Natural Scaffolds for Renal Differentiation of Human Embryonic Stem Cells for Kidney Tissue Engineering

Abstract

Despite the enthusiasm for bioengineering of functional renal tissues for transplantation, many obstacles remain before the potential of this technology can be realized in a clinical setting. Viable tissue engineering strategies for the kidney require identification of the necessary cell populations, efficient scaffolds, and the 3D culture conditions to develop and support the unique architecture and physiological function of this vital organ. Our studies have previously demonstrated that decellularized sections of rhesus monkey kidneys of all age groups provide a natural extracellular matrix (ECM) with sufficient structural properties with spatial and organizational influences on human embryonic stem cell (hESC) migration and differentiation. To further explore the use of decellularized natural kidney scaffolds for renal tissue engineering, pluripotent hESC were seeded in whole- or on sections of kidney ECM and cell migration and phenotype compared with the established differentiation assays for hESC. Results of qPCR and immunohistochemical analyses demonstrated upregulation of renal lineage markers when hESC were cultured in decellularized scaffolds without cytokine or growth factor stimulation, suggesting a role for the ECM in directing renal lineage differentiation. hESC were also differentiated with growth factors and compared when seeded on renal ECM or a new biologically inert polysaccharide scaffold for further maturation. Renal lineage markers were progressively upregulated over time on both scaffolds and hESC were shown to express signature genes of renal progenitor, proximal tubule, endothelial, and collecting duct populations. These findings suggest that natural scaffolds enhance expression of renal lineage markers particularly when compared to embryoid body culture. The results of these studies show the capabilities of a novel polysaccharide scaffold to aid in defining a protocol for renal progenitor differentiation from hESC, and advance the promise of tissue engineering as a source of functional kidney tissue.

Strategies based on organ decellularization and recellularization

“…were the first group to show the proliferation and differentiation capacity of these cells in a kidney scaffold. The Batchelder group reported similar observations . Bonandrini et al .…”

“…The cells used for recellularization need guidance for their rearrangement and maturation, a task that is better performed by the ECM and its residual components. Indeed, as mentioned above, the preservation of the organ‐specific ECM components such as growth factors and various structural proteins facilitates an optimal recellularization process . However, an organ might be reconstructed by cultivating organ‐specific cells in an ECM derived from another organ (e.g.…”

Reconstruction of structure and function in tissue engineering of solid organs: Toward simulation of natural development based on decellularization

“…According to increased expression of surface markers, ESCs were induced to differentiate into kidney progenitors. Besides, hESCs were seeded onto renal ECM microscaffolds and cultured with sequential application of growth factors, which further confirmed the differentiation potential of ESCs into renal cells (Batchelder, Martinez, & Tarantal, ). Additionally, Song et al established a double cell perfusion system into complete decellularized kidney matrix: Human umbilical vein endothelial cells were perfused through renal artery, and rat neonatal kidney epithelial cells were reversely perfused via urinary tract so that both vascular structure and renal tubular can be produced.…”

Comparative study of two perfusion routes with different flow in decellularization to harvest an optimal pulmonary scaffold for recellularization

“…We also found that decellularization through both PR could effectively remove cell content, and the ECM structure was preserved, and microscopic examination showed that the ECaM fibers were not only present but that the ultrastructure and 3D‐organization were preserved well. Conservation of the 3D‐ECM ultrastructure can facilitate cell adhesion, survival, and integration . This technique without using any enzymatic degradations also could significantly reduce the time of production and better preserve scaffold architecture and ECM components.…”

“…Conservation of the 3D-ECM ultrastructure can facilitate cell adhesion, survival, and integration. 26,27 This technique without using any enzymatic degradations also could significantly reduce the time of production and better preserve scaffold architecture and ECM components.…”