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1.
J Cancer ; 15(10): 3114-3127, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38706891

RESUMO

Objective: This study investigated the significance of HECT domain and ankyrin repeat containing E3 ubiquitin protein ligase 1 (HACE1) in esophageal cancer (ESCA) and its underlying mechanism in ESCA regulation through the induction of RAC1 ubiquitination and degradation. Methods: Characterization studies of HACE1 in ESCA clinical tissues and cell lines were performed. Next, the effects of HACE1 on the biological behavior of ESCA cells were examined by silencing and overexpressing HACE1. Protein-protein interactions (PPIs) involving HACE1 were analyzed using data from the String website. The function of HACE1 in RAC1 protein ubiquitination was validated using the proteasome inhibitor MG132. The effects of HACE1 on ESCA cells through RAC1 were elucidated by applying the RAC1 inhibitor EHop-016 in a tumor-bearing nude mouse model. To establish the relationship between HACE1 and TRIP12, rescue experiments were conducted, mainly to evaluate the effect of TRIP12 silencing on HACE1-mediated RAC1 regulation in vitro and in vivo. The PPI between HACE1 and TRIP12 and their subcellular localization were further characterized through co-immunoprecipitation and immunofluorescence staining assays, respectively. Results: HACE1 protein expression was notably diminished in ESCA cells but upregulated in normal tissues. HACE1 overexpression inhibited the malignant biological behavior of ESCA cells, leading to restrained tumor growth in mice. This effect was coupled with the promotion of RAC1 protein ubiquitination and subsequent degradation. Conversely, silencing HACE1 exhibited contrasting results. PPI existed between HACE1 and TRIP12, compounded by their similar subcellular localization. Intriguingly, TRIP12 inhibition blocked HACE1-driven RAC1 ubiquitination and mitigated the inhibitory effects of HACE1 on ESCA cells, alleviating tumor growth in the tumor-bearing nude mouse model. Conclusion: HACE1 expression was downregulated in ESCA cells, suggesting that it curbs ESCA progression by inducing RAC1 protein degradation through TRIP12-mediated ubiquitination.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38772043

RESUMO

Caries is a destructive condition caused by bacterial infection that affects the hard tissues of the teeth, significantly reducing the quality of life for individuals. Photothermal therapy (PTT) offers a noninvasive and painless treatment for caries, but the use of unsafe laser irradiance limits its application. To address this challenge, we prepared nanoparticles of silver ion-doped Prussian blue (AgPB), which was encased within cationic guar gum (CG) to form the antibacterial PTT hydrogel CG-AgPB with a photothermal conversion efficiency of 34.4%. When exposed to an 808 nm laser at a power density of 0.4 W/cm2, the hydrogel readily reached a temperature of over 50 °C in just 3 min, synchronized by the discharge of Ag+ ions from the interstitial sites of AgPB crystals, resulting in broad-spectrum and synergistic antibacterial activities (>99%) against individual oral pathogens (Streptococcus sanguinis, Streptococcus mutans, and Streptococcus sobrinus) and pathogen-induced biofilms. In vivo, CG-AgPB-mediated PTT demonstrated a capability to profoundly reduce the terminal number of cariogenic bacteria to below 1% in a rat model of caries. Given the outstanding biocompatibility, injectability, and flushability, this CG-AgPB hydrogel may hold promise as a next-generation oral hygiene adjunct for caries management in a clinical setting.

3.
Adv Healthc Mater ; : e2400083, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38447228

RESUMO

Prussian blue (PB) nanozymes are demonstrated as effective therapeutics for ulcerative colitis (UC), yet an unmet practical challenge remains in the scalable production of these nanozymes and uncertainty over their efficacy. With a novel approach, a series of porous manganese-iron PB (MnPB) colloids, which are shown to be efficient scavengers for reactive oxygen species (ROS) including hydroxyl radical, superoxide anion, and hydrogen peroxide, are prepared. In vitro cellular experiments confirm the capability of the nanozyme to protect cells from ROS attack. In vivo, the administration of MnPB nanozyme through gavage at a dosage of 10 mg kg-1 per day for three doses in total potently ameliorates the pathological symptoms of acute UC in a murine model, resulting in mitigated inflammatory responses and improved viability rate. Significantly, the nanozyme produced at a large scale can be achieved at an unprecedented yield weighting ≈11 g per batch of reaction, demonstrating comparable anti-ROS activities and treatment efficacy to its small-scale counterpart. This work represents the first demonstration of the scale-up preparation of PB analog nanozymes for UC without compromising treatment efficacy, laying the foundation for further testing of these nanozymes on larger animals and promising clinical translation.

