A Biomimetic Electrospun Membrane Supports the Differentiation and Maturation of Kidney Epithelium from Human Stem Cells

Abstract

Podocytes derived from human induced pluripotent stem (hiPS) cells are enabling studies of kidney development and disease. However, many of these studies are carried out in traditional tissue culture plates that do not accurately recapitulate the molecular and mechanical features necessary for modeling tissue- and organ-level functionalities. Overcoming these limitations requires the design and application of tunable biomaterial scaffolds. Silk fibroin is an attractive biomaterial due to its biocompatibility and versatility, which include its ability to form hydrogels, sponge-like scaffolds, and electrospun fibers and membranes appropriate for tissue engineering and biomedical applications. In this study, we show that hiPS cells can be differentiated into post-mitotic kidney glomerular podocytes on electrospun silk fibroin membranes functionalized with laminin. The resulting podocytes remain viable and express high levels of podocyte-specific markers consistent with the mature cellular phenotype. The resulting podocytes were propagated for at least two weeks, enabling secondary cell-based applications and analyses. This study demonstrates for the first time that electrospun silk fibroin membrane can serve as a supportive biocompatible platform for human podocyte differentiation and propagation. We anticipate that the results of this study will pave the way for the use of electrospun membranes and other biomimetic scaffolds for kidney tissue engineering, including the development of co-culture systems and organs-on-chips microphysiological devices.

Mimicking the Natural Basement Membrane for Advanced Tissue Engineering

“… 276 Electrospun silk fibroin nanofibers fabricated by Mou et al ( Figure 6 .1) were successfully used to mimic glomerular BM, which supported the proliferation and differentiation of human podocytes. 277 Additionally, a hybrid silk fibroin and chitin nanofibers were incorporated with TGF-β, to support the adhesion and proliferation of chondrocytes. 278 Apart from bone tissues, electrospun silk fibroin has also been used to produce stable vascular grafts that proliferate endothelial cell growth.…”

“… Fibrous basement membrane mimics: Electrospinning is a versatile technique to produce fibrous scaffolds of varying properties in order to mimic the native BM in terms of architecture strength and dimensions of the fibers: (1A) A laminin-coated nanofibrous membrane of silk fibroin (SF) was fabricated as glomerular BM mimic, for differentiation of human podocytes from human stem cells, where (A) a podocyte interacts with the laminin coated SF fibers and confocal images of podocytes stained for podocin (red), nephrin (green) and nucleus (blue), on SF without laminin, SF with laminin and on tissue culture plate; adapted with permission from ref ( 277 ). Copyright 2022 Mou, Xingrui et al (changes were made).…”

“…Silk fibroin, alone or in combination with other natural polymers has been used to produce mechanically stable and biocompatible nanofibrous scaffolds. , Electrospun silk fibroin has been used successfully to support many tissue cells including cartilage, mucosal cells, bone, endothelial, and nerve cells . Electrospun silk fibroin nanofibers fabricated by Mou et al (Figure .1) were successfully used to mimic glomerular BM, which supported the proliferation and differentiation of human podocytes . Additionally, a hybrid silk fibroin and chitin nanofibers were incorporated with TGF-β, to support the adhesion and proliferation of chondrocytes .…”

A Concise Review on Electrospun Scaffolds for Kidney Tissue Engineering

“…Silk fibroin (SF) is a natural macromolecular protein polymer promising for TE applications due to its high biocompatibility, biodegradability and outstanding mechanical properties. For instance, the hydrophobic β-sheet-forming domains present on SF contribute to an increased resilient behaviour [ 66 ]. For the first time, Mou et al successfully produced SF fibres through electrospinning that promote the differentiation of mature human podocytes.…”

“…For the first time, Mou et al successfully produced SF fibres through electrospinning that promote the differentiation of mature human podocytes. Furthermore, the manufactured scaffold was able to support long-term culture and cellular viability as well as an upregulated expression of the podocyte-specific markers PAX2, NPHS1 and WT1 and comparable levels of PODXL, SYNPO and NEPH1 to cells cultured on laminin-coated plates [ 66 ]. Prior to cell culture, samples were plasma treated, sterilised in 70% ethanol, washed in sterile water and coated with 25 µg mL −1 laminin-511.…”