The relationship between different sizes of spheroids in the central hypoxia genesis and change of MULTIDIFERENCING potential of human dental pulp stem cells

• Grant number: 19/27001-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2020
• End date: July 31, 2023
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Katiúcia Batista da Silva Paiva
• Grantee: Icaro Paschoal Brito Ribeiro
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 23/00886-0 - Development of dynamic microfluid device for evaluation of angiogenic potential from osteogenic spheroids in vitro, BE.EP.IC

Abstract

The classic Bone Bioengineering approach (top-down) associates stem cells with biomaterials and signaling molecules. Recently, the bottom-up approach has been very interesting because it reproduces the cell-cell and cell-extracellular matrix interactions in the tissue environment. Thus, new three-dimensional (3D) cellular technologies such as spheroids, cell sheet and organoids have been increasingly used because they have a greater potential for clinical application in relation to monolayer or 2D culture. However, there is a problem with spheroids which is the diffusion of oxygen into the spheroid directly related to the increase in its diameter. This results in the generation of central hypoxia and, in some cases, necrosis. There is still a big debate as to whether this phenomenon would be important to trigger other events, such as cell differentiation. Spheroids of Dental pulp stem cell (DPSCs) have been studied for their potential use in Bone Bioengineering and it has been shown that large spheroids cultured in osteogenic media can differentiate into other cell types besides osteoblasts, and this could be associated with cell death events. However, no detailed study linking the increased size of DPSCs spheroids with the increase in central hypoxia and the modulation of cell multi-differentiation potential has been performed. Therefore, the focus of this work is to evaluate the presence of central hypoxia in different spheroid sizes (100, 500 and 1,000 µm) of human DPSCs and relate it to possible alterations of the multi-differentiation potential when cultured in osteogenic medium.