Stem Cell Differentiation by Functionalized Micro- and Nanostructured Surfaces

Abstract

Apoptosis is a common pathway that finally mediated the killing functions of anticancer drugs, which is an important cause of multidrug resistance (MDR). The aim of this study was to investigate the potential benefit of combination therapy with magnetic nanoparticle of Fe3O4 (MNP(Fe3O4)) and 5-bromotetrandrin (BrTet). Analysis of the apoptosis percentage showed that combination of daunorubicin (DNR) with either MNP(Fe3O4) or BrTet exerted a potent cytotoxic effect on K562/A02 cells, while MNP(Fe3O4) and BrTet cotreatment can synergistically enhance DNR-induced apoptosis. Importantly, we confirmed that the distinct synergism effect of that composite on reverse multidrug resistance may owe to the regulation of various proliferative and antiapoptotic gene products, including P53 and caspase-3. Thus our in vitro data strongly suggests a potential clinical application of MNP(Fe3O4) and BrTet combination on CML.

Topographically and Chemically Modified Surfaces for Expansion or Differentiation of Embryonic Stem Cells

“…The generally appreciated idea of how microscale topography induces a cellular response involves irregular tension imposed on the cell in the encounter with the geometric features. This cytoskeletal stress leads to a change in nucleus shape and possibly concomitant alterations in gene expression (Martínez et al, 2009 …”

“…In addition, topography in the range 0-250 nm affects adsorption, conformation, and therefore biological functionality of ECM proteins (Martínez et al, 2009). Whenever the effect of topography relies on focal adhesions it is relevant that both nano and microscale topographies contribute a spatial organisation of focal adhesion formation.…”

“…These signals are perceived by the cell as topographical, mechanical, and chemical cues (Martínez et al, 2009). One example of a defined physical topography embedded in the extracellular matrix (ECM) is provided by the collagen structure.…”

“…Collagen molecules are about 300 nm long and 1.5 nm wide and can form fibrils up to tens of microns in length and with a diameter of 260-410 nm (Bettinger et al, 2009). Furthermore, the spatial organisation and density of ECM is characteristic of individual tissue types (Martínez et al, 2009), and these natural structures serve to guide interacting cells in terms of cell morphology, migration, and function. Among mechanical cues, tissue elasticity has been found to vary from 0.1-0.3 kPa for embryonic stem (ES) cells and endoderm through increasing values for various differentiated cells to more than 30 kPa for demineralised bone (Reilly & Engler 2010).…”

Molding Micropatterns of Elasticity on PEG‐Based Hydrogels to Control Cell Adhesion and Migration

“…[51] The so-called contact guidance is an outstanding example of the important role of nano-and micro scale structures in cell adhesion and migration processes. [52][53][54][55][56][57][58][59][60] With the development of FIMIC (FIll-Molding In Capillaries), which is a novel technique that partly relies on the soft lithography technique MIMIC (MIcroMolding In Capillaries), [61] we intend to provide a versatile strategy to obtain a defined, two-dimensional elasticity pattern on an otherwise smooth substrate in a simple, low-cost, and reproducible manner. The PEG-based biocompatible hydrogel material herein was prepared via UV photopolymerization of starPEG acrylate macromonomers in the presence of a photoinitiator and eventually a crosslinker (CL).…”