3D melt electrowritten MXene-reinforced scaffolds for tissue engineering applications

Official URL: https://dx.doi.org/10.1088/1758-5090/adf803

2D Ti3C2Tx (MXene) is attracting significant attention in tissue engineering. The incorporation of these promising materials into conventional scaffolds remains challenging, particularly with physicochemical properties compatible with biological systems. Melt electrowriting (MEW) has emerged as a powerful additive manufacturing technique for biofabrication of customized three-dimensional (3D) scaffolds composed of bioactive materials. This study introduces MEW of 2D MXene and polycaprolactone (PCL) nanocomposite scaffolds for tissue engineering applications. First, Ti3C2Tx was functionalized using (3-aminopropyl) triethoxysilane (referred to as f-MXene) to obtain a blended nanocomposite in PCL matrix (referred to as MX/PCL). Fourier transform infrared spectroscopy revealed the nanocomposite composition. X-ray diffraction analysis showed the reduced crystallinity in PCL after incorporation of f-MXene. Differential scanning calorimetry helped to establish the optimal MEW parameters. Thermogravimetric analysis conducted on nanocomposites containing 0.1, 0.5, and 1% (w/w) f-MXene showed the thermal stability of MXene during the MEW process. The extrudability and printability of the nanocomposites with varying concentrations was demonstrated using MEW in 0-90-degree mesh scaffolds with fine filament dimensions. Scanning electron microscopy and Energy-dispersive x-ray spectroscopy mapping showed the shape fidelity, printing accuracy, and structural integrity of 3D MEW scaffolds with uniform distribution of f-MXene, respectively. Further characterization showed the concentration-dependent enhancement in hydrophilicity and compressive modulus and yield strength of scaffolds upon integration of f-MXene. Atomic force microscopy analysis demonstrated that the topography of the 3D MEW MX/PCL scaffolds changed compared to the pristine PCL and the roughness of the surfaces increased as the concentration of the f-MXene increased. Accelerated degradation tests demonstrated that increasing filler concentration in the reinforced scaffolds progressively delayed degradation compared to the control. The in vitro characterization showed the adherence of MC3T3-E1 preosteoblast cells on MX/PCL scaffolds and their enhanced osteogenic differentiation. The findings indicate that 3D printed MX/PCL nanocomposite scaffolds have significant potential as mechanically robust scaffolds with controlled degradation rate and cytocompatibility for tissue regeneration, with properties tunable for specific applications.