Purpose Periprosthetic joint infections induced by methicillin-resistant Staphylococcus aureus (MRSA) pose a major socioeconomic burden. Given the fact that MRSA carriers are at high risk for developing periprosthetic infections regardless of the administration of eradication treatment pre-operatively, the need for developing new prevention modalities is high. Methods The antibacterial and antibiofilm properties of vancomycin, Al 2 O 3 nanowires, and TiO 2 nanoparticles were evaluated in vitro using MIC and MBIC assays. MRSA biofilms were grown on titanium disks simulating orthopedic implants, and the infection prevention potential of vancomycin-, Al 2 O 3 nanowire-, and TiO 2 nanoparticle-supplemented Resomer® coating was evaluated against biofilm controls using the XTT reduction proliferation assay. Results Among the tested modalities, high- and low-dose vancomycin-loaded Resomer® coating yielded the most satisfactory metalwork protection against MRSA (median absorbance was 0.1705; [IQR = 0.1745] vs control absorbance 0.42 [IQR = 0.07]; p = 0.016; biofilm reduction was 100%; and 0.209 [IQR = 0.1295] vs control 0.42 [IQR = 0.07]; p < 0.001; biofilm reduction was 84%, respectively). On the other hand, polymer coating alone did not provide clinically meaningful biofilm growth prevention (median absorbance was 0.2585 [IQR = 0.1235] vs control 0.395 [IQR = 0.218]; p < 0.001; biofilm reduction was 62%). Conclusions We advocate that apart from the well-established preventative measures for MRSA carriers, loading implants with bioresorbable Resomer® vancomycin-supplemented coating may decrease the incidence of early post-op surgical site infections with titanium implants. Of note, the payoff between localized toxicity and antibiofilm efficacy should be considered when loading polymers with highly concentrated antimicrobial agents.

Early failure of silicone voice prostheses resulting from fungal colonization and biofilm formation poses a major concern in modern ear nose throat surgery. Therefore, developing new infection prevention techniques to prolong those implants' survivorship is crucial. We designed an in vitro laboratory study to include nanomaterial-enhanced polymer coating with a plasma spraying technique against Candida albicans growth to address this issue. The anti-biofilm effects of high- and low-dose Al2O3 nanowire and TiO2 nanoparticle coatings were studied either alone or in conjunction with each other using checkerboard testing. It was demonstrated that both nanomaterials were capable of preventing fungal biofilm formation regardless of the anti-fungal agent concentration (median absorbance for high-dose Al2O3-enhanced polymer coating was 0.176 [IQR = 0.207] versus control absorbance of 0.805 [IQR = 0.381], p = 0.003 [98% biofilm reduction]; median absorbance for high-dose TiO2-enhanced polymer coating was 0.186 [IQR = 0.024] versus control absorbance of 0.766 [IQR = 0.458], p < 0.001 [93% biofilm reduction]). Furthermore, synergy was revealed when the Bliss model was applied. According to the findings of this work, it seems that simultaneous consideration of Al2O3 and TiO2 could further increase the existing antibiofilm potential of these nanomaterials and decrease the likelihood of localized toxicity.

Ultrafast laser patterning is an essential technology for the low-cost and large area production of flexible Organic Electronic (OE) devices, such as Organic Photovoltaics (OPVs). In order to unleash the potential of ultrafast laser processing to perform the selective and high precision removal of complex multilayers from printed OPV stacks without affecting the underlying nanolayers, it is necessary to optimize its parameters for each nanolayer combination. In this work, we developed an efficient on-the-fly picosecond (ps) laser scribing process (P1, P2 and P3) using single wavelength and single step/pass for the precise and reliable in-line patterning of Roll-to-Roll (R2R) slot-die-coated nanolayers. We have investigated the effect of the key process parameters (pulse energy and overlap) on the patterning quality to obtain high selectivity on the ablation of each individual nanolayer. Finally, we present the implementation of the ultrafast laser patterning process in the manufacturing of fully R2R printed flexible semitransparent OPV modules with a 3.4% power conversion efficiency and 91% Geometric Fill Factor (GFF).

