Red-Light-Photosensitized Tyrosine 10 Nitration of ß-Amyloid1-42 Diverts the Protein from Forming Toxic Aggregates.

Several studies have highlighted the presence of nitration damage following neuroinflammation in Alzheimer's disease (AD). Accordingly, post-transcriptional modifications of ß-amyloid (Aß), including peptide nitration, have been explored as a marker of the disease. However, the implications of Aß nitration in terms of aggregation propensity and neurotoxicity are still debated. Here, we show new data obtained using a photoactivatable peroxynitrite generator (BPT-NO) to overcome the limitations associated with chemical nitration methods. We found that the photoactivation of BPT-NO with the highly biocompatible red light selectively induces the nitration of tyrosine 10 of freshly solubilized full-length Aß1-42. Photonitrated Aß1-42 was, therefore, investigated for aggregation states and functions. It resulted that photonitrated Aß1-42 did not aggregate into small oligomers but rather self-assembled into large amorphous aggregates. When tested on neuronal-like SH-SY5Y cells and microglial C57BL/6 BV2 cells, photonitrated Aß1-42 showed to be free of neurotoxicity and able to induce phagocytic microglia cells. We propose that light-controlled nitration of the multiple forms in which Aß occurs (i.e., monomers, oligomers, fibrils) could be a tool to assess in real-time the impact of tyrosine nitration on the amyloidogenic and toxic properties of Aß1-42.

Phasor-FLIM analysis of cellulose paper ageing mechanism with carbotrace 680 dye.

Ageing of paper is a complex process of great relevance for application purposes because of its widespread use as support for information storage in books and documents, and as common low-cost and green packaging material, to name a few. A key factor in paper ageing is the oxidation of cellulose, a macromolecule of natural origin that constitutes the main chemical component of paper. Such a complex process results in changes in the cellulose polymeric chains in chemical and structural properties. The scope of this work is to explore the effects of oxidation of cellulose as one of the principal mechanisms of ageing of paper using a fluorescence-based approach. To this aim, fluorescence-lifetime imaging microscopy (FLIM) measurements on pure cellulose samples stained using Carbotrace 680 dye were performed, and data were analyzed by phasor approach. The comparison with results from conventional techniques allowed to map paper microstructure as a function of the sample oxidation degree correlating the fluorescence-lifetime changes to cellulose oxidation. A two-step oxidation kinetics that produced specific modification in paper organization was highlighted indicating that FLIM measurements using Carbotrace 680 dye may provide a simple tool to obtain information on the oxidation process also adding spatial information at sub-micrometric scale.

Label-free approaches for extracellular vesicle detection.

Extracellular vesicles (EVs) represent pivotal mediators in cell-to-cell communication. They are lipid-membranous carriers of several biomolecules, which can be produced by almost all cells. In the current Era of precision medicine, EVs gained growing attention thanks to their potential in both biomarker discovery and nanotherapeutics applications. However, current technical limitations in isolating and/or detecting EVs restrain their standard use in clinics. This review explores all the state-of-the-art analytical technologies which are currently overcoming these issues. On one end, several innovative optical-, electrical-, and spectroscopy-based detection methods represent advantageous label-free methodologies for faster EV detection. On the other end, microfluidics-based lab-on-a-chip tools support EV purification from low-concentrated samples. Altogether, these technologies will strengthen the routine application of EVs in clinics.

Vertically Aligned Nanowires and Quantum Dots: Promises and Results in Light Energy Harvesting.

The synthesis of crystals with a high surface-to-volume ratio is essential for innovative, high-performance electronic devices and sensors. The easiest way to achieve this in integrated devices with electronic circuits is through the synthesis of high-aspect-ratio nanowires aligned vertically to the substrate surface. Such surface structuring is widely employed for the fabrication of photoanodes for solar cells, either combined with semiconducting quantum dots or metal halide perovskites. In this review, we focus on wet chemistry recipes for the growth of vertically aligned nanowires and technologies for their surface functionalization with quantum dots, highlighting the procedures that yield the best results in photoconversion efficiencies on rigid and flexible substrates. We also discuss the effectiveness of their implementation. Among the three main materials used for the fabrication of nanowire-quantum dot solar cells, ZnO is the most promising, particularly due to its piezo-phototronic effects. Techniques for functionalizing the surfaces of nanowires with quantum dots still need to be refined to be effective in covering the surface and practical to implement. The best results have been obtained from slow multi-step local drop casting. It is promising that good efficiencies have been achieved with both environmentally toxic lead-containing quantum dots and environmentally friendly zinc selenide.

Self-Cleaning Bending Sensors Based on Semitransparent ZnO Nanostructured Films.

