Decellularization of bovine small intestinal submucosa and its use for the healing of a critical-sized full-thickness skin defect, alone and in combination with stem cells, in a small rodent model

In this study, we initially described an efficient decellularization protocol for bovine-derived small intestinal submucosa (bSIS), involving freeze-thaw cycles, acid/base treatment and alcohol and buffer systems. We compared the efficacy of our protocol to some previously established ones, based on DNA content and SEM and histochemical analyses. DNA content was reduced by ~89.4%, significantly higher than compared protocols. The sulphated GAG content of the remaining interconnected fibrous structure was 5.738 ± 0.207 µg/mg (55% retained). An in vitro study was performed to evaluate whether rat bone marrow mesenchymal stem cells (MSCs) could attach and survive on bSIS membranes. Our findings revealed that MSCs can preserve their viability and proliferate on bSIS for > 2 weeks in culture. We conducted in vivo applications for the treatment of an experimental rat model of critical sized (7 cm2 ) full-thickness skin defect. The wound models treated with either MSCs-seeded (1.5 × 106 cells/cm2 ) or non-seeded bSIS membranes were completely closed by week 7 without significant differences in closure time; on the other hand, the open wound control was closed at ~47% at this time point. Immunohistopathology results revealed that the group which received MSCs-seeded bSIS had less scarring at the end of the healing process and was in further stages of appendage formation in comparison with the non-seeded bSIS group. Copyright © 2015 John Wiley & Sons, Ltd.