The number of patients in need of a total hip replacement is increased constantly. However, infections and acute-chronic inflammations associated with implants are considered to be two of the major causes of implant failure after an invasive orthopedic surgery. In this work, a drug delivery nanoplatform system was fabricated of vancomycin loaded polycaprolactone scaffolds and dexamethasone loaded cellulose acetate scaffolds via dual syringe electrospinning system. Scanning electron microscopy applied to prove the scaffolds' successful fabrication. The controllable release of both drugs assessment and the mass loss estimation were examined through drug release kinetics and degradation studies, respectively. In vitro investigation of non-woven fibrous meshes-coated titanium implants took place and showed good cell adhesion and proliferation. Due to the results, these drug delivery nanoplatforms may be a promising approach, to prevent and treat not only orthopedic implant-associated infections, but also acute and chronic inflammations.

Purpose Even though effective techniques in diagnosis of periprosthetic joint infections (PJIs) have been developed, the optimal modality has yet to be determined. The present meta-analysis aimed to compare the diagnostic accuracy of dithiothreitol (DTT) and sonication against the Musculoskeletal Infection Society criteria in patients undergoing revision joint surgery. Methods We searched the PubMed, Scopus, and Central Cochrane register of controlled trials as well as gray literature until the 9th of November, 2021. We included articles considering the comparative diagnostic accuracy of sonication and DTT in adult patients having revision hip and knee arthroplasty for septic or aseptic reasons. We calculated pooled sensitivity, specificity, and diagnostic accuracy of the above diagnostic techniques against the Musculoskeletal Infection Society (MSIS) criteria and created receiver operating characteristics (ROC) curves to enable comparisons between each other. The quality of included papers was evaluated utilizing QUADAS-2 and QUADAS-C tools. Results Data from five comparative studies totaling 726 implants were pooled together. The diagnostic accuracy of DTT and sonication were 86.7% (95% CI 82.7 to 90.1) and 83.9% (95% CI 79.7 to 87.5), respectively. Pooled sensitivity and specificity showed no statistically significant differences between DTT and sonication (0.7 [95% CI 0.62 to 0.77] vs 0.72 [95% CI 0.65 to 0.78], p = 0.14; and 0.99 [95% CI 0.97 to 1] vs 0.97 [95% CI 0.93 to 0.99], p = 5.5, respectively). Conclusions This meta-analysis did not identify any clinically meaningful difference between the diagnostic potential of sonication and the chemical-based biofilm dislodgment methods. This finding remained robust after adjusting for the administration of antibiotics prophylaxis, implementation of the polymerase chain reaction of sonicated fluid, and study quality.

In the present study, spray-coated blends of 6,13-Bis(triisopropylsilylethynyl)pentacene (TIPS-PEN) with Polystyrene (PS) insulating polymer were employed to improve the performance of spray-coated neat TIPS-PEN Organic Field-Effect Transistors (OFETs) on plastic substrates. By combining TIPS-PEN with PS insulating polymer, control over the TIPS-PEN crystallization behavior can be achieved. A surface morphology study on the TIPS-PEN blended with PS films at an optimized weight ratio of 0.8:0.2 was carried out, in order to investigate the phase separation phenomena between the two components within the blend. The crystallinity and the crystalline characteristics of the sprayed TIPS-PEN:PS blend films were also investigated and compared to those of the sprayed neat TIPS-PEN films. Finally, these improved characteristics of the blend-based films are correlated with the extracted electrical parameters (mobility value, on/off current ratio, threshold voltage value) of the sprayed TIPS-PEN:PS blend OFETs and are compared with those of the sprayed neat TIPS-PEN OFETs, both in terms of values and inter-device uniformity.

