3D Microporous Scaffolds Manufactured via Fused Filament Fabrication combined with Direct Laser Writing Ablation and Polymerization

Abstract

A 3D printing (Fused Filament Fabrication (FFF)) approach has been implemented for the creation of microstructures having internal 3D microstructure geometry. These objects were produced without any sacrificial structures or additional support materials, just by precisely tuning the nozzle heating, fan cooling and translation velocity parameters. The manufactured microporous structures out of polylactic acid (PLA) had fully controllable porosity (20-60%) and consisted of desired volume pores ~0.056 µm³). The prepared scaffolds were suitable for the primary stem cell growth and the 3D structure was relevant for specific myogenic cell arrangement and it seems likely for cell differentiation.

In addition, direct laser writing (DLW) ablation was employed to modify the surfaces of the PLA structures, drill holes as well as shape the outer geometries of the created objects. The proposed combination of FFF printing with DLW offers successful fabrication of 3D microporous structures with functionalization capabilities such as modification of surfaces, generation of grooves and microholes, cutting out precisely shaped structures (microarrows, microgears). The produced structures could serve as biomedical templates for cell culturing as well as biodegradable implants for tissue engineering. The additional micro-architecture is important in connection with the cell types used for the intention of cell growing. Moreover, we show that surface roughness can be modified at the nanoscale by immersion into acetone bath, thus increasing the hidrophilicity. The approach is not limited to biomedical applications, it could be employed for the manufacturing of bioresorbable 3D microfluidic and micromechanic structures.

Finally, the printed PLA structures are used as 3D substrates for direct laser polymerization [1]. This approach covers two Additive Manufacturing (AM) techniques which differs in structuring spatial resolution and fabrication throughput by 3 orders of magnitude. Thus it combines flexible 3D structuring in both micro- and nano-scales joining commercially available table top devices with state of the art laboratory equipment.