On 3D printed thermoresponsive PCL-PLA nanofibers based architected smart nanoporous scaffolds for tissue reconstruction

Abstract

Previous studies have reported that polycaprolactone (PCL)-polylactic acid (PLA) based scaffolds are one of the most acceptable composite materials in tissue engineering/reconstruction applications. However, little has been reported on the fabrication of nanoporous smart scaffolds (having sensing capability, programmable cell growth, and programmable shape memory capabilities, etc.). In this study, nanoporous smart scaffolds have been fabricated using the fused filament fabrication (FFF) process by architecting the PLA nanofibers in between the PCL polymer matrix to introduce the smart properties. The results have revealed an acceptable modulus of toughness (7.304 MPa) (as crash resistance property for scaffolds) when fabricated using thermal stress relieved/pre-heat treated (PHT), PCL granules at 64 °C-barrel processing temperature (optimized setting) of a screw extruder. The recrystallization has ensured the tuning of crystallinity (increased from 6.06 % to 9.53) as confirmed by differential scanning calorimetry (DSC) analysis. On the optimized extrusion setting, the dielectric constant (ϵr) (∼12) has shown acceptable sensing capabilities in scaffolds. The results of the crash resistance, thermal, and sensing properties have been supported by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic analysis. Deposition of the PLA nanofibers mat in the PCL matrix ensured improved cell proliferation and it was 180 % when 1 mat was deposited. Also, PCL + 1 PLA nanofiber mat scaffolds recovered their original shape in less time (by 25 %) as compared to PCL scaffolds under the thermal stimulus.