Two-photon polymerized “nichoid” substrates maintain function of pluripotent stem cells when expanded under feeder-free conditions

Abstract

BackgroundThe use of pluripotent cells in stem cell therapy has major limitations, mainly related to the high costs and risks of exogenous conditioning and the use of feeder layers during cell expansion passages.MethodsWe developed an innovative three-dimensional culture substrate made of “nichoid” microstructures, nanoengineered via two-photon laser polymerization. The nichoids limit the dimension of the adhering embryoid bodies during expansion, by counteracting cell migration between adjacent units of the substrate by its microarchitecture. We expanded mouse embryonic stem cells on the nichoid for 2 weeks. We compared the expression of pluripotency and differentiation markers induced in cells with that induced by flat substrates and by a culture layer made of kidney-derived extracellular matrix.ResultsThe nichoid was found to be the only substrate, among those tested, that maintained the expression of the OCT4 pluripotency marker switched on and, simultaneously, the expression of the differentiation markers GATA4 and α-SMA switched off. The nichoid promotes pluripotency maintenance of embryonic stem cells during expansion, in the absence of a feeder layer and exogenous conditioning factors, such as the leukocyte inhibitory factor.ConclusionsWe hypothesized that the nichoid microstructures induce a genetic reprogramming of cells by controlling their cytoskeletal tension. Further studies are necessary to understand the exact mechanism by which the physical constraint provided by the nichoid architecture is responsible for cell reprogramming. The nichoid may help elucidate mechanisms of pluripotency maintenance, while potentially cutting the costs and risks of both feed-conditioning and exogenous conditioning for industrial-scale expansion of stem cells.Electronic supplementary materialThe online version of this article (doi:10.1186/s13287-016-0387-z) contains supplementary material, which is available to authorized users.

3D printing hybrid organometallic polymer‐based biomaterials via laser two‐photon polymerization

“…7,[22][23][24] 3D structures capable of supporting embryonic stem cells in an undifferentiated state without the use of feeder cells have been demonstrated before. 25 A widely investigated class of materials for LTPP are hybrid organic-inorganic materials, some of which are based on organometallic polymers. 26 These materials are composed of metal alkoxides and acrylates that often contain silicon oxide.…”

Tissue engineering and regenerative medicine strategies for the female breast

“…Mechanical, molecular, structural cues, and scaffold properties are key (Nava et al, ) to maintaining the architecture and the functionality of this tissue (Nava et al, ; Wang et al, ) thus leading to ADSC proliferation and differentiation (Sterodimas et al, ).…”

“…They cultured the cells with the MammoCult medium (Hassiotou et al, 2012), usually employed to enrich breast stem cells with nonneural ectoderm ones susceptible for the formation of mammary-like cells, then directing the human iPSC differentiation toward the nonneural ectodermal type as a precursor of the desired tissue formation. Mechanical, molecular, structural cues, and scaffold properties are key (Nava et al, 2015) to maintaining the architecture and the functionality of this tissue (Nava et al, 2016;Wang et al, 2010) thus leading to ADSC proliferation and differentiation (Sterodimas et al, 2010).…”

Polymers for Regenerative Medicine Structures Made via Multiphoton 3D Lithography

“…Such colonies can be up to mm in size, making the entire amount of growth chambers in the range of tens or even hundreds. Furthermore, it can induce the genetic reprogramming of the cell, once again showing the importance of the scaffold shape and subsequent cytoskeletal tension in the cell [187]. While direct cell therapies have huge promise, in some cases, movement of the liquids in the body might destroy new cell colonies.…”