Investigation of bioactive molecules released by MSCs seeded on decellularized tracheal scaffolds for airway tissue engineering

Abstract

Background & Aim The use of Mesenchymal stromal cells (MSCs) in tissue engineering applications has expanded exponentially. Their relative ease of isolation, expansion and differentiation potential in addition to the ever-expanding knowledge of their paracrine mediated effects such as anti-inflammatory, immunomodulatory and anti-scarring and supportive effects. This has made them an attractive source that could improve tissue healing, repair and regeneration. We and others have used MSCs for recellularization of decellularized, cadaveric donor tracheal scaffolds in several clinical compassionate cases of airway tissue engineering for stenosis. However, the role of these cells in the engineered airway remains not fully explored. The aim of this study was to investigate viability, proliferation and differential gene expression of selected angiogenic and growth factors of human MSCs seeded onto decellularized tracheal scaffolds. Methods, Results & Conclusion Methods Human umbilical cord MSCs were isolated by expanded in GMP-compliant, serum-free culture conditions to a maximum of 10 population doublings. Cells were recovered, suspended in culture media and seeded by passive adhesion onto human decellularized tracheal scaffolds at a density of 500 × 103/cm2. The seeded constructs were cultured in 5% CO2 at 37°C and assessed at days 3, 7 and 14 for viability and proliferation using live/ dead staining and KI67 staining. RNA extraction was performed on day 3 and reverse transcriptase polymerase chain reaction (RT-PCR) was used to test gene expression changes of VEGF, PTGES (PGE2), CSF2 (GM-CSF), TGF-B and BMP4 as opposed to two-dimensional culture flasks. Results & conclusion The study demonstrated the cytocompatibility of the scaffolds. Cells remained viable and continued to proliferate during 14 days of culture. RT-PCR analysis revealed an upregulation of VEGFA, PTGES (PGE2), CSF2 (GM-CSF), TGF-B and downregulation of BMP4. The results of this preliminary study indicate that seeded MSCs are able to engraft into the scaffold and proliferate whilst producing angiogenic and supportive factors that could enhance constructive remodelling of tissue engineered airway upon implantation.