Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 26
Filter
1.
Drug Deliv ; 28(1): 856-864, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1947906

ABSTRACT

SARS-CoV-2 is a novel coronavirus that was isolated and identified for the first time in Wuhan, China in 2019. Nowadays, it is a worldwide danger and the WHO named it a pandemic. In this investigation, a functionalization post-synthesis method was used to assess the ability of an adapted SBA-15 surface as a sorbent to load the drug from an aqueous medium. Different characterization approaches were used to determine the characterization of the substance before and after functionalization such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), nitrogen adsorption-desorption porosimetry (Brunauer-Emmett-Teller) BET surface area analysis, and thermal gravimetric analysis (TGA). Batch adsorption testing was carried out in a single adsorption device to find the impact of multiple variables on the drug amoxicillin charge output. The following parameters were studied: 0-72 hr. contact time, 20-120 mg/l initial concentration, and 20-250 mg of NH2-SBA-15 dose. The outcomes from such experiments revealed the strong influence and behavior of the amino-functional group to increase the drug's load. Drug delivery outcomes studies found that amoxicillin loading was directly related to NH2-SBA-15 contact time and dose, but indirectly related to primary concentration. It was observed that 80% of amoxicillin was loaded while the best release test results were 1 hour and 51%.


Subject(s)
Amoxicillin/therapeutic use , COVID-19/drug therapy , Silicon Dioxide/chemistry , Amoxicillin/administration & dosage , Chemistry, Pharmaceutical , Dose-Response Relationship, Drug , Drug Delivery Systems , Humans , Microscopy, Electron, Scanning , Porosity , SARS-CoV-2 , Spectroscopy, Fourier Transform Infrared , Surface Properties , X-Ray Diffraction
2.
Sci Rep ; 12(1): 10693, 2022 Jul 01.
Article in English | MEDLINE | ID: covidwho-1915279

ABSTRACT

Infectious diseases are among the leading causes of mortality worldwide. A new coronavirus named severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) was identified in Wuhan, China in 2019, and the World Health Organization (WHO) declared its outbreak, coronavirus disease 2019 (COVID-19), as a global pandemic in 2020. COVID-19 can spread quickly from person to person. One of the most challenging issues is to identify the infected individuals and prevent potential spread of SARS-CoV-2. Recently, anti-SARS-CoV-2 immunoglobulin M (IgM) and immunoglobulin G (IgG) antibody tests using immunochromatographic methods have been used as a complement to current detection methods and have provided information of the approximate course of COVID-19 infection. However, blood sampling causes pain and poses risks of infection at the needle puncture site. In this study, a novel patch sensor integrating porous microneedles and an immunochromatographic assay (PMNIA) was developed for the rapid detection of anti-SARS-CoV-2 IgM/IgG in dermal interstitial fluid (ISF), which is a rich source of protein biomarkers, such as antibodies. Biodegradable porous microneedles (MNs) made of polylactic acid were fabricated to extract ISF from human skin by capillary effect. The extracted ISF was vertically transported and flowed into the affixed immunoassay biosensor, where specific antibodies could be detected colorimetrically on-site. Anti-SARS-CoV-2 IgM/IgG antibodies were simultaneously detected within 3 min in vitro. Moreover, the limit of detection of anti-SARS-CoV-2 IgM and IgG concentrations was as low as 3 and 7 ng/mL, respectively. The developed device integrating porous MNs and immunochromatographic biosensors is expected to enable minimally invasive, simple, and rapid anti-SARS-CoV-2 IgM/IgG antibody testing. Furthermore, the compact size of the MN and biosensor-integrated device is advantageous for its widespread use. The proposed device has great potential for rapid screening of various infectious diseases in addition to COVID-19 as an effective complementary method with other diagnostic tests.


