Development of an Oriented Co-Culture System Using 3D Scaffolds Fabricated via Non-Linear Lithography.

Damage in the Peripheral Nervous System (PNS) is related to numerous neurodegenerative diseases and has consequently drawn the attention of Tissue Engineering (TE), which is considered a promising alternative to already established methods such as surgery and autografts. TE focuses on the design, optimization, and use of scaffolds in vitro and in vivo. In this work, the authors used a novel scaffold geometry fabricated via Multiphoton Lithography (MPL), a commonly used fabrication method, for the mono- and co-cultures of glial Schwann (SW10) and neuronal Neuro-2a (N2a) cells.

Combined effect of shear stress and laser-patterned topography on Schwann cell outgrowth: synergistic or antagonistic?

Although the peripheral nervous system exhibits a higher rate of regeneration than that of the central nervous system through a spontaneous regeneration after injury, the functional recovery is fairly infrequent and misdirected. Thus, the development of successful methods to guide neuronal outgrowth, in vitro, is of great importance. In this study, a precise flow controlled microfluidic system with specific custom-designed chambers, incorporating laser-microstructured polyethylene terephthalate (PET) substrates comprising microgrooves, was fabricated to assess the combined effect of shear stress and topography on Schwann cells' behavior.

Response of NIH 3T3 Fibroblast Cells on Laser-Induced Periodic Surface Structures on a 15×(Ti/Zr)/Si Multilayer System.

Ultrafast laser processing with the formation of periodic surface nanostructures on the 15×(Ti/Zr)/Si multilayers is studied in order to the improve cell response. A novel nanocomposite structure in the form of 15x(Ti/Zr)/Si multilayer thin films, with satisfying mechanical properties and moderate biocompatibility, was deposited by ion sputtering on an Si substrate. The multilayer 15×(Ti/Zr)/Si thin films were modified by femtosecond laser pulses in air to induce the following modifications: (i) mixing of components inside of the multilayer structures, (ii) the formation of an ultrathin oxide layer at the surfaces, and (iii) surface nano-texturing with the creation of laser-induced periodic surface structure (LIPSS).

Laser-induced topographies enable the spatial patterning of co-cultured peripheral nervous system cells.

The peripheral nervous system comprises glia and neurons that receive the necessary cues for their adhesion and proliferation from their extracellular milieu. In this study, a spatial platform of pseudoperiodic morphologies including patterns of nano- and micro- structures on Si were developed via direct ultrafast-laser structuring and were used as substrates for the patterning of co-cultured neuronal cells. The response of murine Schwann (SW10) and Neuro2a (N2a) cells were investigated both in monocultures and in a glia and neuronal co-culture system.

Biofabrication for neural tissue engineering applications.

Unlike other tissue types, the nervous tissue extends to a wide and complex environment that provides a plurality of different biochemical and topological stimuli, which in turn defines the advanced functions of that tissue. As a consequence of such complexity, the traditional transplantation therapeutic methods are quite ineffective; therefore, the restoration of peripheral and central nervous system injuries has been a continuous scientific challenge. Tissue engineering and regenerative medicine in the nervous system have provided new alternative medical approaches.

Engineering Cell Adhesion and Orientation via Ultrafast Laser Fabricated Microstructured Substrates.

Cell responses depend on the stimuli received by the surrounding extracellular environment, which provides the cues required for adhesion, orientation, proliferation, and differentiation at the micro and the nano scales. In this study, discontinuous microcones on silicon (Si) and continuous microgrooves on polyethylene terephthalate (PET) substrates were fabricated via ultrashort pulsed laser irradiation at various fluences, resulting in microstructures with different magnitudes of roughness and varying geometrical characteristics. The topographical models attained were specifically developed to imitate the guidance and alignment of Schwann cells for the oriented axonal regrowth that occurs in nerve regeneration.

Iron Oxide Colloidal Nanoclusters as Theranostic Vehicles and Their Interactions at the Cellular Level.

Advances in surfactant-assisted chemical approaches have led the way for the exploitation of nanoscale inorganic particles in medical diagnosis and treatment. In this field, magnetically-driven multimodal nanotools that perform both detection and therapy, well-designed in size, shape and composition, are highly advantageous. Such a theranostic material—which entails the controlled assembly of smaller (maghemite) nanocrystals in a secondary motif that is highly dispersible in aqueous media—is discussed here.

Cells on hierarchically-structured platforms hosting functionalized nanoparticles.

In this work, we report on a novel approach to develop hierarchically-structured cell culture platforms incorporating functionalized gold nanoparticles (AuNPs). In particular, the hierarchical substrates comprise primary pseudo-periodic arrays of silicon microcones combined with a secondary nanoscale pattern of homogeneously deposited AuNPs terminated with bio-functional moieties. AuNPs with various functionalities (i.

Controlling the Outgrowth and Functions of Neural Stem Cells: The Effect of Surface Topography.

