Evaluation of biodegradable electric conductive tube-guides and mesenchymal stem cells

Figure 1 Synthetic biodegradable tubes of polyvinyl alcohol, polyvinyl alcohol loaded with COOH-functionalized multiwall carbon nanotubes MWCNTs (polyvinyl alcohol-carbon nanotubes, polyvinyl alcohol-carbon nanotubes tube-guides), and polyvinyl alcohol loaded with polypyrrole (polyvinyl alcohol-polypyrrole, polyvinyl alcohol-polypyrrole tube-guides).

Figure 2 Mesenchymal stem cells culture and expansion. A: Isolated mesenchymal stem cells (MSCs) from the Wharton’s jelly of umbilical cord presented a fusiform, fibroblast-like morphology in culture (magnification: 100 ×); B: Selected metaphases from MSCs in culture, showing normal number of chromossomes (46, XY) (magnification: 1000 ×).

Figure 3 Surgery of the rat sciatic nerve neurotmesis injury model. Under deep anesthesia the right sciatic nerve was exposed unilaterally through a skin incision extending from the greater trochanter to the mid-half distally followed by a muscle splitting incision (A). After nerve mobilization (B), a transection injury was performed (neurotmesis) using a straight microsurgical scissors (C). In group 5 (End-to-End) after neurotmesis, immediate cooptation with 7/0 monofilament polypropylene suture was performed (D). Implantation of the tube-guide in the 10 mm gap (E). Local application of the mesenchymal stem cells (MSCs), the MSCs suspension filled the polyvinyl alcohol (PVA)-carbon nanotubes (CNTs) tube-guide lumen (group 6: PVA-CNTs-MSCs) (F).

Figure 4 Kinematic plots in the sagittal plane for the ankle angle (°) as it moves through the stance phase, during the transection injury study. The mean of each group is plotted. PVA: Polyvinyl alcohol; CNTs: Carbon nanotubes; PPy: Polypyrrole; MSCs: Mesenchymal stem cells.

Figure 5 Graphical representation of the mean of area (A) and “minimal Feret’s diameter” (B) of control, regenerated tibialis anterior muscle fibers at week-20 after neurotmesis (Graft) and neurotmesis with the proximal and distal nerve stumps sutured to a polyvinyl alcohol (polyvinyl alcohol) tube and polyvinyl alcohol coated tubes (polyvinyl alcohol, polyvinyl alcohol polypyrrole and polyvinyl alcohol carbon nanotubes). Values are presented as mean ± SEM. ^aP < 0.05 vs Graft; ^cP < 0.05 vs Graft PVA CNTs MSCs; ^eP < 0.05 vs Graft PVA; ^gP < 0.05 vs Graft PVA PPy; ⁱP < 0.05 vs Graft PVA CNTs. PVA: Polyvinyl alcohol; CNTs: Carbon nanotubes; PPy: Polypyrrole; MSCs: Mesenchymal stem cells.

Figure 6 Macroscopic appearance of control tibialis anterior muscle and histological haematoxylin and eosin staining of a transverse section of tibialis anterior muscle. A: Macroscopic appearance of control tibialis anterior (TA) muscle (left) and 20 wk following neurotmesis and surgical treatment with PVA CNTs MSCs (right); B: Histological haematoxylin and eosin staining of a transverse section of TA muscle from PVA CNTs MSCs group. Magnification 40 ×. PVA: Polyvinyl alcohol; CNTs: Carbon nanotubes; MSCs: Mesenchymal stem cells.

Figure 7 Histological appearance of regenerated nerve fiber in the different groups of neurotmesis. A: PVA; B: PVA-CNTs; C: PVA-PPy; D: PVA-CNTs-MSCs; E: Graft; F: End-to-end suture (magnification: 1000 ×). PVA: Polyvinyl alcohol; CNTs: Carbon nanotubes; PPy: Polypyrrole; MSCs: Mesenchymal stem cells.