Engineering cell–material interfaces for long-term expansion of human pluripotent stem cells

Department of Bioengineering, University of California, San Diego, 9500 Gilman Drive, MC 0412, La Jolla, CA 92093, USA.
Biomaterials (Impact Factor: 8.56). 11/2012; 34(4). DOI: 10.1016/j.biomaterials.2012.10.020
Source: PubMed


Cost-effective and scalable synthetic matrices that support long-term expansion of human pluripotent stem cells (hPSCs) have many applications, ranging from drug screening platforms to regenerative medicine. Here, we report the development of a hydrogel-based matrix containing synthetic heparin-mimicking moieties that supports the long-term expansion of hPSCs (≥20 passages) in a chemically defined medium. HPSCs expanded on this synthetic matrix maintained their characteristic morphology, colony forming ability, karyotypic stability, and differentiation potential. We also used the synthetic matrix as a platform to investigate the effects of various physicochemical properties of the extracellular environment on the adhesion, growth, and self-renewal of hPSCs. The observed cellular responses can be explained in terms of matrix interface-mediated binding of extracellular matrix proteins, growth factors, and other cell-secreted factors, which create an instructive microenvironment to support self-renewal of hPSCs. These synthetic matrices, which comprise of "off-the-shelf" components and are easy to synthesize, provide an ideal tool to elucidate the molecular mechanisms that control stem cell fate.

Download full-text


Available from: Yongsung Hwang, Oct 11, 2014
  • Source
    • "The hiPSC line (IMR90p18-iPS) was procured from WiCell Research Institute, which was generated as described elsewhere [38]. The hiPSC were maintained on feeder layers of mitotically inactivated mouse embryonic fibroblasts, using a medium consisting of knockout DMEM (Life Technologies, catalog number: 10829-018), 10 v/v% knockout serum replacement (Life Technologies , catalog number: 10828028), 10 v/v% human plasmanate (Talecris Biotherapeutics), 1 v/v% non-essential amino acids, 1 v/v% penicillin/streptomycin, 1 v/v% Gluta-MAX and 55 lM 2-mercap- toethanol, as previously reported [39]. The medium was changed daily with 30 ng ml À1 of bFGF (Life Technologies) supplementation. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Human induced pluripotent stem cells (hiPSCs) are a promising cell source with pluripotency and self-renewal properties. Design of simple and robust biomaterials with an innate ability to induce lineage-specificity of hiPSCs is desirable to realize their applications in regenerative medicine. In this study, we investigated the potential of biomaterials containing calcium phosphate minerals to induce osteogenic differentiation of hiPSCs. hiPSCs cultured using mineralized gelatin methacrylate-based matrices underwent osteogenic differentiation ex vivo, both in two- dimensional (2-D) and three-dimensional (3-D) cultures, in growth medium devoid of any osteogenic-inducing chemical components or growth factors. Our findings that osteogenic differentiation of hiPSCs can be achieved through biomaterial-based cues alone present new avenues for personalized regenerative medicine. Such biomaterials that could not only act as structural scaffolds, but could also provide tissue-specific functions such as directing stem cell differentiation commitment, have great potential in bone tissue engineering.
    Full-text · Article · Dec 2014 · Acta Biomaterialia
  • Source
    • "Population doubling time (PDT) of PDGFRA+ cell populations while undergoing myogenic differentiation either in serum-containing medium or serum-free medium was calculated using the equation below [23]: "
    [Show abstract] [Hide abstract]
    ABSTRACT: Development of human embryonic stem cell (hESC)-based therapy requires derivation of in vitro expandable cell populations that can readily differentiate to specified cell types and engraft upon transplantation. Here, we report that hESCs can differentiate into skeletal muscle cells without genetic manipulation. This is achieved through the isolation of cells expressing a mesodermal marker, platelet-derived growth factor receptor-α (PDGFRA), following embryoid body (EB) formation. The ESC-derived cells differentiated into myoblasts in vitro as evident by upregulation of various myogenic genes, irrespective of the presence of serum in the medium. This result is further corroborated by the presence of sarcomeric myosin and desmin, markers for terminally differentiated cells. When transplanted in vivo, these pre-myogenically committed cells were viable in tibialis anterior muscles 14 days post-implantation. These hESC-derived cells, which readily undergo myogenic differentiation in culture medium containing serum, could be a viable cell source for skeletal muscle repair and tissue engineering to ameliorate various muscle wasting diseases.
    Full-text · Article · Sep 2013 · PLoS ONE
  • [Show abstract] [Hide abstract]
    ABSTRACT: This review provides an overview on the incorporation of heparin into biomaterials with a focus on drug delivery and the use of heparin-based biomaterials for self-assembly of polymer networks. Heparin conjugation to biomaterials was originally explored to reduce the thrombogenicity of materials in contact with blood. Many of the conjugation strategies that were developed for these applications are still popular today for other applications. More recently heparin has been conjugated to biomaterials for drug delivery applications. Many of the delivery approaches have taken advantage of the ability of heparin to bind to a wide variety of growth factors, protect them from degradation and to potentiate their interactions with cell surface receptors. More recently, the use of heparin as a base polymer for scaffold fabrication has also been explored, often utilizing non-covalent binding of heparin with peptides or proteins to promote self-assembly of hydrogel networks. This review will highlight recent advances in each of these areas.
    No preview · Article · Sep 2013 · Acta biomaterialia
Show more