A novel composite biomaterial for bone-soft tissue fixation applications was developed. MgO-Silk-PCL, Silk-PCL and MgO-PCL composites were prepared with variable filler concentrations (0, 10, 20 and 30% w/w of MgO nanoparticles and 0%, 5%, 10%, 20% and 30% of degummed silk fiber) in PCL polymer. The highest mechanical properties were obtained with 10% MgO and 20% Silk composite (MSP) wih 1.7× better tensile strength and 7.5× tensile modulus over PCL. It exhibited good cell viability, adhesion and hemocompatibility, increased cell proliferation and differentiation. MgO filler contributed more in increasing tensile strength, whereas silk fiber towards modulus, imparting a synergistic effect on mechanical performance. Prototype bone screws were molded using the MSP composite in a custom-designed mold. It showed significantly increased degradation (2.7 fold after 60 days) in PBS attributable to binary filler phase as compared to PCL. In vivo biosafety studies of MgO-silk-PCL composite screw in SD rats by subcutaneous implantation showed moderate inflammation at 2 weeks which subsided after 4th week. No toxic effect was seen in histopathology of vital organs and in blood parameters. Composite screw showed 2× pull-out strength of PCL in synthetic bone, therefore a potential candidate for bone-soft fixation applications like resorbable orthopedic screws for ACL reconstruction.