Langmuir–Schaefer films of fibronectin as designed biointerfaces for culturing stem cells

Abstract

Glycoproteins adsorbing on an implant upon contact with body fluids can affect the biological response in vitro and in vivo, depending on the type and conformation of the adsorbed biomacromolecules. However, this process is poorly characterized and so far not controllable. Here, protein monolayers of high molecular cohesion with defined density are transferred onto polymeric substrates by the Langmuir–Schaefer (LS) technique and were compared with solution deposition (SO) method. It is hypothesized that on polydimethylsiloxane (PDMS), a substrate with poor cell adhesion capacity, the fibronectin (FN) layers generated by the LS and SO methods will differ in their organization, subsequently facilitating differential stem cell adhesion behavior. Indeed, atomic force microscopy visualization and immunofluorescence images indicated that organization of the FN layer immobilized on PDMS was uniform and homogeneous. In contrast, FN deposited by SO method was rather heterogeneous with appearance of structures resembling protein aggregates. Human mesenchymal stem cells showed reduced absolute numbers of adherent cells, and the vinculin expression seemed to be higher and more homogenously distributed after seeding on PDMS equipped with FN by LS in comparison with PDMS equipped with FN by SO. These divergent responses could be attributed to differences in the availability of adhesion molecule ligands such as the Arg‐Gly‐Asp (RGD) peptide sequence presented at the interface. The LS method allows to control the protein layer characteristics, including the thickness and the protein orientation or conformation, which can be harnessed to direct stem cell responses to defined outcomes, including migration and differentiation. Copyright © 2016 John Wiley & Sons, Ltd.

Langmuir Monolayers as Tools to Study Biodegradable Polymer Implant Materials

“…On a Langmuir trough, monolayers with a precisely defined degree of degradation can be prepared conveniently and rapidly. After Langmuir–Schäfer transfer to solid substrates, the bioresponse to materials prepared on a Langmuir trough can be investigated, for example, in cell culture . Another aspect related to the bioresponse to a biodegradable material is the nature of the fragments generated during the degradation process.…”

Evaluating polymeric biomaterial–environment interfaces by Langmuir monolayer techniques

“…Both proteins exhibit a change in the specific area depending on the pH value. FN monolayers of high molecular cohesion with defined surface density have been transferred onto polydimethylsiloxane (PDMS) substrates by the LS-method to improve stem cell adhesion behaviour [139]. LS layers are shown to be uniform and homogeneous as indicated by AFM and immunofluorescence images, whereas layers prepared by solution deposition method are rather heterogeneous with the appearance of resembling protein aggregates.…”

Langmuir-Blodgett monolayers holding a wound healing active compound and its effect in cell culture. A model for the study of surface mediated drug delivery systems

“…For example, Fernandes et al demonstrated the penetration of nano-penicillin G spheres within Langmuir monolayers formed by L-α-phosphatidylethanolamine, the principal phospholipid extracted from E. coli [16]. However, despite remarkable examples of cell culture over Langmuir, Langmuir-Blodgett and Langmuir-Sch€ afer layers [17,18], to the best of our knowledge, few studies have been developed using monomolecular Langmuir-Blodgett films acting as biomimetic drug reservoir and delivery systems [11,12,19]. Higuchi et al demonstrated that fibroblast L929 cells cultured on collagen adhered and spread better on synthetic polymeric films prepared by the LB method than on films obtained by the casting method [20].…”

“…Also, human interferon-β was produced by inoculation of fibroblast cells cultured on polymeric films obtained by the Langmuir-Blodgett technique [21]. Recently, Bhuvanesh et al reported the building of artificial biomimetic structures, where the cell stem adhesion can be directed by the surface areal density of collagen type-4 in Langmuir films [17]. Similarly, hippocampal pyramidal neurons were cultured onto LB films of insulin with different surface packing density, showing that the neuron polarization through the activation of the Insulin-like Growth Factor-1 receptor can be selectively modulated by the lateral packing of insulin, organized as a monomolecular surface for cell growth [22].…”