Fast one-pot microwave-assisted green synthesis of highly fluorescent plant-inspired S,N-self-doped carbon quantum dots as a sensitive probe for the antiviral drug nitazoxanide and hemoglobin

In this study, we report a one-pot, green, cost-efficient, and fast synthesis of plant-based sulfur and nitrogen self-co-doped carbon quantum dots (S,N-CQDs). By 4-min microwave treatment of onion and cabbage juices as renewable, cheap, and green carbon sources and self-passivation agents, blue emissive S,N-CQDs have been synthesized (λex/λem of 340/418 nm) with a fluorescence quantum yield of 15.2%. A full characterization of the natural biomass-derived quantum dots proved the self-doping with nitrogen and sulfur. The S,N-CQDs showed high efficiency as a fluorescence probe for sensitive determination of nitazoxanide (NTZ), that recently found wide applicability as a repurposed drug for COVID-19, over the concentration range of 0.25–50.0 μM with LOD of 0.07 μM. The nanoprobe has been successfully applied for NTZ determination in pharmaceutical samples with excellent % recovery of 98.14 ± 0.42. Furthermore, the S,N-CQDs proved excellent performance as a sensitive fluorescence nanoprobe for determination of hemoglobin (Hb) over the concentration range of 36.3–907.5 nM with a minimum detectability of 10.30 nM. The probe has been applied for the determination of Hb in blood samples showing excellent agreement with the results documented by a medical laboratory. The greenness of the developed probe has been positively investigated by different greenness metrics and software. The green character of the proposed analytical methods originates from the synthesis of S,N-CQDs from sustainable, widely available, and cheap plants via low energy/low cost microwave-assisted technique. Omission of organic solvents and harsh chemicals beside dependence on mix-and-read analytical approach corroborate the method greenness. The obtained results demonstrated the substantial potential of the synthesized green, safe, cheap, and sustainable S,N-CQDs for pharmaceutical and biological applications. © 2022 Elsevier B.V.

Covering the Broad Spectrum of Intelligent Systems: From Neuromorphic Engineering to Robotics

Table 1 Highly cited articles published in Advanced Intelligent Systems in 2019/2020 with more than 25 citations in 2021 (Web of Science, 13 December 2022) Article Title (Article Type) Authors (Corresponding*) DOI 2021 Citations Wearable and Stretchable Strain Sensors: Materials, Sensing Mechanisms, and Applications (Review) Hamid Souri*, Hritwick Banerjee, Ardian Jusufi, Norbert Radacsi, Adam A. Stokes, Inkyu Park, Metin Sitti, Morteza Amjadi* https://doi.org/10.1002/aisy.202000039 61 Robotics, Smart Wearable Technologies, and Autonomous Intelligent Systems for Healthcare During the COVID-19 Pandemic: An Analysis of the State of the Art and Future Vision (Essay) Mahdi Tavakoli*, Jay Carriere, Ali Torabi https://doi.org/10.1002/aisy.202000071 52 Soft Actuators for Soft Robotic Applications: A Review (Review) Nazek El-Atab, Rishabh B. Mishra, Fhad Al-Modaf, Lana Joharji, Aljohara A. Alsharif, Haneen Alamoudi, Marlon Diaz,Nadeem Qaiser, Muhammad Mustafa Hussain* https://doi.org/10.1002/aisy.202000128 35 Magnetic Actuation Systems for Miniature Robots: A Review (Review) Zhengxin Yang, Li Zhang* https://doi.org/10.1002/aisy.202000082 29 Artificial Intelligence and Machine Learning Empower Advanced Biomedical Material Design to Toxicity Prediction (Review) Ajay Vikram Singh*, Daniel Rosenkranz, Mohammad Hasan Dad Ansari, Rishabh Singh, Anurag Kanase, Shubham Pratap Singh, Blair Johnston, Jutta Tentschert, Peter Laux, Andreas Luch https://doi.org/10.1002/aisy.202000084 29 Complementary Metal-Oxide Semiconductor and Memristive Hardware for Neuromorphic Computing (Progress Report) Mostafa Rahimi Azghadi*, Ying-Chen Chen, Jason K. Eshraghian, Jia Chen,Chih-Yang Lin, Amirali Amirsoleimani, Adnan Mehonic, Anthony J. Kenyon, Burt Fowler, Jack C. Lee, Yao-Feng Chang* https://doi.org/10.1002/aisy.201900189 25 However, impact factor won't be the only metric reported by Wiley journals anymore. The scope of Advanced Intelligent Systems covers timely topics that are not only of interest to scientists and engineers but are also closely followed by the general public. Since the launch of the journal, several papers published in the journal have been highlighted by social media platforms and news outlets. Table 2 Papers published in 2022 with an Altmetric score above 40 (Altmetric, 13 Dec 2022) Article Title Authors (Corresponding*) DOI Altmetric Score An Autonomous Chemically Fueled Artificial Protein Muscle Matthias C. Huber, Uwe Jonas, Stefan M. Schiller* https://doi.org/10.1002/aisy.202100189 189 Neuromorphic Metamaterials for Mechanosensing and Perceptual Associative Learning Katherine S. Riley, Subhadeep Koner, Juan C. Osorio, Yongchao Yu, Harith Morgan, Janav P. Udani, Stephen A. Sarles*, Andres F. Arrieta* https://doi.org/10.1002/aisy.202200158 178 All-Electric Nonassociative Learning in Nickel Oxide Sandip Mondal*, Zhen Zhang, A. N. M. Nafiul Islam, Robert Andrawis, Sampath Gamage, Neda Alsadat Aghamiri, Qi Wang, Hua Zhou, Fanny Rodolakis, Richard Tran, Jasleen Kaur, Chi Chen, Shyue Ping Ong, Abhronil Sengupta, Yohannes Abate, Kaushik Roy, Shriram Ramanathan https://doi.org/10.1002/aisy.202200069 110 Autonomous Nanocrystal Doping by Self-Driving Fluidic Micro-Processors Fazel Bateni, Robert W. Epps, Kameel Antami, Rokas Dargis, Jeffery A. Bennett, Kristofer G. Reyes, Milad Abolhasani* https://doi.org/10.1002/aisy.202200017 61 Overcoming the Force Limitations of Magnetic Robotic Surgery: Magnetic Pulse Actuated Collisions for Tissue-Penetrating-Needle for Tetherless Interventions Onder Erin*, Xiaolong Liu, Jiawei Ge, Justin Opfermann, Yotam Barnoy, Lamar O. Mair, Jin U. Kang, William Gensheimer, Irving N. Weinberg, Yancy Diaz-Mercado, Axel Krieger* https://doi.org/10.1002/aisy.202200072 43 Our promotional activities to enhance the visibility of the journal and its papers continued in 2022.

