A miniaturized multicellular platform to mimic the 3D structure of the alveolar-capillary barrier

Several diseases affect the alveoli, and the efficacy of medical treatments and pharmaceutical therapies is hampered by the lack of pre-clinical models able to recreate in vitro the diseases. Microfluidic devices, mimicking the key structural and compositional features of the alveoli, offer several advantages to medium and high-throughput analysis of new candidate therapies. Here, we developed an alveolus-on-a-chip recapitulating the microanatomy of the physiological tissue by including the epithelium, the fibrous interstitial layer and the capillary endothelium. A PDMS device was obtained assembling a top layer and a bottom layer obtained by replica molding. A polycaprolactone/gelatin (PCL-Gel) electrospun membrane was included within the two layers supporting the seeding of 3 cell phenotypes. Epithelial cells were grown on a fibroblast-laden collagen hydrogel located on the top side of the PCL-Gel mats while endothelial cells were seeded on the basolateral side of the membrane. The innovative design of the microfluidic device allows to replicate both cell-cell and cell-extracellular matrix interactions according to the in vivo cell arrangement along with the establishment of physiologically relevant air-liquid interface conditions. Indeed, high cell viability was confirmed for up to 10 days and the formation of a tight endothelial and epithelial barrier was assessed by immunofluorescence assays.

Organic Electrochemical Transistor Immuno-Sensors for Spike Protein Early Detection

The global COVID-19 pandemic has had severe consequences from the social and economic perspectives, compelling the scientific community to focus on the development of effective diagnostics that can combine a fast response and accurate sensitivity/specificity performance. Presently available commercial antigen-detecting rapid diagnostic tests (Ag-RDTs) are very fast, but still face significant criticisms, mainly related to their inability to amplify the protein signal. This translates to a limited sensitive outcome and, hence, a reduced ability to hamper the spread of SARS-CoV-2 infection. To answer the urgent need for novel platforms for the early, specific and highly sensitive detection of the virus, this paper deals with the use of organic electrochemical transistors (OECTs) as very efficient ion-electron converters and amplifiers for the detection of spike proteins and their femtomolar concentration. The electrical response of the investigated OECTs was carefully analyzed, and the changes in the parameters associated with the transconductance (i.e., the slope of the transfer curves) in the gate voltage range between 0 and 0.3 V were found to be more clearly correlated with the spike protein concentration. Moreover, the functionalization of OECT-based biosensors with anti-spike and anti-nucleocapside proteins, the major proteins involved in the disease, demonstrated the specificity of these devices, whose potentialities should also be considered in light of the recent upsurge of the so-called "long COVID" syndrome.

Pumpless deterministic lateral displacement separation using a paper capillary wick

Deterministic lateral displacement (DLD) is a passive separation method that separates particles by hydrodynamic size. This label-free method is a promising technique for cell separation because of its high size resolution and insensitivity to flow rate. Development of capillary-driven microfluidic technologies allows microfluidic devices to be operated without any external power for fluid pumping, lowering their total cost and complexity. Herein, we develop and test a DLD-based particle and cell sorting method that is driven entirely by capillary pressure. We show microchip self-filling, flow focusing, flow stability, and capture of separated particles. We achieve separation efficiency of 92% for particle-particle separation and more than 99% efficiency for cell-particle separation. The high performance of driven flow and separation along with simplicity of the operation and setup make it a valuable candidate for point-of-care devices.

Immuno-Sensing at Ultra-Low Concentration of TG2 Protein by Organic Electrochemical Transistors

Transglutaminase 2 (TG2) is a ubiquitously expressed member of the transglutaminase family with Ca2+-dependent protein crosslinking activity. Its subcellular localization is crucial in determining its function, and indeed, TG2 is found in the extracellular matrix, mitochondria, recycling endosomes, plasma membrane, cytosol, and nucleus because it is associated with cell growth, differentiation, and apoptosis. It is involved in several pathologies, such as celiac disease, cardiovascular, hepatic, renal, and fibrosis diseases, carrying out opposite functions of up and down regulation in the progression of the same pathology. Therefore, this fine regulation requires a very sensitive and specific method of identification of TG2, which is to be detected in very small quantities in a deregulated condition. Here, we demonstrate the possibility of detecting TG2 down to attomolar concentration by using organic electrochemical transistors driven by gold electrodes functionalized with anti-TG2 antibodies. In particular, a direct correlation between the TG2 concentration and the transistor transconductance values, as extracted from typical transfer curves, was found. Overall, our findings highlight the potentialities of this new biosensing approach for the detection of TG2 in the context of pathological diseases, offering a rapid and cost-effective alternative to traditional methods.

Organic Bioelectronics Development in Italy: A Review

In recent years, studies concerning Organic Bioelectronics have had a constant growth due to the interest in disciplines such as medicine, biology and food safety in connecting the digital world with the biological one. Specific interests can be found in organic neuromorphic devices and organic transistor sensors, which are rapidly growing due to their low cost, high sensitivity and biocompatibility. This trend is evident in the literature produced in Italy, which is full of breakthrough papers concerning organic transistors-based sensors and organic neuromorphic devices. Therefore, this review focuses on analyzing the Italian production in this field, its trend and possible future evolutions.