4.
Chempluschem ; : e202400080, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38514396

RESUMO

Gaseous signaling molecules (GSMs) including nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) have presented excellent therapeutic efficacy such as anti-inflammatory, anti-microbial and anti-cancer effects and multiple biomedical applications in recent years. As the three most vital signaling molecules in human physiology, these three GSMs show so intertwined and orchestrated interactions that the synergy of multiple gases may demonstrate a more complex therapeutic potential than single gas delivery. Consequently, researchers have been devoted to developing codelivery systems of GSMs by synthesizing a single molecule as a dual donor to maximize the gaseous therapeutic efficacy. In this minireview, we summarize the recent developments of molecules or materials enabling codelivery of GSMs for biomedical applications. It appears that compared with the abundant cases of codelivery of NO and H2S, research on codelivery of CO and the other two GSMs separately remains to be explored.

5.
PeerJ ; 12: e17015, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38529305

RESUMO

The coupling effects created by transboundary and local factors on ecosystem services are often difficult to determine. This poses great challenges for ecosystem protection and management in border areas. To decrease uncertainty, it is crucial to quantify and spatialize the impact multiple factors have on ecosystem services within different scenarios. In this study, we identified key transboundary and local factors from a set of 15 sorted factors related to four main ecosystem services. We employed a Bayesian Network-Geographic Information System (BN-GIS) model to simulate 90 scenarios with multiple factors combinations, quantifying and spatializing the coupling effects on the main ecosystem services. These simulations were conducted in the Pu'er region, which is situated alongside three countries, and serves as a representative border area in southwest China. The results showed that: (1) The coupling effects of multiple factors yield significant variations when combined in different scenarios. Managers can optimize ecosystem services by strategically regulating factors within specific areas through the acquisition of various probabilistic distributions and combinations of key factors in positive coupling effect scenarios. The outcome is a positive coupling effect. (2) Among the four main ecosystem services in the Pu'er region, food availability and biodiversity were affected by key transboundary and local factors. This suggests that the coupling of transboundary and local factors is more likely to have a significant impact on these two ecosystem services. Of the 45 combination scenarios on food availability, the majority exhibit a negative coupling effect. In contrast, among the 45 combination scenarios on biodiversity, most scenarios have a positive coupling effect. This indicates that food availability is at a higher risk of being influenced by the coupling effects of multiple factors, while biodiversity faces a lower risk. (3) Transboundary pests & diseases, application of pesticides, fertilizer & filming , population density, and land use were the key factors affecting food availability. Bio-invasion, the normalized differential vegetation index, precipitation, and the landscape contagion index were the key factors affecting biodiversity. In this case, focusing on preventing transboundary factors such as transboundary pests & disease and bio-invasion should be the goal. (4) Attention should also be paid to the conditions under which these transboundary factors combine with local factors. In the areas where these negative coupling effects occur, enhanced monitoring of both transboundary and local factors is essential to prevent adverse effects.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Teorema de Bayes , Conservação dos Recursos Naturais/métodos , Biodiversidade , China
6.
Comput Biol Med ; 170: 107968, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38244472

