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1.
Artigo em Inglês | MEDLINE | ID: mdl-38605670

RESUMO

Recently, conductive hydrogels have emerged as promising materials for smart, wearable devices. However, limited mechanical properties and low sensitivity greatly restrict their lifespan. Based on the design of biomimetic-layered structure, the conductive hydrogels with nacre-mimetic structure were prepared by using layered acrylic bentonite (AABT) and phytic acid (PA) as multifunctional "brick" and "mortar" units. Among them, the unique rigid cyclic multihydroxyl structure of the "organic mortar" PA preserves both ultrastretchability (4050.02%) and high stress (563.20 kPa) of the hydrogel, which far exceeds most of the reported articles. Because of the synergistic effect of AABT and PA, the hydrogel exhibits an excellent adhesive strength (87.74 kPa). The role of AABT in the adhesive properties of hydrogels is proposed for the first time, and a general strategy for improving the adhesive properties of hydrogels by using AABT is demonstrated. Furthermore, AABT provides ion channels and PA ionizes abundant H+, conferring a high gauge factor (GF = 14.95) and excellent antimicrobial properties to the hydrogel. Also, inspired by fruit batteries, simple self-powered flexible sensors were developed. Consequently, this study provides knowledge for functional bentonite filler modified hydrogel, and the prepared multifunctional ionic conductive hydrogel shows great application potential in the field of intelligent wearable devices.

2.
ACS Macro Lett ; : 475-482, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38591821

RESUMO

The development of antioxidant wound dressings to remove excessive free radicals around wounds is essential for wound healing. In this study, we developed an efficient strategy to prepare antioxidant self-healing hydrogels as wound dressings by combining multicomponent reactions (MCRs) and postpolymerization modification. A polymer containing ferrocene and phenylboronic acid groups was developed via the Biginelli reaction, followed by efficient modification. This polymer is antioxidant due to its ferrocene moieties and can rapidly cross-link poly(vinyl alcohol) to realize an antioxidant self-healing hydrogel through dynamic borate ester linkages. This hydrogel has low cytotoxicity and is biocompatible. In in vivo experiments, this hydrogel is superior to existing clinical dressings in promoting wound healing. This study demonstrates the value of the Biginelli reaction in exploring biomaterials, potentially offering insights into the design of other multifunctional polymers and related materials using different MCRs.

3.
ACS Appl Mater Interfaces ; 16(15): 18411-18421, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38584383

RESUMO

Cell necroptosis has presented great potential, acting as an effective approach against tumor apoptotic resistance, and it could be further enhanced via accompanying reactive oxygen species (ROS) overexpression. However, whether overproduced ROS assists the necroptotic pathway remains unclear. Thus, iron-palladium nanozyme (FePd NZ)- and shikonin (SKN)-encapsulated functional lipid nanoparticles (FPS-LNPs) were designed to investigate the ROS overexpression-enhanced SKN-induced necroptosis. In this system, SKN acts as an effective necroptosis inducer for cancer cells, and FePd NZ, a sensitive Fenton reaction catalyst, produces extra-intracellular ROS to reinforce the necroptotic pathway. Both in vitro and in vivo antitumor evaluation revealed that FPS-LNPs presented the best tumor growth inhibition efficacy compared with FP-LNPs or SKN-LNPs alone. Meanwhile, induced necroptosis by FPS-LNPs can further trigger the release of damage-associated molecular patterns (DAMPs) and antigens from dying tumor cells to activate the innate immune response. Taking biosafety into consideration, this study has provided a potential nanoplatform for cancer nanotherapy via inducing necroptosis to avoid apoptosis resistance and activate CD8+ T cell immune response.


Assuntos
Lipossomos , Nanopartículas , Naftoquinonas , Necroptose , Neoplasias , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular Tumoral , Apoptose
4.
Colloids Surf B Biointerfaces ; 238: 113888, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38599077