Buriti oil and natural surfactant improve the properties of cassava starch and carboxymethylcellulose films

Due to the environmental problem related to the disposal of non-biodegradable packaging and its aggravation during the COVID-19 pandemic, buriti oil (BO) and Yucca schidigera (YS) surfactant were added to the cassava starch and carboxymethyl-cellulose films to create a new emulsified biofilm with better properties. The influence of BO and YS on mechanical and barrier properties was evaluated. All properties differed significantly (p < 0.05) compared to the base film. Incorporation of BO and YS increased tensile strength by 1.100% and opacity by 375% and reduced elongation. In addition, the two variables generated a reduction in water vapour permeability (similar to 47%) and water solubility (similar to 70%), making the films less hydrophilic. Both attenuated total reflectance (ATR)-Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were able to generate important correlations, observing the effects of BO and YS on the uniformity and cohesion of the structures of the emulsified films. Overall, the emulsified films showed great potential for application as primary and/or secondary packaging.

N-Doped Carbon Quantum Dots for Differential Detection of Doxycycline in Pharmaceutical Sewage and in Bacterial Cell

For the past two years, doxycycline has been employed hugely for the treatment of COVID 19 over the globe. Excessive use of doxycycline can result in bacteria and gene resistance, which affects the future treatment of infectious diseases. Furthermore, unused doxycycline left from the hospital and pharmaceutical industries may have an adverse effect on the environment, posing a significant menace to modern society. As a result, doxycycline detection is required. Herein, we developed blue luminous nitrogen-doped carbon quantum dots (N-CQDs) using ascorbic acid and diethylenetriamine (DETA) as carbon and nitrogen sources via a microwave-assisted technique for the differential detection of doxycycline (DC) via a fluorescence quenching mechanism, even when other tetracycline derivatives interfere. The quenching mechanism has been elaborately explained by using a Stern-Volmer plot, UV-vis and fluorescence spectroscopy, and TCSPC to attribute the static quenching and inner filter effect. In addition, the limit of detection of our suggested sensor is 0.25 μM. To confirm the structural properties and the size of the N-CQDs, FT-IR, Raman spectroscopy, HRTEM, DLS, and EDX have been performed. Moreover, this approach was used to identify doxycycline in pharmaceutical waste and bacterial cells. Because of its great sensitivity and selectivity, N-CQDs are ideal for measuring DC in environmental applications. © 2022 American Chemical Society. All rights reserved.