RESUMO

When performing stent intervention for iliac vein compression syndrome, the operator selects the appropriate stent and determines its implantation depth according to the type and severity of iliac vein stenosis in the patient. However, there is still uncertainty regarding how the structure of the stent and its implantation depth affect hemodynamics at the site of lesion. In this paper, we analyzed three commonly used stents (Vena stent from Venmedtch, Venovo from Bard, and Smart stent from Cordis) with different implantation depths (0, 10, 20 mm) using computational fluid dynamics (CFD). We focused on evaluating hemorheological parameters such as time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), etc., within one pulsatile cycle after stent implantation. The correlation between geometric parameters of the stents and hemodynamic indicators was assessed using Pearson correlation coefficient (r), which was further validated through PIV velocity measurement experiment. The results revealed that an increase in implantation depth led to a more pronounced disturbance effect on blood flow at bifurcation for densely arranged support body-type stents. This effect was particularly significant during periods of smooth blood flow. On the other hand, crown-shaped Vena stents exhibited relatively less disruption to blood flow post-implantation. Implantation depth showed a strong negative correlation with TAWSS but a strong positive correlation with OSI and RRT. These findings suggest an increased risk of thrombosis at iliac vein bifurcation following stent placement. Amongst all three tested stents, Vena Stent demonstrated more favorable periodic parameters after implantation compared to others. These results provide valuable theoretical insights into understanding contralateral circulation thrombosis associated with iliac vein stenting.


Assuntos
Veia Ilíaca , Trombose , Humanos , Veia Ilíaca/cirurgia , Hemodinâmica , Stents/efeitos adversos
7.
Adv Mater ; 36(9): e2309315, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37944553

RESUMO

Polypeptide materials offer scalability, biocompatibility, and biodegradability, rendering them an ideal platform for biomedical applications. However, the preparation of polypeptides with specific functional groups, such as semicarbazide moieties, remains challenging. This work reports, for the first time, the straightforward synthesis of well-defined methoxy-terminated poly(ethylene glycol)-b-polypeptide hybrid block copolymers (HBCPs) containing semicarbazide moieties. This synthesis involves implementing the direct polymerization of environment-stable N-phenoxycarbonyl-functionalized α-amino acid (NPCA) precursors, thereby avoiding the handling of labile N-carboxyanhydride (NCA) monomers. The resulting HBCPs containing semicarbazide moieties enable facile functionalization with aldehyde/ketone derivatives, forming pH-cleavable semicarbazone linkages for tailored drug release. Particularly, the intracellular pH-triggered hydrolysis of semicarbazone moieties restores the initial semicarbazide residues, facilitating endo-lysosomal escape and thus improving therapeutic outcomes. Furthermore, the integration of the hypoxic probe (Ir(btpna)(bpy)2 ) into the pH-responsive nanomedicines allows sequential responses to acidic and hypoxic tumor microenvironments, enabling precise detection of metastatic tumors. The innovative approach for designing bespoke functional polypeptides holds promise for advanced drug delivery and precision therapeutics.


Assuntos
Neoplasias , Semicarbazonas , Humanos , Neoplasias/tratamento farmacológico , Semicarbazidas , Peptídeos , Microambiente Tumoral
8.
Angew Chem Int Ed Engl ; 62(52): e202314563, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-37964723

RESUMO

The development of dual gasotransmitter donors can not only provide robust tools to investigate their subtle interplay under pathophysiological conditions but also optimize therapeutic efficacy. While conventional strategies are heavily dependent on multicomponent donors, we herein report an ultrasound-responsive water-soluble copolymer (PSHF) capable of releasing carbon monoxide (CO) and hydrogen sulfide (H2 S) based on single-component sulfur-substituted 3-hydroxyflavone (SHF) derivatives. Interestingly, sulfur substitution can not only greatly improve the ultrasound sensitivity but also enable the co-release of CO/H2 S under mild ultrasound irradiation. The co-release of CO/H2 S gasotransmitters exerts a bactericidal effect against Staphylococcus aureus and demonstrates anti-inflammatory activity in lipopolysaccharide-challenged macrophages. Moreover, the excellent tissue penetration of ultrasound irradiation enables the local release of CO/H2 S in the joints of septic arthritis rats, exhibiting superior therapeutic efficacy without the need for any antibiotics.