RESUMO

Gallium (Ga) is a well-known liquid metals (LMs) that possesses the features, such as fluidity, low viscosity, high electrical and thermal conductivity, and relative low toxicity. Owing to the weak interactions between Ga atoms, Ga LMs can be adopted for fabrication of various Ga LMs-based functional materials via ultrasonic treatment and mechanical grinding. Moreover, many organic compounds/polymers can be coated on the surface of LMs-based materials through coordination between oxidized outlayers of Ga LMs and functional groups of organic components. Over the past decades, different strategies have been reported for synthesizing Ga LMs-based functional materials and their biomedical applications have been intensively investigated. Although some review articles have published over the past few years, a concise review is still needed to advance the latest developments in biomedical fields. The main context can be majorly divided into two parts. In the first section, various strategies for fabrication of Ga LMs-based functional materials via top-down strategies were introduced and discussed. Following that, biomedical applications of Ga LMs-based functional materials were summarized and design Ga LMs-based functional materials with enhanced performance for cancer photothermal therapy (PTT) and PTT combined therapy were highlighted. We trust this review article will be beneficial for scientists to comprehend this promising field and greatly advance future development for fabrication of other Ga LMs-based functional materials with better performance for biomedical applications.

5.
Polymers (Basel) ; 16(4)2024 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-38399876

RESUMO

In recent years, the incidence of bone defects has been increasing year by year. Bone transplantation has become the most needed surgery after a blood transfusion and shows a rising trend. Three-dimensional-printed implants can be arbitrarily shaped according to the defects of tissues and organs to achieve perfect morphological repair, opening a new way for non-traumatic repair and functional reconstruction. In this paper, strontium-doped mineralized collagen was first prepared by an in vitro biomimetic mineralization method and then polylactic acid was homogeneously blended with the mineralized collagen to produce a comprehensive bone repair scaffold by a gas extrusion 3D printing method. Characterization through scanning electron microscopy, X-ray diffraction, and mechanical testing revealed that the strontium-functionalized composite scaffold exhibits an inorganic composition and nanostructure akin to those of human bone tissue. The scaffold possesses uniformly distributed and interconnected pores, with a compressive strength reaching 21.04 MPa. The strontium doping in the mineralized collagen improved the biocompatibility of the scaffold and inhibited the differentiation of osteoclasts to promote bone regeneration. This innovative composite scaffold holds significant promise in the field of bone tissue engineering, providing a forward-thinking solution for prospective bone injury repair.

6.
Front Oncol ; 14: 1305720, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38406805

RESUMO

Introduction: Brain metastases commonly occur in patients with non-small cell lung cancer (NSCLC). Standard first-line treatment for NSCLC, without an EGFR, ALK or ROS1 mutation, is either chemoimmunotherapy or anti-PD-1 monotherapy. Traditionally, patients with symptomatic or untreated brain metastases were excluded from the pivotal clinical trials that established first-line treatment recommendations. The intracranial effectiveness of these treatment protocols has only recently been elucidated in small-scale prospective trials. Methods: Patients with NSCLC and brain metastases, treated with first-line chemoimmunotherapy or anti-PD-1 monotherapy were selected from the Australian Registry and biObank of thoracic cancers (AURORA) clinical database covering seven institutions. The primary outcome was a composite time-to-event (TTE) outcome, including extracranial and intracranial progression, death, or need for local intracranial therapy, which served as a surrogate for disease progression. The secondary outcome included overall survival (OS), intracranial objective response rate (iORR) and objective response rate (ORR). Results: 116 patients were included. 63% received combination chemoimmunotherapy and 37% received anti-PD-1 monotherapy. 69% of patients received upfront local therapy either with surgery, radiotherapy or both. The median TTE was 7.1 months (95% CI 5 - 9) with extracranial progression being the most common progression event. Neither type of systemic therapy or upfront local therapy were predictive of TTE in a multivariate analysis. The median OS was 17 months (95% CI 13-27). Treatment with chemoimmunotherapy was predictive of longer OS in multivariate analysis (HR 0.35; 95% CI 0.14 - 0.86; p=0.01). The iORR was 46.6%. The iORR was higher in patients treated with chemoimmunotherapy compared to immunotherapy (58% versus 31%, p=0.01). The use of chemoimmunotherapy being predictive of iORR in a multivariate analysis (OR 2.88; 95% CI 1.68 - 9.98; p=0.04). Conclusion: The results of this study of real-world data demonstrate the promising intracranial efficacy of chemoimmunotherapy in the first-line setting, potentially surpassing that of immunotherapy alone. No demonstrable difference in survival or TTE was seen between receipt of upfront local therapy. Prospective studies are required to assist clinical decision making regarding optimal sequencing of local and systemic therapies.