Recent Advances in Metal Chalcogenide Quantum Dots: From Material Design to Biomedical Applications

With the rapid progress in nanomaterials and biochemistry, there has been an explosion of interest in biomolecule-modified quantum dots (QDs) for biomedical applications. Metal chalcogenide quantum dots (MCQDs), as the most widely studied QDs, have attracted tremendous attention in the biomedical field on account of their unique and excellent optical properties and the ease of biomolecular modifications. Herein, important advances in MCQDs over recent years are reviewed, from materials design to biomedical applications. Especially, this review focuses on the challenges encountered in the applications of MCQDs in biomedical fields and how these problems can be solved by rational design of synthesis methods and modifications, which have opened a universal route to develop the functionalized MCQDs. Moreover, recent processes in bioimaging, biosensing, and cancer therapy based on MCQDs are examined, including the rapid detection and diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This review provides broad insights into MCQDs in the biomedical field and will inspire material researchers to develop MCQDs in the future.

Elucidating the neuropathophysiology of COVID-19 using quantum dot biomimetics of SARS-CoV-2

Quantum dots were encapsulated in polymeric phospholipid micelles conjugated to multiple ligands of SARS-CoV-2 spike protein to form fluorescent biomimetic nanoparticles for SARS-CoV-2 (COVID-QDs). Phosphatidylethanolaminepolyethylene glycol (PE:PEG) was appended with bis(4-methylphenyl)sulfone to form PE:PEG:bis-sulfone and self-assembled into micelles around CdSe/CdS core/shell quantum dots via thin-film rehydration. The introduction of the bis-sulfone group the surface of the micelle-encapsulated quantum dots provides multiple sites for conjugation to his-tagged SARS-CoV-2 spike protein via a bisalkylation mechanism. Based on the eluted unconjugated fraction, we estimate that an average of seven spike proteins are conjugated per COVID-QD. We treated an in-vitro model system for the neurovascular unit (NVU) with these COVID-QD constructs to investigate the COVID-QDs, and by proxy SARS-CoV-2, may modulate the NVU leading to the COVID-19 associated neuropathophysiology. © 2022 SPIE

Biopolymeric sustainable materials and their emerging applications

Advancements in polymer science and engineering have helped the scientific community to shift its attention towards the use of environmentally benign materials for reducing the environmental impact of conventional synthetic plastics. Biopolymers are environmentally benign, chemically versatile, sustainable, biocompatible, biodegradable, inherently functional, and ecofriendly materials that exhibit tremendous potential for a wide range of applications including food, electronics, agriculture, textile, biomedical, and cosmetics. This review also inspires the researchers toward more consumption of biopolymer-based composite materials as an alternative to synthetic composite materials. Herein, an overview of the latest knowledge of different natural- and synthetic-based biodegradable polymers and their fiber-reinforced composites is presented. The review discusses different degradation mechanisms of biopolymer-based composites as well as their sustainability aspects. This review also elucidates current challenges, future opportunities, and emerging applications of biopolymeric sustainable composites in numerous engineering fields. Finally, this review proposes biopolymeric sustainable materials as a propitious solution to the contemporary environmental crisis. © 2022 Elsevier Ltd.

Graphite nanocrystals coated paper-based electrode for detection of SARS-Cov-2 gene using DNA-functionalized Au@carbon dot core-shell nanoparticles.

Currently, the development of biosensors is an urgent need due to the rapid spread of SARS-CoV-2 and the limitations of current standard methods for the diagnosis of COVID-19. Hence, many researchers have focused on the design of high-performance biosensors for measuring coronavirus genes. In this study, a voltammetric genosensor was developed for the determination of SARS-CoV-2 RdRP gene based on the format of cDNA probe/Au@CD core-shell NPs/graphite nanocrystals (GNCs)/paper electrode. For the first time, graphite nanocrystals were used in the electrochemical biosensor design. This genosensor was exposed to different concentrations of virus gene and then the hybridization between cDNA probe and RdRP gene was monitored by redox-active toluidine blue (TB). With increasing the RdRP concentration, the reduction peak current of TB enhanced in a linear range of 0.50 pM-12.00 nM according to the regression equation of I (µA) = 7.60 log CRdRP (pM) + 25.78. The repeatability with a RSD of 2.2% clearly exhibited that the response of modified electrode is stable because of the high adhesion of GNC layer on the paper substrate and the high stability of cDNA-Au@CD bioconjugates. The spike-and-recovery studies showed the acceptable recoveries for the sputum samples (>95%).