Assuntos
Gasotransmissores , Sulfeto de Hidrogênio , Ratos , Animais , Monóxido de Carbono , Macrófagos , Enxofre
9.
Nat Commun ; 14(1): 7510, 2023 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-37980361

RESUMO

The formation of biofilms is closely associated with persistent and chronic infections, and physiological heterogeneity such as pH and oxygen gradients renders biofilms highly resistant to conventional antibiotics. To date, effectively treating biofilm infections remains a significant challenge. Herein, we report the fabrication of micellar nanoparticles adapted to heterogeneous biofilm microenvironments, enabling nitric oxide (NO) release through two distinct photoredox catalysis mechanisms. The key design feature involves the use of tertiary amine (TA) moieties, which function as sacrificial agents to avoid the quenching of photocatalysts under normoxic and neutral pH conditions and proton acceptors at acidic pH to allow deep biofilm penetration. This biofilm-adaptive NO-releasing platform shows excellent antibiofilm activity against ciprofloxacin-resistant Pseudomonas aeruginosa (CRPA) biofilms both in vitro and in a mouse skin infection model, providing a strategy for combating biofilm heterogeneity and biofilm-related infections.


Assuntos
Anti-Infecciosos , Óxido Nítrico , Animais , Camundongos , Óxido Nítrico/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Ciprofloxacina/farmacologia , Biofilmes , Anti-Infecciosos/farmacologia , Pseudomonas aeruginosa/fisiologia , Testes de Sensibilidade Microbiana
10.
Chin J Nat Med ; 21(10): 789-800, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37879796

RESUMO

Five new saponins, including three steroid saponins, paristenoids A-C (1-3), and two triterpenoid saponins, paristenoids D-E (4-5), along with four known ones (6-9) were isolated from the rhizomes of Paris polyphylla var. stenophylla. The structures of the isolated compounds were identified mainly by detailed spectroscopic analysis, including extensive 1D and 2D NMR, MS, as well as chemical methods. Compound 3 is a new cyclocholestanol-type steroidal saponin with a rare 6/6/6/5/5 fused-rings cholestanol skeleton, and this skeleton has been first found from the genus Paris. The cytotoxicities of the isolated compounds against three human three glioma cell lines (U87MG, U251MG and SHG44) were evaluated, and compound 7 displayed certain inhibitory effect with IC50 values of 15.22 ± 1.73, 18.87 ± 1.81 and 17.64 ± 1.69 µmol·L-1, respectively.


Assuntos
Liliaceae , Saponinas , Triterpenos , Humanos , Rizoma/química , Esteroides/farmacologia , Esteroides/química , Liliaceae/química , Saponinas/química , Triterpenos/farmacologia , Triterpenos/análise
11.
J Am Chem Soc ; 145(42): 23176-23187, 2023 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-37822292

RESUMO

Polymeric nanoparticles (NPs) have been extensively designed for theranostic agent delivery. Previous methods for tracking their biological behavior and assessing theranostic efficacy heavily rely on fluorescence or isotope labeling. However, these labeling techniques may alter the physicochemical properties of the labeled NPs, leading to inaccurate biodistribution information. Therefore, it is highly desirable to develop label-free techniques for accurately assessing the biological fate of polymeric NPs. Here, we create discrete oligourethane amphiphiles (DOAs) with methoxy (OMe), hydroxyl (OH), and maleimide (MI) moieties at the dendritic oligo(ethylene glycol) (dOEG) ends. We obtained four types of digital nanorods (NRs) with distinct surface functional groups through self-assembly of a single DOA (OMe and OH NRs) or coassembly of two DOAs (OMe-MI and OH-MI NRs). These unique NRs can be directly quantified in a label-free manner by using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Specifically, OMe-MI NRs exhibited the best blood circulation, and OH-MI showed the highest area under the curve (AUC) value after intravenous injection. Biodistribution studies demonstrated that MI-containing NRs generally had lower accumulation in the liver and spleen compared to that of MI-free NRs, except for the comparison between OMe and OMe-MI NRs in the liver. Proteomics studies unveiled the formation of distinct protein coronas that may greatly affect the biological behavior of NRs. This study not only provides a label-free technique for quantifying the pharmacokinetics and biodistribution of polymeric NRs but also highlights the significant impact of surface functional groups on the biological fate of polymeric NPs.


