The influence of glancing angle deposited nano-rough platinum surfaces on the adsorption of fibrinogen and the proliferation of primary human fibroblasts

Abstract

We have used the glancing angle deposition (GLAD) method as a simple and fast method to generate nano-rough surfaces for protein adsorption experiments and cell assays. The surface roughness and the detailed geometrical surface morphology of the thin films were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). As the GLAD deposition angle approaches grazing incidence, sharp and whisker-like columnar protrusions are formed. Smaller and less sharp surface features appear for the thin films synthesized at higher deposition angles. By changing the GLAD deposition angle together with the total amount of mass deposited per area on the respective surfaces, the size of the surface features can be varied on the nanoscale. Using the GLAD topographies as model surfaces, we have investigated the influence of the nano-roughness on fibrinogen adsorption and on the proliferation of primary human fibroblasts. It is found that fibrinogen, an important blood protein, preferentially adheres on the whisker-like nano-rough substrates in comparison to a flat surface. Furthermore, the proliferation of the human fibroblasts is significantly reduced on the nano-rough substrates. These results demonstrate that the GLAD technique can be used to fabricate nano-rough surface morphologies that significantly influence both protein and cellular adhesion to surfaces and are therefore well suited for biological assays.

Preservation, sterilization and de-epithelialization of human amniotic membrane for use in ocular surface reconstruction

“…TEM confirmed the SEM observation and also revealed the presence of intact BM [74]. The existence of the epithelial cell remnants may be beneficial to the growth of the seeded cells, as it has been suggested in other biomaterials that micro-or nano-roughness on the surface can enhance the cell growth [122,123]. ECM components: collagens I, II, IV, VI and VII, laminin-5, fibronectin, elastin and thrombospondin, and growth factors: TGF-a, -b1 and -b2 receptor, EGFR, KGF, bFGF, VEGF, and PDGF are expressed in the denuded form [74].…”

Perspectives on oblique angle deposition of thin films: From fundamentals to devices

“…To this end, patterned substrates consisting of well-ordered nano-structured array patterns or seed layers have been prepared through a variety of lithographic methods, laser writing, embossing or other top-down fabrication methods [24,87,[98][99][100][101][102][103][104][105][106][107][108][109]. Among these, the use of colloidal lithography (i.e., OAD on a substrate pre-coated with packed nanospheres of different materials) has gained much popularity over the last few years thanks largely to its simplicity [110][111][112][113]. With the aid of selected examples, Fig.…”

“…For example, mass-produced metal wire grid polarizers are being fabricated via the OAD deposition of antireflection FeSi and SiO 2 layers on previously deposited aluminum columnar arrays [87,114,115]. Other emerging applications in biomedical areas [107,116,110,117], or for controlling the wetting properties of substrates [102,118], also rely on the use of patterned surfaces rather than the direct OAD of thin films (see Section 5.5).…”

“…In a series of works on the OAD of platinum films, either directly onto flat substrates or onto polymer-packed nanospheres to provide a second nanostructuring pattern to the layers (see Section 2.5), Dolatshahi-Pirouz et al [110,116,117] showed that the particular surface topography of these latter layers promotes the growth and proliferation of osteoblast cells. For different in-vivo applications it is also critical that certain cells grow preferentially over others, a possibility that has been explored in-vitro by these same authors using OAD Pt films.…”

Synthesis of Functional Nanomaterials via Colloidal Mask Templating and Glancing Angle Deposition (GLAD)

“…[13] In particular porous low refractive index thin films have proven promising as antireflection coatings [5] and noble metal nanoparticles/nanostructured thin films (Pt, Au, Ag) are known to support localized surface plasmon resonances (LSPRs) due to the collective excitation of conduction electrons inside the delicate nanofeatures by electromagnetic radiation, [4] an ability which in principle could enhance the performance of biosensors and optical devices. [4,6] Nanoscale surface topographies have also been reported to significantly affect both protein adsorption and cellular responses to biomaterial surfaces [7][8][9][10][13][14][15][16][17][18] making it a key parameter in the basic research and optimization of artificial biomaterials. [19] Thin films with a well-controlled surface morphology can be grown using the simple and efficient self assembly technique known as glancing angle deposition (GLAD) in which a vaporized particle flux arrives at the substrate from an oblique angle of incidence.…”