Design and process optimisation of shape memory polymer based three-dimensional (3D) scaffolds for biomedical applications

Abstract The incorporation of shape memory polymers (SMPs) into three-dimensional (3D) scaffolds offers a promising approach, opening new ways for next-generation biomedical applications specially facilitating potential minimally invasive surgeries. This study gives an understanding of different designs and process of 3D scaffold fabrication. Further it evaluates the shape memory property of the polyurethane based smart polymer with the characteristic to regain its original shape under body’s physiological conditions (37 °C; pH of 7.4). The negatives of the computer aided designs (CAD) were printed using poly lactic acid (PLA) by fused deposition modelling. Further, silicone moulds were used to obtain the final polyurethane structures. The polymeric structures were evaluated for physiochemical characterisation such as fourier transform infrared spectroscopy to confirm the formation of urethane linkages and x-ray diffraction to confirm the nature of the polymers. Shape memory properties were evaluated for the fabricated structures in phosphate buffer saline and recovery to the original shape from the temporary shape was observed. The shape fixity ( R f ) and shape recovery ( R r ) were recorded. Also, compressible scaffolds were designed and fabricated using different infill patterns and the scaffold showing best compressibility was evaluated for shape memory effect as mentioned above. Contact angle analysis was done to understand the surface wettability. Differential scanning calorimetry thermogram was performed to identify the glass transition temperature ( T g ) of the polymers. The smart polymers were also subjected to compression analysis to understand the mechanical properties of the polymers. These findings highlight the importance of the various designs and the potential of SMPs that can serve as dynamic platforms for various biomedical applications.