Fig. 3

Fabrication of DCDS suture, morphology, tensile strength and structural state during stretching. A Fabrication of DCDS suture via DCSS. B DCDS suture laden with fluorescein sodium and methyl orange (b1) showing the double-strand state. The frozen staining and SEM of DCDS suture (b2: frozen section image, b3: SEM image, b4: frozen section in longitude, b5: SEM image in longitude). C Longitude and cross-section of DCDS suture under SEM (c1: longitude, c2: cut end after stitching in tissue, c3: broken end after freezing). D Tensile strength and fracture energy of DCSS (single) and DCDS (double) suture after in PBS for 10 minutes (n = 3). E X-ray diffraction of DCDS (e1), catgut suture (e2) and graph with peaks (e3). F Histogram of FWHM and crystallinity of two sutures (n = 3)