In this work, the optical properties of red-light emitting materials used for active layers in functional red OLED devices were researched. The investigated materials are: a synthesized lab scale complex vinyl-quinoline pyridine homopolymer with Ir P[QPy-Ir-(PPy)2], as well as two commercially supplied materials, Poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV). The samples were spin-coated on ITO/glass substrates. The characterization of the materials was carried out via Spectroscopic Ellipsometry (SE), Photoluminescence Spectroscopy (PL) and Electroluminescence Spectroscopy (EL). Through SE analysis the film thickness, the optical properties and the dielectric function were obtained. PL and EL spectra were derived and evaluated in terms of the emission profile and characteristics of the different photoactive materials. Finally, the colour stability and selectivity of each material were determined, and a comparative study of the red-light emitting materials was conducted.

Nowadays, the most common revascularization procedure to combat coronary artery disease is through Percutaneous Coronary Intervention (PCI) with the use of arterial stents. Two of the most recurrent drawbacks of stenting are restenosis and late stent thrombosis. To render the stent effective, a long-term antiplatelet drug delivery system have to be incorporated into a biodegradable polymer to target directly the malevolent site. A novel drug delivery nanosystem of Poly(D, L-lactic acid) (PLA) nanoparticles (NPs) loaded with Dipyridamole (DPM) was fabricated via electrospraying that forms monodispersed, biodegradable drug loaded NPs, as coating for cardiovascular stents. This study presents a feasible degradable NP delivery system that encapsulates, protects and controls the release of DPM, intended to reduce the possibility of thrombosis inside the stent.

Flexible Organic Field-Effect Transistors (OFETs) constitute nowadays a highly promising field of the organic and printed electronics due to their multiple applications (flexible displays, sensors etc.). However, their cost-effective fabrication by large area Roll-to-Roll compatible printing methods still remains a challenge for their integration to commercial products. In this work, the moderate speed (1 m/min) process of the flexible cross-linked Poly(4-vinyl phenol) (PVP) polymer gate dielectric layer was carried out by integrating a slot-die method that mimics the Roll-to-Roll (R2R) coating conditions, in combination to an airbrush spray method for the solution-processing of the 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-PEN) organic semiconductor. Particularly, the PVP dielectric was slot-die-coated over a 90 x 15 cm(2) substrate, while subsequently the TIPS-PEN semiconductor was sprayed onto the 15 x 20 mm(2) cPVP-patterned plastic substrates. A surface investigation study on the well-formed slot-die-coated cPVP strips was conducted, revealing desirable dielectric film topography as a result of the good control over the coating process. A detailed analysis of the cPVP thickness evolution along the 90 x 1.3 cm(2) patterned stripe, was carried out. The morphological analysis of the sprayed TIPS-PEN layer over the cPVP film revealed well-organized large crystalline domains across the channel area, as a result of the sufficient crystallization time and the excellent cPVP surface morphology. The fabricated bottom gate/top contact flexible OFETs exhibited excellent I-V electrical characteristics with a maximum mobility of 0.21 cm(2)/V, negligible hysteresis, low threshold voltages (average value of - 0.1 V) and on/off current ratios in the range of 10(3) to > 10(4). These results demonstrate the potentiality of the proposed scalable methods for the large scale fabrication of high performance low-cost OFET devices.

Cardiovascular diseases constitute a major public health concern in industrialized nations. Oxidative stress induced free radicals play a critical role in cellular processes implicated in atherosclerosis and many other heart diseases. Quercetin (Qu) is an antioxidant drug which is shown that effectively protects against cardiovascular diseases (CVDs). Encapsulation of drugs in polymeric NPs are widely used in producing sustained and controllable drug release, or to avoid degradation of non-released drugs. In this current work, a novel system of polymeric PLGA NPs loaded with Qu, was fabricated via electrohydrodynamic atomization process (EHDA) in order to improve poor aqueous solubility and stability of the drug with the aim of preventing atherosclerosis. The fabricated nanoparticles collected in a stable glass substrate. The results of atomic force microscopy (AFM) analysis and the scanning electron microscope (SEM), confirmed the fabrication of spherical polymeric nanoparticles with diameter ranging from 300nm to350 nm, narrow size distribution and smooth surface. The release profile of quercetin from the particles was investigated by determining the drug amount released at specific intervals for by luminescence. Furthermore, XRD analysis was used to determine the physical status of Qu encapsulated in NPs compared with that of pure Qu. The information obtained from this study facilitates the design and fabrication of polymeric nanoparticles as possible delivery systems for encapsulation, protection and controlled release of the flavonoid quercetin which is aiming to protect against CVDs.