Subject(s)
COVID-19 , Communicable Diseases , Antibodies, Viral , COVID-19/diagnosis , Enzyme-Linked Immunosorbent Assay , Humans , Immunoassay , Immunoglobulin G , Immunoglobulin M , Porosity , SARS-CoV-2
3.
IET Nanobiotechnol ; 16(3): 85-91, 2022 May.
Article in English | MEDLINE | ID: covidwho-1758388

ABSTRACT

Mesoporous magnetic nanoparticles of haematite were synthesised using plant extracts according to bioethics principles. The structural, physical and chemical properties of mesoporous Fe2 O3 nanoparticles synthesised with the green chemistry approach were evaluated by XRD, SEM, EDAX, BET, VSM and HRTEM analysis. Then, their toxicity against normal HUVECs and MCF7 cancer cells was evaluated by MTT assay for 48 h. These biogenic mesoporous magnetic nanoparticles have over 71% of doxorubicin loading efficiency, resulting in a 50% reduction of cancer cells at a 0.5 µg.ml-1 concentration. Therefore, it is suggested that mesoporous magnetic nanoparticles be used as a multifunctional agent in medicine (therapeutic-diagnostic). The produced mesoporous magnetic nanoparticles with its inherent structural properties such as polygonal structure (increasing surface area to particle volume) and porosity with large pore volume became a suitable substrate for loading the anti-cancer drug doxorubicin.


Subject(s)
Nanoparticles , Silicon Dioxide , Doxorubicin/chemistry , Doxorubicin/pharmacology , Drug Carriers/chemistry , Drug Delivery Systems/methods , Drug Liberation , Humans , Nanoparticles/chemistry , Porosity , Silicon Dioxide/chemistry
4.
Sci Total Environ ; 817: 152995, 2022 Apr 15.
Article in English | MEDLINE | ID: covidwho-1616761

ABSTRACT

With the spread of COVID-19, disposable medical masks (DMMs) have become a significant source of new hazardous solid waste. Their proper disposal is not only beneficial to the safety of biological systems but also useful to achieve considerable economic value. The first step of this study was to investigate the chemical composition of DMMs. It is primarily composed of polypropylene, polyethylene terephthalate and iron, with fibrous polypropylene accounting for approximately 80% of the total weight. Then, DMMs were sulfonated and oxidised by the microwave-driven concentrated sulfuric acid within 8 min based on the fact that the concentrated sulfuric acid exhibits a good microwave absorption capacity. The co-doping of sulfur and oxygen was achieved while improving the thermal stability of DMMs. Subsequently, the self-activation pyrolysis of sulfonated and oxidised DMMs (P-SO@DMMs) was further realized in low-flow-rate argon. The specific surface area of P-SO@DMMs increased from 2.0 to 830.9 m2·g-1. P-SO@DMMs sulfur cathodes have promising electrochemical properties because of their porous structures and the synergistic effect of sulfur and oxygen co-doping. The capacity of the samples irradiated by microwave for 10 min at 0.1, 0.2, 0.5, 1, 2 and 5 C were 1313.6, 1010.9, 816.5, 634.4, 513.4 and 453.1 mAh·g-1, respectively, and after returning to 0.2 C and continuing the cycle for 50 revolutions, maintained 50.5% of the initial capacity. After 400 cycles, its capacity is 38.1% of the initial capacity at 0.5 C. It is slightly higher than the electrochemical performance of the sample treated by microwave for 8 min and significantly higher than the sample treated by 6 min. This work converts structurally complex, biohazardous DMMs into porous carbon with high specific surface area by clean and efficient microwave solvothermal and self-activating pyrolysis, which facilitates the development of carbon based materials at low cost and large scale.


Subject(s)
COVID-19 , Lithium , Carbon/chemistry , Humans , Lithium/chemistry , Masks , Microwaves , Porosity , SARS-CoV-2 , Sulfur/chemistry
5.
J Occup Environ Hyg ; 19(2): 91-101, 2022 02.
Article in English | MEDLINE | ID: covidwho-1553668

