Direct Microfabrication of Topographical and Chemical Cues for the Guided Growth of Neural Cell Networks on Polyamidoamine Hydrogels

Abstract

Cell patterning is an important tool for organizing cells in surfaces and to reproduce in a simple way the tissue hierarchy and complexity of pluri-cellular life. The control of cell growth, proliferation and differentiation on solid surfaces is consequently important for prosthetics, biosensors, cell-based arrays, stem cell therapy and cell-based drug discovery concepts. We present a new electron beam lithography method for the direct and simultaneous fabrication of sub-micron topographical and chemical patterns, on a biocompatible and biodegradable PAA hydrogel. The localized e-beam modification of a hydrogel surface makes the pattern able to adsorb proteins in contrast with the anti-fouling surface. By also exploiting the selective attachment, growth and differentiation of PC12 cells, we fabricated a neural network of single cells connected by neuritis extending along microchannels. E-beam microlithography on PAA hydrogels opens up the opportunity of producing multifunctional microdevices incorporating complex topographies, allowing precise control of the growth and organization of individual cells.

RGD-mimic polyamidoamine-montmorillonite composites with tunable stiffness as scaffolds for bone tissue-engineering applications

“…The samples were then centrifuged at 13000 rpm for 60 min at 4°C, the supernatants drained and the pellets eluted with 1 n NaOH for 15 min at room temperature (RT). The supernatants (100 µl) were transferred to 96‐well plates and their absorbance was measured at 540 nm (Ozkan et al ., ; Beck et al ., ; Richardson et al ., ; Martello et al ., ; Magnaghi et al ., ; Franchini et al ., ; Ranucci et al ., ; Ferruti et al, , •; Emilitri et al ., ; Jacchetti et al ., ; Dos Reis et al ., ; Mauro et al ., , Iyer et al ., ), using a calibration curve obtained with collagen type I from calf's skin (Sigma, Milan, Italy). For comparison purposes, collagen accumulated by cells grown on TCPS under the same culture conditions was determined.…”

“…Polyamidoamines (PAAs) are well‐known, hydrophilic, biodegradable and biocompatible polymers suited for several biotechnological applications (Ferruti, ). Crosslinked PAAs form hydrogels capable, in several instances, of promoting cell adhesion and proliferation (Ferruti et al ., , ; Emilitri et al ., ; Jacchetti et al ., ; Dos Reis et al , ; Mauro et al ., ). Among these, hydrogels based on AGMA1, a guanidine‐substituted peptidomimetic PAA designed to mimic RGD peptide (Figure ), exhibited particularly good performances both in vitro and in vivo .…”

Microscale Architecture in Biomaterial Scaffolds for Spatial Control of Neural Cell Behavior

“…Lithographic patterning of grooves into biomaterial surfaces has been extensively shown to direct NC alignment, migration, and differentiation (Dos Reis et al, 2010;Haring et al, 2017). Astrocytes seeded onto a polystyrene mold patterned with channels that were 10-µm wide and 3-µm deep using photolithography, and subsequently coated with laminin, had elongated process extensions that aligned with the grooves (Recknor et al, 2004).…”

A Novel Approach to Quantitatively Assess the Uniformity of Binary Colloidal Crystal Assemblies

“…However, it remains challenging with such approaches to incorporate multiple signals into the coatings and the precise lateral locality of these signals cannot be readily controlled. In order to generate surface patterns with distinct chemical regions many approaches have been put forward such as dip-pen nanolithography and polymer pen nanolithography [13], UV photolithography [14] and e-beam lithography [15], which can assist in the formation of chemical patterns through, e.g., selective removal of a top layer exposing the underlying material, to name a few. However, currently available techniques for chemical surface patterning normally require specialised equipment and are not suitable for the high throughput fabrication of patterns.…”