Poly(3-hydroxybutyrate) Nanocomposites with Cellulose Nanocrystals.

Poly(3-hydroxybutyrate) (PHB) is one of the most promising substitutes for the petroleum-based polymers used in the packaging and biomedical fields due to its biodegradability, biocompatibility, good stiffness, and strength, along with its good gas-barrier properties. One route to overcome some of the PHB's weaknesses, such as its slow crystallization, brittleness, modest thermal stability, and low melt strength is the addition of cellulose nanocrystals (CNCs) and the production of PHB/CNCs nanocomposites. Choosing the adequate processing technology for the fabrication of the PHB/CNCs nanocomposites and a suitable surface treatment for the CNCs are key factors in obtaining a good interfacial adhesion, superior thermal stability, and mechanical performances for the resulting nanocomposites. The information provided in this review related to the preparation routes, thermal, mechanical, and barrier properties of the PHB/CNCs nanocomposites may represent a starting point in finding new strategies to reduce the manufacturing costs or to design better technological solutions for the production of these materials at industrial scale. It is outlined in this review that the use of low-value biomass resources in the obtaining of both PHB and CNCs might be a safe track for a circular and bio-based economy. Undoubtedly, the PHB/CNCs nanocomposites will be an important part of a greener future in terms of successful replacement of the conventional plastic materials in many engineering and biomedical applications.

Needle-Free Jet Injectors and Nanosuspensions: Exploring the Potential of an Unexpected Pair.

Needle-free liquid jet injectors are medical devices used to administer pharmaceutical solutions through the skin. Jet injectors generate a high-speed stream of liquid medication that can puncture the skin and deliver the drug to the underlying tissues. In this work, we investigated the feasibility of using liquid jet injectors to administer nanosuspensions, assessing the impact of the jet injection on their pharmaceutical and physicochemical properties. For this purpose, the model drug diclofenac was used to prepare a set of nanosuspensions, stabilized by poloxamer 188, and equilibrated at different pHs. The hydrodynamic diameter and morphology of the nanocrystals were analyzed before and after the jet injection across porcine skin in vitro, together with the solubility and release kinetics of diclofenac in a simulated subcutaneous environment. The efficacy of the jet injection (i.e., the amount of drug delivered across the skin) was evaluated for the nanosuspension and for a solution, which was used as a control. Finally, the nanosuspension was administered to rats by jet injector, and the plasma profile of diclofenac was evaluated and compared to the one obtained by jet injecting a solution with an equal concentration. The nanosuspension features were maintained after the jet injection in vitro, suggesting that no structural changes occur upon high-speed impact with the skin. Accordingly, in vivo studies demonstrated the feasibility of jet injecting a nanosuspension, reaching relevant plasma concentration of the drug. Overall, needle-free jet injectors proved to be a suitable alternative to conventional syringes for the administration of nanosuspensions.

Evaluation of the multifunctional activity of silver bionanocomposites in environmental remediation and inhibition of the growth of multidrug-resistant pathogens