ABSTRACT

This study evaluated the efficacy of detergent-based surface cleaning methods against Murine Hepatitis Virus A59 (MHV) as a surrogate coronavirus for SARS-CoV-2. MHV (5% soil load in culture medium or simulated saliva) was inoculated onto four different high-touch materials [stainless steel (SS), Acrylonitrile Butadiene Styrene plastic (ABS), Formica, seat fabric (SF)]. Immediately and 2-hr post-inoculation, coupons were cleaned (damp wipe wiping) with and without pretreatment with detergent solution or 375 ppm hard water. Results identified that physical removal (no pretreatment) removed >2.3 log10 MHV on ABS, SS, and Formica when surfaces were cleaned immediately. Pretreatment with detergent or hard water increased effectiveness over wet wiping 2-hr post-inoculation; pretreatment with detergent significantly increased (p ≤ 0.05) removal of MHV in simulated saliva, but not in culture media, over hard water pretreatment (Formica and ABS). Detergent and hard water cleaning methods were ineffective on SF under all conditions. Overall, efficacy of cleaning methods against coronaviruses are material- and matrix-dependent; pre-wetting surfaces with detergent solutions increased efficacy against coronavirus suspended in simulated saliva. This study provides data highlighting the importance of incorporating a pre-wetting step prior to detergent cleaning and can inform cleaning strategies to reducing coronavirus surface transmission.


Subject(s)
COVID-19 , Murine hepatitis virus , Animals , Detergents , Humans , Mice , Porosity , SARS-CoV-2
6.
Int J Mol Sci ; 22(23)2021 Nov 24.
Article in English | MEDLINE | ID: covidwho-1542582

ABSTRACT

COVID-19 pandemic and associated supply-chain disruptions emphasise the requirement for antimicrobial materials for on-demand manufacturing. Besides aerosol transmission, SARS-CoV-2 is also propagated through contact with virus-contaminated surfaces. As such, the development of effective biofunctional materials that can inactivate SARS-CoV-2 is critical for pandemic preparedness. Such materials will enable the rational development of antiviral devices with prolonged serviceability, reducing the environmental burden of disposable alternatives. This research reveals the novel use of Laser Powder Bed Fusion (LPBF) to 3D print porous Cobalt-Chromium-Molybdenum (Co-Cr-Mo) superalloy with potent antiviral activity (100% viral inactivation in 30 min). The porous material was rationally conceived using a multi-objective surrogate model featuring track thickness (tt) and pore diameter (ϕd) as responses. The regression analysis found the most significant parameters for Co-Cr-Mo track formation to be the interaction effects of scanning rate (Vs) and laser power (Pl) in the order PlVs>Vs>Pl. Contrastively, the pore diameter was found to be primarily driven by the hatch spacing (Sh). The study is the first to demonstrate the superior antiviral properties of 3D printed Co-Cr-Mo superalloy against an enveloped virus used as biosafe viral model of SARS-CoV-2. The material significantly outperforms the viral inactivation time of other broadly used antiviral metals such as copper and silver, as the material's viral inactivation time was from 5 h to 30 min. As such, the study goes beyond the current state-of-the-art in antiviral alloys to provide extra protection to combat the SARS-CoV-2 viral spread. The evolving nature of the COVID-19 pandemic brings new and unpredictable challenges where on-demand 3D printing of antiviral materials can achieve rapid solutions while reducing the environmental impact of disposable devices.


Subject(s)
Antiviral Agents/pharmacology , Chromium/pharmacology , Cobalt/pharmacology , Molybdenum/pharmacology , Printing, Three-Dimensional , Alloys , COVID-19 , Humans , Porosity , SARS-CoV-2/drug effects , Surface Properties , Virus Inactivation/drug effects
7.
Int J Nanomedicine ; 16: 6575-6591, 2021.
Article in English | MEDLINE | ID: covidwho-1533527

ABSTRACT

Public awareness of infectious diseases has increased in recent months, not only due to the current COVID-19 outbreak but also because of antimicrobial resistance (AMR) being declared a top-10 global health threat by the World Health Organization (WHO) in 2019. These global issues have spiked the realization that new and more efficient methods and approaches are urgently required to efficiently combat and overcome the failures in the diagnosis and therapy of infectious disease. This holds true not only for current diseases, but we should also have enough readiness to fight the unforeseen diseases so as to avoid future pandemics. A paradigm shift is needed, not only in infection treatment, but also diagnostic practices, to overcome the potential failures associated with early diagnosis stages, leading to unnecessary and inefficient treatments, while simultaneously promoting AMR. With the development of nanotechnology, nanomaterials fabricated as multifunctional nano-platforms for antibacterial therapeutics, diagnostics, or both (known as "theranostics") have attracted increasing attention. In the research field of nanomedicine, mesoporous silica nanoparticles (MSN) with a tailored structure, large surface area, high loading capacity, abundant chemical versatility, and acceptable biocompatibility, have shown great potential to integrate the desired functions for diagnosis of bacterial infections. The focus of this review is to present the advances in mesoporous materials in the form of nanoparticles (NPs) or composites that can easily and flexibly accommodate dual or multifunctional capabilities of separation, identification and tracking performed during the diagnosis of infectious diseases together with the inspiring NP designs in diagnosis of bacterial infections.


