Characterization of bladder acellular matrix hydrogel with inherent bioactive factors

Bladder acellular matrix (BAM) hydrogel may have great potential in tissue engineering due to outstanding biocompatibility and the presence of inherent bioactive factors in BAM. In this study, we prepared the BAM hydrogel by the method of enzymatic solubilization with pepsin and characterize the microrheological properties of the BAM precursor solution. The structures of the BAM hydrogel were characterized by scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Furthermore, the growth factors including vascular endothelial growth factor (VEGF), platelet-derived growth factor B (PDGF-BB), keratinocyte growth factor (KGF) were quantified by ELISA. The biological performances of the hydrogels were evaluated by cultivating porcine iliac endothelial cells (PIECs) in vitro. Lyophilized BAM showed porous structure with pore diameter ranging from 50 to 100μm. BAM 4-G hydrogel (4mg/mL) with a short gelation time of 3.95±0.07min presents better thermal stability than BAM 6-G hydrogel (6mg/mL). Growth factors in the BAM hydrogel maintain valuable biological activity even after digestion process. The BAM hydrogel supported the adhesion and growth of PIECs well and has great potential for further tissue engineering.