Synthesis of bio-based environmental remedial and antimicrobial products is an urgent need of the 21st century in the COVID-19 pandemic world. Keeping this in mind, cellulose-supported Ag bionanocomposites (AGC NCs) were synthesized by using cellulose as a reducing and stabilizing agent. AGC NCs showed potential antimicrobial activity against Candida albicans, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Bacillus subtilis with a MIC of 15, 15, 35, 15, and 30 mu g ml(-1) respectively. AGC NCs efficiently degraded harmful dyes, Orange G, Phenol red, Brilliant blue FCF, Giemsa stain, Neutral red, and 2-nitro aniline in the presence of sunlight with a rate constant of 0.229 x 10(-2) min(-1), 1.147 x 10(-2) L mol(-1) min(-1), 0.447 x 10(-2) L mol(-1) min(-1), 4.144 x 10(-2) mol L-1 min(-1), 0.317 x 10(-2) L mol(-1) min(-1), and 0.785 x 10(-2) L mol(-1) min(-1) in 60 min respectively. AGC NCs also showed efficient antioxidant activity in DPPH assay with an IC50 value of 52.67 mu g ml(-1). Formation of Ag NPs was confirmed by observing the UV-Visible absorption peak at 418 nm. The FCC structure of AGC NCs was confirmed by the X-ray diffraction (XRD) pattern with well-defined peaks at angles 38.24 degrees, 44.40 degrees, 64.64 degrees, and 77.28 degrees corresponding to the planes 111, 200, 220, and 311, with a d-spacing of 2.35, 2.04, 1.44, and 1.23 (JCPDS no. 00-001-1164). The presence of cellulose in AGC NCs was determined by Fourier transform infrared spectroscopy (FTIR) with bands at 3421.90 cm(-1) and 2899.3 cm(-1) due to O-H stretching and the methylene (-CH2-) group respectively and at 1076-1023 cm(-1) and 903 cm(-1) due to -C-O-C- pyranose ring skeletal vibration and beta-glycosidic linkages. The morphology, shape and size (13.21 nm), and elemental composition of the nanocomposites were determined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS) respectively. The thermal properties (exothermic peaks appear at 335 degrees C and 440 degrees C due to the thermal degradation of Ag NPs and cellulose respectively), surface area (13.892 m(2) g(-1)), stability (-18.43 +/- 0.850 mV), and hydrodynamic diameter (399.10 +/- 30.49 nm) and polydispersity index (PDI) value (0.565 +/- 0.193) of the composites were determined by thermogravimetric analysis (TGA) and differential thermal analysis (DTA), Brunauer-Emmett-Teller (BET) method, Zeta potential studies, and dynamic light scattering (DLS) respectively.

Nano-Glass Composite Scintillators: Opportunities and Challenges

Scintillators as the core materials of radiation detection play an important role in industrial nondestructive testing, medical imaging, high energy physics and safety inspection, etc.. Theexisting scintillator research faces both opportunities and challenges, especially in the context of COVID-19 pandemic period. It is of great practical significance to develop cost-effective scintillators and optimize their overall performance. The nano-glass composites (i.e., glass ceramics) have some advantages like high emission efficiency of scintillator crystals, simple preparation and low cost as an effective star scintillator. Based on the different luminescence centers, such scintillators can be broadly divided into rare-earth element ions doped or rare-earth-free luminescent nanocrystals embedded materials. This review represented recent development on the preparation of these materials, the relationship between the types of nanocrystals and their luminescence properties, and the potential applications of these materials in high-energy X-ray and gamma-ray detection. In addition, the existing problems in the research were discussed and the future development direction of nano-glass composite scintillators was also prospected. © 2022, Editorial Department of Journal of the Chinese Ceramic Society. All right reserved.

Nanocellulose-enabled Membranes in CO2 Gas Separation

Nanocellulose, a more advanced and fascinating form of cellulose has achieved enormous interest and attraction ubiquitously, in many new high-end applications of cellulose in fields as diverse as nanocomposites, biomaterials, cosmetics and medical devices, energy storage, sensing well as in gas-separation technology and many more. Currently, the world is not only facing pandemic COVID 19 but also climate crises such as tropical storms, hurricanes, heatwaves, flooding mostly are the impact of global warming caused by greenhouse gases. Carbon dioxide (CO2) is an important greenhouse gas that helps to trap heat in our atmosphere but its increased amount in the atmosphere cause global warming. Therefore, this review traces the developments in the nanocellulose-enabled membranes in CO2 gas separation. Nanocellulose possesses high surface area, tunable functionality, high strength, biocompatibility, biodegradability, and hydrophilicity, which provides a greener and sustainable substitute to synthetic polymeric membrane. Nanocellulose-enabled membrane in gas separation is an emerging but critical research topic in view of environmental concerns. This review briefly covers the cellulose nanoforms such as cellulose nanofibers (CNF), cellulose nanocrystals (CNC) and bacterial nanocellulose (BNC) and their utilization as a composite membrane and hybrid membrane for CO2 gas separation.

Structure and Properties of Copper Pyrophosphate by First-Principle Calculations.

Investigated the structural, electronic, and magnetic properties of copper pyrophosphate dihydrate (CuPPD) by the first-principle calculations based on the density functional theory (DFT). Simulations were performed with the generalized gradient approximation (GGA) of the exchange-correlation functional (Exc) supplemented by an on-site Coulomb self-interaction (U-Hubbard term). It was confirmed that the GGA method did not provide a satisfactory result in predicting the electronic energy band gap width (Eg) of the CuPPD crystals. Simultaneously, we measured the Eg of CuPPD nanocrystal placed inside mesoporous silica using the ultraviolet-visible spectroscopy (UV-VIS) technique. The proposed Hubbard correction for Cu-3d and O-2p states at U = 4.64 eV reproduces the experimental value of Eg = 2.34 eV. The electronic properties presented in this study and the results of UV-VIS investigations likely identify the semiconductor character of CuPPD crystal, which raises the prospect of using it as a component determining functional properties of nanomaterials, including quantum dots.

