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

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. Different approaches (regarding the material, fabrication technique, topographical charactertistics, etc.) have been implemented. The present review paper aims at reviewing the existing body of literature on the use of artificial micro- and nano-topographical features to control neuronal morphology, outgrowth and neural network topology. The cell responses from phenomenology to investigation of the underlying mechanisms- on the different topographies, including both deterministic and random ones, are summarized

Colloidal Assemblies of Oriented Maghemite Nanocrystals and their NMR Relaxometric Properties

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. 1H-Nuclear Magnetic Resonance (NMR) relaxometric experiments show that the ferrimagnetic cluster-like colloidal entities exhibit a remarkable enhancement (4 to 5 times) in the transverse relaxivity, if compared to that of the superparamagnetic contrast agent Endorem, over an extended frequency range (1-60 MHz). The marked increase of the transverse relaxivity r2 at a clinical magnetic field strength (1.41 T), which is 405.1 and 508.3 mM-1 s-1 for small and large assemblies respectively, allows to relate the observed response to the raised intra-aggregate magnetic material volume fraction. Furthermore, cell tests with murine fibroblast culture medium confirmed the cell viability in presence of the clusters. We discuss the NMR dispersion profiles on the basis of relaxivity models to highlight the magneto-structural characteristics of the materials for improved T2-weighted magnetic resonance images.Comment: Includes supporting informatio

Serum levels of pro- and anti-inflammatory cytokines in non-pregnant women, during pregnancy, labour and abortion.

Disturbance of the cytokine equilibrium has been accused for many pathological disorders. Microbial infections, autoimmune diseases, graft rejection have been correlated to over- or under-production of specific cytokines which are produced as responder molecules to the various immune stimuli. The sole naturally occurring immune reaction in the organism is developed during the gestational period where, despite the presence of a semi-allogeneic graft, maternal immunoreactivity is driven to support fetal growth. The successful embryo development has been attributed to the important intervention of cytokines where some have been characterized as indispensable and others deleterious to fetal growth. However, the physiological levels of many factors during the gestational process have not been determined. Thus, in the present study we have measured and established the values of IL-1alpha, IL-2, IL-3, IL-4, IL-6, IL-10, IL-12, GM-CSF, TNF-alpha and IFN-gamma during all phases of human pregnancy (first, second and third trimester of pregnancy, labour, abortions of the first trimester) as well as in the non-pregnant control state. This is an attempt to assess serum protein concentrations and present the physiological levels of these cytokines at certain time intervals providing thus a diagnostic advantage in pregnancy cases where the mother cannot immunologically support the fetus. Exploitation of this knowledge and further research may be useful for therapeutic interventions in the future

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. It is shown that, depending on the laser processing conditions, distinct cell-philic or cell-repellant patterned areas can be attained with a desired motif. We envisage that our technique could enable spatial patterning of cells in a controllable manner, giving rise to advanced capabilities in cell biology research

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 define the 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 challenge. Tissue engineering and regenerative medicine in the nervous system have provided new alternative medical approaches. These methods use external biomaterial supports, known as scaffolds, in order to create platforms for the cells to migrate to the injury site and repair the tissue. The challenge in neural tissue engineering (NTE) remains the fabrication of scaffolds with precisely controlled, tunable topography, biochemical cues and surface energy, capable of directing and controlling the function of neuronal cells. At the same time, it has been shown that neural tissue engineering provides the potential to model neurological diseases in vitro, mainly via lab-on-a-chip systems, especially in cases for which it is difficult to obtain suitable animal models. As a consequence of the intense research activity in the field, a variety of synthetic approaches and 3D fabrication methods have been developed for the fabrication of NTE scaffolds, including soft lithography and self-assembly, as well as subtractive (top-down) and additive (bottom-up) manufacturing. This article aims at reviewing the existing research effort in the rapidly growing field related to the development of biomaterial scaffolds and lab-on-a-chip systems for NTE applications. Besides presenting recent advances achieved by NTE strategies, this work also delineates existing limitations and highlights emerging possibilities and future prospects in this field

3-Dimensional Laser Structured Scaffolds Improve Macrophage Adherence and Antigen-specific Response

AbstractBiomaterial surface properties are determined by the synergistic effect of the morphology and chemistry. Specific combinations of chemical and topographical cues, similar to those experienced by cells during in vivo development, have been shown to control cellular adhesion, migration and function. The aim of the study was to investigate whether 3D micro and submicron laser textured transplantable Si scaffolds with tunable morphology and chemistry could support macrophage adherence, antigen presentation and specific antibody production. The 3D scaffolds could provide useful materials for in vitro and in vivo applications