Grooved poly(lactide-co-trimethylene carbonate) substrates in tenogenic media maintain human tendon derived cell phenotype in culture – A preliminary report

Tissue engineering strategies for tendon repair and regeneration rely heavily on the use of tendon derived cells. However, these cells frequently undergo phenotypic drift in vitro, which compromises their therapeutic potential. In order to maintain the phenotype of tendon derived cells in vitro, microenvironmental cues (biophysical, biochemical and/or biological in origin) have been used to better imitate the complex tendon microenvironment. Herein, the influence of planar and grooved (groove width of ∼1.0 µm, groove depth of ∼1.4 µm and distance between groves of ∼1.7 µm) poly(glycolide-co-ε-caprolactone) substrates with elastic modulus of 7 kPa and poly(lactide-co-trimethylene carbonate) substrates with elastic modulus of 12 kPa on human tendon derived cell response was assessed, using planar tissue culture plastic substrates of 3 GPa elastic modulus as control, in both basal and tenogenic media. At day 17, the grooved 12 kPa poly(lactide-co-trimethylene carbonate) substrate induced the highest deposition and alignment of collagen type I in tenogenic media. At day 17, the grooved 12 kPa poly(lactide-co-trimethylene carbonate) substrate and the tissue culture plastic induced the highest deposition and the tissue culture plastic and the planar 7 kPa poly(glycolide-co-ε-caprolactone) induced the lowest alignment of tenascin C in tenogenic media. Also at day 17 in tenogenic media, the grooved 12 kPa poly(lactide-co-trimethylene carbonate) substrate induced the upregulation of most tenogenic genes (COL1A1, COL3A1, MKX, TNMD). Our data further support the notion of multifactorial tissue engineering for effective control over cell fate in vitro setting.

This work has also received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie, grant agreement No. 676338, the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme, grant agreement No. 866126 and the European Union's Horizon 2020 research and innovation Widespread: Twinning programme, grant agreement No. 810850. This publication has emanated from research supported in part by grants from Science Foundation Ireland (SFI) under grant agreement No. 15/CDA/3629 and 19/FFP/6982 and Science Foundation Ireland (SFI) and European Regional Development Fund (ERDF) under grant agreement No. 13/RC/2073_2. E.M.F. acknowledges to the project TERM RES Hub – Infraestrutura Científica para a Engenharia de Tecidos e Medicina Regenerativa, grant agreement No. Norte-01–0145-FEDER-02219015. The authors would like to acknowledge the significant contribution of Dr Oonagh Dwane (University of Galway, Ireland) in the writing and management of all grants.