PETG-silk biocomposite for additive manufacturing and biomedical applications

Abstract

Natural fiber-reinforced biocomposites are suitable for the fabrication of biomedical products, including scaffolds, implants, prostheses, and orthoses due to their mechanical and biological properties as well as high availability, low cost, and sustainability. This study explores the mechanical properties, biocompatibility, biodegradability, and thermal stability of a short silk fiber reinforced PETG composite with various silk fiber ratios (2–10 % by weight) for potential tissue engineering scaffolds as well as external supportive biomedical devices like braces and splints using 3D printing. The composites were successfully prepared with a homogeneous distribution of fibers in the matrix without fiber agglomeration or any voids/cracks in the matrix. The prepared composites were found to be thermally stable up to 390 °C. The addition of the reinforcement helped to improve the mechanical properties of the material, and the composite with 10 % silk was observed to have a tensile modulus of 564 MPa, which is almost five times that of pure PETG (97 MPa). Specific strength of composite was also improved by 56.02 % compared to pure PETG. Silk content in composites significantly increased the biocompatibility as well, evidenced by the increased level of cellular metabolic activities in the composites. In terms of processability, the developed composite could be 3D printed with common FDM 3D printers without any significant challenges. Therefore, this material would be suitable for fabricating complex shapes like scaffolds with high strength-to-weight ratio and improved biomedical functionalities.