Traveling into space is one way we satisfy our curiosity. We cannot bear to live on our planet without knowing what lies beyond the horizon. However, the microgravity achieved in low Earth orbit at the International Space Station (ISS) can help us explore some of our many questions as well. For example, it is easier to study cancer cells realistically in the ISS. In the absence of gravity, cells are able to move more like they would inside the human body (Rainey, 2014). The ISS has, thus, provided a place where cancer research can prosper (Ruttley, 2012).
Figure 1: Microscope image of microcapsules containing cancer treatment drugs (Morrison, n.d.).
Cancer researchers in the ISS have three fundamental goals. They want to understand what makes cancer grow in the body, develop better pharmaceuticals for treating cancers and create improved ways of delivering these pharmaceuticals directly to cancerous regions of the body (Rainey, 2014). Let’s further examine their third goal…
In attempting to improve the way we deliver cancer treatments, the development of microencapsulation techniques previously attempted on Earth has been further examined in space (Rainey, 2014). Microencapsulation involves the delivery of small pockets (microcapsules) (see Figure 1) of anti-tumour treatment directly to the affected region of the body. It is much more effective than simply treating cancer with chemotherapy as it completely inhibits tumour growth and often accelerates the destruction of tumours affected by the treatment drugs. Since the microcapsules deliver the drug directly to cancerous regions prior to expelling their contents, they are able to treat cancer more precisely, causing improved outcomes (Ruttley, 2012).
The Microencapsulation Electrostatic Processing System-II experiment occurred on the ISS in 2002, led by Dennis Morrison, Ph.D., of NASA’s Johnson Space Centre. It used microgravity to combine drugs into microcapsules more easily and efficiently so that researchers could experiment with various anti-cancer drugs, along with the addition of magnetic triggering particles (MTPs) to the microcapsules. They were able to advantageously use their environment to forcibly combine two immiscible liquids into a microcapsule, creating capsules held together by surface tension forces (rather than shear fluid forces). This allowed more stable and easily controlled microcapsules to be produced. The MTPs burst the capsules open using diagnostic imaging materials, and allow the drugs to be released when desired. The success of this microencapsulation technique led engineers to search for ways of producing similar production conditions on Earth (Ruttley, 2012).
Figure 2: Diagram of the Pulse-Flow Microencapsulation System, including the important aspects of the system and the flow of the microcapsules (as indicated by the blue arrows) (Adapted from Morrison, 2006).
The Pulse-Flow Microencapsulation System (see Figure 2) is the solution engineers created. It is able to produce a continuous stream of microcapsules that can deliver a variety of therapeutic agents. The entire system operates from only one microprocessor, making it easy to use. The nozzles dispense the initially created microcapsules (from two immiscible liquids) into a flow module that forms a polymer wall around the capsules. These capsules are then washed on a fluidized bed and passed through a flow sensor for quality control. This system, which mimics microgravity, is able to ensure the production of good quality, functional microcapsules, similar to those formed in space (Morrison, 2006).
Microencapsulation is revolutionary in the world of cancer research. When used on humans it is predicted to significantly improve cancer treatment with respect to efficacy (Ruttley, 2012). Its production and refinement, however, would not have been possible without the ISS. So, will the future of cancer research be found in space? I guess we’ll have to wait and find out!
Works Cited:
Morrison, D., n.d. Microencapsulation Electrostatic Processing System (MEPS). [image online] Available at: <https://www.nasa.gov/mission_pages/station/research/experiments/277.html> [Accessed 16 November 2017].
Morrison, D., 2006. Pulse-Flow Microencapsulation System. [pdf] Houston, Texas: Lyndon B. Johnson Space Center. Available at: <https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110013633.pdf> [Accessed 15 November 2017].
Rainey, K., 2014. Running the Race to Cure Cancer From Space. [online] (4 August 2017) Available at: <https://www.nasa.gov/mission_pages/station/research/news/cancer_research_in_space> [Accessed 15 November 2017].
Ruttley, T., 2012. Cancer Treatment Delivery. [online] (4 August 2017) Available at: <https://www.nasa.gov/mission_pages/station/research/benefits/cancer_treatment.html> [Accessed 15 November 2017].