7.
Sci Rep ; 14(1): 4118, 2024 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-38374394

RESUMO

Gelatin was widely used as scaffold materials in 3D bio-printing due to its excellent bioactivity and availability and especially that their arginine-glycine-aspartic acid (RGD) sequences could efficiently promote cell adhesion and proliferation. In this study, an electroactive and 3D bio-printable hydrogel was prepared through a two-step chemical cross-linking process. Specifically, residual free amino groups of methacrylated gelatin (GelMA) were cross-linked with the aldehyde groups of dibenzaldehyde-terminated telechelic polyethylene glycol (DF-PEG) via Schiff base bonds, forming a gel at 37 °C. During the subsequent 3D bio-printing process, GelMA underwent UV curing, forming a secondary cross-linked network to the mechanical strength and stability of the printed structure. The uniform dispersion of carbon nanotubes (CNTs) in the GelMA/DF-PEG composite hydrogel significantly increased its conductivity. The optimized GelMA/DF-PEG composite hydrogel, i.e., 30% GelMA and 25% DF-PEG (G30D25-CNTs), exhibited superior bio-printability. When the content of CNTs was above 4%, the conductivity of G30D25-CNTs hydrogel exceeded 10-2 S/m, which satisfied the needs of cells for micro-current stimulation. Furthermore, the pore microstructures, swelling behavior, degradation ability and cell toxicity of G30D25-CNTs electroactive hydrogels were thoroughly evaluated. Thus, the G30D25-CNTs hydrogel with 4% MWCNTs could be considered for further application in electrical stimulation of tissue regeneration such as muscle and cardiac nerve tissue repair.


Assuntos
Bioimpressão , Nanotubos de Carbono , Gelatina/química , Polietilenoglicóis , Hidrogéis/química , Metacrilatos/química , Materiais Biocompatíveis/química , Impressão Tridimensional , Engenharia Tecidual , Tecidos Suporte/química
8.
Chem Commun (Camb) ; 60(8): 984-987, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38168933

RESUMO

An amphiphilic fluorescent probe (BHSMP) with aggregation-induced emission (AIE) features was synthesized via a one-step route. The probe showed high water dispersibility, low toxicity and the ability of selective and sensitive (limit of detection of 0.11 µM) detection of ClO- with fast-response (≤30 s) in aqueous solution and living organisms. Owing to the donor-acceptor (D-A) structure and existence of cationic groups, BHSMP could also generate reactive oxygen species under light-irradiation and potentially be utilized for photodynamic therapy. The strategy described in this work is of great significance for the design and synthesis of multifunctional AIE-active functional materials to facilitate their biomedical applications.


Assuntos
Fotoquimioterapia , Espécies Reativas de Oxigênio , Corantes Fluorescentes/farmacologia , Corantes Fluorescentes/química
9.
J Am Chem Soc ; 146(7): 4327-4332, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38277433

RESUMO

The structural exploration of three-dimensional covalent organic frameworks (3D COFs) is of great significance to the development of COF materials. Different from structurally diverse MOFs, which have a variety of connectivity (3-24), now the valency of 3D COFs is limited to only 4, 6, and 8. Therefore, the exploration of organic building blocks with higher connectivity is a necessary path to broaden the scope of 3D COF structures. Herein, for the first time, we have designed and synthesized a 12-connected triptycene-based precursor (triptycene-12-CHO) with 12 symmetrical distributions of aldehyde groups, which is also the highest valency reported until now. Based on this unique 12-connected structure, we have successfully prepared a novel 3D COF with lnj topology (termed 3D-lnj-COF). The as-synthesized 3D COF exhibits honeycomb main pores and permanent porosity with a Brunauer-Emmett-Teller surface area of 1159.6 m2 g-1. This work not only provides a strategy for synthesizing precursors with a high connectivity but also provides inspiration for enriching the variety of 3D COFs.