PDAC-on-chip for in vitro modeling of stromal and pancreatic cancer cells crosstalk

Pancreatic ductal adenocarcinoma (PDAC) mainly develops in the head of the pancreas, within the acino-ductal unit composed by acinar and ductal cells surrounded by pancreatic stellate cells (PSCs). PSCs strongly...

Organic electrochemical transistors as novel biosensing platforms to study the electrical response of whole blood and plasma

In this paper, for the first time to the best of our knowledge, organic electrochemical transistors are employed to investigate the electrical response of human blood, plasma and alternative buffer solutions that inhibit red blood cell (RBC) aggregation. Our focus is on selecting a suitable electrolytic platform and the related operating conditions, where the RBC effect on the OECT response can be observed separately from the strong ionic environment of plasma in whole blood. The transient response of whole blood to pulse experiments is characterized by two time constants, which can be related to blood viscosity and to the capacitive coupling between the ionic and electronic components of the overall system. The role of capacitive effects, likely due to enhanced double-layer formation by negatively charged RBCs, is also confirmed by the increase of transconductance which was found in RBC suspensions as compared to the suspending buffer. Overall, the complex behavior found in these experiments provides new insights for the development of innovative blood-based sensing devices for biomedical applications.

Layered Double Hydroxide-Based Gas Sensors for VOC Detection at Room Temperature

Miniaturized low-cost sensors for volatile organic compounds (VOCs) have the potentiality to become a fundamental tool for indoor and outdoor air quality monitoring, to significantly improve everyday life. Layered double hydroxides (LDHs) belong to the class of anionic clays and are largely employed for NO x detection, while few results are reported on VOCs. In this work, a novel LDH coprecipitation method is proposed. For the first time, a study comparing four LDHs (ZnAl-Cl, ZnFe-Cl, ZnAl-NO3, and MgAl-NO3) is carried out to investigate the sensing performances. As explored through several microscopy and spectroscopy analyses, LDHs show a morphology characterized by a large surface area and a three-dimensional hierarchical flowerlike architecture with micro- and nanopores that induce a fast diffusion and highly effective surface interaction of the target gases. The fabricated sensors, operating at room temperature, are able to reversibly and selectively detect acetone, ethanol, ammonia, and chlorine vapors, reaching significant sensing response values up to 6% at 21 °C. The results demonstrate that by changing the LDHs' composition, it is possible to modulate the sensitivity and selectivity of the sensor, helping the discrimination of different analytes, and the consequent integration on a sensor array paves the way for electronic nose development.

Effect of Volatile Organic Compounds Adsorption on 3D-Printed PEGDA:PEDOT for Long-Term Monitoring Devices

We report on the preparation and stereolithographic 3D printing of a resin based on the composite between a poly(ethylene glycol) diacrylate (PEGDA) host matrix and a poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) filler, and the related cumulative volatile organic compounds' (VOCs) adsorbent properties. The control of all the steps for resin preparation and printing through morphological (SEM), structural (Raman spectroscopy) and functional (I/V measurements) characterizations allowed us to obtain conductive 3D objects of complex and reproducible geometry. These systems can interact with chemical vapors in the long term by providing a consistent and detectable variation of their structural and conductive characteristics. The materials and the manufacture protocol here reported thus propose an innovative and versatile technology for VOCs monitoring systems based on cumulative adsorption effects.

Application of a Micro Free-Flow Electrophoresis 3D Printed Lab-on-a-Chip for Micro-Nanoparticles Analysis

The present work describes a novel microfluidic free-flow electrophoresis device developed by applying three-dimensional (3D) printing technology to rapid prototype a low-cost chip for micro- and nanoparticle collection and analysis. Accurate reproducibility of the device design and the integration of the inlet and outlet ports with the proper tube interconnection was achieved by the additive manufacturing process. Test prints were performed to compare the glossy and the matte type of surface finish. Analyzing the surface topography of the 3D printed device, we demonstrated how the best reproducibility was obtained with the glossy device showing a 5% accuracy. The performance of the device was demonstrated by a free-flow zone electrophoresis application on micro- and nanoparticles with different dimensions, charge surfaces and fluorescent dyes by applying different separation voltages up to 55 V. Dynamic light scattering (DLS) measurements and ultraviolet−visible spectroscopy (UV−Vis) analysis were performed on particles collected at the outlets. The percentage of particles observed at each outlet was determined in order to demonstrate the capability of the micro free-flow electrophoresis (µFFE) device to work properly in dependence of the applied electric field. In conclusion, we rapid prototyped a microfluidic device by 3D printing, which ensured micro- and nanoparticle deviation and concentration in a reduced operation volume and hence suitable for biomedical as well as pharmaceutical applications.

