RESUMO
Tissue spheroids represent an innovative solution for tissue engineering and regenerative medicine. They constitute an in vitro three-dimensional cell culture model capable of mimicking the complex composition of a native tissue on a micro-scale; this model can function as a building block and be assembled into larger tissue constructs. Due to the potential tissue spheroids have for the evolution of the health industry, there is a need to assess the research dynamics of this field. Thus far, there have been no studies on their use as building blocks. To fill this gap, a study was performed to characterize the evolution of research where tissue spheroids were used as building blocks to generate tissue constructs. A scientometric analysis of the literature regarding tissue spheroid technologies was developed by quantification of bibliometric performance indicators. For this purpose, articles published during the period January 1, 2015 - December 31, 2021, from the Scopus database were organized and analyzed. The main subject areas, countries, cities, journals, institutions, and top-cited articles as well as the types of techniques, cells, culture time, and principal applications were identified. This research supports the definition and growth of research and development strategies for new technologies such as tissue spheroids.
RESUMO
As an alternative to the classical tissue engineering approach, bottom-up tissue engineering emerges using building blocks in bioassembly technologies. Spheroids can be used as building blocks to reach a highly complex ordered tissue by their fusion (bioassembly), representing the foundation of biofabrication. In this study, we analyzed the biomechanical properties and the fusion capacity of human adipose stem/stromal cell (ASC) we spheroids during an in vitro model of hypertrophic cartilage established by our research group. Hypertrophic induced-ASC spheroids showed a statistically significant higher Young's modulus at weeks 2 (P < .001) and 3 (P < .0005) compared with non-induced. After fusion, non-induced and induced-ASC spheroids increased the contact area and decreased their pairs' total length. At weeks 3 and 5, induced-ASC spheroids did not fuse completely, and the cells migrate preferentially in the fusion contact region. Alizarin red O staining showed the highest intensity of staining in the fused induced-ASC spheroids at week 5, together with intense staining for collagen type I and osteocalcin. Transmission electron microscopy and element content analysis (X-ray Energy Dispersive Spectroscopy) revealed in the fused quartet at week 3 a crystal-like structure. Hypertrophic induction interferes with the intrinsic capacity of spheroids to fuse. The measurements of contact between spheroids during the fusion process, together with the change in viscoelastic profile to the plastic, will impact the establishment of bioassembly protocols using hypertrophic induced-ASC spheroids as building blocks in biofabrication.