10.
Colloids Surf B Biointerfaces ; 234: 113750, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38244482

RESUMO

In this contribution, a novel AIE monomers 2-(4-styrylphenyl)- 1,2-diphenylvinyl)styryl)pyridine (SDVPY) with smart fluorescent pH-sensitivity basing on tetraphenylethylene-pyridine were successfully synthesized for the first time, subsequently, a series of amphiphilic copolymers PEG-PY were achieved by reversible addition-fragmentation chain transfer (RAFT) polymerization of SDVPY and poly(ethylene glycol) methacrylate (PEGMA), which would self-assemble in water solution to form core-shell nanoparticles (PEG-PY FONs) with about 150 nm diameter. The PEG-PY FONs showed obvious fluorescence response to Fe3+, HCO3- and CO32- ions in aqueous solution owing to their smart pH-sensitivity and AIE characteristics, and their maximum emission wavelength could reversibly change from 525 nm to 624 nm. The as-prepared PEG-PY FONs showed also prospective application in cells imaging with the variable fluorescence for different pH cells micro-environment. When PEG-PY copolymers self-assembled with the anti-tumor drug paclitaxel (PTX), the obtained PY-PTX FONs could effectively deliver and release PTX with pH-sensitivity, and could be easily internalized by A549 cells and located at the cytoplasm with high cytotoxicity, which was further confirmed by the Calcein-AM/PI staining of dead and alive A549 cells. Moreover, the flow cytometry results indicated that the PY-PTX FONs could obviously induce the apoptosis of A549 cells, which further showed the great potential of PY-PTX FONs in the application of tumors therapy.


Assuntos
Metacrilatos , Nanopartículas , Neoplasias , Estilbenos , Humanos , Polietilenoglicóis , Polímeros , Corantes , Paclitaxel/farmacologia , Concentração de Íons de Hidrogênio , Piridinas/farmacologia , Microambiente Tumoral
11.
Int J Biol Macromol ; 260(Pt 1): 129322, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38242404

RESUMO

Wormwood leaf is a traditional Chinese herbal medicine with a high medicinal value and long application history and its essential oil is a high-purity plant oil extracted from Wormwood leaf. Pharmacological research reveals that Wormwood leaf and Wormwood essential oil are a broad-spectrum antibacterial and antiviral drug, which can inhibit and kill many bacteria and viruses. We loaded wormwood extract on porous calcium carbonate (Porous-CaCO3) and introduced it and Wormwood essential oil into Natural rubber latex (NRL), thus synthesizing NRL composites with excellent vitro and in vivo antibacterial effect, cell compatibility and mechanical properties. This NRL material can delay the light aging and thermal oxidation of some mechanical properties, which provides a broader avenue for its commercialization.


Assuntos
Artemisia , Hipersensibilidade ao Látex , Óleos Voláteis , Borracha , Látex , Porosidade
12.
Adv Mater ; 36(7): e2310630, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38029790

RESUMO

Nickel oxide (NiOx ) has garnered considerable attention as a prospective hole-transporting layer (HTL) in organic solar cells (OSCs), offering a potential solution to the stability challenges posed by traditional HTL, PEDOT:PSS, arising from acidity and hygroscopicity. Nevertheless, the lower work function (WF) of NiOx relative to donor polymers reduces charge injection efficiency in OSCs. Herein, NiOx nanoparticles are tailored through rare earth doping to optimize WF and the impact of ionic radius on their electronic properties is explored. Lanthanum (La3+ ) and yttrium (Y3+ ) ions, with larger ionic radii, are effectively doped at 1 and 3%, respectively, while scandium (Sc3+ ), with a smaller ion radius, allows enhanced 5% doping. Higher doping ratios significantly enhance WF of NiOx . A 5% Sc3+ doping raises WF to 4.99 eV from 4.77 eV for neat NiOx while maintaining high conductivity. Consequently, using 5% Sc-doped NiOx as HTL improves the power conversion efficiency (PCE) of OSCs to 17.13%, surpassing the 15.64% with the neat NiOx . Further enhancement to 18.42% is achieved by introducing the reductant catechol, outperforming the PEDOT:PSS-based devices. Additionally, when employed in a ternary blend system (D18:N3:F-BTA3), an impressive PCE of 19.18 % is realized, top-performing among reported OSCs utilizing solution-processed inorganic nanoparticles.

