iPSC-derived tenocytes seeded on microgrooved 3D printed scaffolds for Achilles tendon regeneration.
Publication Year:
2023
PubMed ID:
36961351
Funding Grants:
Public Summary:
Tendon and ligament injuries are very common and often heal poorly, leaving many people with lasting pain or loss of movement. Current treatments can’t fully restore the original structure and strength of these tissues. This study explored a new way to repair damaged tendons using 3D-printed scaffolds combined with lab-grown stem cells.
Researchers created special 3D scaffolds made from a biodegradable material called polycaprolactone (PCL). Some scaffolds had a microgrooved surface pattern, designed to guide cell growth in an organized way—similar to how natural tendon fibers align. The scaffolds were then seeded with induced pluripotent stem cell–derived mesenchymal cells (iMSCs) that were genetically modified to produce Scleraxis (SCX), a protein that drives tendon formation.
When tested in the lab, these stem cells grew in an orderly pattern and showed strong signs of becoming tendon cells. In rats with Achilles tendon injuries, implants combining the microgrooved scaffold and SCX-expressing cells led to: Better walking ability, stronger, more flexible repaired tendons, and more natural, organized tissue structure compared to controls.
Scientific Abstract:
Tendons and ligaments have a poor innate healing capacity, yet account for 50% of musculoskeletal injuries in the United States. Full structure and function restoration postinjury remains an unmet clinical need. This study aimed to assess the application of novel three dimensional (3D) printed scaffolds and induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs) overexpressing the transcription factor Scleraxis (SCX, iMSC(SCX+) ) as a new strategy for tendon defect repair. The polycaprolactone (PCL) scaffolds were fabricated by extrusion through a patterned nozzle or conventional round nozzle. Scaffolds were seeded with iMSC(SCX+) and outcomes were assessed in vitro via gene expression analysis and immunofluorescence. In vivo, rat Achilles tendon defects were repaired with iMSC(SCX+) -seeded microgrooved scaffolds, microgrooved scaffolds only, or suture only and assessed via gait, gene expression, biomechanical testing, histology, and immunofluorescence. iMSC(SCX+) -seeded on microgrooved scaffolds showed upregulation of tendon markers and increased organization and linearity of cells compared to non-patterned scaffolds in vitro. In vivo gait analysis showed improvement in the Scaffold + iMSC(SCX+) -treated group compared to the controls. Tensile testing of the tendons demonstrated improved biomechanical properties of the Scaffold + iMSC(SCX+) group compared with the controls. Histology and immunofluorescence demonstrated more regular tissue formation in the Scaffold + iMSC(SCX+) group. This study demonstrates the potential of 3D-printed scaffolds with cell-instructive surface topography seeded with iMSC(SCX+) as an approach to tendon defect repair. Further studies of cell-scaffold constructs can potentially revolutionize tendon reconstruction by advancing the application of 3D printing-based technologies toward patient-specific therapies that improve healing and functional outcomes at both the cellular and tissue level.