Fig. 6: Biocompatibility and biodegradability of Electro-Ox hydrogel tapes in vitro and in vivo.

a, b Fluorescence microscopic images (a) and cell viability (b) of MC 3T3 and MEF cells cultured on Electro-Ox hydrogels. The living and dead cells were stained with a live/dead assay (Calcein-AM/PI Double Staining Kit) after 24 h of culture. P values, two-tailed Student’s t test. No adjustments were made for multiple comparisons. Scale bar = 100 μm. c In vitro biodegradation of Electro-Ox hydrogel tape in phosphate buffer saline (PBS) and simulated body fluid (SBF) with or without protease. Values in b, c represent the mean and standard deviation (n = 3–5 independent experiments). d Representative histological images stained with hematoxylin and eosin (H&E) for assessment of the biocompatibility and biodegradation of the Electro-Ox hydrogel tape in vivo at Days 1, 7, and 14 after subcutaneous implantation. GT and FC indicate granulation tissue and fibrous capsule, respectively. e–g Representative histological images of the control groups, e the fibrin-based glue, f the cyanoacrylate (ACA) glue, and g the sham surgery. SM and GT indicate skeletal muscle and granulation tissue, respectively. All histological experiments were repeated at least three times with similar results. Scale bar = 100 μm. h–m Blood biochemistry examination of the variation in ALT (alanine transferase), AST (aspartate transferase), UREA (urea), CREA (creatinine), Ca²⁺, and K⁺. n–q Hematological examination of the variation in WBC (white blood cell count), RBC (red blood cell count), HGB (hemoglobin), and LY (lymphocyte). r, s Coagulation action test of the variation in APTT (activated partial thromboplastin time) and FIB (fibrinogen). The blood of rats without any surgery was set as the control. In h–s, the samples were taken at Days 1, 7, and 14 after subcutaneous implantation and reported values represent the mean and standard deviation (n = 3 independent animals).