Subject(s)
Bacterial Infections , COVID-19 , Nanoparticles , Bacterial Infections/diagnosis , Bacterial Infections/drug therapy , Humans , Porosity , SARS-CoV-2 , Silicon Dioxide
8.
Biomolecules ; 11(11)2021 11 17.
Article in English | MEDLINE | ID: covidwho-1523862

ABSTRACT

Metal-organic frameworks (MOFs) have been widely used as porous nanomaterials for different applications ranging from industrial to biomedicals. An unpredictable one-pot method is introduced to synthesize NH2-MIL-53 assisted by high-gravity in a greener media for the first time. Then, porphyrins were deployed to adorn the surface of MOF to increase the sensitivity of the prepared nanocomposite to the genetic materials and in-situ cellular protein structures. The hydrogen bond formation between genetic domains and the porphyrin' nitrogen as well as the surface hydroxyl groups is equally probable and could be considered a milestone in chemical physics and physical chemistry for biomedical applications. In this context, the role of incorporating different forms of porphyrins, their relationship with the final surface morphology, and their drug/gene loading efficiency were investigated to provide a predictable pattern in regard to the previous works. The conceptual phenomenon was optimized to increase the interactions between the biomolecules and the substrate by reaching the limit of detection to 10 pM for the Anti-cas9 protein, 20 pM for the single-stranded DNA (ssDNA), below 10 pM for the single guide RNA (sgRNA) and also around 10 nM for recombinant SARS-CoV-2 spike antigen. Also, the MTT assay showed acceptable relative cell viability of more than 85% in most cases, even by increasing the dose of the prepared nanostructures.


Subject(s)
COVID-19/diagnosis , Metal-Organic Frameworks/chemistry , Porphyrins/chemistry , Animals , COVID-19 Testing , CRISPR-Cas Systems , DNA, Single-Stranded , HEK293 Cells , HeLa Cells , Hep G2 Cells , Humans , Hydrogen Bonding , Limit of Detection , Nanocomposites , Nanostructures , Nitrogen/chemistry , PC12 Cells , Porosity , RNA, Guide , RNA, Viral/metabolism , Rats , SARS-CoV-2 , Sensitivity and Specificity , Surface Properties
9.
N Biotechnol ; 66: 36-45, 2022 Jan 25.
Article in English | MEDLINE | ID: covidwho-1521430

ABSTRACT

The COVID-19 pandemic has generated a major need for non-destructive and environmentally friendly disinfection methods. This work presents the development and testing of a disinfection process based on gaseous ozone for SARS-CoV-2-contaminated porous and non-porous surfaces. A newly developed disinfection chamber was used, equipped with a CeraPlas™ cold plasma generator that produces ozone during plasma ignition. A reduction of more than log 6 of infectious virus could be demonstrated for virus-contaminated cotton and FFP3 face masks as well as glass slides after exposure to 800 ppm ozone for 10-60 min, depending on the material. In contrast to other disinfectants, ozone can be produced quickly and cost-effectively, and its environmentally friendly breakdown product oxygen does not leave harmful residues. Disinfection with ozone could help to overcome delivery difficulties of personal protective equipment by enabling safe reuse with further applications, thereby reducing waste generation, and may allow regular disinfection of personal items with non-porous surfaces.


