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1.
BMC Microbiol ; 24(1): 302, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39134973

RESUMO

BACKGROUND: Compost-bedded pack barns (CBP) are getting huge attention as an alternative housing system for dairy cows due to their beneficial impact on animal welfare. Effective microorganisms (EM) inoculums are believed to enhance compost quality, improve soil structure and benefit the environment. However, little information is available on the impact of incubation with external EM combinations on the barn environment, compost quality and microbial diversity in CBP. This experiment was carried out to investigate the effect of inoculating different combinations of EM [Lactobacillus plantarum (L), Compound Bacillus (B) and Saccharomyces cerevisiae (S)] on compost quality and microbial communities of CBP products, as well as the relationship with the heifers' barn environment. CBP barns were subjected to the following four treatments: CON with no EM inoculum, LB/LS/LBS were Incubated with weight ratios of 1:2 (L: B), 1:2 (L: S), 1:1:1 (L: B: S), respectively. RESULTS: The EM inoculation (LB, LS, LBS) reduced the concentration of respirable particulate matter (PM10 and PM2.5) in the CBP, and decreased the serum total protein and total cholesterol levels in heifers. Notably, LBS achieved the highest content of high-density lipoprotein compared to other treatments. Microbiome results revealed that EM inoculation reduced the bacterial abundance (Chao1 index) and fungal diversity (Shannon & Simpson indexes), while increasing the relative abundance of various bacterial genera (Pseudomonas, Paracoccus, Aequorivita) and fungi (Pestalotiopsis), which are associated with cellulose decomposition that ultimately resulted in accelerating organic matter degradation and humification. Furthermore, high nutrient elements (TK&TP) and low mycotoxin content were obtained with EM inoculation, with LBS showing a particularly pronounced effect. Meanwhile, LBS contributed to a decline in the proportion of fungal pathogen categories but also led to an increase in fungal saprotroph categories. CONCLUSION: Generally, EM inoculation positively impacted compost product quality as organic fertilizer and barn environment by modifying the abundance of cellulolytic bacteria and fungi, while inhibiting the reproduction of pathogenic microbes, especially co-supplementing with L, B and S achieved an amplifying effect.


Assuntos
Bactérias , Compostagem , Fungos , Animais , Bovinos , Compostagem/métodos , Fungos/classificação , Bactérias/classificação , Bactérias/isolamento & purificação , Abrigo para Animais , Interações Microbianas , Feminino , Microbiologia do Solo , Microbiota
2.
Opt Express ; 31(23): 37564-37573, 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-38017883

RESUMO

A hole-assisted three-core fiber (HATCF) has been proposed as a sensor for simultaneous measurement of refractive index (RI) and temperature. An 8 mm long HATCF is fused between two single mode fibers (SMFs). One air hole of the HATCF is opened by femtosecond laser ablation technique to expose a suspended core to the external environment. Due to the same diameters of the two suspended cores, the resonance couplings between the center core and the two suspended cores occur at the same wavelength, which leads to a strong resonance dip. When the solution is filled into the open air hole, the resonance dip is split in two dips because the phase matching wavelength between center core and the suspended core in the open air hole is changed. Simultaneous measurement of RI and temperature can be achieved by monitoring the wavelengths of the two dips. The measured RI and temperature sensitivities are 1369 nm/RIU in the range of 1.333-1.388 and 83.48 pm/°C in the range of 25-70 °C. The proposed sensor has outstanding advantages such as simple structure, high integration and dual parameter measurement, making it a potential application in the field of biological detection.

3.
Opt Express ; 31(20): 32543-32553, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37859055

RESUMO

An optical fiber sensor based on a hole-assisted dual-core fiber (HADCF) has been proposed and experimentally demonstrated for dual-parameter measurements. The dual-mode interferometer created uses the LP01 mode and LP11 mode in the suspended core of a specialist optical fiber, combined with a directional coupler formed by using the suspended core and the center core in a 16 mm long HADCF. Using this, the simultaneous measurement of salinity (due to the presence of NaCl) and temperature has been achieved through monitoring the interference dip and resonance dip. The sensitivities of the measurement of salinity and temperature are 190.7 pm/‰ and -188.2 pm/°C, respectively. The sensor developed has the advantages of simplicity of fabrication, a high level of integration and the potential for measurement of dual parameters, supporting its potential applications in marine environment measurements.

