During the upcoming Polish space mission IGNIS, scientists will test whether biodegradable polymer “shields” can extend the shelf life of medicines in space. If successful, this could pave the way for advanced drug delivery systems for astronauts.
“Stability of Drugs” is one of 13 experiments in the IGNIS science and technology mission to the International Space Station (ISS). It will be conducted by Dr. Sławosz Uznański-Wiśniewski, Poland’s project astronaut with the European Space Agency (ESA). Although the mission is officially scheduled for “no earlier than May,” samples for this experiment are launching on April 21 aboard a SpaceX commercial resupply mission.
The main goal of the experiment is to see how conditions in orbit will affect the shelf life of polymeric, biodegradable drug storage and release systems. In other words, whether or not the drugs will last longer in these “covers” than commercially available tablets – or at least, whether they will last as long.
According to Dr. Eng. Jakub Włodarczyk from the Center of Polymer and Carbon Materials of the Polish Academy of Sciences in Zabrze, previous studies show that drugs stored on the ISS degrade faster than on Earth, mainly due to higher levels of cosmic radiation.
“That’s why we decided to use biopolymers to create a protective shield for the drugs,” Włodarczyk explained. “Polymers are composed of light atoms, such as carbon, oxygen and hydrogen, and hydrogen is the best shielding material of the three. This means that it can, as it were, block cosmic radiation that penetrates deep into the station, even reaching the human body or the inside of drugs, as in this case.”
New Frontiers for Polymers
Polymers are already widely used in medicine and pharmaceuticals, and polymer-based drug delivery systems are becoming commercially available. However, researchers are still looking for innovative applications. “In our experiment, we use biodegradable polymers that completely decompose and can be safely absorbed by the body,” Włodarczyk emphasized. “Polymers aren’t just ‘bad plastic’ polluting the planet—they’re materials that can save people’s health and lives and be used in the exploration of new places.”
In this study, researchers mixed medications with polymers and formed them into thin films about 1 mm thick and 24 cm² in area. These polymer-based drug systems will be sent to orbit in this form.
Photo credit: Jakub Włodarczyk
Although not in their final usable shapes, these simple forms serve as a starting point. “Our drug delivery systems are just such a starting point; it is clear that such a film cannot be swallowed or implanted. However, after that, forming an application form that suits us already depends on specific applications – such a drug release system can, for example, be ground, mixed with hydrogel and injected under the skin, or it can be made into fibers, and from them – an implant or a drug-releasing dressing” said Włodarczyk.
Another advantage of polymers is the ability to control the rate of their decomposition under biological conditions, so that the rate of drug release can be programmed, so to speak – so that the therapeutic substance can be dosed over a certain period of time, rather than immediately and in its entirety.
“I’ve been researching biopolymer drug delivery systems for several years. When I learned about the opportunity to conduct an experiment on the ISS, I looked into whether anyone had done it before—and it turned out, no one had. I only found ones that studied, focused on metal-based systems or traditional forms of drug delivery in general. I was surprised by this, because nowadays on Earth this is a very strongly developed topic and most scientific institutions related to pharmacy or chemistry are engaged in innovative drug delivery systems,” he said.
Examples of such biopolymer-based drug delivery systems include wound dressings that are applied once and release the drug over several days or even weeks, as well as subcutaneous implants that deliver the active substance into the bloodstream in consistent doses over, for example, a week. During the release process, the polymer carrier gradually degrades and is absorbed by the body. Its non-toxic degradation products are either processed by cells into energy or excreted, depending on the type of polymer used.
Scientists selected three polymers for the experiment, all of them known and already used in medicine. They differ in several properties, the most important of which are the rate of degradation and crystallinity. They also included various drug types: painkillers, anti-inflammatories, antibiotics, antidepressants, and a radiation therapy drug, chosen for its relevance to potential cosmic radiation protection. In total, 18 drug-polymer combinations will be tested.
The medicinal substances themselves also differ in terms of action and chemical structure. They include painkillers, anti-inflammation drugs, as well as antibiotics, antidepressants, and a drug used for radiation in anti-cancer therapy (the latter was chosen in the context of potential protection against space radiation).
In this particular case, astronauts do not take part in the experiment. Their task is ‘only’ to lift the samples into orbit and place the packages in the Columbus research module on the ISS: one part directly in the laboratory space, at ambient temperature, and the other – in the refrigerator, at a lower temperature, which slows down the decomposition processes, and the housing additionally protects against radiation.
The packages contain three types of samples: pure drugs (in the form of compressed tablets), empty polymer matrices and matrices with drugs introduced into them. One package weighs about 200 g.
The experiment is planned for three years, during which, approximately every year, two packages will be sent back to Earth: one from the lab and one from the refrigerator. In addition, researchers at the Centre of Polymer and Carbon Materials PAS will conduct a parallel experiment, which will serve as a reference point for the results obtained in orbit.
From left to right: Michał Sobota, Monika Musiał-Kulik, Jakub Włodarczyk, Katarzyna Jelonek, and Mateusz Stojko. Photo: Jakub Włodarczyk’s archive.
“People often talk about technology transfer from space to Earth, which has happened many times throughout history. Here, we have the opposite situation—research on Earth is already at an advanced stage, while in orbit, it’s still the future,” Włodarczyk concluded.
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