Embryonically inspired scaffolds regulate tenogenically differentiating cells

Abstract

Tendon injuries heal as scar tissue with significant dysfunction and propensity to re-injure, motivating efforts to develop stem cell-based therapies for tendon regeneration. For these therapies to succeed, effective cues to guide tenogenesis are needed. Our aim is to identify these cues within the embryonic tendon microenvironment. We recently demonstrated embryonic tendon elastic modulus increases during development and is substantially lower than in adult. Here, we examined how these embryonic mechanical properties influence tenogenically differentiating cells, by culturing embryonic tendon progenitor cells (TPCs) within alginate gel scaffolds fabricated with embryonic tendon mechanical properties. We showed that nano- and microscale moduli of RGD-functionalized alginate gels can be tailored to that of embryonic tendons by adjusting polymer concentration and crosslink density. These gels differentially regulated morphology of encapsulated TPCs as a function of initial elastic modulus. Additionally, higher initial elastic moduli elicited higher mRNA levels of scleraxis and collagen type XII but lower levels of collagen type I, whereas late tendon markers tenomodulin and collagen type III were unaffected. Our results demonstrate the potential to engineer scaffolds with embryonic mechanical properties and to use these scaffolds to regulate the behavior of tenogenically differentiating cells.

Mechanical and molecular parameters that influence the tendon differentiation potential of C3H10T1/2 cells in 2D- and 3D-culture systems

“…The tendon phenotype is not maintained in 2D-cultures of tendon cells over passages (Hsieh et al, 2018;Shukunami et al, 2018;Yao et al, 2006). 3D-culture systems in which tendon cells are embedded in hydrogels are recognized to provide an environment closer to that experienced by tendon cells in vivo (Kapacee et al, 2010;Kuo et al, 2010;Marturano et al, 2016;Yeung et al, 2015). The nature of the substrate does not modify gene expression profiles in C3H10T1/2 cells in non-confluent conditions.…”

“…of six biological samples. The mechanical environment provided to tendon cells homogeneously embedded within hydrogel in 3D-culture systems is recognized to act on tendon gene expression (Hsieh et al, 2018;Marturano et al, 2016). Most of the analyses of the effects of 2D and 3D environments have been performed with tendon stem/ progenitor cells; however, the optimum culture conditions that drive tendon cell differentiation from MSCs have not been yet identified.…”

Design of a Bioreactor to Assess the Effect of Passive Joint Loading in a Live Chick Embryo In Ovo

“…However, it is increasingly appreciated that physical forces and movements also play a crucial role in regulating development. [1][2][3][4][5][6] In musculoskeletal tissues, the importance of mechanical cues in development is especially evident. 7 For example, breech position and other risk factors for developmental dysplasia of the hip are associated with reduced kick forces, 8 suggesting a link between mechanical loading and joint development.…”

Nanoscale physicochemical properties of chain‐ and step‐growth polymerized PEG hydrogels affect cell‐material interactions

“…33 Although studies continue to exploit biochemical and mechanical cues to control cell behavior using hydrogels, it is unclear how hydrogel properties (modulus, hydrophobicity) change as a result of polymerization mechanism and how those alterations may affect cell behavior. Both hydrophobicity 12,[36][37][38][39] and mechanics 34,[40][41][42][43][44][45][46][47] are well-documented to affect cell phenotype and function. Using atomic force microscopy (AFM), surface moduli and hydrophobicity were analyzed for macroscopically similar PEG hydrogels polymerized via chain-and step-growth polymerizations.…”