A novel biodegradable nano/micro hybrid structure was obtained by electrospinning P3HB or PCL nanofibers onto a twisted
silk fibroin (SF) structure, with the aim of fabricating a suitable scaffold for tendon and ligament tissue engineering. The
electrospinning (ES) processing parameters for P3HB and PCL were optimized on 2D samples, and applied to produce two
different nano/micro hybrid constructs (SF/ES-PCL and SF/ES-P3HB).
Morphological, chemico-physical and mechanical properties of the novel hybrid scaffolds were evaluated by SEM, ATR
FT-IR, DSC, tensile and thermodynamic mechanical tests. The results demonstrated that the nanofibers were tightly
wrapped around the silk filaments, and the crystallinity of the SF twisted yarns was not influenced by the presence of
the electrospun polymers. The slightly higher mechanical properties of the hybrid constructs confirmed an increase of
internal forces due to the interaction between nano and micro components. Cell culture tests with L929 fibroblasts, in
the presence of the sample eluates or in direct contact with the hybrid structures, showed no cytotoxic effects and a
good level of cytocompatibility of the nano/micro hybrid structures in term of cell viability, particularly at day 1. Cell
viability onto the nano/micro hybrid structures decreased from the first to the third day of culture when compared with
the control culture plastic, but appeared to be higher when compared with the uncoated SF yarns. Although additional
in vitro and in vivo tests are needed, the original fabrication method here described appears promising for scaffolds suitable for tendon and ligament tissue engineering.