Soot-Based Reduced Graphene Quantum Dot/Hemin Conjugate for Favipiravir Sensing

A conjugated system was synthesized from reduced graphene quantum dot (rGQD) and hemin for the selective detection of favipiravir (Fav), an antiviral drug that has come into much attention during the year 2020 for its use as a drug against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The required rGQD was prepared from soot particles using Hummers' method followed by the amino-hydrothermal process. At the first step, its fluorescence was quenched by preparing the conjugate with hemin. Interestingly, the fluorescence intensity gradually increases (turn-on) with increasing concentration of Fav, and develops 9-fold higher fluorescence at 15.6 nM of Fav. The fluorescence enhancement is selective, and the limit of detection (LOD) was calculated to be about 1.96 nM. The fluorescence turn-on is governed by aggregation-induced emission (AIE), which originates from electrostatic interactions between the sensor-analyte systems. A similar fluorescence turn-on was observed for Fav in human blood plasma (BP) as well as in artificial urine (AU), which indicates that the sensor is viable in real-sample analysis. In addition to Fav, its 1:1 cocrystals with theophylline (Theo) and ferulic acid (FRA) also enhance the fluorescence in real samples with an LOD of 3.47 and 12.2 nM, respectively. Therefore, the cocrystals remain intact in biological medium and the sensor interacts with cocrystals too. The detection of Fav and its cocrystals, and the development of cocrystals as alternatives in the pharmaceutical industry, is essential considering the current COVID-19 pandemic worldwide. Therefore, the findings of this work will certainly help in developing fluorescence sensors for quantitative determination of active pharmaceutical ingredients (APIs) in real samples. © 2021 American Chemical Society.

Hyaluronic Acid-Dexamethasone Nanoparticles for Local Adjunct Therapy of Lung Inflammation.

The delivery of a dexamethasone formulation directly into the lung appears as an appropriate strategy to strengthen the systemic administration, reducing the dosage in the treatment of lung severe inflammations. For this purpose, a hyaluronic acid-dexamethasone formulation was developed, affording an inhalable reconstituted nanosuspension suitable to be aerosolized. The physico-chemical and biopharmaceutical properties of the formulation were tested: size, stability, loading of the spray-dried dry powder, reconstitution capability upon redispersion in aqueous media. Detailed structural insights on nanoparticles after reconstitution were obtained by light and X-ray scattering techniques. (1) The size of the nanoparticles, around 200 nm, is in the proper range for a possible engulfment by macrophages. (2) Their structure is of the core-shell type, hosting dexamethasone nanocrystals inside and carrying hyaluronic acid chains on the surface. This specific structure allows for nanosuspension stability and provides nanoparticles with muco-inert properties. (3) The nanosuspension can be efficiently aerosolized, allowing for a high drug fraction potentially reaching the deep lung. Thus, this formulation represents a promising tool for the lung administration via nebulization directly in the pipe of ventilators, to be used as such or as adjunct therapy for severe lung inflammation.

Polyvinyl alcohol/silver electrospun nanofibers: Biocidal filter media capturing virus-size particles.

In response to the nowadays battle against SARS-CoV-2, we designed a new class of high performant filter media suitable to advance the facemask technology and provide new efficient widespread solutions against virus propagation. By means of the electrospinning technology we developed filter media based on polyvinyl alcohol (PVA) nanofibers doped with AgNPs combining three main performance requirements: high air filtration efficiency to capture nanometer-size particles, low airflow resistance essential to ensure breathability and antimicrobial activity to inactivate aerosolized microorganisms. PVA/AgNPs electrospun nanofibers were produced by electrospinning the dispersion of colloidal silver into the PVA water solution. A widespread physicochemical characterization was addressed to the Ag colloidal suspension. The key functional performances of the electrospun nanofibers were proven by water stability, antibacterial activity, and filtration efficiency and pressure drop measurements performed under conditions representative of facemasks. We assessed a total bacterial depletion associated to a filtering efficiency towards nano-aerosolized particles of 97.7% higher than required by the EN149 standard and a pressure drop in line with FFP1 and FFP2 masks, even at the highest filtration velocity. Such results pave the way to the application of PVA/AgNPs electrospun nanofibers in facemasks as advanced filtering media for protecting against airborne microorganisms.