Biological Augmentation Using Electrospun Constructs with Dual Growth Factor Release for Rotator Cuff Repair

Figures

• 

  Figure 1. Schematic illustration of the bilayer film facilitating the delivery of dual growth factors for repairing RCT.

• 

  Figure 2. BMPs immobilization onto PLGA fiber mats via PDA chemistry. (a–d) Morphologies and (a1–d1) fiber diameter distributions of the as-prepared PLGA, PLGA–PDA and BMP@PLGA–PDA electrospun fibrous mats, respectively; (e) FTIR of the as-prepared electrospun fibrous mats; (f) representative images of the contact angle measurement on the fibrous mats; (g) protein absorption efficiency of pure PLGA and PLGA–PDA electrospun fibrous mats (n = 3,**P < 0.01); (h), (i) cumulative release profiles of BMP2 and BMP12 loaded on PLGA–PDA electrospun fibrous mats (n = 3).

• 

  Figure 3. Cell viability and proliferation of osteoblasts in response to BMP2@PLGA–PDA. (a) CCK-8 analysis to qualify the cell viability of osteoblasts when cultured on fibrous mats for 24, 48, and 72 h; (b) immunofluorescence staining images of osteoblasts proliferation for 3 and 7 days on fibrous mats (green cytoskeleton was stained by phalloidin, and blue nuclei was stained by Hoechst; scale bar, 50 μm); (c) the quantitative analysis of the stained cytoskeleton. The data is presented as mean ± SD (n = 4, *P < 0.05 and **P < 0.01).

• 

  Figure 4. Cell viability, proliferation and tenogenic/chondrogenic markers of tenocytes in response to BMP12@PLGA–PDA. (a) Immunostaining of collagen I to identify the successful isolation of tenocytes; (b) CCK-8 analysis to quantify the cell viability of tenocytes when cultured on fibrous mats for 24, 48, and 72 h; (c) immunofluorescence staining images of tenocytes proliferation for 3 and 7 days on fibrous mats; (green cytoskeleton was stained by phalloidin, and blue nuclei was stained by Hoechst; scale bar, 100 μm); (d) western blot analysis of tenocytes cultured on fibrous mats for 7 days; (e–i) quantitative analysis of the protein expression of tenogenic/chondrogenic markers (SOX9, TNMD, SCX, Collagen II, and Collagen I) in (d). The data is presented as mean ± SD (n = 4, *P < 0.05, and **P < 0.01).

• 

  Figure 5. Bilayer fiber mats promote the recovery of tendon-bone interface in vivo. (a) Images of the in vivo surgery; (b) biomechanical testing of the harvested inserts and (c) comparative studies on ultimate load to failure force among groups; (d) safranin O/Fast green staining images of the recovered interface after 4- and 8-weeks post-treatment with PLGA–PDA, single BMP@PLGA–PDA and the dual-BMP mats, with direct suturing as sham control. The data is presented as mean ± SD (n = 6,*P < 0.05 and **P < 0.01).

• 

  Figure 6. Immunohistochemical images and analysis of (a) collagen I and (b) collagen II expression after 4- and 8-weeks following treatments with PLGA–PDA, single BMP@PLGA–PDA and the dual-BMP fiber mats, with direct suturing as sham control. The data is presented as mean ± SD (n = 6, *P < 0.05, and **P < 0.01).