4.
Opt Lett ; 48(17): 4574-4577, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37656558

RESUMO

This Letter proposes a method that balances miniaturization and high performance of fiber optic speckle spectrometers. The periodically tapered coreless fiber is used as the scattering element to excite more higher-order modes in the coreless fiber. As a result, a remarkable spectral resolution of 0.03 nm in the near-infrared spectrum can be achieved with a 5-cm-long fiber. Narrow linewidth and broadband spectra in the wavelength of 1540-1560 nm are reconstructed separately, demonstrating the excellent performance of the designed all-fiber spectrometer. The spectral resolution of our proposed spectrometer is comparable to that of a 2-m multimode fiber spectrometer and has a significant improvement in miniaturization.

5.
Opt Express ; 30(13): 22746-22754, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-36224965

RESUMO

A magnetic field sensor based on a side-polished two-core fiber (SPTCF)-based Michelson interferometer (MI) has been developed and demonstrated. The magnetic field sensor is composed of a standard single mode fiber (SMF) and a section of tapered TCF. By side-polishing a segment of the TCF, the effective index of the exposed core can be made sensitive to the environmental refractive index (RI). To evaluate its performance, a magnetic fluid is used to cover the polished region with a magnetic field sensitive material, where the sensor then measures the magnetic field intensity by sensing the RI change of the magnetic fluid through the evanescent field in the polished core. The SPTCF MI device developed allows for vector magnetic field sensing because of its asymmetric structure, with its highest directional sensitivity being 55.2 pm/degree. Experimental results obtained show that when the magnetic field is parallel to the side-polished plane, a sensitivity of 1.262 nm/mT can be achieved, operating over the magnetic flux density region of 0-5 mT and over a temperature range of 20∼85 °C, where the device is minimally affected by temperature changes. The sensor is well suited to a variety of potential applications given its low cost, strong anti-interference ability, simple structure and high stability.

6.
Macromol Rapid Commun ; 42(12): e2100111, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33871122

RESUMO

An amphiphilic peptide dendrimer conjugated with gemcitabine (GEM), PEGylated dendron-Gly-Phe-Leu-Gly-GEM (PEGylated dendron-GFLG-GEM), is developed as a nano-prodrug for breast cancer therapy. The self-assembled behavior is observed under a transmission electron microscopy and dynamic light scattering. The negatively charged surface and hydrodynamic size of the amphiphilic nanosized prodrug supported that the prodrug can maintain the stability of GEM during circulation and accumulate in the tumor tissue. Drug release assays are conducted to monitor the release of GEM from this nanodrug delivery system in response to the tumor microenvironment, and these assays confirm that GEM released from the nanocarrier is identical to free GEM. The GEM prodrug can prevent proliferation of tumor cells. The therapeutic effect against breast cancer is systematically investigated using an in vivo animal model. Immunohistochemical results are aligned with the significantly enhanced anticancer efficacy of GEM released from the prodrug. This self-assembled amphiphilic drug delivery nanocarrier may broaden the application for GEM and other anticancer agents for breast cancer chemotherapy.


Assuntos
Dendrímeros , Nanopartículas , Neoplasias , Pró-Fármacos , Animais , Linhagem Celular Tumoral , Desoxicitidina/análogos & derivados , Peptídeos , Polietilenoglicóis , Pró-Fármacos/farmacologia , Gencitabina
7.
Front Nutr ; 11: 1409026, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38765820