Assuntos
Nanopartículas , Nanotubos , Distribuição Tecidual , Nanotubos/química , Nanopartículas/química , Espectrometria de Massas
12.
Artigo em Inglês | MEDLINE | ID: mdl-37599621

RESUMO

After the implantation of lower limb artery stents, the complex loading conditions imposed on the limb can lead to fatigue failure, which may induce inflammation and restenosis. To investigate the effect of multi-axial loading conditions on the fatigue performance of stents, five stents, namely APsolute Pro (APbott Vascular, USA), Complete SE (Medtronic, USA), Protégé EverFlex (PE3, USA), Pulsar-35 (Biotronik, Germany), and E-luminexx-B (Bard, USA), were analyzed based on the finite element method (FEM). Besides, their fatigue strength was determined under three levels of loading conditions, including tension-bending-torsion and compression-bending-torsion. Based on that, the fatigue life of these stents was predicted. The results showed that based on the nominal stress method, tension-bending-torsion loading had a more significant impact on the fatigue life of stents than compression-bending-torsion loading. Besides, two different types of initial cracks were analyzed by the fracture mechanics method. The results suggested that both the initial crack and the external load were the main causes of stent fatigue fractures. Compared with the loading nature, the influence of the initial crack on stent fatigue life was more significant. Under the same loading condition, the APsolute Pro stent had the longest fatigue life, while the E-luminexx-B stent had the shortest. Moreover, the mechanism of stent fatigue failure was revealed by exploring the fatigue performance and life prediction of stents under complex loading conditions. These findings have important implications for improving the structural design of stents and their clinical selection.

13.
J Xray Sci Technol ; 31(4): 811-824, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37334644

RESUMO

BACKGROUND: Photon counting spectral CT is a significant direction in the development of CT technology and material identification is an important application of spectral CT. However, spectrum estimation in photon counting spectral CT is highly complex and may affect quantification accuracy of material identification. OBJECTIVE: To address the problem of energy spectrum estimation in photon-counting spectral CT, this study investigates empirical material decomposition algorithms to achieve accurate quantitative decomposition of the effective atomic number. METHODS: The spectrum is first calibrated using the empirical dual-energy calibration (EDEC) method and the effective atomic number is then quantitatively estimated based on the EDEC method. The accuracy of estimating the effective atomic number of materials under different calibration conditions is investigated by designing different calibration phantoms, and accurate quantitation is achieved using suitable calibration settings. Last, the validity of this method is verified through simulations and experimental studies. RESULTS: The results demonstrate that the error in estimating the effective atomic number is reduced to within 4% for low and medium Z materials, thereby enabling accurate material identification. CONCLUSION: The empirical dual-energy correction method can solve the problem of energy spectrum estimation in photon counting spectral CT. Accurate effective atomic number estimation can be achieved with suitable calibration.


Assuntos
Algoritmos , Fótons , Imagens de Fantasmas , Calibragem , Tomografia Computadorizada por Raios X/métodos
14.
Angew Chem Int Ed Engl ; 62(33): e202306119, 2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37357832

RESUMO

Discrete polymers offer an excellent platform for comprehending the interplay between precise chain structures, distinctive self-assembly behavior, and functional applications, whereas the development of discrete polymers with self-immolative properties remains scarce. Here, we modularly synthesize a library of discrete self-immolative oligourethanes containing N-naphthylcarbamate or N-(3-fluorophenyl)carbamate repeating units via iterative stepwise growth. These oligourethanes undergo not only cascade 1,6-elimination depolymerizations via photo-mediated removal of o-nitrobenzyl carbamate triggers but also selective cleavage of benzyl-O linkages under MS/MS conditions even without UV light irradiation. In aqueous media, these discrete oligourethanes self-assemble into different morphologies such as flat nanosheets, nanofibers, and nanoribbons, depending on the chain lengths and backbone compositions, and further morphological transitions are observed upon thermal annealing.