13.
Small ; 20(4): e2305903, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37715331

RESUMO

Solar-driven interfacial evaporation is a potential water purification solution. Here, a novel regenerable hydrogel interfacial evaporator is designed with tunable water production. Such an evaporator is fabricated by readily mixing hydroxypropyl chitosan (HPCS) and dibenzaldehyde-functional poly(ethylene glycol) (DF-PEG) at ambient conditions. Dynamic Schiff base bonds bestow on the HPCS/DF-PEG hydrogel (HDH) evaporator self-adaptivity and pH responsiveness. The as-prepared HDH is enabled to spontaneously change shape to adapt to different molds, endowing the evaporator with adjustable evaporation area. The water production performance of the intelligent evaporator is first evaluated using tunable evaporation index (TEI, the tunable evaporated water mass per hour), which can be altered from 0 kg h-1 to 3.21 kg h-1 under one sun. Besides, the large-scale evaporator can be expediently fabricated by virtue of the self-adaptivity. Benefiting from the pH responsiveness, the HDH evaporator is successfully regenerated with the removal of organic dye by the liquefaction-dialysis-regeneration operations. Meanwhile, the re-created evaporator maintains the self-adaptive characteristic and almost constant water evaporation rate compared to that of the initial evaporator. Therefore, this distinctive concept provides a facile strategy to develop smart and recyclable solar-driven interfacial evaporators for flexible water purification.

14.
Chemistry ; : e202303586, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38079233

RESUMO

Liquid crystalline nanoparticles (LC NPs) are a kind of polymer NPs with LC mesogens, which can form special anisotropic morphologies due to the influence of LC ordering. Owing to the stimuli-responsiveness of the LC blocks, LC NPs show abundant morphology evolution behaviors in response to external regulation. LC NPs have great application potential in nano-devices, drug delivery, special fibers and other fields. Polymerization-induced self-assembly (PISA) method can synthesize LC NPs at high solid content, reducing the harsh demand for reaction solvent of the LC polymers, being a better choice for large-scale production. In this review, we introduced recent research progress of PISA-LC NPs by dividing them into several parts according to the LC mesogen, and discussed the improvement of experimental conditions and the potential application of these polymers.

15.
Research (Wash D C) ; 6: 0290, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38125698

RESUMO

Solar-driven desalination systems have been recognized as an effective technology to address the water crisis. Recently, evaporators prepared based on advanced manufacturing technologies have emerged as a promising tool in enhancing ocean energy utilization. In this review, we discussed the thermal conversion, energy flow, salt deposition mechanisms, and design strategies for solar-driven desalination systems, and explored how to improve the desalination performance and energy use efficiency of the systems through advanced manufacturing technologies. In future perspectives, we determined the feasibility of coupling solar-driven solar desalination systems with multi-stage energy utilization systems and emerging artificial intelligence technologies, for which conclusions are given and new directions for future desalination system development are envisioned. Finally, exciting opportunities and challenges in the face of basic research and practical implementation are discussed, providing promising solutions and blueprints for green and novel desalination technologies while achieving sustainable development.

16.
ACS Macro Lett ; 12(11): 1491-1497, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37874180

RESUMO

Polymer synthesis via multicomponent reactions (MCRs) has opened avenues in polymer chemistry and led to the development of various types of functional polymers. Herein, we developed a strategy to prepare multifunctional polymers via the successive modification of dihydropyrimidin-2(1H)-thione (DHPMT), which can be generated by the tricomponent Biginelli reaction. Four hydrophobic polymers were efficiently prepared by using DHPMT derivatives. These polymers can be dip-coated onto the oxidized copper mesh to obtain superhydrophobic meshes because of the strong attractive forces between the DHPMT derivatives and Cu(II). The optimized mesh has self-cleaning properties and outstanding stability in various liquid environments; it has also been successfully applied for oil/water separation with high separation efficiency and good durability. These results demonstrate that successive modification of DHPMT is a promising method for fabricating multifunctional polymers, which may have applications in polymer chemistry and materials science.

17.
J Phys Chem A ; 127(41): 8639-8649, 2023 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-37812074

RESUMO

Smart superwetting membranes with finely tunable properties have attracted increased attention recently. However, they mostly focus on controllable wettability rather than controllable permeability. Also, the oil/water separation performance is usually tested with laboratory-simulated samples, making it hard for the materials to meet practical applications. Herein, we fabricate thermally responsive superwetting membranes with wax, polystyrene-B-poly(ethylene-ran-butylene)-B-polys (SEBS, a kind of elastomer), and polydopamine (PDA) to realize emulsion separation with controllable permeability. Benefiting from the elasticity of SEBS and the fluidity difference of wax at different temperatures, the pore size of the membrane could be readily tuned, resulting in different permeability. The separation flux is 0 at ambient temperature (pore size 0.394 µm) and is over 100 L m-2 h-1 at a high temperature (pore size 0.477 µm). The membrane could realize the separation of simulated oil-in-water emulsions with efficiency above 99.4%. Furthermore, it successfully achieved crude oil-in-water emulsion separation from the oil field with oil residues of less than 300 mg L-1 in the temperature range of 60-80 °C, which is the actual working temperature adopted in industrial production. Such a polydopamine/wax-SEBS modified membrane with unprecedented controllable permeability can promote the development of the emulsion treatment field and provide a new direction for designing smart superwetting materials.