Electrospun Nanofibers: from Food to Energy by Engineered Electrodes in Microbial Fuel Cells

Microbial fuel cells (MFCs) are bio-electrochemical devices able to directly transduce chemical energy, entrapped in an organic mass named fuel, into electrical energy through the metabolic activity of specific bacteria. During the last years, the employment of bio-electrochemical devices to study the wastewater derived from the food industry has attracted great interest from the scientific community. In the present work, we demonstrate the capability of exoelectrogenic bacteria used in MFCs to catalyze the oxidation reaction of honey, employed as a fuel. With the main aim to increase the proliferation of microorganisms onto the anode, engineered electrodes are proposed. Polymeric nanofibers, based on polyethylene oxide (PEO-NFs), were directly electrospun onto carbon-based material (carbon paper, CP) to obtain an optimized composite anode. The crucial role played by the CP/PEO-NFs anodes was confirmed by the increased proliferation of microorganisms compared to that reached on bare CP anodes, used as a reference material. A parameter named recovered energy (Erec) was introduced to determine the capability of bacteria to oxidize honey and was compared with the Erec obtained when sodium acetate was used as a fuel. CP/PEO-NFs anodes allowed achieving an Erec three times higher than the one reached with a bare carbon-based anode.

P3HT Processing Study for In-Liquid EGOFET Biosensors: Effects of the Solvent and the Surface

In-liquid biosensing is the new frontier of health and environment monitoring. A growing number of analytes and biomarkers of interest correlated to different diseases have been found, and the miniaturized devices belonging to the class of biosensors represent an accurate and cost-effective solution to obtaining their recognition. In this study, we investigate the effect of the solvent and of the substrate modification on thin films of organic semiconductor Poly(3-hexylthiophene) (P3HT) in order to improve the stability and electrical properties of an Electrolyte Gated Organic Field Effect Transistor (EGOFET) biosensor. The studied surface is the relevant interface between the P3HT and the electrolyte acting as gate dielectric for in-liquid detection of an analyte. Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS) characterizations were employed to study the effect of two solvents (toluene and 1,2-dichlorobenzene) and of a commercial adhesion promoter (Ti Prime) on the morphological structure and electronic properties of P3HT film. Combining the results from these surface characterizations with electrical measurements, we investigate the changes on the EGOFET performances and stability in deionized (DI) water with an Ag/AgCl gate electrode.

Scaling Organic Electrochemical Transistors Down to Nanosized Channels

The perspective of downscaling organic electrochemical transistors (OECTs) in the nanorange is approached by depositing poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) on electrodes with a nanogap designed and fabricated by electromigration induced break junction (EIBJ) technique. The electrical response of the fabricated devices is obtained by acquiring transfer characteristics in order to clarify the specific main characteristics of OECTs with sub-micrometer-sized active channels (nanogap-OECTs). On the basis of their electrical response to different scan times, the nanogap-OECT shows a maximum transconductance unaffected upon changing scan times in the time window from 1 s to 100 µs, meaning that fast varying signals can be easily acquired with unchanged amplifying performance. Hence, the scaling down of the channel size to the nanometer scale leads to a geometrical paradigm that minimizes effects on device response due to the cationic diffusion into the polymeric channel. A comprehensive study of these features is carried out by an electrochemical impedance spectroscopy (EIS) study, complemented by a quantitative analysis made by equivalent circuits. The propagation of a redox front into the polymer bulk due to ionic diffusion also known as the "intercalation pseudocapacitance" is identified as a limiting factor for the transduction dynamics.

Photofabrication of polymeric biomicrofluidics: New insights into material selection

We propose a versatile method to evaluate the suitability of polymers for the fabrication of microfluidic devices for biomedical applications, based on the concept that the selection and the design of convenient materials should involve different properties depending on the final microfluidic application. Here polymerase chain reaction (PCR) is selected as biological model and target microfluidic reaction. A class of photocured siloxanes is introduced as device building polymers and copolymerization is adopted as strategy to finely tune and optimize the final material properties. All-polymeric flexible devices are easily fabricated exploiting the rapidity of the photopolymerization reaction: they resist to thermal cycles without leakage or de-bonding (i.e., without separation of different chip parts made of the same material bonded together), show very limited water swelling and permeability, are bioinert and prevent the inhibition of the biochemical reaction. PCR is thus successfully conducted in the photocured microfluidic devices made with a specifically designed siloxane copolymer.