Subject(s)
Disinfection/methods , Ozone , SARS-CoV-2/drug effects , Virus Inactivation/drug effects , Equipment Contamination , Masks/virology , Ozone/pharmacology , Porosity
10.
ACS Appl Bio Mater ; 4(11): 7921-7931, 2021 11 15.
Article in English | MEDLINE | ID: covidwho-1500415

ABSTRACT

The advent of COVID-19 pandemic has made it necessary to wear masks across populations. While the N95 mask offers great performance against airborne infections, its multilayered sealed design makes it difficult to breathe for a longer duration of use. The option of using highly breathable cloth or silk masks especially for a large populace is fraught with the danger of infection. As a normal cloth or silk mask absorbs airborne liquid, it can be a source of plausible infection. We demonstrate the chemical modification of one such mask, Eri silk, to make it hydrophobic (contact angle of water is 143.7°), which reduces the liquid absorption capacity without reducing the breathability of the mask significantly. The breathability reduces only 22% for hydrophobic Eri silk compared to the pristine Eri silk, whereas N95 shows a 59% reduction of breathability. The modified hydrophobic silk can repel the incoming aqueous liquid droplets without wetting the surface. The results indicate that a multilayered modified silk mask to make it hydrophobic can be an affordable and breathable alternative to the N95 mask.


Subject(s)
COVID-19/prevention & control , Masks , Nanostructures/chemistry , Breath Tests , COVID-19/virology , Humans , Hydrophobic and Hydrophilic Interactions , Porosity , Respiratory Protective Devices/virology , SARS-CoV-2/isolation & purification , Silanes/chemistry , Silk/chemistry
11.
ACS Appl Mater Interfaces ; 13(40): 47996-48008, 2021 Oct 13.
Article in English | MEDLINE | ID: covidwho-1440455

ABSTRACT

Use of masks is a primary tool to prevent the spread of the novel COVID-19 virus resulting from unintentional close contact with infected individuals. However, detailed characterization of the chemical properties and physical structure of common mask materials is lacking in the current literature. In this study, a series of commercial masks and potential mask materials, including 3M Particulate Respirator 8210 N95, a material provided by Oak Ridge National Laboratory Carbon Fiber Technology Facility (ORNL/CFTF), and a Filti Face Mask Material, were characterized by a suite of techniques, including scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Wetting properties of the mask materials were quantified by measurements of contact angle with a saliva substitute. Mask pass-through experiments were performed using a dispersed metal oxide nanoparticle suspension to model the SARS-CoV-2 virus, with quantification via spatially resolved X-ray fluorescence mapping. Notably, all mask materials tested provided a strong barrier against respiratory droplet breakthrough. The comparisons and characterizations provided in this study provide useful information when evaluating mask materials for respiratory protection.


Subject(s)
Filtration , Masks , Materials Testing/methods , N95 Respirators , COVID-19/prevention & control , Metal Nanoparticles/chemistry , Microscopy, Electron, Scanning , Photoelectron Spectroscopy , Polyesters/chemistry , Polypropylenes/chemistry , Porosity , SARS-CoV-2 , Spectrum Analysis, Raman , Wettability , X-Ray Diffraction
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120237, 2022 Jan 05.
Article in English | MEDLINE | ID: covidwho-1380807

ABSTRACT

Here, we reported the synthesis of reduced porous graphene oxide (rPGO) decorated with gold nanoparticles (Au NPs) to modify the ITO electrode. Then we used this highly uniform Au NPs@rPGO modified ITO electrode as a surface-enhanced Raman spectroscopy-active surface and a working electrode. The uses of the Au nanoparticles and porous graphene enhance the Raman signals and the electrochemical conductivity. COVID-19 protein-based biosensor was developed based on immobilization of anti-COVID-19 antibodies onto the modified electrode and its uses as a probe for capturing the COVID-19 protein. The developed biosensor showed the capability of monitoring the COVID-19 protein within a concentration range from 100 nmol/L to 1 pmol/L with a limit of detection (LOD) of 75 fmol/L. Furthermore, COVID-19 protein was detected based on electrochemical techniques within a concentration range from 100 nmol/L to 500 fmol/L that showed a LOD of 39.5 fmol/L. Finally, three concentrations of COVID-19 protein spiked in human serum were investigated. Thus, the present sensor showed high efficiency towards the detection of COVID-19.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Metal Nanoparticles , Electrochemical Techniques , Electrodes , Gold , Humans , Porosity , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
13.
ACS Appl Mater Interfaces ; 13(35): 41445-41453, 2021 Sep 08.
Article in English | MEDLINE | ID: covidwho-1371587

