumors in just three weeks.
In addition to the successful demonstration of production of microcapsules and their utilization for drug delivery, the MEPS system and follow-on technologies that were developed have been awarded patents. (Evans et al. 2009)
Morrison DR, Morrison DR, Haddad RS. Microencapsulation of Drugs: New cancer therapies and improved drug delivery derived from microgravity research. 40th Space Congress, Cape Canaveral, FL; 2003
Le Pivert PJ, Le Pivert PJ, Morrison DR, Morrison DR, Haddad RS, Doulat J, Renard M, Aller A, Titus K. Percutaneous tumor ablation: microencapsulated echo-guided interstitial chemotherapy combined with cryosurgery increases necrosis in prostate cancer. Technology in Cancer Research and Treatment. 2009; 8(3): 207-216. PMID: 19445538.
Le Pivert PJ, Le Pivert PJ, Haddad RS, Aller A, Titus K, Doulat J, Renard M, Morrison DR, Morrison DR. Ultrasound Guided, Combined Cryoablation and Microencapsulated 5-Fluorouracil, Inhibits Growth of Human Prostate Tumors in Xenogenic Mouse Model Assessed by Fluorescence Imaging. Technology in Cancer Research and Treatment. 2004; 3(2): 135-142.