The design of multifunctional nanostructured materials is the key to the development of smart wearable devices. For instance, nanostructures endowed with both piezoelectric and photocatalytic activities could well be the workhorse for solar-light-driven self-cleaning wearable sensors. In this work, a simple strategy for the assembly of a flexible, semitransparent piezophotocatalytic system is demonstrated by leveraging rational wet chemistry synthesis of ZnO-based nanosheets/nanoflowers (NSs/NFs) under basic pH conditions onto flexible ITO/PET supports. A KMnO4 pretreatment before the ZnO synthesis (seeded ZnO) allows for the control of the density, size, and orientation of the NSs/NFs systems compared to the systems produced in the absence of seeding (seedless ZnO). The electrical response of the sensors is extracted at a 1 V bias as a function of bending in the interval between 0 and 90°, being the responsivity toward bending significantly enhanced by the KMnO4 treatment effect. The photocatalytic activity of the sensors is analyzed in aqueous solution (methylene blue, 25 µM) by a solar simulator, resulting in similar values between seedless and seeded ZnO. Upon bending the sensor, the photocatalytic activity of seedless ZnO is almost unaffected, whereas that of seeded ZnO is improved by about 25%. The sensor's reusability and repeatability are tested in up to three different cycles. These results open up the way toward the seamless integration of bending sensitivity and photocatalysis into a single device.

Insight into mechanisms of creatinine optical sensing using fluorescein-gold complex.

Creatinine level in biological fluids is a clinically relevant parameter to monitor vital functions and it is well assessed that measuring creatinine levels in the human body can be of great utility to evaluate renal, muscular, or thyroid dysfunctions. The accurate detection of creatinine levels may have a critical role in providing information on health status and represents a tool for the early diagnosis of severe pathologies. Among different methods for creatinine detection that have been introduced and that are evolving with increasing speed, fluorescence-based and colorimetric sensors represent one of the best alternatives, thanks to their affordability, sensitivity and easy readability. In this work, we demonstrate that the fluorescein-Au3+complex provides a rapid, selective, and sensitive tool for the quantification of creatinine concentrations in ranges typical of sweat and urine. UV-visible absorption, diffuse reflectance spectroscopy, steady state and time resolved fluorescence spectroscopy were used to shed light on the molecular mechanisms involved in the changes of optical properties, which underlie the multiplexed sensor analytical reply. Interestingly, sensing can be performed in solution or on solid nylon support accessing different physiological concentrations from micromolar to millimolar range. As a proof-of-concept, the nylon-based platform was used to demonstrate its effectiveness in creatinine detection on a solid and flexible substrate, showing its analytical colorimetric properties as an easy and disposable creatinine point-of-care test.

Postoperative Anticoagulation in Vascular Reconstructions Associated with Malignancies.

BACKGROUND: The invasion of truncal arteries and veins by malignant neoplasms is rare and the surgical treatment remains a challenge. Several techniques can be used to re-establish blood flow in a resected vessel and choice of the ideal vascular substitute frequently arises a debate. Comparative studies between prosthetic and autologous grafts disclose conflicting patency results. The aim of this study is to compare patency outcomes of vascular reconstructions performed using autologous or prosthetic replacement grafts in surgical oncology, in light of a standardized antithrombotic protocol used in our institution since 1997. METHODS: This retrospective study compared patency of prosthetic versus autologous interposition grafts following the resection of malignancies in 117 patients between September 1997 and February 2020. The 181 reconstruction procedures performed were analyzed according to the body segment involved, and divided into: head and neck, thorax, abdomen, and extremities. RESULTS: Overall survival estimates after 24 and 60 months were 53.2% (standard error 4.8%) and 38.1% (standard error 4.9%), respectively. No significant difference was observed between overall arterial patency, using autologous or synthetic grafts (P = 0.41). Overall venous patency showed a tendency to be lower in synthetic grafts, although no significant difference was observed (P = 0.062). For both arterial and venous reconstructions in the extremities (upper and lower limbs), significantly higher patency was observed using autologous grafts. CONCLUSIONS: Autologous long-term graft patency may be superior to prosthetic in vascular reconstructions associated with malignancies of the extremities. This outcome was obtained using a standardized post-operative anticoagulation protocol.

"Writing biochips": high-resolution droplet-to-droplet manufacturing of analytical platforms.

