Histological views of the nanofiber scaffolds (PCL, 5MNP, 10MNP and 15MNP) after implantation in rat subcutaneous tissue for 4 weeks.

<p>Images at (a) low and (b) high magnification. Tissue samples were H&E stained and visualized under optical microscopy. Connective tissue was formed in areas between the scaffold and adjacent tissues. Neovascularization was also found within the scaffolds (indicated as arrows in (b)). Considerable degradation of scaffolds was noticed particularly in 10MNP and 15MNP, which was not readily observed in pure PCL and 5MNP (‘NF’ in (a) indicates the remaining part of nanofiber scaffold without being degraded). Fibroblasts actively migrated to the site of degradation, and activated fibroblasts were easily detected within the remaining scaffold area.