Design of anisotropic biomimetic scaffolds for patient-specific heart valve tissue engineering by melt electrospinning writing

Tissue Engineered Heart Valvs (TEHVs) have the potential to replace synthetic and non-bioactive prosthestics which are incapable of supporting tissue remodelling and regeneraition. However, TEHVs need to withstand the severe mechanical loading conditions due to systemic blood cisculation. For this purpose, we have designed biologically inspired electro-spun fibres to mimic the wavy-like orientation of collagen fibres apparent in the Fibrosa and Ventricularis layer recapitulating the composition, dimensions and mechanical properties of the native valve while providing a biomimetic structure for extracellular matrix (ECM) deposition. Leveraging the capabilities of Melt Electrospinning Writing (MEW), medical grade of PCL fibers were deposited in predefined helical patterns with various radius, pore-size and layer number displaying de Jshaped stress-strain curve and anisotropic mechanical characteristics of a native leaflet tissue. Objective: this study will demonstrate the potential of MEW for the fabrication of mechanically viable biomimentic scaffolds for patient-specific heart valve tissue engineering.Outgoin

Biomimetic scaffolds for heart valve tissue engineering

The number of patients who need heart valve replacement is likely to triple over the next five decades due to the continuously increasing aging of the population in developed countries. Several approaches have raised such as synthetic and non-biodegradable prostheses. Nonetheless, their limited lifetime and the fact that they do not support tissue remodelling and regeneration have lead the research field towards regenerative medicine. In that direction, a well established procedure consists on cell-laden hydrogel casting in a polymer scaffold. Melt Electrowriting is a 3D printing novel technique which allows to build biodegradable polymer tubular constructs whose microfibres might mimic the microarchitecture of collagen filaments present in the native aortic valve matrix. In order to make this possible, though, a code needs to be specifically designed for this application and printing technique. In this project, we propose Matlab as a code generator. Several patterns and geometries must be printed in order to mimic the inner architecture of the native aortic valve while preserving its mechanical integrity as well as its macroscopic shape and features. Also, it must respond to the technical requirements of the MEW and translate the desired accuracy to the tubular scaffold. Besides, Mach3 is used as a code reader to translate the commands into movement of the motors in the machine, and therefore validate the performance and printability of the code. The results show the capability and efficiency of Matlab in generating a program which contains the instructions to be followed by MEW machine. The code introduces a maximum error of 4.55% when comparing the code-adjusted parameters with the initially desired values. Furthermore, its customizable character enables to print scaffolds with different specifications in diameter, pore size and leaflet length, among others. The achievement of printing such a complex microarchitecture means a step forward in the way to produce an aortic valve replacement which mimics native mechanical properties while allowing tissue regeneration. Furthermore, this customizable coding approach will be beneficial not only to Heart Valve Tissue Engineering (HVTE) purposes, but also to other applications where Tubular MEW might be needed.Outgoin

Design of anisotropic biomimetic scaffolds for patient-specific heart valve tissue engineering by melt electrospinning writing

Tissue Engineered Heart Valvs (TEHVs) have the potential to replace synthetic and non-bioactive prosthestics which are incapable of supporting tissue remodelling and regeneraition. However, TEHVs need to withstand the severe mechanical loading conditions due to systemic blood cisculation. For this purpose, we have designed biologically inspired electro-spun fibres to mimic the wavy-like orientation of collagen fibres apparent in the Fibrosa and Ventricularis layer recapitulating the composition, dimensions and mechanical properties of the native valve while providing a biomimetic structure for extracellular matrix (ECM) deposition. Leveraging the capabilities of Melt Electrospinning Writing (MEW), medical grade of PCL fibers were deposited in predefined helical patterns with various radius, pore-size and layer number displaying de Jshaped stress-strain curve and anisotropic mechanical characteristics of a native leaflet tissue. Objective: this study will demonstrate the potential of MEW for the fabrication of mechanically viable biomimentic scaffolds for patient-specific heart valve tissue engineering.Outgoin