TGFβ3 secretion by three-dimensional cultures of human dental apical papilla mesenchymal stem cells Rodrigo A. Somoza 1 *, Cristian A. Acevedo 1 , Fernando Albornoz 1 , Patricia Luz-Crawford 2 , Flavio Carrión 2 , Manuel E. Young 1 and Caroline Weinstein-Oppenheimer 3 1 Centro de Biotecnología, Universidad Técnica Federico Santa María, Valparaíso, Chile 2 Laboratorio de Inmunología, Universidad de los Andes, Santiago, Chile 3 Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Chile Abstract Mesenchymal stem cells (MSCs) can be isolated from dental tissues, such as pulp and periodontal lig- ament; the dental apical papilla (DAP) is a less-studied MSC source. These dental-derived MSCs are of great interest because of their potential as an accessible source for cell-based therapies and tissue- engineering (TE) approaches. Much of the interest regarding MSCs relies on the trophic-mediated re- pair and regenerative effects observed when they are implanted. TGFβ3 is a key growth factor in- volved in tissue regeneration and scarless tissue repair. We hypothesized that human DAP-derived MSCs (hSCAPs) can produce and secrete TGFβ3 in response to micro-environmental cues. For this, we encapsulated hSCAPs in different types of matrix and evaluated TGFβ3 secretion. We found that dynamic changes of cell–matrix interactions and mechanical stress that cells sense during the transi- tion from a monolayer culture (two-dimensional, 2D) towards a three-dimensional (3D) culture con- dition, rather than the different chemical composition of the scaffolds, may trigger the TGFβ3 secretion, while monolayer cultures showed almost 10-fold less secretion of TGFβ3. The study of these interactions is provided as a cornerstone in designing future strategies in TE and cell therapy that are more efficient and effective for repair/regeneration of damaged tissues. Copyright © 2015 John Wiley & Sons, Ltd. Received 3 February 2014; Revised 2 October 2014; Accepted 7 January 2015 Keywords mesenchymal stem cells; SCAP; TGFβ3; alginate; fibrin; 3D culture 1. Introduction It is estimated that, every year, millions of people worldwide are left with skin scars after damage caused by trauma or degenerative diseases. Tissue engineering (TE) has enabled the development of novel strategies that allow proper tissue healing under conditions in which tra- ditional therapeutic methods are not effective. These ap- proaches are based mainly on the development of skin substitutes using scaffolds and cells, which are implanted after damage. Mesenchymal stem cells (MSCs) have great therapeutic potential because of their multilineage differentiation capacity (Somoza and Rubio, 2012), ease of isolation from multiple adult tissues (da Silva Meirelles et al., 2006; Huang et al., 2009) and secretion of growth factors (GFs) (Caplan and Dennis, 2006; Meirelles et al., 2009). This trophic activity has emerged as the main ther- apeutic effect of MSCs when implanted for tissue regener- ation purposes (Meirelles et al., 2009). These findings have allowed the elucidation of a perivascular in vivo niche of MSCs as pericytes, in which they participate in the homeostasis and repair of vascularized tissues (Crisan et al., 2008). MSCs secrete a great variety of cytokines and GFs that mediate anti-apoptotic, angiogenic, immunoreg- ulatory and anti-scarring processes, along with others (Meirelles et al., 2009). Several of these GFs are impor- tant in TE approaches, including basic fibroblast GF (bFGF), vascular endothelial growth factor (VEGF), platelet-derived GF (PDGF) and hepatocyte GF (HGF) *Correspondence to: R. A. Somoza, Centro de Biotecnologia, Universidad Federico Santa Maria; Avda España 1680, Valparaiso, Chile. E-mail: rodrigo.somoza@gmail.com Copyright © 2015 John Wiley & Sons, Ltd. JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE RESEARCH ARTICLE J Tissue Eng Regen Med (2015) Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/term.2004