Growth factor and macromolecular crowding supplementation in human tenocyte culture

Dimitrios Tsiapalis; Stephen Kearns; Jack L Kelly; Dimitrios I Zeugolis

doi:10.1016/j.bbiosy.2021.100009

Growth factor and macromolecular crowding supplementation in human tenocyte culture

Biomater Biosyst. 2021 Jan 30:1:100009. doi: 10.1016/j.bbiosy.2021.100009. eCollection 2021 Mar.

Authors

Dimitrios Tsiapalis^{1

2}, Stephen Kearns³, Jack L Kelly⁴, Dimitrios I Zeugolis^{1

2

5}

Affiliations

¹ Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), Galway, Ireland.
² Science Foundation Ireland (SFI) Centre for Research in Medical Devices (CÚRAM), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), Galway, Ireland.
³ Merlin Park University Hospital, Galway, Ireland.
⁴ Galway University Hospital, Galway, Ireland.
⁵ Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Faculty of Biomedical Sciences, Università della Svizzera Italiana (USI), Lugano, Switzerland.

Abstract

Cell-assembled tissue engineering strategies hold great potential in regenerative medicine, as three-dimensional tissue-like modules can be produced, even from a patient's own cells. However, the development of such implantable devices requires prolonged in vitro culture time, which is associated with cell phenotypic drift. Considering that the cells in vivo are subjected to numerous stimuli, multifactorial approaches are continuously gaining pace towards controlling cell fate during in vitro expansion. Herein, we assessed the synergistic effect of simultaneous and serial growth factor supplementation (insulin growth factor-1, platelet-derived growth factor ββ, growth differentiation factor 5 and transforming growth factor β3) to macromolecular crowding (carrageenan) in human tenocyte function; collagen synthesis and deposition; and gene expression. TGFβ3 supplementation (without/with carrageenan) induced the highest (among all groups) DNA content. In all cases, tenocyte proliferation was significantly increased as a function of time in culture, whilst metabolic activity was not affected. Carrageenan supplementation induced significantly higher collagen deposition than groups without carrageenan (without/with any growth factor). Of all the growth factors used, TGFβ3 induced the highest collagen deposition when used together with carrageenan in both simultaneous and serial fashion. At day 13, gene expression analysis revealed that TGFβ3 in serial supplementation to carrageenan upregulated the most and downregulated the least collagen- and tendon- related genes and upregulated the least and downregulated the most osteo-, chondro-, fibrosis- and adipose- related trans-differentiation genes. Collectively, these data clearly advocate the beneficial effects of multifactorial approaches (in this case, growth factor and macromolecular crowding supplementation) in the development of functional cell-assembled tissue surrogates.

Keywords: Excluded volume effect; In vitro microenvironment; Media supplements; Tendon tissue engineering; Tenogenic phenotype.