Effects of Simulated Microgravity on the Internalization of Cerium Oxide Nanoparticles by Proliferating Human Skeletal Myoblasts

Spaceflight typically exerts detrimental effects on living organisms by promoting/accelerating some degenerative processes associated with aging and pathology onset Earth, like muscle degeneration. As possible countermeasures to spaceflight effects, a few recent studies successfully tested the administration of nanomaterials for tuning cellular activities promotion certain cell phenotypes in microgravity, but largely missed investigation early interactions these their targets under altered gravity conditions. This study aims at filling this gap elucidation selected typology redox-active nanoparticles (cerium oxide nanoparticles, also termed nanoceria, NC) proliferating human skeletal myoblasts (HSkM) concomitant exposure simulated microgravity (achieved random positioning machine, RPM). To purpose, NC were synthesized direct precipitation method chemically, structurally, functionally characterized several independent techniques prior cultures loading RPM. Confocal electron microscopy evidence nanoparticle internalization mechanisms (mostly involving macropinocytosis) HSkM is provided, along transcriptional regulation key antioxidant response markers (Nos1, Sod2, Sod3), promising oxidative stress alleviation protection mechanical unloading