Characterization of three-dimensional printed thermal-stimulus polylactic acid-hydroxyapatite-based shape memory scaffolds

The shape memory polymers have attained huge attention as smart materials owing to their enormous benefits in the context of the common class of thermoplastics. In this study, novel thermal-stimulus-based hydroxyapatite (HA) reinforced polylactic acid (PLA) scaffolds have been developed through three-dimensional (3D) printing technology. Initially, the effect of various processing parameters, such as the proportion of HA in PLA and infill density, and level of stimulating temperature, on tensile, flexural, and compression strength of the developed composite scaffolds have been studied to understand their effects, through statistically assisted single and multiobjective optimization techniques. The shape recovery factor of the prestrained composite scaffolds has been assessed by providing thermal-stimulus. Finally, the biological performance of the developed scaffolds has been evaluated throughin vitrocell culture and wettability analysis. The morphological study of the composite scaffolds, at different stages, has been performed for understanding the effect of processing parameters on the mechanical, shape recovery effect, and biological responses. Overall, the results of the study highlighted that the 3D printed scaffolds possessed nearly 95.77% shape memory effect along with desirable mechanical,in vitrobiocompatibility, and hydrophilic morphology suitable to be a potential candidate of fabricating customized biomedical devices with activated shape recovery abilities.