Electroactive nanoparticles of molecularly imprinted polymers (MIP NPs) specific for a non-electroactive template (i.e., the antibiotic vancomycin) were for the first time synthesized by solid-phase ...synthesis adding two ferrocene-derivative monomers (namely, vinylferrocene and ferrocenylmethyl methacrylate) in different amount to polymerization mixture. MIP NPs were characterized by dynamic light scattering and by cyclic voltammetry studies. This latter allowed identifying the synthetic conditions determining the highest MIP NP electroactivity. The content of electrochemical label was verified by X-Ray Photoelectron Spectroscopy, which provided an estimation of the amount of ferrocene moieties in nanoparticle structure. In the attempt to apply MIP NPs for sensing applications, nanoparticles were anchored to a Nafion modified electrode by a simple self-assembly process and the indirect electrochemical detection of vancomycin was allowed by the change of ferrocene group redox properties upon the exposure to vancomycin. The observed behavior is believed to be due to hindering of the electron transfer process of the ferrocene redox sites within nanoparticles by their interaction with non-electroactive vancomycin. A novel sensing platform is thus developed by directly anchoring to the electrode surface an electroactive probe integrated within the imprinted polymer thus allowing the selective, easy and rapid electrochemical detection of non-electroactive target molecules.
User-friendly and energy-efficient methods able to work in noncontinuous mode for in situ purification of olive mill wastewater (OMW) are necessary. Herein we determined the potential of oxidized ...multiwalled carbon nanotubes entrapped in a microporous polymeric matrix of polydimethylsiloxane in the removal and recovery of phenolic compounds (PCs) from OMW. The fabrication of the nanocomposite materials was straightforward and evidenced good adsorption capacity. The adsorption process is influenced by the pH of the OMW. Thermodynamic parameters evidenced the good affinity of the entrapped nanomaterial towards phenols. Furthermore, the kinetics and adsorption isotherms are studied in detail. The presence of oil inside the OMW can speed up the uptake process in batch adsorption experiments with respect to standard aqueous solutions, suggesting a possible use of the nanocomposite for fast processing of OMW directly in the tank where they are stored. Moreover, the prepared nanocomposite is safe and can be easily handled and disposed of, thus avoiding the presence of specialized personnel. After the adsorption process the surface of the nanomaterial can be easily regenerated by mild treatments with diluted acetic acid, thus permitting both the recyclability of the nanomaterial and the recovery of phenolic compounds for a possible use as additives in food and nutraceutical industries and the recovery of OMW for fertirrigation.
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.
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 characteristic of terminal differentiation and physiological growth, with a 2-fold increase of α-myosin heavy chain (P < 0.001) and upregulation of sarcoplasmic reticulum Ca2+ ATPase 2a. In contrast, markers of pathological hypertrophy remain unchanged (β-myosin heavy chain, skeletal α-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.
Magnetic iron oxide nanoparticles have been extensively investigated due to their applications in various fields such as biomedicine, sensing, and environmental remediation. However, they need to be ...coated with a suitable material in order to make them biocompatible and to add new functionalities on their surface. This review is intended to give a comprehensive overview of recent advantages and applications of iron oxide nanoparticles coated by polydopamine film. The synthesis method of magnetic nanoparticles, their functionalization with bioinspired materials and (in particular) with polydopamine are discussed. Finally, some interesting applications of polydopamine-coated magnetic iron oxide nanoparticles will be pointed out.
The removal of pollutants, such as heavy metals, aromatic compounds, dyes, pesticides and pharmaceuticals, from water is still an open challenge. Many methods have been developed and exploited for ...the purification of water from contaminants, including photocatalytic degradation, biological treatment, adsorption and chemical precipitation. Absorption-based techniques are still considered among the most efficient and commonly used approaches thanks to their operational simplicity. In recent years, polydopamine-coated magnetic nanoparticles have emerged for the uptake of heavy metals in water treatment, since they combine specific affinity towards pollutants and magnetic separation capacity. In this context, this work focuses on the synthesis of polydopamine (PDA)-coated Super Paramagnetic Iron Oxide Nanoparticles (PDA@SPIONs) as adsorbents for Cu2+ ions, designed to serve as functional nanostructures for the removal of Cu2+ from water by applying a magnetic field. The synthetic parameters, including the amount of SPIONs and PDA, were thoroughly investigated to define their effects on the nanostructure features and properties. Subsequently, the ability of the magnetic nanostructures to bind metal ions was assessed on Cu2+-containing solutions. A systematic investigation of the prepared functional nanostructures was carried out by means of complementary spectroscopic, morphological and magnetic techniques. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) measurements were performed in order to estimate the Cu2+ binding ability. The overall results indicate that these nanostructures hold great promise for future bioremediation applications.
