Architected poly(lactic acid)/poly(ε-caprolactone)/halloysite nanotube composite scaffolds enabled by 3D printing for biomedical applications

Abstract

Herein, we report the physicochemical, thermal, mechanical and biological characteristics, including bioactivity, biodegradation and cytocompatibility of additive manufacturing-enabled novel nanocomposite scaffolds. The scaffolds comprise a blend of polylactic acid (PLA) and poly-ε-caprolactone (PCL) reinforced with halloysite nanotubes (HNTs). The nanoengineered filaments were developed by melt blending, and the nanocomposite scaffolds were manufactured by fused filament fabrication. Uniform dispersion of HNTs in the PLA/PCL blend is revealed via scanning electron microscopy. Mechanical property loss due to the addition of PCL to realize a suitable biodegradation rate of PLA was fully recovered by the addition of HNTs. Bioactivity, as revealed by the fraction of apatite growth quantified from XRD analysis, was 5.4, 6.3, 6.8 and 7.1% for PLA, 3, 5 and 7 wt% HNT in PLA/PCL blend, respectively, evidencing enhancement in the bioactivity. The degradation rate, in terms of weight loss, was reduced from 4.6% (PLA) to 1.3% (PLA/PCL) upon addition of PCL, which gradually increased to 4.4% by the addition of HNTs (at 7 wt% HNT). The results suggest that the biodegradation rate, mechanical properties and biological characteristics, including cytocompatibility and cell adhesion, of the 3D printed, microarchitected PLA/PCL/HNT composite scaffolds can be tuned by an appropriate combination of HNT and PCL content in the PLA matrix, demonstrating their promise for bone replacement and regeneration applications. Graphical abstract

Expanding Poly(lactic acid) (PLA) and Polyhydroxyalkanoates (PHAs) Applications: A Review on Modifications and Effects

“…Alam et al [ 171 ] reported the mechanical properties of 3D-printed novel nanocomposite scaffolds. The scaffolds consisted of a blend of PLA and PCL reinforced with halloysite nanotubes (HNTs).…”

“…However, that was gradually increased to 4.4% after the addition of 7 wt.% HNTs. Results showed that the mechanical properties, biodegradation rate as well as biological characteristics of the 3D-printed micro architected PLA/PCL/HNT composite scaffolds can be tuned by a suitable combination of PCL and HNTs contents inside the PLA matrix [ 171 ].…”

“…Figure 15 shows a schematic of production of filament as well as 3D-printed scaffolds using FFF. According to Alam et al [ 171 ], the process involves (i) solvent casting followed by (ii) filaments fabrication via extrusion and finally (iii) 3D printing of scaffolds.…”

“… ( a ) Schematic of filament fabrication and 3D printing of scaffolds and ( b ) optical images of various scaffolds (( i ) for neat PLA, ( ii ) PLA/PCL (50/50 wt.%), ( iii ) PLA/PCL/HNTs (50/50/1 wt.%), ( iv ) PLA/PCL/HNTs (50/50/3 wt.%), ( v ) PLA/PCL/HNTs (50/50/5 wt.%) and ( vi ) PLA/PCL/HNTs (50/50/7 wt.%)) [ 171 ]. …”

Combining Materials Obtained by 3D-Printing and Electrospinning from Commercial Polylactide Filament to Produce Biocompatible Composites

“…For brevity, some selected images are presented in Figure 13 in order to show that fibroblasts adhered in the 3D-printed piece and in the electrospun fibers of the composite. Although we used a commercial 3D-printer filament to print the scaffolds, in all the composites cultured with 3T3 cells we observed cells attached to the main 3D-printed structure (Figure 13A,B), showing the potential of commercial PLA to produce biocompatible materials [62]. The morphology of cells found spread over the surface of 3D-printed pieces of the composite are a blend between some apoptotic cells showing a round shape and a shrunk nucleus, besides a well-formed and interconnected network of fibroblasts linked by polarized filipodia protrusions [63][64][65].…”