ABSTRACT

Airborne transmission of exhaled virus can rapidly spread, thereby increasing disease progression from local incidents to pandemics. Due to the COVID-19 pandemic, states and local governments have enforced the use of protective masks in public and work areas to minimize the disease spread. Here, we have leveraged the function of protective face coverings toward COVID-19 diagnosis. We developed a user-friendly, affordable, and wearable collector. This noninvasive platform is integrated into protective masks toward collecting airborne virus in the exhaled breath over the wearing period. A viral sample was sprayed into the collector to model airborne dispersion, and then the enriched pathogen was extracted from the collector for further analytical evaluation. To validate this design, qualitative colorimetric loop-mediated isothermal amplification, quantitative reverse transcription polymerase chain reaction, and antibody-based dot blot assays were performed to detect the presence of SARS-CoV-2. We envision that this platform will facilitate sampling of current SARS-CoV-2 and is potentially broadly applicable to other airborne diseases for future emerging pandemics.


Subject(s)
Breath Tests/instrumentation , COVID-19 Testing/instrumentation , Masks , SARS-CoV-2/isolation & purification , Air Microbiology , Antibodies, Viral/immunology , Breath Tests/methods , COVID-19 Testing/methods , Collodion/chemistry , Colorimetry/methods , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , Polycarboxylate Cement/chemistry , Porosity , Proof of Concept Study , RNA, Viral/analysis , Real-Time Polymerase Chain Reaction/methods , SARS-CoV-2/chemistry , Viral Proteins/analysis , Viral Proteins/immunology
14.
Rev Sci Instrum ; 92(7): 074101, 2021 Jul 01.
Article in English | MEDLINE | ID: covidwho-1338585

ABSTRACT

A fluid mechanics model of inhaled air gases, nitrogen (N2) and oxygen (O2) gases, and exhaled gas components (CO2 and water vapor particles) through a facial mask (membrane) to shield the COVID-19 virus is established. The model was developed based on several gas flux contributions that normally take place through membranes. Semiempirical solutions of the mathematical model were predicted for the N95 facial mask accounting on several parameters, such as a range of porosity size (i.e., 1-30 nm), void fraction (i.e., 10-3%-0.3%), and thickness of the membrane (i.e., 10-40 µm) in comparison to the size of the COVID-19 virus. A unitless number (Nr) was introduced for the first time to describe semiempirical solutions of O2, N2, and CO2 gases through the porous membrane. An optimum Nr of expressing the flow of the inhaled air gases, O2 and N2, through the porous membrane was determined (NO2 = NN2 = -4.4) when an N95 facial mask of specifications of a = 20 nm, l = 30 µm, and ε = 30% was used as a personal protection equipment (PPE). The concept of the optimum number Nr can be standardized not only for testing commercially available facial masks as PPEs but also for designing new masks for protecting humans from the COVID-19 virus.


Subject(s)
COVID-19/prevention & control , Masks , SARS-CoV-2 , Biomechanical Phenomena , Carbon Dioxide , Equipment Design , Exhalation , Gases , Humans , Hydrodynamics , Inhalation , Mathematical Concepts , Membranes, Artificial , Models, Theoretical , N95 Respirators , Nitrogen , Oxygen , Personal Protective Equipment , Porosity , Steam
15.
J Colloid Interface Sci ; 604: 113-121, 2021 Dec 15.
Article in English | MEDLINE | ID: covidwho-1293924

