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Abstract Giant unilamellar vesicles (GUVs) are composed of lipophilic layers and are sensitive to the action of reactive oxygen species (ROS). The use of GUVs as microcarriers of biological macromolecules is particularly interesting since ROS produced by gametes or embryos during in vitro culture can induce the opening of pores in the membrane of these vesicles and cause the release of their content. This study investigated the behavior of GUVs [composed of 2-dioleoyl-sn-glycero-3-phosphocholine and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(lissamine rhodamine B sulfonyl)] in co-culture with in vitro produced bovine embryos, as well as their embryotoxicity and effectiveness as cysteine carriers in culture medium. Embryonic developmental rates were unaffected, demonstrating the absence of toxicity of GUVs co-cultured with the embryos. No increase of intracellular ROS levels was observed in the embryos co-cultured with GUVs, indicating that the higher lipid content of the culture environment resulting from the lipid composition of the GUV membrane itself did not increase oxidative stress. Variations in the diameter and number of GUVs demonstrated their sensitivity to ROS produced by embryos cultured under conditions that generate oxidative stress. Encapsulation of cysteine in GUVs was found to be more effective in controlling the production of ROS in embryonic cells than direct dilution of this antioxidant in the medium. In conclusion, the use of GUVs in in vitro culture was found to be safe since these vesicles did not promote toxic effects nor did they increase intracellular ROS concentrations in the embryos. GUVs were sensitive to oxidative stress, which resulted in structural changes in response to the action of ROS. The possible slow release of cysteine into the culture medium by GUV rupture would therefore favor the gradual supply of cysteine, prolonging its presence in the medium. Thus, the main implication of the use of GUVs as cysteine microcarriers is the greater effectiveness in preventing the intracytoplasmic increase of ROS in in vitro produced bovine embryos.

Objectives: This study aimed to investigate oxidative stress markers in the oral mucosal cells of individuals diagnosed with major depressive disorder (MDD). Methods: A case-control design was used, including twenty patients diagnosed with MDD, based on the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria, and twenty healthy controls. Oral exfoliated cells were collected from all participants. Intracellular levels of reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm), caspase-3 and -7 activity, and reduced glutathione (GSH) were measured in Arbitrary Fluorescence Units (AFU). Results: The MDD group demonstrated significantly elevated intracellular ROS levels (p = 0.0012) and caspase-3 and -7 activity (p = 0.0171) in comparison to the control group. Additionally, a decrease in ΔΨm expression was observed in the oral cells of MDD patients (p = 0.0265), whereas GSH expression levels did not differ significantly between the two groups (p = 0.8908). Conclusions: The findings indicate heightened oxidative stress in the oral exfoliated cells of individuals with MDD. This study supports the potential use of oral cells as a non-invasive biomarker source for assessing oxidative stress in depressive disorders.