In the last decade, carbon nanotube growth substrates have been used to investigate neurons and neuronal networks formation in vitro when guided by artificial nano-scaled cues. Besides, ...nanotube-based interfaces are being developed, such as prosthesis for monitoring brain activity. We recently described how carbon nanotube substrates alter the electrophysiological and synaptic responses of hippocampal neurons in culture. This observation highlighted the exceptional ability of this material in interfering with nerve tissue growth. Here we test the hypothesis that carbon nanotube scaffolds promote the development of immature neurons isolated from the neonatal rat spinal cord, and maintained in vitro. To address this issue we performed electrophysiological studies associated to gene expression analysis. Our results indicate that spinal neurons plated on electro-conductive carbon nanotubes show a facilitated development. Spinal neurons anticipate the expression of functional markers of maturation, such as the generation of voltage dependent currents or action potentials. These changes are accompanied by a selective modulation of gene expression, involving neuronal and non-neuronal components. Our microarray experiments suggest that carbon nanotube platforms trigger reparative activities involving microglia, in the absence of reactive gliosis. Hence, future tissue scaffolds blended with conductive nanotubes may be exploited to promote cell differentiation and reparative pathways in neural regeneration strategies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Producing sustainable microfluidic devices on a large scale has become a trend in the biomedical field. However, the transition from laboratory prototyping to large-scale industrial production poses ...several challenges due to the gap between academia and industry. In this context, prototyping with a mass production approach could be the novel strategy necessary to bridge academic research to the market. Here, the performance of polymer inserts to produce PMMA microfluidic devices using the microinjection moulding process is presented. Inserts were fabricated with an additive manufacturing process: material jetting technology. The importance of the inserts’ orientation on the printing plate in order to produce samples with more uniform thickness and lower roughness has been demonstrated using a flat cavity insert. In addition, preliminary tests were carried out on microstructured inserts with inverted channels of various cross-section shapes (semi-circular or trapezoidal) and widths (200 or 300 µm) in order to investigate the microstructures’ resistance during the moulding cycles. The best geometry was found in the channel with the trapezoidal cross-section with a width equal to 300 µm. Finally, a preliminary microfluidic test was performed to demonstrate the devices’ workability.
The growing interest in piezoresistive sensors has favored the development of numerous approaches and materials for their fabrication. Within this framework, carbon nanotubes (CNTs) are often ...employed. However, CNTs are a heterogeneous material with different morphological characteristics in terms of length and diameter, and, so far, experimental studies have not usually considered the effect of these parameters on the final sensor performances. Here, we observe how, by simply changing the CNTs length in a solvent-free mechanochemistry fabrication method, different porous 3D elastomeric nanocomposites with different electrical and mechanical properties can be obtained. In particular, the use of longer carbon nanotubes allows the synthesis of porous nanocomposites with better mechanical stability and conductivity, and with a nine-times-lower limit of detection (namely 0.2 Pa) when used as a piezoresistive sensor. Moreover, the material prepared with longer carbon nanotubes evidenced a faster recovery of its shape and electrical properties during press/release cycles, thus allowing faster response at different pressures. These results provide evidence as to how CNTs length can be a key aspect in obtaining piezoresistive sensors with better properties.
The screening and early diagnosis of diseases are crucial for a patient’s treatment to be successful and to improve their survival rate, especially for cancer. The development of non-invasive ...analytical methods able to detect the biomarkers of pathologies is a critical point to define a successful treatment and a good outcome. This study extensively reviews the electrochemical methods used for the development of biosensors in a liquid biopsy, owing to their ability to provide a rapid response, precise detection, and low detection limits. We also discuss new developments in electrochemical biosensors, which can improve the specificity and sensitivity of standard analytical procedures. Electrochemical biosensors demonstrate remarkable sensitivity in detecting minute quantities of analytes, encompassing proteins, nucleic acids, and circulating tumor cells, even within challenging matrices such as urine, serum, blood, and various other body fluids. Among the various detection techniques used for the detection of cancer biomarkers, even in the picogram range, voltammetric sensors are deeply discussed in this review because of their advantages and technical characteristics. This widespread utilization stems from their ability to facilitate the quantitative detection of ions and molecules with exceptional precision. A comparison of each electrochemical technique is discussed to assist with the selection of appropriate analytical methods.
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