ABSTRACT

The development of colorimetric assays for rapid and accurate diagnosis of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is of practical importance for point-of-care (POC) testing. Here we report the colorimetric detection of spike (S1) protein of SARS-CoV-2 based on excellent peroxidase-like activity of Au@Pt nanoparticles, with merits of rapidness, easy operation, and high sensitivity. The Au@Pt NPs were fabricated by a facile seed-mediated growth approach, in which spherical Au NPs were premade as seeds, followed by the Pt growth on Au seeds, producing uniform, monodispersed and porous Au@Pt core-shell NPs. The as-obtained Au@Pt NPs showed a remarkable enhancement in the peroxidase-mimic catalysis, which well abided by the typical Michaelis-Menten theory. The enhanced catalysis of Au@Pt NPs was ascribed to the porous nanostructure and formed electron-rich Pt shells, which enabled the catalytic pathway to switch from hydroxyl radical generation to electron transfer process. On a basis of these findings, a colorimetric assay of spike (S1) protein of SARS-CoV-2 was established, with a linear detection range of 10-100 ng mL-1 of protein concentration and a low limit of detection (LOD) of 11 ng mL-1. The work presents a novel strategy for diagnosis of COVID-19 based on metallic nanozyme-catalysis.


Subject(s)
Colorimetry , Gold , Metal Nanoparticles , Spike Glycoprotein, Coronavirus/isolation & purification , Peroxidases , Porosity , SARS-CoV-2
16.
Proc Natl Acad Sci U S A ; 118(19)2021 05 11.
Article in English | MEDLINE | ID: covidwho-1214016

ABSTRACT

Here, we present a physiologically relevant model of the human pulmonary alveoli. This alveolar lung-on-a-chip platform is composed of a three-dimensional porous hydrogel made of gelatin methacryloyl with an inverse opal structure, bonded to a compartmentalized polydimethylsiloxane chip. The inverse opal hydrogel structure features well-defined, interconnected pores with high similarity to human alveolar sacs. By populating the sacs with primary human alveolar epithelial cells, functional epithelial monolayers are readily formed. Cyclic strain is integrated into the device to allow biomimetic breathing events of the alveolar lung, which, in addition, makes it possible to investigate pathological effects such as those incurred by cigarette smoking and severe acute respiratory syndrome coronavirus 2 pseudoviral infection. Our study demonstrates a unique method for reconstitution of the functional human pulmonary alveoli in vitro, which is anticipated to pave the way for investigating relevant physiological and pathological events in the human distal lung.


Subject(s)
Lab-On-A-Chip Devices , Models, Biological , Pulmonary Alveoli/physiology , Alveolar Epithelial Cells , Antiviral Agents/pharmacology , Cigarette Smoking/adverse effects , Dimethylpolysiloxanes/chemistry , Gelatin/chemistry , Humans , Hydrogels/chemistry , Methacrylates/chemistry , Porosity , Pulmonary Alveoli/cytology , Pulmonary Alveoli/pathology , Respiration , Respiratory Mucosa/cytology , Respiratory Mucosa/physiology , SARS-CoV-2/drug effects , SARS-CoV-2/pathogenicity
17.
Sci Total Environ ; 786: 147461, 2021 Sep 10.
Article in English | MEDLINE | ID: covidwho-1213514

ABSTRACT

This paper presents the results of an experimental study on the acoustic efficiency of plastic surgical face masks. Since the very high number of disposable masks being used globally on a daily basis to face the Covid19 pandemic is posing new environmental risks, mainly connected to improper disposal, any possible improvements in the management of this waste stream is very important. In this work their potential use as sound porous absorber is discussed. Surgical face masks are mainly made of polypropylene fibers which show good acoustical properties. Their porous structure was studied through the measurement of some non-acoustic properties: bulk density, fiber diameter, porosity, flow resistivity and tortuosity. Moreover, the sound absorption performance of samples, made of scrapped face masks, with different thicknesses was evaluated using an impedance tube according to ISO 10534-2. The results obtained from the sound absorption spectra and two single indexes, Noise Reduction Coefficient and Sound Absorption Average showed a high sound absorption value over a frequency range of interest. Finally, the sound absorption spectra obtained for surgical face masks were compared with those obtained for fibrous materials currently used in building sector, suggesting that this fibrous waste could act as a possible substitute to traditional ones.