Multifunctional Operation of an Organic Device with Three-Dimensional Architecture

This work aims to show the feasibility of an innovative approach for the manufacturing of organic-based devices with a true three-dimensional and customizable structure that is made possible by plastic templates, fabricated by additive manufacturing methods, and coated by conducting organic thin films. Specifically, a three-dimensional prototype based on a polyamide structure covered by poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) using the dip-coating technique demonstrated a multifunctional character. The prototype is indeed able to operate both as a three-terminal device showing the typical response of organic electrochemical transistors (OECTs), with a higher amplification performance with respect to planar (2D) all-PEDOT:PSS OECTs, and as a two-terminal device able to efficiently implement a resistive sensing of water vaporization and perspiration, showing performances at least comparable to that of state-of-art resistive humidity sensors based on pristine PEDOT:PSS. To our knowledge, this is the first reported proof-of-concept of a true 3D structured OECT, obtained by exploiting a Selective laser sintering approach that, though simple in terms of 3D layout, paves the way for the integration of sensors based on OECTs into three-dimensional objects in various application areas.

PEDOT:PSS Morphostructure and Ion-To-Electron Transduction and Amplification Mechanisms in Organic Electrochemical Transistors

Organic electrochemical transistors (OECTs) represent a powerful and versatile type of organic-based device, widely used in biosensing and bioelectronics due to potential advantages in terms of cost, sensitivity, and system integration. The benchmark organic semiconductor they are based on is poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), the electrical properties of which are reported to be strongly dependent on film morphology and structure. In particular, the literature demonstrates that film processing induces morphostructural changes in terms of conformational rearrangements in the PEDOT:PSS in-plane phase segregation and out-of-plane vertical separation between adjacent PEDOT-rich domains. Here, taking into account these indications, we show the thickness-dependent operation of OECTs, contextualizing it in terms of the role played by PEDOT:PSS film thickness in promoting film microstructure tuning upon controlled-atmosphere long-lasting thermal annealing (LTA). To do this, we compared the LTA-OECT response to that of OECTs with comparable channel thicknesses that were exposed to a rapid thermal annealing (RTA). We show that the LTA process on thicker films provided OECTs with an enhanced amplification capability. Conversely, on lower thicknesses, the LTA process induced a higher charge carrier modulation when the device was operated in sensing mode. The provided experimental characterization also shows how to optimize the OECT response by combining the control of the microstructure via solution processing and the effect of postdeposition processing.

Complete urological evaluation including sperm DNA fragmentation in male systemic lupus erythematosus patients

Objective

To evaluate sperm DNA fragmentation analysis in non-azoospermic male systemic lupus erythematosus (SLE) patients.

Methods

Twenty-eight consecutive male SLE patients (American College of Rheumatology criteria) and 34 healthy controls were evaluated for demographic/exposures data, urological evaluation, hormone profile and sperm analysis (including sperm DNA fragmentation). Clinical features, disease activity/damage scores and treatment were also evaluated.

Results

The median age (33 (20–52) vs. 36.5 (25–54) years, P = 0.329) and frequency of varicocele (25% vs. 32%, P = 0.183) were similar in SLE patients and healthy controls. Sperm DNA fragmentation showed significantly higher levels of cells class III (44 (9–88) vs. 16.5 (0–80)%, P = 0.001) and cell class IV (10.5 (3–86) vs. 7 (0–36)%, P = 0.039) in SLE. The sperm DNA fragmentation index was also significantly higher in SLE patients (62 (31–97) vs. 25.5 (0–100)%, P < 0.001). Conventional sperm parameters (including sperm count, motility and morphology) were similar in both groups. In SLE patients no correlations were observed between sperm DNA fragmentation index and age, disease duration, Systemic Lupus Erythematosus Disease Activity Index 2000 and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index scores, and cumulative dose of prednisone, hydroxychloroquine, intravenous cyclophosphamide, methotrexate, azathioprine and mycophenolate mofetil ( P > 0.05). Further analysis of SLE patients treated with and without intravenous cyclophosphamide showed that total sperm motility was significantly lower in the former group (64% (15–83) vs. 72% (57–86), P = 0.024). The sperm DNA fragmentation index was alike in both groups (52.5 (31–95) vs. 67.5 (34–97)%, P = 0.185).

Conclusions

To our knowledge, this is the first demonstration that male non-azoospermic SLE patients have increased sperm DNA fragmentation without evident gonadal dysfunction. Intravenous cyclophosphamide does not seem to be a major determinant for this abnormality. Future prospective study is necessary to determine the impact of this alteration in these patients' fertility.

Integration of organic electrochemical transistors and immuno-affinity membranes for label-free detection of interleukin-6 in the physiological concentration range through antibody–antigen recognition

A label-free immunosensor based on an organic electrochemical transistor integrated with an immuno-affinity membrane for cytokine detection at physiologically relevant concentrations is reported.

Impact of body mass index, age and varicocele on reproductive hormone profile from elderly men

OBJECTIVES

To study the impact of obesity, age and varicocele on sexual hormones of adult and elderly men.

MATERIALS AND METHODS

875 men who were screened for prostate cancer were enrolled in this study. Data recorded comprised age, body mass index (BMI), serum levels of total testosterone (TT), free testosterone (FT), sex hormone-binding globulin (SHBG), luteinizing hormone (LH) and follicular stimulating hormone (FSH). Patients were divided in groups according to their BMI in underweight, normal weight, overweight and obese grades 1, 2 or 3. First, it was studied the association between age, BMI, and hormone profile. Then, clinical varicocele was evaluated in 298 patients to assess its correlation to the others parameters.

