Fibroblastic (NCTC 929) 3D-cell spheroids: a comparative study

The safety assessment of nanomaterials is a primary concern of industry and academia. These materials, due to their nanoscale size, can have chemical, physical, and biological properties that differ from those of their larger counterparts. Nevertheless, in vitro assays are typically performed as two-dimensional (2D) cell monolayers that inadequately mimic tissue environments found in vivo. Here, we investigated the Fibroblastic NCTC 929 3D-cell spheroids production through two different methods: hanging spherical drop system and micro-mold spheroids. The spheroids produced were used as safety assessment models by laser scanning confocal fluorescence microscopy regarding polymeric nanovesicles. Results indicated that the hanging spherical drop (2.5×105cells/drop) system was a suitable model for NCTC 929 cells since the spheroids could be formed in 24 hours. The spheroids formed in the micro-mold did not achieve the adequate morphology and cell adhesion profile in 24 hours. Once formed, the spheroids were transferred to a 96-well plate and incubated with the nanovesicle for 24 hours. The results indicated the spheroids could predict not only the cytotoxicity effect of polymeric nanovesicles on NCTC 929 cells but also elucidated the delivery profile of these nanocarriers. In conclusion, these results made an essential contribution to the safety assessment of nanomaterials.