RESUMEN
Titanium dioxide (TiO2) is manufactured worldwide as crystalline and amorphous forms for multiple applications, including tissue engineering, but our study proposes analyzing the impact of crystalline phases of TiO2 on Mesenchymal Stem Cells (MSCs). Several studies have already described the regenerative potential of MSCs and TiO2 has been used for bone regeneration. In this study, polydispersity index and sizes of TiO2 nanocrystals (NCs) were determined. Adipose tissue-derived Mesenchymal Stem Cells (AT-MSCs) were isolated and characterized in order to evaluate cellular viability and the internalization of nanocrystals (NCs). All of the assays were performed using the TiO2 NCs with 100% anatase (A), 91.6% anatase/9.4% rutile (AR), 64.6% rutile/35.4% anatase (RA), and 84.0% rutile/16% brookite (RB), submitted to several concentrations in 24-h treatments. Cellular localization of TiO2 NCs in the AT-MSCs was resolved by europium-doped NCs. Viability was significantly improved under the predominance of the rutile phase in NCs with localization restricted at the cytoplasm, suggesting that AR and RA NCs are not genotoxic and can be associated with most cellular activities and metabolic pathways, including glycolysis and cell division.
RESUMEN
Mesenchymal stem cells (MSC) are multipotent cells derived from layer mesoderm and that have potential for self-renewal and cellular differentiation. These cells can be extracted from various tissues, being the main sources the bone marrow (BM) and adipose tissue (AT). Therefore, human Adipose-derived Mesenchymal Stem Cells (AdMSCs) are potentially able to differentiate in several cell types such as neurons, adipocytes and osteoblasts. The objective of this work was to quantify levels of the cytokines TGF-1 and IL-10 in the conditioned medium (CM) of AdMSCs c u l t i v a t e d in 2D and 3D culture after the induction of hypoxia by Cobalt chloride chemistry (CoCl2). When the AdMSCs reached 80% of confluence, the cells were transferred to t h e 24 plates wells, where they were treated with CoCl2 in 2D and 3D culture. Quantification assay was made using human TGF-1 and IL- 10 kits. The analysis was done through the sandwich ELISA assay. The IL-10 and TGF-1 production have increased when the AdMSCs were in three-dimensional culture and under hypoxic conditions, indicating that supplies of oxygen associated to the 3D culture influenced significantly the production of these cytokines. This can be a potent and low-cost strategy to improve Adipose-derived Stem Cells conditioned medium when it comes to the release of IL-10 and TGF- cytokines.
Células-tronco mesenquimais (CTMs) são células multipontes derivadas da camada mesoderma e que possuem potenciais de auto-renovação e diferenciação celular. Estas células podem ser extraídas de diversos tecidos, sendo as principais fontes a medula óssea (MO) e o tecido adiposo (TA). Assim, CTM-TA são potencialmente capazes de se diferenciarem em diversos tipos celulares como adipócitos, neurônios e osteoblastos através de ações parácrinas do microambiente de cultivo. Este trabalho teve como objetivo dosar os níveis das citocinas TGF- e IL-10 no meio condicionado de CTM-TA cultivadas em 2D e 3D após a indução de hipóxia química por Cloreto de Cobalto (CoCl2). As CTM-TA foram cultivadas até atingirem a confluência de 80% e em seguida foram transferidas para placas de 24 poços, onde foram tratadas com meio indutor de hipóxia em cultivos realizados em 2D e 3D. A quantificação foi realizada utilizando os kits TGF-1 e IL10 humanos. Nas análises foi utilizado o ensaio ELISA sanduíche. Os resultados mostraram que a produção de citocinas IL10 e TGF- aumentaram quando o cultivo celular foi tridimensional em condições de hipóxia, indicando que os fornecimentos de oxigênio associado ao cultivo em 3D influenciaram de maneira significativa na produção de tais citocinas. Esta pode ser uma estratégia potente e de baixo custo para aumentar a liberação TGF- e IL- 10 no meio condicionado de CTM-TA.