15.
J Environ Manage ; 342: 118037, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37178462

RESUMO

Revealing the effects of reforestation on soil antibiotic resistome is essential for assessing ecosystem health, yet related studies remain scarce. Here, to determine the responses of the soil antibiotic resistome to reforestation, 30 pairs of cropland and forest soil samples were collected from southwestern China, a region with high environmental heterogeneity. All the forests had been derived from croplands more than one decade ago. The diversity and abundance of soil antibiotic resistance genes (ARGs), metal resistance genes (MRGs), mobile genetic elements (MGEs), and pathogens were determined by metagenomic sequencing and real-time PCR. The results showed that reforestation significantly increased soil microbial abundance and the contents of Cu, total carbon, total nitrogen, total organic carbon, and ammonium nitrogen. Nevertheless, it decreased the contents of soil Zn, Ba, nitrate nitrogen, and available phosphorus. The main soil ARGs identified in this region were vancomycin, multidrug, and bacitracin resistance genes. Reforestation significantly increased the soil ARG abundance by 62.58%, while it decreased the ARG richness by 16.50%. Reforestation exerted no significant effects on the abundance of heavy metal resistance genes and pathogens, but it doubled the abundance of MGEs. Additionally, reforestation substantially decreased the co-occurrence frequencies of ARGs with MRGs and pathogens. In contrast, the correlation between ARGs and MGEs was greatly enhanced by reforestation. Similarly, the correlations between soil ARG abundance and environmental factors were also strengthened by reforestation. These findings suggest that reforestation can substantially affect the soil antibiotic resistome and exerts overall positive effects on soil health by decreasing ARG richness, providing critical information for assessing the effects of "grain for green" project on soil health.


Assuntos
Genes Bacterianos , Solo , Antibacterianos/farmacologia , Ecossistema , Microbiologia do Solo , Sequências Repetitivas Dispersas
16.
Adv Healthc Mater ; 12(20): e2202827, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36977522

RESUMO

Cardiovascular disease remains the leading cause of mortality worldwide. The inability of cardiac tissue to regenerate after an infarction results in scar tissue formation, leading to cardiac dysfunction. Therefore, cardiac repair has always been a popular research topic. Recent advances in tissue engineering and regenerative medicine offer promising solutions combining stem cells and biomaterials to construct tissue substitutes that could have functions similar to healthy cardiac tissue. Among these biomaterials, plant-derived biomaterials show great promise in supporting cell growth due to their inherent biocompatibility, biodegradability, and mechanical stability. More importantly, plant-derived materials have reduced immunogenic properties compared to popular animal-derived materials (e.g., collagen and gelatin). In addition, they also offer improved wettability compared to synthetic materials. To date, limited literature is available to systemically summarize the progression of plant-derived biomaterials in cardiac tissue repair. Herein, this paper highlights the most common plant-derived biomaterials from both land and marine plants. The beneficial properties of these materials for tissue repair are further discussed. More importantly, the applications of plant-derived biomaterials in cardiac tissue engineering, including tissue-engineered scaffolds, bioink in 3D biofabrication, delivery vehicles, and bioactive molecules, are also summarized using the latest preclinical and clinical examples.


Assuntos
Materiais Biocompatíveis , Alicerces Teciduais , Animais , Materiais Biocompatíveis/farmacologia , Engenharia Tecidual/métodos , Medicina Regenerativa/métodos , Colágeno
17.
Angew Chem Int Ed Engl ; 62(20): e202219153, 2023 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-36929516

RESUMO

The peroxynitrite anion (ONOO- ) is closely associated with many diseases and the creation of ONOO- donors is an essential means of understanding its pathophysiological functions. However, it is challenging to develop ONOO- donors due to the difficulties in simultaneously producing highly reactive and short-lived nitric oxide (NO) and superoxide anion (O2 ⋅- ). Here, we report a novel strategy for constructing ONOO- donors by combining near-infrared (NIR)-mediated type I photosensitization and photoredox catalysis. The key design using a Nile blue analogue that can serve as both a type I photosensitizer and a metal-free photocatalyst. Intriguingly, the formation of O2 ⋅- via type I photosensitization avoids oxygen interference and instead activates nitrobenzofurazan-based NO donors via oxygen-tolerant NIR photoredox catalysis. The simultaneous release of O2 ⋅- and NO leads to ONOO- release, showing both antibacterial and antibiofilm activities.


