Pluripotency maintenance of amniotic fluid-derived stem cells cultured on biomaterials

Abstract

The stem cell fates of pluripotency and differentiation are regulated by not only soluble biological cues but also insoluble biochemical cues (i.e., extracellular matrix (ECM)) and the physical cues of cell culture biomaterials (i.e., elasticity). We investigated the maintenance of pluripotency and the differentiation lineages of human amniotic fluid-derived stem cells (hAFSCs) cultured on poly(vinyl alcohol-co-itaconic acid) (PVA) hydrogels grafted with several types of ECM and corresponding oligopeptides in expansion medium. hAFSCs cultured on soft PVA hydrogels (12.2 kPa) that were grafted with oligopeptides derived from fibronectin and vitronectin showed high pluripotency, which was evaluated by Oct4, Sox2 and Nanog expression. The hAFSCs grown on soft PVA hydrogels (12.2 kPa) grafted with each oligopeptide showed higher pluripotency, as assessed by Oct4 and Nanog expression, than hAFSCs grown on stiff PVA hydrogels (25.3 kPa) grafted with the same oligopeptides and a much higher pluripotency than those grown on rigid tissue-culture polystyrene dishes. Soft biomaterials appeared to be adequate to maintain the pluripotency of hAFSCs. Surprisingly, hAFSCs that showed higher pluripotency on PVA hydrogels grafted with oligopeptides derived from fibronectin and vitronectin also expressed higher levels of early differentiation markers for three germ layers in expansion medium. This result suggests that hAFSCs are heterogeneous and that this population contains highly pluripotent stem cells and stem cells that can be easily differentiated.

Human Pluripotent Stem Cell Culture on Polyvinyl Alcohol-Co-Itaconic Acid Hydrogels with Varying Stiffness Under Xeno-Free Conditions

“…24 h crosslinking of P-IA hydrogels produces optimal hydrogels for human ES/iPS cell culture. Any oligopeptides and ECMs can be grafted on P-IA hydrogels using this protocol, where the oligopeptides and ECMs have free amino groups 25,28,29,30,31,32 . The surface density of the oligopeptides or ECMs can be detected by X-ray photoelectron spectroscopy (XPS) measurements, although XPS cannot present an absolute value of the surface density, but the existence of the oligopeptides or ECMs can be safely analyzed.…”

“…P-IA hydrogels with and without grafted oligopeptides or ECMs can be prepared, which have storage modulus from 3-30 kPa, depending on the crosslinking time. It is rather difficult to prepare P-IA hydrogels having less storage modulus than 3 kPa and higher storage modulus than 30 kPa 25,28,29,30,31,32 . This is the limitation of the present hydrogel preparation method of chemical crosslinking of P-IA hydrogels.…”

“…Therefore, it is important to develop another type of hydrogel, of which the stiffness can be controlled by crosslinking of the hydrogels. For this purpose, bioinert hydrogels were developed, which were prepared from polyvinyl alcohol-co-itaconic acid (P-IA) with a different stiffness, which was controlled by the crosslinking degree with a changing crosslinking time 25,26,27,28,29,30,31,32 . The stem cells can be cultivated on nonmodified P-IA hydrogels, as well as P-IA hydrogels grafted with extracellular matrices (ECMs) and oligopeptides.…”

A Wearable Strain Sensor Based on Electroconductive Hydrogel Composites for Human Motion Detection

“…[ 11 ] Poly(vinyl alcohol) (PVA) hydrogels have become especially prominent [ 12–15 ] owing to their excellent mechanical strength, biocompatibility, substantial water retention, and porous structure. [ 16–18 ] Freeze/thaw (FT) techniques offer a facile, environmentally friendly, and efficient means of fine‐tuning PVA gel behavior, whilst avoiding potentially toxic and costly chemical additives (e.g., solvents, monomers or crosslinking agents). [ 19 ] Despite the discovery of this crosslinking approach almost half a century ago, [ 20 ] the subject of FT hydrogels remains under‐developed.…”

Structure and properties of PVA/silk fibroin hydrogels and their effects on growth behavior of various cell types

“…Polyvinyl alcohol (PVA) hydrogels possess excellent biocompatibility, high strength, water retention, and a porous structure [10][11][12]. However, the lack of biological activity does not support cell adhesion [13].…”