Figure 3.

The bCS is biocompatible in vivo when implanted in a rat subacute MI model. (A) Representative pictures of hearts that were implanted with bCS taken at 7 and 30 days post-implant, as well as pictures of the Sirius red-stained sections of the hearts. The collagen patch (delineated in yellow) shows good bCS integration into the heart at 7 days post-implant. bCS is practically degraded on day 30. The blue line delimits the bCS from the cardiac tissue. Scale bars: 1 mm (top) and 200 μm (bottom). (B) H&E-stained heart sections at the infarct zones treated with the bCS and not treated with the bCS (control). The blue arrows indicate the presence of the CS, and the asterisks indicate the location of the CH. A strong inflammatory reaction against the bCS in the infarcted hearts is not found at day 7 or day 30 post-implant. Scale bars: 200 μm. (C) The fold increase in the number of inflammatory cells, counted at the infarct zone of the bCS-treated hearts, compared to that of the nontreated ones (control group). (D) Representative immunofluorescence pictures that show the macrophage infiltration in the ischemic heart at the infarct/implant zone (red: anti-CD68, green: anti-CCR7 (M1) or anti-CD206 (M2), and blue: nuclei DAPI staining) in the control and bCS groups. Scale bars: 50 μm. (E) The macrophage M1/M2 ratio at 7 and 30 days after bCS implantation for both the control group (which had no implants performed) and the bCS group (which had implants performed). Data were obtained from 2 to 3 animals per group. Values are represented as mean ± SEM.