The impressive increase of power conversion efficiency of hybrid perovskites within a few years has made perovskites one of the most promising materials for photovoltaic applications. However, the route to their commercialization necessitates the establishment of reliable and reproducible large-area fabrication of high efficient perovskite-based solar cells. In this paper, we report the fabrication of flexible, printed, lead acetate - based perovskite solar cells under ambient conditions by slot-die coating. The adoption of lead acetate as a precursor ensured the fast crystallization of the perovskite by one-step deposition method, without a further annealing step, suggesting a rapid and low-temperature procedure. The optimization of the processing temperature and the thickness of PCBM layer were proved to be key factors for device performance. The crystal formation of perovskite was confirmed by X-Ray Diffraction and the thickness values of each layer of the inverted device structure were derived by Spectroscopic Ellipsometry. Moreover, Atomic Force Microscopy verified the low value of roughness of perovskite film along with the effective planarization of PC60BM layer. Finally, we report a reproducible, scalable, Roll-to-Roll compatible fabrication process of efficient perovskite solar cells exhibiting performance up to 6.5%.

Perovskite based solar cells (PSCs) have attracted a huge scientific interest due to their high power conversion efficiencies (PCE) reached already over 20%. However, for solution processed perovskite photovoltaics there are several issues like for i.e. ink concentration, deposition process, temperature, humidity of the environment, etc that have to be addressed in order to obtain devices with high efficiencies and reproducibility of the fabrication process. In addition, it seems that perovskite based photovoltaics will be a very challenging topic for the future, especially for large scale roll-to-roll (R2R) printed PSCs. In this work, a systematic investigation of the morphological and the structural features of perovskite based thin films has been performed. Initially, spin coated devices have been fabricated and characterised (scanning electron microscopy-SEM, X-Ray diffraction-XRD, Photoluminescence-PL) using methylammonium iodide (MAI) mixed with lead acetate (PbAc2) in dimethylformamide (DMF) as the perovskite precursor ink. The same ink was used also for printing a perovskite layer in ambient atmosphere by slot die coating. Perovskite devices by spin coating have been reached a PCE of 9.4%, while very important has been found to be the thickness of the PCBM layer that from 2000 rpm to 4000 rpm affected the device performance from 4.58% to 9.4%. XRD, SEM and PL have been found to give valuable structural and morphological information, and revealed the optimum experimental parameters for the perovskite absorber formation for high performance operating devices. Printing of Perovskite thin films has been performed with slot die and morphological analysis has been performed to fully realise the perovskite crystallisation process and reveal the optimum conditions for future fully printed PSCs. (C) 2017 Elsevier Ltd. All rights reserved.

Bacterial infections are a leading cause of death for millions of people worldwide, while few antibiotics have been proved effective against multidrug-resistant bacteria. Recently, nanoparticles have been used for the delivery of therapeutic agents to reduce bacterial infections due to their antimicrobial activity and unique mode of action. In our studies, silver nanoparticles (Ag NPs) have been used in order to meddle with associated infections for orthopaedic applications, due to their unique morphology and size. Nanoprecipitation method was used for the development of the NPs, using PVP (polyvinylpyrrolidone) as a reducing agent. Chitosan was used as a stabilizing and a coating agent at different concentrations (0.1%, 0.01% and 0.001%) in order to evaluate the most optimum capped coating. Atomic Force Microscopy (AFM) was the appropriate indicator for the morphological and topography analysis. Results showed that chitosan-capped NPs with 0.01% were found to be the most optimum. Transmittance measurements at plasmon emission at ∼320nm wavelength have showed Ag nanoparticles which were identified due to the sharp absorption peak. Variations of the absolute transmittance values due to the different thickness of the samples confirmed the coating of chitosan in Ag NPs. XRD measurements further took place and successfully have indicated the presence of chitosan in Ag nanoparticles’ surface. Electrospinning System was used for the formation of PCL (poly-ε-caprolactone) scaffolds where Ag NPs were deposited via Electrospraying System. The final scaffolds were then studied with AFM and SEM (Scanning Electron Microscopy) Images. As a conclusion, the fabricated Ag NPs into polymer scaffolds appeared to be a valuable tool with antibacterial properties towards implant-associated orthopedic infections.