The development of high-resolution molecular printing allows the engineering of analytical platforms enabling applications at the interface between chemistry and biology, i.e. in biosensing, electronics, single-cell biology, and point-of-care diagnostics. Their successful implementation stems from the combination of large area printing at resolutions from sub-100 nm up to macroscale, whilst controlling the composition and volume of the ink, and reconfiguring the deposition features in due course. Similar to handwriting pens, the engineering of continuous writing systems tackles the issue of the tedious ink replenishment between different printing steps. To this aim, this review article provides an unprecedented analysis of the latest continuous printing methods for bioanalytical chemistry, focusing on ink deposition systems based on specific sets of technologies that have been developed to this aim, namely nanofountain probes, microcantilever spotting, capillary-based polymer pens and continuous 3D printing. Each approach will be discussed revealing the most important applications in the fields of biosensors, lab-on-chips and diagnostics.

Improved Photocatalytic Activity of Polysiloxane TiO2 Composites by Thermally Induced Nanoparticle Bulk Clustering and Dye Adsorption.

Fine control of nanoparticle clustering within polymeric matrices can be tuned to enhance the physicochemical properties of the resulting composites, which are governed by the interplay of nanoparticle surface segregation and bulk clustering. To this aim, out-of-equilibrium strategies can be leveraged to program the multiscale organization of such systems. Here, we present experimental results indicating that bulk assembly of highly photoactive clusters of titanium dioxide nanoparticles within an in situ synthesized polysiloxane matrix can be thermally tuned. Remarkably, the controlled nanoparticle clustering results in improved degradation photocatalytic performances of the material under 1 sun toward methylene blue. The resulting coatings, in particular the 35 wt % TiO2-loaded composites, show a photocatalytic degradation of about 80%, which was comparable to the equivalent amount of bare TiO2 and two-fold higher with respect to the corresponding composites not subjected to thermal treatment. These findings highlight the role of thermally induced bulk clustering in enhancing photoactive nanoparticle/polymer composite properties.

Identification of microplastics using 4-dimethylamino-4'-nitrostilbene solvatochromic fluorescence.

In this work, we introduce the use of 4-dimethylamino-4'-nitrostilbene (DANS) fluorescent dye for applications in the detection and analysis of microplastics, an impendent source of pollution made of synthetic organic polymers with a size varying from less than 5 mm to nanometer scale. The use of this dye revealed itself as a versatile, fast and sensitive tool for readily discriminate microplastics in water environment. The experimental evidences herein presented demonstrate that DANS efficiently absorbs into a variety of polymers constituting microplastics, and its solvatochromic properties lead to a positive shift of the fluorescence emission spectrum according to the polarity of the polymers. Therefore, under UV illumination, microplastics glow a specific emission spectrum from blue to red that allows for a straightforward polymer identification. In addition, we show that DANS staining gives access to different detection and analysis strategies based on fluorescence microscopy, from simple epifluorescence fragments visualization, to confocal microscopy and phasor approach for plastic components quantification.

Inferior Vena Cava Filter in Cancer Patients: On Whom Should We Be Placing Them?

BACKGROUND: Standard treatment for venous thromboembolism is anticoagulation; vena cava filter placement is an alternative in special situations. We aimed to evaluate the outcomes in patients with cancer undergoing filter placement in a cancer center during a 10-year period and assess which preoperatory variables were associated with poorer survival. METHODS: Retrospective unicenter analysis during a 10-year period was carried out in patients with cancer who had undergone placement of vena cava filter. Early deaths were those that occurred less than 30 days after the filter placement or that occurred during the same hospital stay of the placement. RESULTS: About 250 patients were analyzed. About 51.6% were females; 77.2% had proximal lower limb deep vein thrombosis; 34.8% had contraindications to anticoagulation; 32.8% presented bleeding after the onset of anticoagulation; and 18.4% had the filter implanted because they were going to undergo surgery and could not be anticoagulated immediately after. About 51.2% of the filters were removable. However, only 2 had the filter removed. About 59.2% had metastatic disease at the time of filter placement. About 31.2% fulfilled criteria for early death. Of those, 34 patients were put in palliative care after filter insertion (median, 13.5 days). Body mass index >18 kg/m2, the absence of metastatic disease, and filter placement during the same anesthesia of another surgery (especially if elective and curative) were associated with a higher chance of survival. CONCLUSIONS: Multidisciplinary evaluation (and possibly consideration for palliation) should take place before the decision to insert a vena cava filter in severe oncologic cases depending on overall status. Patients with a greater chance of survival at a 3 or 5 years interval seem to be those whose filters were placed in the perioperative context of other surgeries (specially elective and curative), who were not undernourished, and whose disease was not metastatic at that time. For patients who survived, an active investigation protocol for filter removal should be implemented.

Bending Sensors Based on Thin Films of Semitransparent Bithiophene-Fulleropyrrolidine Bisadducts.

