Myocardial tissue engineering currently represents one of the most realistic strategies for cardiac repair. We have recently discovered the ability of carbon nanotube scaffolds to promote cell division and maturation in cardiomyocytes. Here, we test the hypothesis that carbon nanotube scaffolds promote cardiomyocyte growth and maturation by altering the gene expression program, implementing the cell electrophysiological properties and improving networking and maturation of functional syncytia. In our study, we combine microscopy, biological and electrophysiological methodologies, and calcium imaging, to verify whether neonatal rat ventricular myocytes cultured on substrates of multiwall carbon nanotubes acquire a physiologically more mature phenotype compared to control (gelatin). We show that the carbon nanotube substrate stimulates the induction of a gene expression profile differentiation and physiological growth, with a 2-fold increase of a-myosin heavy chain (P < 0.001) and upregulation of sarcoplasmic reticulum Ca2+ ATPase 2a. In contrast, markers of pathological hypertrophy remain unchanged (beta-myosin heavy chain, skeletal a-actin, atrial natriuretic peptide). These modifications are paralleled by an increase of connexin-43 gene expression, gap junctions and functional syncytia. Moreover, carbon nanotubes appear to exert a protective effect against the pathologic stimulus of phenylephrine. Finally, cardiomyocytes on carbon nanotubes demonstrate a more mature electrophysiological phenotype of syncytia and intracellular calcium signaling. Thus, carbon nanotubes interacting with cardiomyocytes have the ability to promote physiological growth and functional maturation. These properties are unique in the current vexing field of tissue engineering, and offer unprecedented perspectives in the development of innovative therapies for cardiac repair.

Nanoscale manipulations of the extracellular microenvironment are increasingly attracting attention in tissue engineering. Here, combining microscopy, biological, and single-cell electrophysiological methodologies, we demonstrate that neonatal rat ventricular myocytes cultured on substrates of multiwall carbon nanotubes interact with carbon nanotubes by forming tight contacts and show increased viability and proliferation. Furthermore, we observed changes in the electrophysiological properties of cardiomyocytes, suggesting that carbon nanotubes are able to promote cardiomyocyte maturation.

The present work describes the development of a simple and cost-effective electrochemical sensor for sulfadimethoxine (SDM) based on molecularly imprinted overoxidized polypyrrole (PPy). An all electrochemical approach is used for sensor fabrication and application consisting in molecularly imprinted polymer (MIP) galvanostatic deposition on a gold electrode and its overoxidation under different experimental conditions and in SDM amperometric detection. Several parameters influencing the imprinting effect are critically discussed and evaluated. A key role of the electrolyte used in electropolymerization (tetrabuthylammonium perchlorate and lithium perchlorate) has emerged demonstrating its effect on sensing performances of imprinted PPy and, related to this, on its morphology, as highlighted by atomic force microscopy (AFM). The effect of different overoxidation conditions in removing template is evaluated by analyzing MIP films before and after the treatment by X-ray photoelectron spectroscopy (XPS) also evidencing the correlation between MIP chemical structure and its rebinding ability. MIP-template interaction is verified also by Fourier Transform Infrared (FT-IR) spectroscopy. Under the selected optimal conditions, MIP sensor shows a linear range from 0.15 to 3.7 mM SDM, a limit of detection of 70 μM, a highly reproducible response (RSD 4.2%) and a good selectivity in the presence of structurally related molecules. SDM was determined in milk samples spiked at two concentration levels: 0.2 mM and 0.4 mM obtaining a satisfactory recovery of (97±3)% and (96±8)%, respectively.

To recreate in vitro 3D neuronal circuits will ultimately increase the relevance of results from cultured to whole-brain networks and will promote enabling technologies for neuro-engineering applications. Here we fabricate novel elastomeric scaffolds able to instruct 3D growth of living primary neurons. Such systems allow investigating the emerging activity, in terms of calcium signals, of small clusters of neurons as a function of the interplay between the 2D or 3D architectures and network dynamics. We report the ability of 3D geometry to improve functional organization and synchronization in small neuronal assemblies. We propose a mathematical modelling of network dynamics that supports such a result. Entrapping carbon nanotubes in the scaffolds remarkably boosted synaptic activity, thus allowing for the first time to exploit nanomaterial/cell interfacing in 3D growth support. Our 3D system represents a simple and reliable construct, able to improve the complexity of current tissue culture models.

In this work a new original amperometric sensor forH2O2 detection based on a Pt electrode modified with Te-microtubes was developed. Te-microtubes, synthesized by the simple thermal evaporation of Te powder, have a tubular structure with a hexagonal cross-section and are open ended. Modified electrode was prepared by direct drop casting of the mixture of Te-microtubes dispersed in ethanol on Pt surface. The spectroscopic characterization of synthesized Te-microtubes and Pt/Te-microtubes modified electrodes was performed by scanning electron microscopy (SEM), energy-dispersive X-rays microanalysis (EDX), X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS). Moreover a complete electrochemical characterization of the new composite material Pt/Te-microtubes was performed by cyclic voltammetry (CV) and cronoamperometry (CA) in phosphate buffer solution (PBS) at pH 7. Electrochemical experiments showed that the presence of Te-microtubes on modified electrode was responsible for an increment of both cathodic and anodic currents in presence of H2O2 with respect to bare Pt. Specifically, data collected from amperometric experiments at −150mV vs. SCE in batch and −200mV vs. SCE in flow injection analysis (FIA) experiments show a remarkable increment of the cathodic current. The electrochemical performances of tested sensors make them suitable for the quantitative determination of H2O2 substrate both in batch and in FIA.

In this work, we introduce a hybrid atomic-force/near-field scanning microwave microscope, exploiting the tomographic capabilities of the microwave microscopy to explore structures of relevant interest, namely, samples involving both biological and non-biological materials at the same time. In particular, we show imaging of C2C12 muscle cells grown in the presence of bundles of multi-walled carbon nanotubes: here, the microwave microscopy, by virtue of its tomographic potentiality, highlights how cells incorporate some nanotubes in their fibers.