Due to the increasing demand of alternative energy resources, considerable research interest has been devoted for the development of new thermoelectric materials. Thermoelectric materials are potential candidates for harvesting green energy, due to their ability to generate voltage upon exposure to a temperature difference. Herein, an interesting material used for engineering applications; glass fibers (GFs), were chemically grafted with single- and multi-wall carbon nanotubes (MWCNTs, SWCNTs) and utilized as flexible thermoelectric power generators. CNT-networks were covalently attached onto the surface of intrinsically insulating glass fiber yarns (GF-yarns) following a dip-coating deposition process. The fiber/CNT functional hierarchical yarns showed a maximum power factor (PF) of ∼109.8 μW/mK-2 (GF-SWCNT). The PF values were found in general to be increased with the increased amount of CNTs grafted onto the fiber surface. The idea of fiber/CNT structures for thermal energy harvesting could be further applied to several consumer applications, such as to smart textiles for wearable applications with the potential of harvesting thermal energy.

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is among the most widely used polymers that are used as printed transparent electrodes for flexible Organic Electronic (OE) devices, such as Organic Photovoltaics (OPVs). The understanding of their optical properties and the correlation of the optical properties with their electronic properties and metallic-like behavior can lead to the optimization of their functionality as transparent electrodes in multilayer OE device architectures. In this work, we study the optical properties of different PEDOT:PSS formulations by non-destructive Spectroscopic Ellipsometry (SE), from the infrared to the far ultraviolet spectral regions. The optical response of PEDOT:PSS includes an intense optical absorption originated from the conductive part (PEDOT) at lower photon energies, whereas the electronic transition energies of the non-conductive PSS part have been measured at higher photon energies. Based on the different PEDOT:PSS formulations, the optical investigation revealed significant information on the relative contribution of conductive PEDOT and insulating PSS parts of the PEDOT:PSS formulation in the overall optical response, which can strongly impact the final device functionality and its optical transparency.

In the present study we focus on the optimization of NP concentration of ZnO used as an ETL for the fabrication of fully printed inverted OPVs by lab-scale Sheet-to-Sheet gravure technique. The inverted OPV architecture consistσ of the layer sequence: PET/ITO/ZnO/P3HT:PCBM/PEDOT:PSS/Ag. By diversifying ZnO nanoparticle concentration, we track the optimum concentration for better OPV efficiencies and try to correlate concentration to the electrical characteristics of the OPV and other ETL characteristics such as thickness, surface morphology and roughness, hydrophilicity etc. Further goal of this work is to achieve a cost-efficient scalability of flexible organic photovoltaics (OPVs), the optimization of the ZnO NPs and of the printing processes.

We report on a simple and scalable process for the synthesis of core-shell Au@Ag (Gold core @ Ag shell) bimetallic plasmonic nanoparticles (NPs) with an average size in the range of 40 nm, endowing a remarkable improvement of the power conversion efficiency (PCE) of air processed organic photovoltaics (OPVs) upon being deposited onto the active layer. The beauty of the current work lies on the fact that the spin coated OPV devices; exhibiting a normal architecture consisting of a Glass/ITO (Indium Tin Oxide) anode, a poly-3,4-ethylenedioxy-thiophene: poly(styrenesulfonic-acid) (PEDOT:PSS) hole transport layer (HTL), a poly(3-hexylthiophene) (P3HT) and methanofullerene derivative (PCBM) bulk heterojunction (BHJ) photoactive blend layer (P3HT: PCBM), a Au@Ag plasmonic NPs layer, a Calcium (Ca) electron transport layer (ETL), and an Aluminium (Al) cathode, were processed in ambient conditions. The plasmonic NP layer, which was deposited onto the active layer after a short period of O-2 plasma treatment to enhance the adhesion of the water based NP dispersion (limited time of plasma treatment for 20 sec at a pressure of 1.12 mbar and at 10 Watts power), resulted in a 20.1% enhancement of the PCE compared to reference devices. Namely, the PCE was enhanced from 2.24 to 2.69%. The spin coating parameters for the optimum film morphology, thickness, optical properties, etc of all the OPV layers, as well as the desirable morphology at the nanometer scale of the BHJ have been followed according to previous established protocols. Ultraviolent visible (UV-vis) spectroscopy demonstrated the localised surface plasmon resonance (LSPR) peak of the plasmonic NPs. Scanning and transmission electron microscopy (SEM, TEM) depicted the distribution and the surface coverage of Au@Ag NPs above the active layer as well as their geometry and size, respectively. This study shows for the first time the utilization of plasmonic NPs as a means to improve the PCE of air processed OPVs, which is known to get deteriorated by ambient conditions processing. (C) 2016 Elsevier Ltd. All rights reserved.

