(395e) Non-Invasive Structural Investigation of Renal Scaffold By Magnetic Resonance Imaging (MRI)

Nafiseh Poornejad, Jonathan J. Wisco, Beverly L. Roeder, Alonzo D. Cook

Brigham Young University, Provo, Utah

Naturally obtained scaffolds combined with patient-specific cells could result in improved regeneration of human tissues. Scaffold fabrication is the first step in this technology, which is decellularization of the native tissue and sterilization of resulting scaffold. Decellularization, as the most effective procedure, could be done by exposing the native tissue to cell lysing agents that remove all cellular materials leading to the intact collagenous structure of extracellular matrices (ECMs). The majority of cellular remnants should be withdrawn to avoid immune response induction while the ECM should remain intact. In complex organs such as the kidney, the ultrastructure is of significant importance since it is essential for the filtration function of the kidney. Examining the fabricated ECM for structural integrity and intactness of the vascular network was pursued in this study via a novel method.

In this study, we decellularized whole porcine kidneys via our previously developed fabrication method (1-3) and investigated the ultrastructure of renal tissue by magnetic resonance imaging (MRI). Initially, we intended to perfuse a solution of nano iron particles, as contrast medium, through the vascular network to obtain high-resolution imaging with MRI. However, the nanoparticles would diffuse out of vessels in a decellularized ECM because of the lack of endothelial cells lining the vessels. So instead, human renal cells were loaded with nano iron particles and perfused through the renal artery (to image the vascular network) and renal ureter (to examine tubule structures) of native and decellularized porcine kidneys. The MRI scanning was performed on a 3 Tesla MR scanner (Trio, Siemens, Erlangen, Germany) with a 32-channel head matrix coil. The obtained results confirmed structural intactness of decellularized ECM compared with native tissue.

In summary, we developed a feasible method to investigate the vascular network and ultrastructural integrity of any decellularized organ including kidney, heart, liver, and lung by perfusing the organs with cells loaded with nano iron particles, and imaging the organs using MRI.

1. Poornejad, N., Frost, T.S., Scott, D.R., Elton, B.B., Reynolds, P.R., Roeder, B.L., andCook, A.D. Freezing/thawing without cryoprotectant damages native but not decellularized porcine renal tissue. Organogenesis 11, 30, 2015.

2. Poornejad, N., Nielsen, J.J., Morris, R.J., Gassman, J.R., Reynolds, P.R., Roeder, B.L., andCook, A.D. Comparison of four decontamination treatments on porcine renal decellularized extracellular matrix structure, composition, and support of human renal cortical tubular epithelium cells. Journal of biomaterials applications, 0885328215615760, 2015.

3. Poornejad, N.M., N.; Salehi, A.S.M.; Scott, D.R.; Fronk, C.A.; Roeder, B.L.; Reynolds, P.R.; Bundy, B.C.; Cook, A.D. Efficient decellularization of whole porcine kidneys improves reseeded cell behavior. Biomedical Materials 11, 025003, 2016.