RESULTS

Obese patients had lower levels of TT, FT and SHBG (p<0.001) compared to underweight or normal weight patients. There were no differences in age (p=0.113), FSH serum levels (p=0.863) and LH serum levels (p=0.218) between obese and non-obese patients. Obese grade 3 had lower levels of TT and FT compared to obese grade 1 and 2 (p<0.05). There was no difference in the SHBG levels (p=0.120) among obese patients. There was no association between varicocele and BMI; and varicocele did not impact on testosterone or SHBG levels.

CONCLUSIONS

Men with higher BMI have a lower serum level of TT, FT and SHBG. The presence of clinical varicocele as well as its grade has no impact on hormone profile in elderly men.

Modeling, Fabrication and Testing of a Customizable Micromachined Hotplate for Sensor Applications

In the sensors field the active sensing material frequently needs a controlled temperature in order to work properly. In microsystems technology, micro-machined hotplates represent a platform consisting of a thin suspended membrane where the sensing material can be deposited, usually integrating electrical stimuli and temperature readout. The micro-hotplate ensures a series of advantages such as miniaturized size, fast response, high sensitivity, low power consumption and selectivity for chemical sensing. This work compares the coplanar and the buried approach for the micro-hotplate heaters design with the aim to optimize the fabrication process and to propose a guideline for the choice of the suitable design with respect to the applications. In particular, robust Finite Element Method (FEM) models are set up in order to predict the electrical and thermal behavior of the micro-hotplates. The multiphysics approach used for the simulation allows to match as close as possible the actual device to the predictive model: geometries, materials, physics have been carefully linked to the fabricated devices to obtain the best possible accuracy. The materials involved in the fabrication process are accurately selected in order to improve the yield of the process and the performance of the devices. The fabricated micro-hotplates are able to warm the active region up to 400 °C (with a corresponding power consumption equal to 250 mW @ 400 °C) with a uniform temperature distribution in the buried micro-hotplate and a controlled temperature gradient in the coplanar one. A response time of about 70 ms was obtained on the virtual model, which perfectly agrees with the one measured on the fabricated device. Besides morphological, electrical and thermal characterizations, this work includes reliability tests in static and dynamic modes.

A new method to integrate ZnO nano-tetrapods on MEMS micro-hotplates for large scale gas sensor production

A new method, which is easily scalable to large scale production, has been developed to obtain gas sensor devices based on zinc oxide (ZnO) nanostructures with a 'tetrapod' shape. The method can be easily extended to other kinds of nanostructures and is based on the deposition of ZnO nanostructures through polymeric masks by centrifugation, directly onto properly designed MEMS micro-hotplates. The micromachined devices, after the mask is peeled off, are ready for electrical bonding and sensing test. Sensor response has been successfully measured for some gases and volatile organic compounds with different chemical properties (ethanol, methane, nitrogen dioxide, hydrogen sulfide).

Oxygen-Inhibition Lithography for the Fabrication of Multipolymeric Structures

The oxygen inhibition of UV curable polymers is exploited in novel technology for the fabrication of patterns and closed devices. Multiscale structures with thicknesses ranging from few micro-meters to millimeters are rapidly fabricated. Multipolymeric and multifunctional structures are also prepared: adequately choosing the material of each layer, a set of different properties is arranged in the same device.

On-chip purification and detection of hepatitis C virus RNA from human plasma

Hepatitis C virus (HCV) is one of the main causes of chronic liver disease worldwide. The diagnosis and monitoring of HCV infection is a crucial need in the clinical management. The conventional diagnostic technologies are challenged when trying to address molecular diagnostics, especially because they require a complex and time-consuming sample preparation phase. Here, a new concept based on surface functionalization was applied to viral RNA purification: first of all polydimethylsiloxane (PDMS) flat surfaces were modified to hold RNA adsorption. After a careful chemical and morphological analysis of the modified surfaces, the functionalization protocols giving the best RNA adsorbing surfaces were applied to PDMS microdevices. The functionalized microdevices were then used for RNA purification from HCV infected human plasma samples. RNA purification and RT were successfully performed in the same microdevice chamber, saving time of analysis, reagents, and labor. The PCR protocol for HCV cDNA amplification was also implemented in the microdevice, demonstrating that the entire process of HCV analysis, from plasma to molecular readout, could be performed on-chip. Not only HCV but also other microdevice-based viral RNA detection could therefore result in a successful Point-of-Care (POC) diagnostics for resource-limited settings.

