Laser microfabricated poly(glycerol sebacate) scaffolds for heart valve tissue engineering

Abstract

Microfabricated poly(glycerol sebacate) (PGS) scaffolds may be applicable to tissue engineering heart valve leaflets by virtue of their controllable microstructure, stiffness, and elasticity. In the current study, PGS scaffolds were computationally designed and microfabricated by laser ablation to match the anisotropy and peak tangent moduli of native bovine aortic heart valve leaflets. Finite element simulations predicted PGS curing conditions, scaffold pore shape, and strut width capable of matching the scaffold effective stiffnesses to the leaflet peak tangent moduli. Based on simulation predicted effective stiffnesses of 1.041 MPa and 0.208 MPa for the scaffold preferred (PD) and orthogonal, cross-preferred (XD) material directions, scaffolds with diamond-shaped pores were microfabricated by laser ablation of PGS cured 12 hours at 160°C. Effective stiffnesses measured for the scaffold PD (0.83 ± 0.13 MPa) and XD (0.21 ± 0.03 MPa) were similar to both predicted values and peak tangent moduli measured for bovine aortic valve leaflets in the circumferential (1.00 ± 0.16 MPa) and radial (0.26 ± 0.03 MPa) directions. Scaffolds cultivated with fibroblasts for 3 weeks accumulated collagen (736 ± 193 μg/g wet weight) and DNA (17 ± 4 μg/g wet weight). This study provides a basis for the computational design of biomimetic microfabricated PGS scaffolds for tissue engineered heart valves.

Nanoengineering in Cardiac Regeneration: Looking Back and Going Forward

“…Laser ablation was used on biological scaffold (agarose) inducing improved attachment and differentiation of C2C12 myoblasts [ 31 ]. The same method was used for the production of multi-layered elastomeric scaffolds having an accordion-like honeycomb structure in order to replicate the native myocardium microenvironment and anisotropy of the left ventricular tissue [ 32 , 33 ].…”

Current Status of Tissue Engineering Heart Valve

“…48 After that, various synthetic materials have been proposed and reported, such as polyhydroxyalkanoates (PHAs) and poly-4hydroxybutyrate (P4HB), 49,50 polyhydroxyoctanoate (member of the PHA family), 51 PGA and P4HB, 52 poly(DL-lactide-cocaprolactone) (PLCL) and poly(D,L-lactide-co-glycolide) (PLGA), 53 and poly(glycerol sebacate) (PGS). 54 In general, there are three TEHV scaffold types, and they include 3D porous scaffolds, fibrous scaffolds, and hydrogels. The techniques to fabricate 3D porous scaffolds include particulate leaching, solvent casting, gas foaming, high internal phase emulsion, microfabrication, solid freeform, and 3D printing.…”

Biomaterials for Cardiac Regeneration

“…Thermoplastic polyesters have been explored to overcome this, but have so far been met with diffi culties in degradation and Stock et al 2000 ). While the ideal polymer scaffold remains elusive, novel microfabrication techniques including laser microablation Masoumi et al 2013a ), micromolding (Masoumi et al 2013b ), and electrospinning (Hinderer et al 2014 ) enable fi ne-tuning of mechanical properties and cell attachment, although these experiments are still in in vitro stages of investigation.…”