Fabrication and Characterization of an Acellular Human Kidney ECM-derived Hydrogel

Abstract

Today, more than 900,000 patients in the United States live with end-stage renal disease, with many more suffer from poor renal regeneration1. Current methods commonly use synthetic tissue-engineered constructs to deliver cells, drugs, or as scaffolds for reconstruction of injured tissues2, 3, 4, 5, 6. However, these constructs usually lack vascularization in vivo, and have poor nutrient diffusion abilities that limit their effectiveness7. On the other hand, we have found that extracellular matrix (ECM) hydrogels can be used as scaffolds to facilitate the repair and reconstruction of various tissues. The objective of this study is to fabricate and characterize the mechanics and cell response in vitro of ECM hydrogels prepared from decellularized human kidney tissues. Our preliminary data indicate that Sodium dodecyl sulfate (SDS) decellularization of human kidney tissue sections gives the most optimal results in terms of cellular material removal and ECM structure preservation; decellularized human kidney ECM, when mixed with collagen gel on a 1:1 ratio, shows similar mechanical properties as commonly used type I collagen gel. These data suggest that decellularized human kidney ECM hydrogels are able to provide the structural support necessary for cellular activities. Given these findings and the fact that ECM hydrogels are derived from naturally occurring kidney materials, I hypothesize that decellularized human kidney ECM hydrogel is able to not only provide structural support for cell growth and proliferation, but also to enhance bioactivity and vascularization. To test this hypothesis, I performed angiogenesis and tubulogenesis studies by seeding human umbilical vein endothelial cells and human kidney microvascular endothelial cells onto or in the decellularized human kidney ECM hydrogel as well as type I collagen gel.