A novel bithiophene-fulleropyrrolidine bisadducts system (bis-Th2PC60 ) was synthesized and electropolymerized by chronoamperometry onto flexible ITO/PET substrates. The resulting semitransparent thin film was characterized by XPS, FT-IR, cyclic voltammetry and optical techniques, confirming the good outcome of the electropolymerization process. AFM investigations permitted to highlight an inherent disordered granular morphology, in which the grain-to-grain separation depends upon the application of bending. The electrical resistance of the thin film was characterized as a function of bending (in the range 0°-90°), showing promising responsivity to low bending angles (10°-30°). The ΔR/R0 variations turn out to be 8 %,16 % and 20 % for bending angles equal to 10°, 20° and 30°, respectively. This study represents a first step towards the understanding of piezoresistive properties in electropolymerized fullerenes-based thin films, opening up applications as bending sensor.

Mastering the Tools: Natural versus Artificial Vesicles in Nanomedicine.

Naturally occurring extracellular vesicles and artificially made vesicles represent important tools in nanomedicine for the efficient delivery of biomolecules and drugs. Since its first appearance in the literature 50 years ago, the research on vesicles is progressing at a fast pace, with the main goal of developing carriers able to protect cargoes from degradation, as well as to deliver them in a time- and space-controlled fashion. While natural occurring vesicles have the advantage of being fully compatible with their host, artificial vesicles can be easily synthetized and functionalized according to the target to reach. Research is striving to merge the advantages of natural and artificial vesicles, in order to provide a new generation of highly performing vesicles, which would improve the therapeutic index of transported molecules. This progress report summarizes current manufacturing techniques used to produce both natural and artificial vesicles, exploring the promises and pitfalls of the different production processes. Finally, pros and cons of natural versus artificial vesicles are discussed and compared, with special regard toward the current applications of both kinds of vesicles in the healthcare field.

Artificial Biosystems by Printing Biology.

The continuous progress of printing technologies over the past 20 years has fueled the development of a plethora of applications in materials sciences, flexible electronics, and biotechnologies. More recently, printing methodologies have started up to explore the world of Artificial Biology, offering new paradigms in the direct assembly of Artificial Biosystems (small condensates, compartments, networks, tissues, and organs) by mimicking the result of the evolution of living systems and also by redesigning natural biological systems, taking inspiration from them. This recent progress is reported in terms of a new field here defined as Printing Biology, resulting from the intersection between the field of printing and the bottom up Synthetic Biology. Printing Biology explores new approaches for the reconfigurable assembly of designed life-like or life-inspired structures. This work presents this emerging field, highlighting its main features, i.e., printing methodologies (from 2D to 3D), molecular ink properties, deposition mechanisms, and finally the applications and future challenges. Printing Biology is expected to show a growing impact on the development of biotechnology and life-inspired fabrication.

On the Interaction between 1D Materials and Living Cells.

One-dimensional (1D) materials allow for cutting-edge applications in biology, such as single-cell bioelectronics investigations, stimulation of the cellular membrane or the cytosol, cellular capture, tissue regeneration, antibacterial action, traction force investigation, and cellular lysis among others. The extraordinary development of this research field in the last ten years has been promoted by the possibility to engineer new classes of biointerfaces that integrate 1D materials as tools to trigger reconfigurable stimuli/probes at the sub-cellular resolution, mimicking the in vivo protein fibres organization of the extracellular matrix. After a brief overview of the theoretical models relevant for a quantitative description of the 1D material/cell interface, this work offers an unprecedented review of 1D nano- and microscale materials (inorganic, organic, biomolecular) explored so far in this vibrant research field, highlighting their emerging biological applications. The correlation between each 1D material chemistry and the resulting biological response is investigated, allowing to emphasize the advantages and the issues that each class presents. Finally, current challenges and future perspectives are discussed.

Tackling Performance Challenges in Organic Photovoltaics: An Overview about Compatibilizers.

Organic Photovoltaics (OPVs) based on Bulk Heterojunction (BHJ) blends are a mature technology. Having started their intensive development two decades ago, their low cost, processability and flexibility rapidly funneled the interest of the scientific community, searching for new solutions to expand solar photovoltaics market and promote sustainable development. However, their robust implementation is hampered by some issues, concerning the choice of the donor/acceptor materials, the device thermal/photo-stability, and, last but not least, their morphology. Indeed, the morphological profile of BHJs has a strong impact over charge generation, collection, and recombination processes; control over nano/microstructural morphology would be desirable, aiming at finely tuning the device performance and overcoming those previously mentioned critical issues. The employ of compatibilizers has emerged as a promising, economically sustainable, and widely applicable approach for the donor/acceptor interface (D/A-I) optimization. Thus, improvements in the global performance of the devices can be achieved without making use of more complex architectures. Even though several materials have been deeply documented and reported as effective compatibilizing agents, scientific reports are quite fragmentary. Here we would like to offer a panoramic overview of the literature on compatibilizers, focusing on the progression documented in the last decade.