A novel approach for the fabrication of flexible organic photovoltaic (OPV) modules with an inverted architecture by gravure printing process is presented. The printing has been carried out using a sheet-to-sheet (S2S) lab scale proofer, while all the printing steps were performed in ambient conditions and optimized for each of the OPV layers. Commercially available Zinc Oxide (ZnO) ink was used as the electron transport (ETL) layer, poly(3-hexylthiophene):[6,6]-phenyl C61 butyric acid methyl ester (P3HT:PCBM) blend comprised the bulk heterojunction (BHJ) photoactive layer, poly-3,4-ethylenedioxy-thiophene:poly(styrenesulfonic-acid) (PEDOT:PSS) was used as the hole transport layer (HTL), and silver (Ag) nanoparticle (NP) ink was used as the top contact electrode. The four OPV layers have been successively printed on indium tin oxide (ITO) coated polyethylene terephthalate (PET) flexible substrate using the same printing parameters. The OPV modules have size of 45 cm2 with an active area of 8 cm2 composed of 8 interconnected cells and exhibited a maximum power conversion efficiency (PCE) of over 2%. The printing parameters were optimized by the contribution of extensive morphological characterization by scanning and transmission electron microscopy (SEM, TEM), as well as from Spectroscopic Ellipsometry (SE) for the determination of the printed layers thickness, optical properties and photoactive layer blend morphology. The above approach reveals the required printing parameters for large-scale manufacturing of flexible OPVs by a R2R process.

In this work, we describe a novel approach for the fabrication of flexible organic photovoltaic (OPV) modules with an inverted architecture by a versatile and scalable gravure printing process. The printing has been carried out using a sheet-to-sheet (S2S) lab scale proofer, while all the printing steps were performed in ambient conditions and were optimized for each of the OPV layers. Commercially available zinc oxide (ZnO) ink was used as the electron transport (ETL) layer, poly(3-hexylthiophene):[6,6]-phenyl C61 butyric acid methyl ester (P3HT:PCBM) blend comprised the bulk heterojunction (BHJ) photoactive layer, poly-3,4-ethylenedioxy-thiophene:poly(styrenesulfonic-acid) (PEDOT:PSS) was used as the hole transport layer (HTL), and silver (Ag) nanoparticle ink was used as the top contact electrode. The four OPV layers have been successively printed on indium tin oxide (ITO) coated polyethylene terephthalate (PET) flexible substrate using the same printing parameters, allowing the high production throughput in a roll-to-roll (R2R) printing process. The printed OPV modules have size of 45cm2 with an active area of 8cm2 composed of 8 interconnected cells and exhibited a maximum power conversion efficiency (PCE) of 2.22%. The printing parameters were optimized by the contribution from extensive morphological characterization carried out by scanning and transmission electron microscopy (SEM, TEM), as well as from Spectroscopic Ellipsometry (SE) for the determination of the printed layers thickness, optical properties and photoactive layer blend morphology. The above approach revealed the required printing parameters for the further optimization of the layer interface, morphology, thickness and substrate properties in order to implement the above methodology for large-scale manufacturing of flexible OPVs by a R2R process.