Robust tissue growth and angiogenesis in large-sized scaffold by reducing H₂O₂-mediated oxidative stress

The implantation of cell-seeded large-sized scaffold often results in insufficient tissue regeneration, which is still a challenge for successful grafting. Excess hydrogen peroxide (H₂O₂) released by cells propagates oxidative stress, which is the primary cause of tissue injury leading to failure in tissue regeneration. Hence, preventing tissue from oxidative damage becomes imperative. For the first time, we entrapped catalase, an antioxidant in a scaffold as a novel approach in bioengineering to prevent tissue from H₂O₂-induced damage. The gel prepared from the mixture of decellularized adipose tissue and high viscous sodium alginate was used to entrap the catalase, and was coated to 3D polycaprolactone porous scaffolds. This study showed that our 3D design would regulate the release of catalase in a sustained and efficient manner protecting human turbinate mesenchymal stem cells cultured in 2D/3D in vitro oxidative microenvironment provided by H₂O₂, and supporting their robust growth. Interestingly, in vivo study revealed that our design was successful in tissue engineering by both an increase in tissue growth (≥45%) throughout the large-sized scaffold with substantial reduction in inflammation (≥40%), and an increase in the induction of angiogenesis (≥40%). This novel design, therefore, would be highly applicable for successful grafting to replace a damaged tissue in future.