Synergies and compromises between charge and energy transfers in three-component organic solar cells.

In this paper, we developed different three-component organic heterojunction structures supported by PET/ITO substrates with the aim to study the possible synergies and/or compromises between charge transfer (CT) and energy transfer (ET) processes in organic solar cells (OSCs). As components, we employed poly(3-hexylthiophene-2,5-diyl) (P3HT; donor), [6,6]-phenyl-C61-butyric acid methyl ester (PCBM; acceptor) and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) that is known to give good ET to P3HT. At first, we observed that in a planar heterojunction (PHJ) solar cell, F8BT has to be properly located in between P3HT and PCBM to get a cascade energy level configuration allowing for a better CT and power conversion efficiency. Then, we observed that by producing a P3HT:F8BT blend, the energy transfer process can be improved in the P3HT:F8BT/PCBM active layer. This may enable decreasing the thickness of the active layer while maintaining a similar PCE that is very interesting for the development of transparent OSCs. However, the P3HT:F8BT blend limits the P3HT-PCBM CT with respect to a P3HT/F8BT/PCBM PHJ, showing that a compromise between CT and ET is needed to get a higher PCE or higher transparency. By the above approach, in this paper, we developed highly transparent heterojunction structures for solar cell devices with PCEs comparable to those observed from the colorful reference P3HT/PCBM PHJ solar cells on PET/ITO substrates.

An alternative approach to treatment of inferior vena cava filter perforation.

We report a case of inferior vena cava filter perforation immediately after filter implantation, recognized intraoperatively in a patient undergoing laparotomy for resection of locally advanced ovarian cancer. We describe an alternative approach with strut resection, less invasive than filter removal, enabling the device to be maintained and bleeding to be controlled.

Relatamos um caso de perfuração de veia cava inferior imediatamente após o implante de um filtro. A complicação foi reconhecida no intraoperatório de uma laparotomia para ressecção de um câncer de ovário localmente avançado. Descrevemos uma abordagem alternativa, menos invasiva do que a remoção do filtro, consistindo na ressecção das hastes do dispositivo. Essa abordagem permitiu a manutenção do filtro e o controle efetivo do sangramento.

Aqueous Processed Biopolymer Interfaces for Single-Cell Microarrays.

Single-cell microarrays are emerging tools to unravel intrinsic diversity within complex cell populations, opening up new approaches for the in-depth understanding of highly relevant diseases. However, most of the current methods for their fabrication are based on cumbersome patterning approaches, employing organic solvents and/or expensive materials. Here, we demonstrate an unprecedented green-chemistry strategy to produce single-cell capture biochips onto glass surfaces by all-aqueous inkjet printing. At first, a chitosan film is easily inkjet printed and immobilized onto hydroxyl-rich glass surfaces by electrostatic immobilization. In turn, poly(ethylene glycol) diglycidyl ether is grafted on the chitosan film to expose reactive epoxy groups and induce antifouling properties. Subsequently, microscale collagen spots are printed onto the above surface to define the attachment area for single adherent human cancer cells harvesting with high yield. The reported inkjet printing approach enables one to modulate the collagen area available for cell attachment in order to control the number of captured cells per spot, from single-cells up to double- and multiple-cell arrays. Proof-of-principle of the approach includes pharmacological treatment of single-cells by the model drug doxorubicin. The herein presented strategy for single-cell array fabrication can constitute a first step toward an innovative and environmentally friendly generation of aqueous-based inkjet-printed cellular devices.

An alternative approach to treatment of inferior vena cava filter perforation / Tratamento alternativo para perfuração de veia cava inferior por filtro

Abstract We report a case of inferior vena cava filter perforation immediately after filter implantation, recognized intraoperatively in a patient undergoing laparotomy for resection of locally advanced ovarian cancer. We describe an alternative approach with strut resection, less invasive than filter removal, enabling the device to be maintained and bleeding to be controlled.

Resumo Relatamos um caso de perfuração de veia cava inferior imediatamente após o implante de um filtro. A complicação foi reconhecida no intraoperatório de uma laparotomia para ressecção de um câncer de ovário localmente avançado. Descrevemos uma abordagem alternativa, menos invasiva do que a remoção do filtro, consistindo na ressecção das hastes do dispositivo. Essa abordagem permitiu a manutenção do filtro e o controle efetivo do sangramento.