A polymer lab-on-a-chip for genetic analysis using the arrayed primer extension on microarray chips

In this work a polymer lab-on-a-chip (LOC), fabricated through MEMS technology, was employed to execute a genetic protocol for the Single Nucleotide Polymorphisms (SNPs) detection. The LOC was made in Poly (methyl methacrylate) (PMMA) and has two levels: the lower one for the insertion and mixing of the reagents, the upper one for the interfacing with the DNA microarray chip. The hereditary hearing loss was chosen as case of study, since the demand for testing such a particular disorder is high and genetics behind the condition is quite clear. The Arrayed Primer EXtension (APEX) genetic protocol was implemented on the LOC to analyze the SNPs. A low density (for detection of up to 10 mutations) and a high density microarray chips (for detection of 245 mutations in 12 genes), containing the primers for the extension, were employed to carry out the APEX reaction on the LOC. Both the microarray chips provide a signal to noise ratio and efficiency comparable with a detection obtained in a conventional protocol in standard conditions. Moreover, significant reduction of the employed PCR volume (from 30 μL to 10 μL) was obtained using the low density chip.

Metal–elastomer nanostructures for tunable SERS and easy microfluidic integration

Stretchable plasmonic nanostructures constituted by Ag nanoparticles on flexible elastomeric matrices are synthesized and used as surface-enhanced Raman scattering (SERS) substrates.

OncomiR detection in circulating body fluids: a PDMS microdevice perspective

There is an increasing interest in circulating microRNAs (miRNAs) as potential minimally invasive diagnostic biomarkers in oncology. Considerable efforts are being made in the development of lab-on-a-chip devices for biomedical applications to purify and detect miRNAs from biological fluids. Here, we report the development of an innovative polydimethylsiloxane (PDMS)-based parallel device whose internal surface can opportunely be functionalized with positively charged 3-aminopropyltriethoxysilane (APTES) alone or mixed with two different neutral poly(ethylene glycol) silanes (PEG-s). The differently functionalized internal surfaces of the PDMS chip were characterized with s-SDTB (sulfosuccinimidyl-4-o-(4,4-dimethoxytrityl) butyrate) and the portion of the surface able to adsorb a synthetic fluorescently labeled miRNA was determined. Interestingly, the adsorbed miRNA (both synthetic and cell supernatant-derived) was found mainly on the bottom surface of the chip and could be reverse transcribed into cDNA directly on the same PDMS chip used for its purification, saving hours with respect to the use of standard purification kits. We identified 0.1% APTES/0.9% PEG-silane as the most efficient PDMS functionalization to capture both synthetic and extracellular miRNA. Moreover, the amount of captured miRNA was increased by treating the cell supernatant with a commercially available lysis buffer for RNA extraction. We assessed that the available miRNA binding sites on the functionalized surface were efficiently saturated with only one incubation, shortening the time and greatly simplifying the protocol for miRNA purification from biological samples. Finally, the extracellular miRNA purification efficiency of the PDMS functionalized multichip determined via real-time quantitative polymerase chain reaction (RT-qPCR) was confirmed by droplet digital PCR (ddPCR) quantification. This work shows an innovative, rapid and easy to use microdevice for the purification and reverse transcription of circulating miRNAs, approaching the realization of diagnostic and prognostic oncomiR-based assays.

PDMS membranes with tunable gas permeability for microfluidic applications

The air permeability of PDMS membranes is easily tuned acting on their composition. Varying the mixing ratio it is possible to strongly influence the gas molecules permeation across the PDMS membrane.

Direct photolithography of perfluoropolyethers for solvent-resistant microfluidics

In this work, photocurable perfluoropolyethers (PFPEs) have been used for the fabrication of microfluidic devices by a direct photolithographic process. During this mask-assisted photopolymerization technique, the material is directly photopolymerized in the presence of a mask, avoiding the use of a master. We demonstrate the high level of control in transferring micropattern features with high density, a minimum transferred size of 15 μm, a high aspect ratio (at least up to 6.5), and complex shapes useful for microfluidic applications. Moreover, we successfully apply this technology to fabricate sealed devices; the fabrication time scale for the overall process is around 5 min. The devices are able to withstand a flow pressure of up to 3.8 bar, as required for most microfluidics. Finally, the devices are tested with a model reaction employing organic solvents.

Liposome sensing and monitoring by organic electrochemical transistors integrated in microfluidics

BACKGROUND

Organic electrochemical transistors (OECTs), which are becoming more and more promising devices for applications in bioelectronics and nanomedicine, are proposed here as ideally suitable for sensing and real time monitoring of liposome-based structures. This is quite relevant since, currently, the techniques used to investigate liposomal structures, their stability in different environments as well as drug loading and delivery mechanisms, operate basically off-line and/or with pre-prepared sampling.

METHODS

OECTs, based on the PEDOT:PSS conductive polymer, have been employed as sensors of liposome-based nanoparticles in electrolyte solutions to assess sensitivity and monitoring capabilities based on ion-to-electron amplified transduction.

