Morphological Differentiation of Neurons on Microtopographic Substrates Fabricated by Rolled‐Up Nanotechnology

Abstract

Arrays of transparent rolled‐up microtubes can easily be mass‐produced using a combination of conventional photolithography, electron beam depositioning, and chemical etching techniques. Here, we culture primary mouse motor neurons and immortalised CAD cells, a cell line derived from the central nervous system, on various microtube substrates to investigate the influence of topographical surface features on the growth and differentiation behaviour of these cells. Our results indicate that the microtube chips not only support growth of both cell types but also provide a well‐defined, geometrically confined 3D cell culture scaffold. Strikingly, our micropatterns act as a platform for axon guidance with protruding cell extensions aligning in the direction of the microtubes and forming complex square‐shaped grid‐like neurite networks. Our experiments open up a cost‐efficient and bio‐compatible way of analysing single cell behaviour in the context of advanced micro‐/nanostructures with various biological applications ranging from neurite protection studies to cell sensor development.

A Strategy for Depositing Different Types of Cells in Three Dimensions to Mimic Tubular Structures in Tissues

“…[21,22] Because of the unique tubular structure, these technologies show remarkable advantages that could be used for biological applications, such as the capture/isolation of cancer cells, [23] as a platform for cell culturing, [24] and so forth. [25,26] Existing methods, however, are not directly useful for culturing cells in the context of tissue mimicry because they are comparatively small in size, [27] or they require harsh conditions to form tubes, for example, heating at 58 °C [28] or using hydrochloric acid to etch the metal.…”

Guided neuronal growth on arrays of biofunctionalized GaAs/InGaAs semiconductor microtubes

“…Guidance has previously been achieved by using chemical guidance cues [3,4] as well as by exploiting the geometrical properties of the growth substrate [5,6]. It has been shown [7,8] that arrays of micrometer-sized silicon-based tubes can sucessfully direct the outgrowth of neurons, where the neurites show a remarkable attraction towards the tube orifices.…”

Biomimetic Microelectronics for Regenerative Neuronal Cuff Implants

“…Inorganic rolled-up microtubes less than 10 µm in diameter have previously been shown to act as ultracompact microfl uidic channels with fully integrated electrodes and fi eld effect transistors, able to detect polar and ionic fl uids down to subnanomolar concentrations, sense single cancer cells, and guide neuronal outgrowth. [20][21][22] Medical applications of such tubular architectures have been envisioned for topographically mediated nerve growth, tissue engineering, and regeneration. [ 22 ] The opportunity to open/close such microscale devices upon external stimulation brings these applications closer to reality and is particularly appealing for neuronal cuff implant applications to enclose and guide the growth of nervous fi bers with a typical size of 10-50 µm.…”

“…[20][21][22] Medical applications of such tubular architectures have been envisioned for topographically mediated nerve growth, tissue engineering, and regeneration. [ 22 ] The opportunity to open/close such microscale devices upon external stimulation brings these applications closer to reality and is particularly appealing for neuronal cuff implant applications to enclose and guide the growth of nervous fi bers with a typical size of 10-50 µm. [ 18 ] The achieved device diameters of 50 µm are at least two orders of magnitude smaller compared to the stateof-the-art neuronal cuff implants.…”