A new strategy for prevention of anastomotic stricture using tacrolimus-eluting biodegradable nanofiber

Overall appearance of TEBN. TEBN looked like a “cotton wool” formation.

In vitro tacrolimus-releasing test with TEBN. Longitudinal axis of this graph indicates the remaining percentage of tacrolimus in the TEBN (%). The remaining tacrolimus curve seems to be logarithmic. TEBN, Tacrolimus-eluting biodegradable nanofiber.

In vivo tacrolimus-releasing test with TEBN. Longitudinal axis of this graph indicates remaining percentage of tacrolimus in the TEBN (%). Tacrolimus was released at a fast initial burst phase during the first few days followed by a slow sustained phase during the following 4 weeks. TEBN, Tacrolimus-eluting biodegradable nanofiber.

Ratio of intimal area. The neointimal hyperplasia is significantly inhibited by 1.0 wt% TEBN. TEBN, Tacrolimus-eluting biodegradable nanofiber.

Histologic findings in the anastomotic site 2 weeks after operation. H&E staining of control group ×200 (A) and ×40 (B), and TEBN containing 1.0 wt% tacrolimus ×200 (C) and ×40 (D). Neointimal hyperplasia is significantly decreased in TEBN containing 1.0 wt% tacrolimus. A and C, Scale bar = 100 μm. B and D, Scale bar = 500 μm.

Immunohistochemical staining in the anastomotic site 2 weeks after operation. Micrographs (original magnification, ×200) are representative photographs. A–C, Control group. D–F, TEBN-containing 1.0 wt% tacrolimus group. A and D, Stained with alpha-smooth muscle actin antibody. Alpha-smooth muscle actin antibody-positive cells are shown in neointimal hyperplasia and adventitia. B and E, Stained with SMemb. SMemb-positive cells are shown in neointimal hyperplasia in control group. The longitudinal sections of (C) and (F) are stained with Factor VIII. Factor VIII-positive cells cover the surface of the inner lumen. Scale bar = 100 μm.