RESUMO

Moringa oleifera (M. oleifera) is a natural plant that has excellent nutritional and medicinal potential. M. oleifera leaves (MOL) contain several bioactive compounds. The aim of this study was to evaluate the potential effect of MOL polysaccharide (MOLP) on intestinal flora in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mice. DSS-induced colitis was deemed to be a well-characterized experimental colitis model for investigating the protective effect of drugs on UC. In this study, we stimulated the experimental mice with DSS 4% for 7 days and prepared the high dose of MOLP (MOLP-H) in order to evaluate its effect on intestinal flora in DSS-induced UC mice, comparing three experimental groups, including the control, DSS model, and DSS + MOLP-H (100 mg/kg/day). At the end of the experiment, feces were collected, and the changes in intestinal flora in DSS-induced mice were analyzed based on 16S rDNA high throughput sequencing technology. The results showed that the Shannon, Simpson, and observed species indices of abundance decreased in the DSS group compared with the control group. However, the indices mentioned above were increased in the MOLP-H group. According to beta diversity analysis, the DSS group showed low bacterial diversity and the distance between the control and MOLP-H groups, respectively. In addition, compared with the control group, the relative abundance of Firmicutes in the DSS group decreased and the abundance of Helicobacter increased, while MOLP-H treatment improves intestinal health by enhancing the number of beneficial organisms, including Firmicutes, while reducing the number of pathogenic organisms, such as Helicobacter. In conclusion, these findings suggest that MOLP-H may be a viable prebiotic with health-promoting properties.

8.
Adv Mater ; : e2405075, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39136067

RESUMO

Bacterial-derived micro-/nanomedicine has garnered considerable attention in anticancer therapy, owing to the unique natural features of bacteria, including specific targeting ability, immunogenic benefits, physicochemical modifiability, and biotechnological editability. Besides, bacterial components have also been explored as promising drug delivery vehicles. Harnessing these bacterial features, cutting-edge physicochemical and biotechnologies have been applied to attenuated tumor-targeting bacteria with unique properties or functions for potent and effective cancer treatment, including strategies of gene-editing and genetic circuits. Further, the advent of bacteria-inspired micro-/nanorobots and mimicking artificial systems has furnished fresh perspectives for formulating strategies for developing highly efficient drug delivery systems. Focusing on the unique natural features and advantages of bacteria, this review delves into advances in bacteria-derived drug delivery systems for anticancer treatment in recent years, which has experienced a process from living entities to artificial mimicking systems. Meanwhile, a summary of relative clinical trials is provided and primary challenges impeding their clinical application are discussed. Furthermore, future directions are suggested for bacteria-derived systems to combat cancer.

9.
Acta Psychol (Amst) ; 248: 104381, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38943873

RESUMO

Socioeconomic status' (SES) impact on depressive symptoms has been extensively examined; however, previous studies have generally used variable-centered approaches and cross-sectional designs. Therefore, this study explored the subtypes of depression and examined the degree of association between SES and latent transition probabilities. We used latent profile and latent transition analyses with the 2015 and 2018 waves of data from the China Health and Retirement Longitudinal Study (N = 4904). Three subtypes of depression were identified based on symptoms: severe symptom (SS), low symptom (LS), and sub-health (MS). The SS subtype had the highest probability of staying within the original subtype. Individuals in the MS subtype were more likely to move to the SS subtype than those in the LS subtype. The heterogeneity analysis also showed that the effect of SES on latent transition probabilities is heterogeneous to the satisfaction with their relationship with their children, as well as the number of children. Additionally, decision tree analysis found SES and gender can predict transitioning. These findings add to literature on the effects of SES on the heterogeneity of depression and have implications for depression screening and identifying individuals in need of targeted interventions.


Assuntos
Depressão , Classe Social , Humanos , Masculino , Feminino , Estudos Longitudinais , China , Idoso , Pessoa de Meia-Idade , População do Leste Asiático
10.
Adv Sci (Weinh) ; 11(11): e2307154, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38161213

RESUMO

Nanozyme catalytic therapy for cancer treatments has become one of the heated topics, and the therapeutic efficacy is highly correlated with their catalytic efficiency. In this work, three copper-doped CeO2 supports with various structures as well as crystal facets are developed to realize dual enzyme-mimic catalytic activities, that is superoxide dismutase (SOD) to reduce superoxide radicals to H2 O2 and peroxidase (POD) to transform H2 O2 to ∙OH. The wire-shaped CeO2 /Cu-W has the richest surface oxygen vacancies, and a low level of oxygen vacancy (Vo) formation energy, which allows for the elimination of intracellular reactive oxygen spieces (ROS) and continuous transformation to ∙OH with cascade reaction. Moreover, the wire-shaped CeO2 /Cu-W displays the highest toxic ∙OH production capacity in an acidic intracellular environment, inducing breast cancer cell death and pro-apoptotic autophagy. Therefore, wire-shaped CeO2 /Cu nanoparticles as an artificial enzyme system can have great potential in the intervention of intracellular ROS in cancer cells, achieving efficacious nanocatalytic therapy.


