Acanthamoeba keratitis (AK) is a rare cornea disease caused by species of the Acanthamoeba genus. The antifungal voriconazole blocks the ergosterol synthesis in the protozoan membrane and is active against the cysts and trophozoites of Acanthamoeba spp. Due to the low stability of voriconazole, its options for eye drops are scarce. This study aimed to investigate the stability of the biological activity of voriconazole against two strains of Acanthamoeba castellanii and one clinical isolate from a patient with AK. To evaluate the stability of the biological activity of voriconazole, strains of A. castellanii (ATCC 50492) were exposed to different periods and voriconazole concentrations stored at 4 °C for 7, 15, and 30 days. The cytotoxicity assays were performed using SIRC (ATCC CCL-60™) cell line. The results indicated the amoebicidal effect of voriconazole against Acanthamoeba spp. within 24 h and 48 h of exposure, and the voriconazole solution was stable and retained antiamoebic activity when stored at 4 °C for up to 30 days. In the cytotoxicity test, the result demonstrated low cytotoxicity of the drug to the corneal rabbit cell line. However, there is a need to carry out further synergistic effects with other antiamoebic drugs and then in vivo experiments in the AK animal model.
Adipogenesis is a complex process influenced by various cellular interactions within adipose tissue, which plays a critical role in metabolic homeostasis. This study aimed to develop a novel in vitro three-dimensional (3D) co-culture model using murine 3T3-L1 pre-adipocytes, J774 macrophages, and NIH-3T3 fibroblasts to investigate adipogenic differentiation and inflammatory pathways. We first validated an adipogenic differentiation protocol in a two-dimensional (2D) model, where 3T3-L1 pre-adipocytes were subjected to a hormonal medium containing 3-isobutyl-1-methylxanthine, dexamethasone and insulin. After 7 days, differentiated cells were analyzed using Oil Red O and Nile Red staining, confirming lipid accumulation. Subsequently, spheroids were formed in 3D cultures, with monospheroids and heterospheroids maintained in either control medium or MDI for 11 days. Size measurements indicated significant growth in heterospheroids, particularly in the 3T3-L1:J774 combination, underscoring the importance of cellular interactions. Confocal microscopy and flow cytometry analyses demonstrated that even in the absence of hormonal stimuli, control spheroids exhibited adipogenic differentiation, evidenced by a notable proportion of Nile Red-positive cells (75.7 ± 1.7%). Inflammatory profiling revealed that the heterospheroid 3:J produced the highest levels of nitric oxide (NO), with no significant differences observed between control and MDI conditions. This study highlights the potential of 3D co-culture systems for elucidating the intricate interactions among adipocytes, macrophages, and fibroblasts. The findings may provide valuable insights into novel therapeutic targets for metabolic disorders.