Bulk Compounding of PCL-PEO Blends for 3D Plotting of Scaffolds for Cardiovascular Tissue Engineering

Abstract

Abstract3D plotting of micro-extruded filaments is a promising method for the additive manufacturing of porous scaffolds (for tissue engineering) in thermoplastic polymers. A much investigated polymer for degradable scaffolds is poly-ε-caprolactone (PCL). One of the remaining issues with the material is its inherent hydrophilicity, which leads to nonspecific protein adsorption. Specifically for cardiovascular applications, it has also been found that PCL is insufficiently flexible to mimic the mechanic-elastic behavior of the natural tissue. Earlier research has shown that blending with low molecular weight poly-ethylene-oxide (PEO) may offer an improvement in terms of both hydrophilicity and flexibility. Until now, solution-based blending has been used as a manufacturing method for these blends, since PCL and PEO are largely immiscible in the melt. This, however, is tedious work which yields only a few grams of material at a time. Therefore, in the current research, a method has been developed for the bulk compounding of PCL-PEO blends, using a twin-screw extruder. The manufactured blends were evaluated for composition, dispersion of the PEO and crystalline morphology. It was found that by re-compounding the blends after the first extrusion step, a good dispersion of the PEO within the PCL matrix was achieved.

Material Considerations for Fused-Filament Fabrication of Solid Dosage Forms

“…For the interested reader, a recent paper by Solanki et al [ 61 ] describes a formulation strategy for FFF that maintains the immediate release properties of PVP-VA through melt-blending with hydroxypropyl methylcellulose and hydroxypropyl methylcellulose acetate succinate. PEO was also included in the current formulation trials since we wished to reduce the hydrophobicity of the PCL [ 62 ]. We have previously had success blending PCL with PEO to form an oral tablet [ 38 ] and such blends have been reported elsewhere as efficient drug carriers [ 63 , 64 , 65 ].…”