On mechanically recycled PLA-HAP-CS-based filaments for 3D printing of smart biomedical scaffolds

Polylactic acid (PLA)-hydroxyapatite (HAP)-chitosan (CS)-based thermoplastic composite matrix has proven scaffolding and implant applications. But hitherto little has been reported on the recycling of PLA-HAP-CS-based 3D printed biomedical scaffolds/implants collected as waste (for tunable mechanical, rheological, morphological, voltage (V)–current (I), and shape memory properties). This paper reports the fabrication of PLA composite-based filament for 3D printing of smart biomedical scaffolds. The composite was prepared by melt processing of recycled PLA with reinforcement of HAP and CS (for possible online health monitoring) by tuning mechanical, rheological, morphological, V–I, and shape memory properties. For 3D printing of biomedical scaffolds/implants, a single screw extruder was used in this study with input parameters; the number of shredding cycles (for ensuring recyclability), screw rpm, and processing temperature (for ensuring uniform blending). The mechanical properties such as ultimate tensile strength, Young’s modulus (E), and modulus of toughness were explored for the fabrication of functional prototypes. The results have been supported by scanning electron microscopy, energy dispersive spectroscopy, Fourier transformed infrared, and X-ray diffraction analysis. For enhancing the functional capabilities of scaffolds 4D capabilities for one-way programming (in terms of shape memory characterization) were ascertained. Finally, possibilities for 3D printed biomedical scaffolds with the capability of online health monitoring (based on V–I characteristics) have been established.