18.
Adv Mater ; 35(51): e2306683, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37672294

RESUMO

Stable solid electrolyte interface (SEI) is the key to improve the electrochemical performance of lithium metal batteries (LMBs). However, there are still many puzzles about SEI film that have not been well explained, due to the complexity of electrochemical reactions involving in SEI formation and the absence of direct observation methods for SEI. Here, this work realizes the direct observation of SEI by skillfully designed fluorescent tracers acting as an SEI film-forming additive for electrolytes. These fluorescent tracers have three important moieties: an olefin group for polymerization on anode surface so as to participate in SEI film formation during charge/discharge cycles, a polar group for Li-ion conduction, and an AIEgen for fluorescent tracing. Therefore, the tracers participate in SEI film-forming and result in a shining SEI film. This shining SEI film with intrinsic fluorescence signal allows direct observation and quantification on the distribution, relative abundance, and macro morphology of SEI. These fluorescent tracers can also reveal the SEI formation growth destruction regularity during charge/discharge cycles. Several summarized typical macro morphologies and evolution stages of SEI will enrich knowledge and understanding of SEI and help to gain insight into the interaction between electrolyte and anode, electrochemical performance, and cycle life of batteries.

19.
Int J Infect Dis ; 136: 151-157, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37758170

RESUMO

BACKGROUND: Early in the COVID-19 pandemic, there was a global shortage of masks. Although mask reprocessing was practiced, no clinical study has assessed systematically the impact of repeated cycles of wear and decontamination on the integrity of N95 filtering facepiece respirators (FFRs). METHODS: We evaluated mask fit assessed by qualitative respirator fit test (QRFT) after each cycle of wear and decontamination, as well as four measures of mask integrity-bacterial filtration efficacy, particle filtration efficacy, differential pressure, and splash resistance through five cycles of wear and decontamination using one of the four modalities (moist heat, steam, ultraviolet-C irradiation, and hydrogen peroxide plasma). RESULTS: A total of 60.6% (hydrogen peroxide plasma) to 77.5% (moist heat) of the FFRs passed five cycles of wear and decontamination, as assessed by the wearers passing QRFT all five times. Moist heat-decontaminated FFRs retained all technical measures of integrity through all five cycles. CONCLUSIONS: This is the first large-scale study to assess systematically the impact (clinically and quantitatively) on N95 FFR integrity of repeated cycles of wearing followed by decontamination. Our results suggest that moist heat is a promising method for decontaminating N95 FFRs. Performing QRFT after every cycle of wear and decontamination ensures wearer safety. Although there is currently no mask shortage, reprocessing may reduce medical waste and improve sustainability.


Assuntos
Respiradores N95 , Dispositivos de Proteção Respiratória , Humanos , Vapor , Peróxido de Hidrogênio , Temperatura Alta , Descontaminação/métodos , Pandemias/prevenção & controle , Reutilização de Equipamento , Máscaras
20.
Int J Biol Macromol ; 251: 126308, 2023 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-37573919

RESUMO

It is of great significance to develop natural renewable polymer materials for different applications. Herein, the nano-sized hexagonal boron nitride nanosheets (hBNNSs) were facilely exfoliated through liquid-nitrogen, microwave, and ultrasonication treatments, and novel chitosan/hBNNSs (CS/hBNNSs) films were fabricated via solution casting. The obtained transparent CS/hBNNSs films demonstrated outstanding UV shielding ability with 98.51 % UV-A and 96.40 % UV-B lights being resisted. Compared to those properties of CS film, the oxygen permeability (OP) and carbon dioxide permeability (CO2P) of CS/hBNNSs films are significantly lowered by 96.35 % and 94.06 %, respectively, which are much better than CS/graphene oxide or other CS nanocomposite films. Moreover, the addition of hBNNSs in CS films also obviously improves their water vapor barrier ability, thermostability, mechanical properties, and antibacterial activity. The CS/hBNNSs films and the strategy developed in this work prove their great prospect in producing high-performance packaging films with desirable excellent UV shielding and oxygen barrier qualities.

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