"Hydrogels are considered as very promising materials to be used as scaffolds in tissue engineering. Their relatively tunable mechanical properties make them particularly suitable for different tissues including vascular ones. It is well known that, during the regeneration phase, the mechanical properties of the scaffolds can play a relevant role in cellular growth and adhesion.
When performing experiments in altered gravity, it is crucial to understand if cellular-related phenomena, such as gene expressions or cell migrations, are the result of the direct influence of the changing the gravitational level or the indirect consequence of mutations in the cellular environment - mainly represented by complex fluids and swelling, soft materials. The possibility to discriminate and reduce the number of affecting factors allow for better modelling cellular behaviours in altered gravity conditions but also to disentangle phenomena on-ground.
In this study, we present the results of a parabolic flight campaign supported by the European Space Agency. Bone-shaped hydrogels subjectede to mechanical loading conditions were tested at different degree of swelling during both hypergravity and microgravity phase. Statistical analysis of the variation of the Young modulus was then performed to spot differences in the mechanical behaviour of the samples. Preliminary results confirm that, outside the region of high swelling, gravity has weak relevance against the imposed tensile cycling. Although more results are expected from a future campaign, it is possible to assert that hydrogel scaffolds are suitable from the mechanical point of view to be used as test beds for cellular experiments."