Possibilities of use of 3D cultures
3D models such as spheroids and organoids present innumerous advantages as research tools, since they predict more vividly human responses due to the structural complexity, as well as mechanical, biochemical and integrative aspects (Bhatia and Ingber, 2014). Besides the capacity of offering microphysiological environments that mimic in vivo morphology and function, resembling tissues and organs, 3D models also allow researchers to monitor activities and responses in real time, such as medical interactions or external interferences. So far, considering the enormous range of tissues and organs that can be replicated using 3D models, both spheroids and organoids have proved to be handful for a diversity of researches, including development, drug screenings, disease mechanisms and organization aspects (Little, 2017).
Although the immediate assumption of use of 3D cultures in general for research, it must be considered that they also hold promise of being used as reparative tool in the case of damaged tissue (Perkhofer et al., 2018). Since it is possible to derive organoids from patients, and thus generate patient-specific cultures, and the fact that it is possible to genetically manipulate the culture, soon we hope to observe more cases in which 3D cultivated cells are used as regenerative medicine approaches, including genetic manipulation for diseases to which there is no effective treatment nor cure (Costa et al., 2018).
Nevertheless, some limiting aspects must be considered when working with 3D cultures. One of the main limitations is the ethic concern, such as the one that emerges in case of using PSCs of embryonic origin; under this aspect, it is possible to turn to iPSCs or ATCs (Simunovic and Brivanlou, 2017). Another point is the establishment of cerebral organoids with functional and firing neurons that present synapses, and how the cerebral-like culture could present moral status (Little, 2017; Munsie et al., 2017). The financial demand to generate and maintain some cultures must also be taken as a possible limitation (Verjans et al., 2018), since some of the required components, such as Matrigel and growth factors, along with some specific cell lineages, can end up in a large sum. In addition, some research groups report difficulties in regard to reproducibility and instability of culture, what depends directly on protocol patterning and validation, but also good laboratorial practices (Costa et al., 2018; Little, 2017; Perkhofer et al., 2018).