Subject(s)
COVID-19 , Masks , Humans , Models, Theoretical , Porosity , SARS-CoV-2
18.
Biomaterials ; 273: 120824, 2021 06.
Article in English | MEDLINE | ID: covidwho-1184843

ABSTRACT

Sponge particulates have attracted enormous attention in biomedical applications for superior properties, including large porosity, elastic deformation, capillary action, and three-dimensional (3D) reaction environment. Especially, the tiny porous structures make sponge particulates a promising platform for drug delivery, tissue engineering, anti-infection, and wound healing by providing abundant reservoirs of broad surface and internal network for cargo shielding and shuttling. To control the sponge-like morphology and improve the diversity of drug loading, some optimized preparation techniques of sponge particulates have been developed, contributing to the simplified preparation process and improved production reproducibility. Bio-functionalized strategies, including target modification, cell membrane camouflage, and hydrogel of sponge particulates have been applied to modulate the properties, improve the performance, and extend the applications. In this review, we highlight the unique physical properties and functions, current manufacturing techniques, and an overview of spongy particulates in biomedical applications, especially in inhibition of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infectivity. Moreover, the current challenges and prospects of sponge particulates are discussed rationally, providing an insight into developing vibrant fields of sponge particulates-based biomedicine.


Subject(s)
COVID-19 , Precision Medicine , Drug Delivery Systems , Humans , Porosity , Reproducibility of Results , SARS-CoV-2
19.
Sci Rep ; 11(1): 5887, 2021 03 15.
Article in English | MEDLINE | ID: covidwho-1135699

ABSTRACT

Based on the current knowledge of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) transmission, wearing a mask has been recommended during the COVID-19 pandemic. Bacterial filtration efficiency (BFE) measurements enable designing and regulating medical masks to prevent bioaerosol dissemination; however, despite the simplicity of these measurements, several scientific questions remain unanswered regarding BFE tests. Here, we investigated (1) the impact of substituting 100-mm Petri dishes with 90-mm disposable Petri dishes, (2) the impact of colony-counting methods on the bioaerosol aerodynamic size, and (3) the impact of colony-counting methods on the total viable particle counts. We demonstrated that disposable 90-mm Petri dishes can be used to replace the 100-mm dishes. We also showed that an automatic high-resolution colony counter can be used to directly count viable particles on collection substrates and to measure the bioaerosol size parameters. Our results enable possible modernization of the outdated testing methods recommended in the US and European standards for BFE measurements. Specifically, use of a modernized colony counter should be clearly regulated and permitted to avoid the counting of positive holes. The median aerodynamic diameter appears to be the most relevant parameter for characterizing bioaerosol size.


Subject(s)
Bacteria , Filtration/standards , Masks/standards , Bacterial Load , Environmental Microbiology , Filtration/methods , Humans , Masks/microbiology , Particle Size , Porosity
20.
Sci Rep ; 11(1): 984, 2021 01 13.
Article in English | MEDLINE | ID: covidwho-1065930

ABSTRACT

The spread of COVID-19 in healthcare settings is concerning, with healthcare workers representing a disproportionately high percentage of confirmed cases. Although SARS-CoV-2 virus has been found to persist on surfaces for a number of days, the extent and duration of fomites as a mode of transmission, particularly in healthcare settings, has not been fully characterized. To shed light on this critical matter, the present study provides the first comprehensive assessment of SARS-CoV-2 stability on experimentally contaminated personal protective equipment (PPE) widely used by healthcare workers and the general public. Persistence of viable virus was monitored over 21 days on eight different materials, including nitrile medical examination gloves, reinforced chemical resistant gloves, N-95 and N-100 particulate respirator masks, Tyvek, plastic, cotton, and stainless steel. Unlike previous reports, viable SARS-CoV-2 in the presence of a soil load persisted for up to 21 days on experimentally inoculated PPE, including materials from filtering facepiece respirators (N-95 and N-100 masks) and a plastic visor. Conversely, when applied to 100% cotton fabric, the virus underwent rapid degradation and became undetectable by TCID50 assay within 24 h. These findings underline the importance of appropriate handling of contaminated PPE during and following use in high-risk settings and provide interesting insight into the potential utility of cotton in limiting COVID-19 transmission.


Subject(s)
Personal Protective Equipment , SARS-CoV-2/physiology , Porosity , RNA, Viral/genetics , SARS-CoV-2/genetics , Surface Properties
SELECTION OF CITATIONS
SEARCH DETAIL