RESULTS

We demonstrate that OECTs are very efficient, reliable and sensitive devices for detecting liposome-based nanoparticles on a wide dynamic range down to 10(-5)mg/ml (with a lowest detection limit, assessed in real-time monitoring, of 10(-7)mg/ml), thus matching the needs of typical drug loading/drug delivery conditions. They are hence particularly well suited for real-time monitoring of liposomes in solution. Furthermore, OECTs are shown to sense and discriminate successive injection of different liposomes, so that they could be good candidates in quality-control assays or in the pharmaceutical industry.

GENERAL SIGNIFICANCE

Drug loading and delivery by liposome-based structures is a fast growing and very promising field that will strongly benefit from real-time, highly sensitive and low cost monitoring of their dynamics in different pharma and biomedical environments, with a particular reference to the pharmaceutical and production processes, where a major issue is monitoring and measuring the formation and concentration of liposomes and the relative drug load. The demonstrated ability to sense and monitor complex bio-structures, such as liposomes, paves the way for very promising developments in biosensing and nanomedicine. This article is part of a Special Issue entitled Organic Bioelectronics-Novel Applications in Biomedicine.

Solid phase DNA extraction on PDMS and direct amplification

In this paper we report an innovative use of Poly(DiMethyl)Siloxane (PDMS) to design a microfluidic device that combines, for the first time, in one single reaction chamber, DNA purification from a complex biological sample (blood) without elution and PCR without surface passivation agents. This result is achieved by exploiting the spontaneous chemical structure and nanomorphology of the material after casting. The observed surface organization leads to spontaneous DNA adsorption. This property allows on-chip complete protocols of purification of complex biological samples to be performed directly, starting from cells lysis. Amplification by PCR is performed directly on the adsorbed DNA, avoiding the elution process that is normally required by DNA purification protocols. The use of one single microfluidic volume for both DNA purification and amplification dramatically simplifies the structure of microfluidic devices for DNA preparation. X-Ray Photoelectron Spectroscopy (XPS) was used to analyze the surface chemical composition. Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscopy (FESEM) were employed to assess the morphological nanostructure of the PDMS-chips. A confocal fluorescence analysis was utilized to check DNA distribution inside the chip.

Primary antiphospholipid syndrome: morphofunctional penile abnormalities with normal sperm analysis

OBJECTIVE

To perform a global gonadal and sexual functions assessment in primary antiphospholipid syndrome (PAPS) patients.

METHODS

A cross-sectional study was conducted in 12 male PAPS patients and 20 healthy controls. They were assessed by demographic data, clinical features, systematic urological examination, sexual function, testicular ultrasound, seminal parameters according to the World Health Organization (WHO), seminal sperm antibodies, and hormone profile, including follicle stimulating hormone (FSH), luteinizing hormone (LH), morning total testosterone, and thyroid hormones.

RESULTS

The median of current age and age of spermarche were similar in PAPS patients and controls (37.5 vs. 32.4 years, p = 0.270, and 13.1 vs. 12.85 years, p = 0.224, respectively), with a higher frequency of erectile dysfunction in the former group (25% vs. 0%, p = 0.044). Further analysis of PAPS patients with and without previous arterial thrombosis demonstrated that the median penis circumference was significantly lower in PAPS with arterial thrombosis than in PAPS without this complication (8.1 [6-10] vs. 10.2 [10-11] cm, p = 0.007). In addition, the median penis circumference was significantly lower in PAPS patients with erectile dysfunction than in patients without this complication (7.5 [6-9.5] vs. 9.5 [7.5-11] cm, p = 0.039). Regarding seminal analysis, the median sperm concentration, sperm motility, and normal sperm forms by WHO guidelines were comparable in PAPS patients and controls (141.5 [33-575] vs. 120.06 [34.5-329] × 10(6)/ml, p = 0.65; 61.29 [25-80] vs. 65.42 [43-82]%, p = 0.4; 21.12 [10-42.5] vs. 23.95 [10-45]%, p = 0.45, respectively), and none of them had oligo/azoospermia. No differences were observed between PAPS patients and controls regarding the frequency of antisperm antibodies, testicular volume by ultrasound, or hormone profile (FSH, LH, morning total testosterone, and thyroid hormone) (p > 0.05).

CONCLUSIONS

Normal testicular function has been identified in PAPS patients, in spite of morphofunctional penile abnormalities. Previous arterial thrombosis may underlie penile anthropometry alteration.

