ABEA048 - Enhanced Stem Cell Attachment And Better Tracheal Regeneration By 3d Printed Scaffold Wrapped With Polycaprolactone Nanotrap Fabricated By Ethanol Wet Electrospinning
Objective: Tracheal tissue engineering requires harmonization of various factors such as mucosal regeneration, cartilage regeneration, vascularization, anti-inflammation to reduce restenosis. Mesenchymal stem cell (MSC) secretes angiogenic factors such as vascular endothelial growth factor that is therapeutically advantageous for tissue regeneration. However, cell delivery to the tracheal scaffold is difficult leading to low cell attachment efficiency and uneven cell coating on tubular-shaped artificial scaffold, and transplantation to the trachea is even more difficult since the trachea where cell engraftment should take place is exposed to the external air and bacteria, and there are no sufficient blood vessels around it, so it is a very harsh environment from the standpoint of stem cells.
Method: Poly (caprolactone) was electrospun in an ethanol bath and collected on a rotating drum. We named this threadlike nanofiber “Nanotrap”. Nanotrap was characterized by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR). Nanotrap was incubated with MSCs overnight and immunostained with vinculin antibody. Nanotrap/MSCs were wrapped on 3D printed PCL tubular scaffold (Nanotrap/MSC/Scaffold), and implanted to tracheal partial defect animal model (New Zealand White rabbits). 4 weeks after implantation, histological analysis was performed (H&E, CD11b, alpha-SMA, beta-tubulin, Muc5ac, aquaporin5).
Results: Nanotrap showed characteristics such as a lower density nanofiber network and a more hydrophilic surface than the nanofiber sheet collected by dry electrospinning. For the cell adhesion test, MSCs were attached better and spread faster on Nanotrap. The extracellular matrix formed by stem cells was easily stretched following the surface of every single fiber of Nanotrap which was confirmed by SEM and vinculin staining. MSCs implanted Nanotrap showed complete mucous layer regeneration confirmed by ciliogenesis and goblet cell 4 weeks after transplantation. Moreover, the inflammatory reaction was minimal with Nanotrap/MSC/Scaffold animal group.
Conclusion: Nanotrap is an efficient tool for local implantation of MSCs, and resulted in better tracheal regeneration in animal model.