Assuntos
Oxigênio , Ácido Peroxinitroso , Superóxidos , Óxido Nítrico , Antibacterianos/farmacologia , Catálise
18.
J Am Chem Soc ; 145(6): 3636-3646, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36724078

RESUMO

Single-unit monomer insertion (SUMI) has become an important strategy for the synthesis of sequence-controlled vinyl polymers due to its strong versatility and high efficiency. However, all reported SUMI processes are based on a free-radical mechanism, resulting in a limited number of monomer types being applicable to SUMI or a limited number of sequences of structural units that SUMI can synthesize. Herein, we developed a novel SUMI based on a cationic mechanism (cSUMI), which operates through a degenerative (similar to radical SUMI) but cationic chain transfer process. By optimizing the chain transfer agent (CTA) and monomer pairs, a high-efficiency cSUMI was achieved for vinyl ether and styrene monomers. Based on this reaction, a range of discrete oligomers containing vinyl ether and styrene moieties, and even α-/ω-end and in-chain sequence-regulated polymers were synthesized, most of which cannot be achieved by radical SUMI. In addition, we explored the application of these sequence-regulated polymers in the preparation of miktoarm star polymers, delivery of photosensitizers, and solubilization of fluorescence probes. The development of SUMI with a new mechanism will certainly broaden the scope of structures and sequences in precise vinyl-based polymers.

19.
J Nanobiotechnology ; 21(1): 58, 2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36810201

RESUMO

Over the past decade, a proliferation of research has used nanoparticles to deliver gaseous signaling molecules for medical purposes. The discovery and revelation of the role of gaseous signaling molecules have been accompanied by nanoparticle therapies for their local delivery. While most of them have been applied in oncology, recent advances have demonstrated their considerable potential in diagnosing and treating orthopedic diseases. Three of the currently recognized gaseous signaling molecules, nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S), are highlighted in this review along with their distinctive biological functions and roles in orthopedic diseases. Moreover, this review summarizes the progress in therapeutic development over the past ten years with a deeper discussion of unresolved issues and potential clinical applications.


Assuntos
Gases , Sulfeto de Hidrogênio , Transdução de Sinais , Sulfeto de Hidrogênio/uso terapêutico , Monóxido de Carbono , Óxido Nítrico
20.
ACS Appl Mater Interfaces ; 15(2): 3476-3485, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36621816

RESUMO

Pressure sensing is highly demanding in wearable devices, robotics, and artificial intelligence, whereas it is still a big challenge to develop a pressure sensor with an excellent linear response in a broad detection range. Herein, a flexible and porous carbon nanotube (CNT)/carbon black (CB)/carbonyl iron powder (CIP)/silicone composite is proposed by a simple strategy of mixing, curing, and washing. Due to the porous structure induced by the sacrifice of sugar particles, an excellent linear response (R2 = 0.999) is achieved for the composite sensor by manipulating the contributions of contact resistance and tunnel resistance to the sensing performance via the alternation of CB and CNT contents. Moreover, the porous structure donates the composite sensor a low compressive modulus at a low pressure level, while the CIPs introduced lead to a high compressive modulus at a high pressure level with the assistance of an external magnetic field. As a result, the sensor produced has a wide linear response range of 80 Pa to 220 kPa, much wider than most of the linear response pressure sensors reported previously. The wide detection range is demonstrated by cyclic pressure tests in the frequency range of 0.1-5 Hz, durability tests, and monitoring human or robot motions including breathing, walking, lifting, and boxing, etc. Taking the advantages of low cost, high sensitivity, and excellent linear response in a wide pressure range, the current composite sensor is promising for precise monitoring of human motions and delicate controlling of robots.


Assuntos
Nanotubos de Carbono , Dispositivos Eletrônicos Vestíveis , Humanos , Inteligência Artificial , Nanotubos de Carbono/química , Porosidade , Pressão
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