Properties of 3D-printed continuous silk fiber-reinforced poly(caprolactone)

In this study, poly(caprolactone)/continuous mulberry silk (PCL/MS) composite filaments were prepared via the pre-impregnation method and were employed for FDM technology. The MS was treated with alkali. The tensile properties and morphology of PCL/MS composite filaments were investigated using a universal mechanical testing machine and a scanning electron microscope. Results demonstrated that the incorporation of MS markedly enhanced the tensile properties of the filament. The interfacial adhesion between PCL and MS was dramatically improved after the NaOH treatment. The effects of print temperature on the flexural properties and porosity of the 3D-printed composites were examined. Results showed that a reduction in print temperature enhanced the flexural strength by 37.1%, and the porosity decreased from 35.33% to 15.29%. Finally, PCL/MS composite porous scaffolds with various pore sizes were fabricated successfully. These scaffolds exhibited excellent compressive strength and rigidity. The cell experiments showed that the composite scaffolds provided a non-toxic and favorable microenvironment for cells, supported both cell survival and proliferation, making them a promising candidate for further bone tissue engineering applications. Therefore, the results presented in this paper indicate that the PCL/MS composite scaffolds possessed the potential to serve as bone repair materials and facilitate their integration into human tissue engineering.