Cell Culturing on Nanostructured Substrates

Cell Culturing on Nanoporous Alumina

Over the past decade there has been an explosion in the number of publications on cell culturing on the surface of nanoporous Anodic Aluminum Oxide (AAO).

The interaction between the living cell cultures and the nanoscale topography of AAO has been studied for a wide variety of cell types, including:

  • Neuronal cells, such as  hippocampal cells
  • Connective tissue cells, such as human osteoblasts and primary bone marrow stromal cells
  • Epithelial cells, such as squamous cancer cells and Hepatomas
  • Smooth muscle cells
  • Blood cells, such as neutrophils and macrophages

The core parameters of AAO nanostructure –  pore diameter, period and length, surface roughness and surface chemistry  – have been found to have a strong impact on cell-substrate interactions.    The remarkable tunability of these parameters makes AAO an attractive substrate for cell culture research, enabling new discoveries and applications in cell biology [1].   Our ‘Top Ten List’ includes:

  1. Neuronal cells ‘sense’ nanotopography and respond with improved neurite growth; pore diameter and period influence both the growth rate and the overall length.  Neurites grow faster and longer on AAO compared to glass slides [2, 3].  AAO pore size significantly affects the extent of cellular responses of adherent neutrophils [4].
  2. Cells’ adhere better to AAO than they do on conventional glass slides, cell and protein adhesion is dependent on pore size [5, 6, 7] and zeta-potential [8].
  3. Cell proliferation increases on AAO, in many cases significantly, when compared to other substrates [9].
  4. Filopodia attach well to AAO by protruding into AAO pore structure, especially for certain pore diameters [10].
  5. Cells exhibit increased extra cellular matrix production on AAO [11].
  6. AAO pore depth influences cell adhesion and proliferation, but only in certain ranges. Small differences of short pores (<300nm length) appear to have little impact [7].
  7. Cell functionality (as measured by albumin secretion from HepG2 cells into cell medium) is impacted by pore diameter, with smaller pore leading to greater secretions [2].
  8. Cell migration is influenced by AAO pore diameter [12].
  9. Cells have been shown to communicate via diffusion through AAO nanopores, with the pore diameter used to control the diffusion [13].
  10. AAO pore sizes has been shown to influence whole blood cells, with smaller pores increasing procoagulant activity, but larger pores increasing platelet microparticle generation and adhesion [14].

For an excellent recent review, see D.Bruggemann, Nanoporous Aluminum Oxide Membranes as Cell Interfaces, Journal of Nanomaterials, 2013.

InRedox offers high quality AAO substrates for cell culturing and bioimaging.

Cell Culturing on Nanotubular Titania

Due partly to the importance of titanium in biomedical applications (it is a common orthopedic and dental implant material) and the interesting optical properties of nanotubular Anodic Titanium Oxide (ATO), such as photo-induced superhydrophilicity, researchers have begun to study the interactions of living cells with the TiO2 nanotubes.  This field has had a number of exciting publications in recent years, with investigators reporting on how key variables, such as tube diameter, length, UV treatment, and annealing, impacts cells of interest to many applications.  Some highlights of this recent work includes: