Fig 1.
Procedure of surgery, macroscopic images, and quantification of macroscopic appearance of regenerated tendons at two and four weeks.
(A): Surgical procedure of FTD and intratendinous injection of saline or UC MSCs. (B): Macroscopic appearance of the tendon (Left side image: Supraspinatus tendon immediately after harvest; Right side image: the tendon removing the loose connective tissue surrounding the injury site to observe the original defect shape). (C): The total macroscopic score. Bar charts present mean ± standard deviation; Statistically significant at p < .05. Abbreviations: UC MSCs, umbilical cord derived mesenchymal stem cells.
Fig 2.
Representative histological images of general structure and quantification of the changes in regenerated tendon at two and four weeks.
(A): H&E staining of tendon (magnification; X200). (B): the total degeneration score and detail parameters. (C): Integration of structure between the tendon defect and adjacent tendon. (D): Inflammation at the tendon defect. Bar charts present mean ± standard deviation; statistically significant at p < .05. Abbreviations: UC MSCs, umbilical cord derived mesenchymal; H&E, hematoxylin and eosin.
Fig 3.
Representative histologic images of collagen matrix and quantification of the changes in regenerated tendon at two and four weeks.
(A): PSR staining of the tendon (magnification; X200). (B): collagen organization of the tendon. (C): collagen fiber coherency of the tendon. Bar charts present mean ± standard deviation; statistically significant at p < .05. Abbreviations: UC MSCs, umbilical cord derived mesenchymal; PSR, picrosirius red.
Fig 4.
Representative histological images of nuclei morphology and cartilage formation of regenerated tendons and quantification of the changes at two and four weeks.
(A): Nuclei morphology of fibroblasts at the tendon (magnification; X400) (B): Density of fibroblasts of the tendon. (C): Nuclear aspect ratio of fibroblasts of the tendon. (D): Nuclear angle of fibroblasts of the tendon. (E): Saf-O staining of the tendon (magnification; X200). (F): Area of cartilage-related GAG of the tendon. Bar charts present mean ± standard deviation; statistically significant at p < .05. Abbreviations: UC MSCs, umbilical cord derived mesenchymal; GAG, glycosaminoglycan; Saf-O, safranin-O.
Fig 5.
Biomechanical test procedure and quantification of biomechanical properties of regenerated tendons at two and four weeks.
(A): an extracted specimen and procedure of biomechanical testing. (B): Cross-sectional area of the supraspinatus tendon at defect site. (C): ultimate failure load. (D): stiffness. (E): ultimate stress. Bar charts present mean ± standard deviation; statistically significant at p < .05. Abbreviations: UC MSCs, umbilical cord derived mesenchymal stem cells.
Fig 6.
Representative fluorescent images of implanted PKH26 labeled UC MSCs within the SST and quantification of the injected cells at 3 hours and two and four weeks.
(A): Implanted UC MSCs with DAPI and PKH26 dye of the tendon (magnification; X200 and X400). (B): The number of the injected UC MSCs per area (mm2). Bar charts present mean ± standard deviation; statistically significant at p < .05. Abbreviations: DAPI, 4′,6-diamidino-2-phenylindole; UC MSCs, umbilical cord derived mesenchymal stem cells.