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. Author manuscript; available in PMC: 2024 Jun 19.
Published in final edited form as: Sci Transl Med. 2017 Oct 4;9(410):eaai7466. doi: 10.1126/scitranslmed.aai7466

Fig. 5. In vivo function of MeTro sealants using rat incision model of lungs.

Fig. 5.

(A) In vivo tests on rat lungs sealed by MeTro. (i) Schematic diagram showing the experimental setup. (ii) Image of the sealed lung pressurized with air, demonstrating that MeTro could adhere to the lung surface and seal the incision, but the lung tissue burst from other areas (the source of the bubbles) when pressures of >5.5 kPa were applied. (iii) Burst pressure values for lungs sealed with the MeTro sealant on day 0 (n = 4) and day 4 (n = 3) as compared to lungs sealed by Evicel (n = 3), Progel (n = 6), and suture only (n = 6) as well as healthy lung (n = 3) on day 0. Representative (B) SEM and (C) H&E-stained images from the interface between the explanted rat lung and the MeTro sealant. Tight interfaces between the MeTro hydrogel and the tissues indicate strong bonding and interlocking at the interfaces. (D) H&E staining of MeTro sections at days (i) 7 and (ii) 28 and MeTro-MMP sections at days (iii) 7 and (iv) 28 after sealing. (E) Fluorescent immunohistochemical analysis of the MeTro and MeTro-MMP sealants, showing no significant local lymphocyte infiltration (CD3) at days (i) 7 and (ii) 28 for MeTro samples and at days (iii) 7 and (iv) 28 for MeTro-MMP samples. Also, the images exhibit remarkable macrophage (CD68) expression at day 7 (i and iii) but reduced expression at day 28 for MeTro and remained the same for MeTro-MMP samples (ii and iv). Green, red, and blue colors in (E) represent the macrophages, lymphocytes, and cell nuclei (DAPI), respectively. Data are means ± SD. P values were determined by one-way ANOVA followed by Tukey’s multiple comparisons test for (A) (**P < 0.01, ***P < 0.001).