The dynamic development of the space industry makes space flights more accessible and opens up new opportunities for biological research to better understand cell physiology under real microgravity. Whereas specialized studies in space remain out of our reach, preliminary experiments can be performed on Earth under simulated microgravity (sµg). Based on this concept, we used a 3D-clinostat (3D-C) to analyze the effect of short exposure to sµg on human keratinocytes HaCaT and melanoma cells A375 cultured on all-glass Lab-on-a-Chip (LOC). Our preliminary studies included viability evaluation, mitochondrial and caspase activity, and proliferation assay, enabling us to determine the effect of sµg on human cells. By comparing the results concerning cells cultured on LOCs and standard culture dishes, we were able to confirm the biocompatibility of all-glass LOCs and their potential application in microgravity research on selected human cell lines. Our studies revealed that HaCaT and A375 cells are susceptible to simulated microgravity; however, we observed an increased caspase activity and a decrease of proliferation in cancer cells cultured on LOCs in comparison to standard cell cultures. These results are an excellent basis to conduct further research on the possible application of LOCs systems in cancer research in space.

In the paper, the microaquarium fabricated in a form of entirely glass lab-on-a-chip for culturing and microscale study of microorganisms has been presented. A new approach towards cellular studies that brings a significant improvement over commonly utilized – polymer-based solutions has been shown. For the first time, all-borosilicate glass chip was applied for the culturing of the selected microorganisms and enabled notable population growth and behaviorism investigation. The chip fabrication method in comparison to typical glass chip technology was notably simplified, including quick patterning and low temperature bonding in 80 °C. In the studies, both a single-cell (Euglena gracilis and Euglena viridis) and multi-cell microorganisms (Lepadella patella) were cultured in the microaquarium. Behaviorism of the selected microorganisms was investigated by supplying various proportions of carbon dioxide, nitrogen and air into the chip. Tests included studies of microorganisms chemotaxis, viability (mostly based on photosynthesis process) and coexistence in the lab-on-a-chip environment. The experiments confirmed that the developed chip is a tool that fits the requirements for the culturing and behavioral studies of microorganisms and constitute ground-works to propel its further application in broadly defined cellular study field.

This paper presents a full-featured microfluidic platform ensuring long-term culturing and behavioral analysis of the radically different biological micro-objects. The platform uses all-glass lab-chips and MEMS-based components providing dedicated micro-aquatic habitats for the cells, as well as their intentional disturbances on-chip. Specially developed software was implemented to characterize the micro-objects metrologically in terms of population growth and cells’ size, shape, or migration activity. To date, the platform has been successfully applied for the culturing of freshwater microorganisms, fungi, cancer cells, and animal oocytes, showing their notable population growth, high mobility, and taxis mechanisms. For instance, circa 100% expansion of porcine oocytes cells, as well as nearly five-fold increase in E. gracilis population, has been achieved. These results are a good base to conduct further research on the platform versatile applications.

In the paper, the lab-on-chip platform applicable for the long-term cultivation of human cancer cells, as a solution meeting the demands of the CubeSat biological missions, is presented. For the first time, the selected cancer cell lines—UM-UC-3 and RT 112 were cultured on-chip for up to 50 days. The investigation was carried out in stationary conditions (without medium microflow) in ambient temperature and utilizing the microflow perfusion system in the incubation chamber assuring typical cultivation atmosphere (37 °C). All the experiments were performed to imitate the conditions that are provided before the biological mission starts (waiting for the rocket launch) and when the actual experiment is initialized on a CubeSat board in space microgravity. The results of the tests showed appropriate performance of the lab-on-chip platform, especially in the context of material and technological biocompatibility. Cultured cells were characterized by adequate morphology—high attachment rate and visible signs of proliferation in each of the experimental stage. These results are a good basis for further tests of the lab-on-chip platform in both terrestrial and space conditions. At the end of the manuscript, the authors provide some considerations regarding a potential 3-Unit CubeSat biological mission launched with Virgin Orbit company. The lab-on-chip platform was modelled to fit a 2-Unit autonomous laboratory payload.

A miniature 3D printed membrane-based gas microflow regulator which delivers gaseous media to on-chip cell cultures is presented in this paper. The device uses a polydimethylosiloxane (PDMS) membrane to act as a diffusion barrier and maintain gas flow at the desired rate. The regulator was characterized, and repeatable flow values for different membrane thicknesses and gas types in the function of pressure were obtained. As a result, a long-term on-chip culture of Euglena gracilis was achieved, this was due to constant and stable carbon dioxide release from the regulator (flow rate: 0.3 μL/min).

In this paper, a lab-on-chip system dedicated to fungi cultivation in Earth’s gravity and simulated microgravity, being a solution that could be used in future nanosatellite missions, is shown. For the first time, a fully glass lab-on-chip structure enabling the proper environment for cultivation of fungi species—Fusarium culmorum—is presented. Apart from the biological validation of the fungi cultures with the use of the lab-on-chip system, tests were carried out under induced microgravity utilising a Rotary Wall Vessel. Correct functioning of the lab-on-chip system was obtained, enabling the growth of fungi spores both in ground and in simulated microgravity conditions. Interestingly, culturing tests have shown that microgravity stimulates the growth of fungi notably, compared to the ground-based experimentation performed simultaneously. The findings of this study can provide substantial new knowledge on microscopic fungi cultivation in lab-on-chip devices, other soil organisms, as well as a potential behavior of these species in microgravity conditions. Culturing system shown in this work can help mycologists to provide better understanding of microscopic fungi nature and their development mechanisms at a single spore level. This opens the way towards regular usage of microfluidic tools in agriculture and horticulture fields and more importantly, in future research on microscopic fungi in space, e.g., as a part of nanosatellite missions.