Neural stem cells (NSCs) are self-renewing cells that generate the major cell types of the central nervous system, namely neurons, astrocytes and oligodendrocytes, during embryonic development and in the adult brain. NSCs reside in a complex niche where they are exposed to a plethora of signals, including both soluble and physical signals such as compressive and shear stresses, but also discontinuities and differences in morphology of the extracellular environment, termed as topographical features. Different approaches that incorporate artificial micro- and nano-scale surface topographical features have been developed aiming to recapitulate the in vivo NSC niche discontinuities and features, particularly for in vitro studies.

Laser processing of protein films as a method for accomplishment of cell patterning at the microscale.

In this study, we propose a photostructuring approach for protein films based on a treatment with nanosecond pulses of a KrF excimer laser. As a model protein we used an amyloid fibril-forming protein. Laser treatment induced a foaming of the sample surface exhibiting an interconnected fibrous mesh with a high degree of control and precision.

Self-Assembled Amyloid Peptides with Arg-Gly-Asp (RGD) Motifs As Scaffolds for Tissue Engineering.

Self-assembled peptides gain increasing interest as biocompatible and biodegradable scaffolds for tissue engineering. Rationally designed self-assembling building blocks that carry cell adhesion motifs such as Arg-Gly-Asp (RGD) are especially attractive. We have used a combination of theoretical and experimental approaches toward such rational designs, especially focusing on modular designs that consist of a central ultrashort amphiphilic motif derived from the adenovirus fiber shaft.

Cell patterning via laser micro/nano structured silicon surfaces.

The surface topography of biomaterials can have an important impact on cellular adhesion, growth and proliferation. Apart from the overall roughness, the detailed morphological features, at all length scales, significantly affect the cell-biomaterial interactions in a plethora of applications including structural implants, tissue engineering scaffolds and biosensors. In this study, we present a simple, one-step direct laser patterning technique to fabricate nanoripples and dual-rough hierarchical micro/nano structures to control SW10 cell attachment and migration.

Controlling the morphology and outgrowth of nerve and neuroglial cells: The effect of surface topography.

Unlabelled: Unlike other tissue types, like epithelial tissue, which consist of cells with a much more homogeneous structure and function, the nervous tissue spans in a complex multilayer environment whose topographical features display a large spectrum of morphologies and size scales. Traditional cell cultures, which are based on two-dimensional cell-adhesive culture dishes or coverslips, are lacking topographical cues and mainly simulate the biochemical microenvironment of the cells. With the emergence of micro- and nano-fabrication techniques new types of cell culture platforms are developed, where the effect of various topographical cues on cellular morphology, proliferation and differentiation can be studied.

Data in support on the shape of Schwann cells and sympathetic neurons onto microconically structured silicon surfaces.

This article contains data related to the research article entitled "Laser fabricated discontinuous anisotropic microconical substrates as a new model scaffold to control the directionality of neuronal network outgrowth" in the Biomaterials journal [1]. Scanning electron microscopy (SEM) analysis is performed to investigate whether Schwann cells and sympathetic neurons alter their morphology according to the underlying topography, comprising arrays of silicon microcones with anisotropic geometrical characteristics [1]. It is observed that although soma of sympathetic neurons always preserves its round shape, this is not the case for Schwann cells that become highly polarized in high roughness microconical substrates.

Laser fabricated discontinuous anisotropic microconical substrates as a new model scaffold to control the directionality of neuronal network outgrowth.

Patterning of neuronal outgrowth in vitro is important in tissue engineering as well as for the development of neuronal interfaces with desirable characteristics. To date, this has been achieved with the aid of micro- and nanofabrication techniques giving rise to various anisotropic topographies, either in the form of continuous or discontinuous structures. In this study we propose a currently unexplored geometry of a 3D culture substrate for neuronal cell growth comprising discontinuous subcellular microstructures with anisotropic geometrical cross-section.

Implantable vaccine development using in vitro antigen-pulsed macrophages absorbed on laser micro-structured Si scaffolds.

To overcome the limiting antigenic repertoire of protein sub-units and the side effects of adjuvants applied in second generation vaccines, the present work combined in vitro and in vivo manipulations to develop biomaterials allowing natural antigen-loading and presentation in vitro and further activation of the immune response in vivo. 3-dimensional laser micro-textured implantable Si-scaffolds supported mouse macrophage adherence, allowed natural seeding with human serum albumin (antigen) and specific antibody and inflammatory cytokine production in vitro. Implantation of Si-scaffolds loaded with antigen-activated macrophages induced an inflammatory reaction along with antigen-specific antibody production in vivo, which could be detected even 30 days post implantation.

Colloidal assemblies of oriented maghemite nanocrystals and their NMR relaxometric properties.

An elevated-temperature polyol-based colloidal-chemistry approach allows for the development of size-tunable (50 and 86 nm) assemblies of maghemite iso-oriented nanocrystals, with enhanced magnetization. (1)H-nuclear magnetic resonance (NMR) relaxometric experiments show that the ferrimagnetic cluster-like colloidal entities exhibit a remarkable enhancement (4-5 times) in transverse relaxivity when compared to that of the superparamagnetic contrast agent Endorem®, over an extended frequency range (1-60 MHz). The marked increase in the transverse relaxivity r2 at a clinical magnetic field strength (∼1.