Penile anthropometry in systemic lupus erythematosus patients

The aim of this study was to evaluate penile anthropometry in systemic lupus erythematosus (SLE) patients compared with healthy controls and the possible relevant pubertal, clinical, hormonal and treatment factors that could influence penile dimensions. Twenty-five consecutive SLE patients were assessed by urological examination, sexual function, testicular ultrasound, hormones, sperm analysis, genetic analysis, clinical features and treatment. The control group included 25 age-matched healthy males. SLE patients had a lower median penis length and circumference [8 (7.5–10) vs. 10 (8–13) cm, p = 0.0001; 8 (7–10) vs. 10 (7–11) cm, p = 0.001; respectively], lower median testicular volume by right and left Prader [15 (10–25) vs. 20 (12–25) ml, p = 0.003; 15 (10–25) vs. 20 (12–25) ml, p = 0.006; respectively], higher median of follicle-stimulating hormone [5.8 (2.1–25) vs. 3.3 (1.9–9) IU/l, p = 0.002] and lower morning total testosterone levels (28% vs. 0%, p = 0.009) compared with controls. In spite of that, erectile dysfunction was not observed in patients or controls. Analyses of lupus patients revealed that the median penis circumference was lower in patients with disease onset before first ejaculation compared with those with disease onset after first ejaculation [7.8 (7–10) vs. 9.0 (7.5–10) cm, p = 0.026]. No differences were observed in the median penile anthropometry regarding sexual dysfunction ( p = 0.610), lower morning total testosterone levels ( p = 0.662), oligo/azoospermia ( p = 0.705), SLE Disease Activity Index ≥ 4 ( p = 0.562), Systemic Lupus International Collaborating Clinics/ACR Damage Index ≥ 1 ( p = 0.478), prednisone cumulative dose ( p = 0.789) and intravenous cyclophosphamide therapy ( p = 0.754). Klinefelteŕs syndrome (46XY/47XXY) was diagnosed in one (4%) SLE patient with decreased penile size whereas Y-chromosomal microdeletions was absent in all of them. In conclusion, we have identified reduced penile dimensions in SLE patients with no deleterious effect in erectile function. Disease onset before first ejaculation seems to affect penis development in pre-pubertal lupus.

Minor sperm abnormalities in young male post-pubertal patients with juvenile dermatomyositis

The objective of the present study was to identify sperm abnormalities in young male patients with juvenile dermatomyositis (JDM). In 2005, 18 male JDM patients, diagnosed according to the criteria of Bohan and Peter, were followed at the Pediatric Rheumatology Unit and Rheumatology Division, of our Institution. Of the 18 males, 11 were pre-pubertal and 7 were post-pubertal. Two of 7 post-pubertal JDM male patients were excluded: one for orchidopexy for cryptorchidism and the other for testicular ectopia in the left testis. The remaining 5 post-pubertal JDM patients were prospectively evaluated on the basis of two semen analyses, according to the World Health Organization (WHO), urologic evaluation, testicular Doppler ultrasound hormone profile. The data of the JDM patients were compared with those of 5 age-matched healthy controls. The median age 18, was similar in JDM patients and controls. All JDM patients had teratozoospermia (abnormal sperm morphology), as did 4 (80%) of the controls. One of JDM patients had previous oligoasthenoteratozoospermia treated with intravenous cyclophosphamide with normalization of the number and concentration of the sperm after 5 years. All sperm parameters (sperm concentration, total sperm count and total motile sperm count by WHO, and sperm morphology by Kruger strict criteria), testicular volumes by Prader orchidometer and ultrasound, and hormones were similar in JDM patients compared with controls. The frequency of anti-sperm antibodies was similar in both groups. All JDM patients had minor sperm abnormalities in the head, midpiece, and/or tail of spermatozoids. Serial semen analyses in larger study populations are necessary to identify the extent and duration of sperm abnormalities in male patients with idiopathic inflammatory myopathies.

Testicular Sertoli cell function in male systemic lupus erythematosus

OBJECTIVE

To assess the testicular Sertoli cell function in male SLE patients.

METHODS

Thirty-four consecutive patients were prospectively selected to evaluate serum inhibin B. Clinical features, treatment, semen analysis, urological evaluation, testicular ultrasound, hormones and anti-sperm antibodies were determined.

RESULTS

Patients were subdivided into two groups: low serum inhibin B (Group 1, n = 8) and normal levels (Group 2, n = 26). The median sperm concentration (P = 0.024), total sperm count (P = 0.023) and total motile sperm count (P = 0.025) were lower in Group 1. Inhibin B levels were positively correlated with sperm concentration (r = 0.343), total motile sperm count (r = 0.357), and negatively correlated with follicule-stimulating hormone (FSH) (r = 0.699) and luteinizing hormone (r = 0.397). The median serum inhibin B was lower in SLE patients treated with intravenous cyclophosphamide (IVCYC) compared with those without this therapy (P = 0.031). Further evaluation of the 26 SLE patients with normal inhibin B and FSH levels revealed that medians of inhibin B/FSH ratio were lower in SLE patients with oligozoospermia compared with normozoospermia (P = 0.004). This ratio was also lower in SLE patients treated with IVCYC than those without this therapy (P = 0.04). In contrast, inhibin B serum level alone did not discriminate the later group of patients (P = 0.12).

CONCLUSIONS

This is the first study to identify a high frequency of testicular Sertoli cell dysfunction in male SLE associated with semen abnormalities. Further prospective studies are necessary to determine if inhibin levels and inhibin B/FSH ratio will be an earlier and useful marker of IVCYC toxicity in these patients.