Assuntos
Cério , Cobre , Neoplasias , Humanos , Espécies Reativas de Oxigênio/metabolismo , Oxigênio
11.
Adv Mater ; 35(48): e2303107, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37730433

RESUMO

Ammonia (NH3 ), known as one of the fundamental raw materials for manufacturing commodities such as chemical fertilizers, dyes, ammunitions, pharmaceuticals, and textiles, exhibits a high hydrogen storage capacity of ≈17.75%. Electrochemical nitrate reduction (NO3 RR) to valuable ammonia at ambient conditions is a promising strategy to facilitate the artificial nitrogen cycle. Herein, copper-doped cobalt selenide nanosheets with selenium vacancies are reported as a robust and highly efficient electrocatalyst for the reduction of nitrate to ammonia, exhibiting a maximum Faradaic efficiency of ≈93.5% and an ammonia yield rate of 2360 µg h-1 cm-2 at -0.60 V versus reversible hydrogen electrode. The in situ spectroscopical and theoretical study demonstrates that the incorporation of Cu dopants and Se vacancies into cobalt selenide efficiently enhances the electron transfer from Cu to Co atoms via the bridging Se atoms, forming the electron-deficient structure at Cu sites to accelerate NO3 - dissociation and stabilize the *NO2 intermediates, eventually achieving selective catalysis in the entire NO3 RR process to produce ammonia efficiently.

12.
Biomaterials ; 302: 122294, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37657175

RESUMO

The advent of immune checkpoint inhibitors ushers in a new era of anti-tumor immunity. However, current clinical anti-PD-L1 antibodies only interdict PD-L1 on the membrane, which cannot diminish the complex cancer-promoting effects of intracellular PD-L1. Therefore, directly reducing the PD-L1 abundance of cancer cells might be a potential PD-L1 inhibitory strategy to circumvent the issues of current anti-PD-L1 antibodies. Herein, we develop a dendritic polymer-functionalized nanomedicine with a potent cellular energy depletion effect on colon cancer cells. Treatment with the nanomedicine significantly promotes phosphorylation of AMPK, which in turn leads to PD-L1 degradation and eventual T cell activation. Meanwhile, the nanomedicine can potently induce immunogenic cell death (ICD) to enhance the anti-cancer immunity. Moreover, the combination of the nanomedicine with PD-1 blockade further enhances the activity of cytotoxic T lymphocytes, and dramatically inhibits tumor growth in vivo without distinct side effects. Overall, this study provides a promising nanoplatform to induce lethal energy crisis and ICD, and suppress PD-L1 expression, thus potentiating cancer immunotherapy.


Assuntos
Dendrímeros , Antígeno B7-H1 , Nanomedicina , Imunoterapia , Colo , Linhagem Celular Tumoral , Microambiente Tumoral
13.
Spectrochim Acta A Mol Biomol Spectrosc ; 293: 122486, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36801737

RESUMO

Selective labelling of the plasma membrane (PM) by fluorescence imaging techniques enables an intuitive analysis of cell status together with dynamic changes, and therefore is of great value. We herein disclose a novel carbazole-based probe, CPPPy, that shows aggregation-induced emission (AIE) property and is observed to selectively accumulate at the PM of living cells. Benefiting from its good biocompatibility and PM-targeted specificity, CPPPy can light up the PM of cells by high-resolution imaging even at a low concentration of 200 nM. Simultaneously, CPPPy is capable of generating both singlet oxygen and free radical-dominated species upon visible light irradiation, which further induces irreversible growth inhibition and necrocytosis of tumor cells. This study thus provides new insight into the construction of multifunctional fluorescence probes with PM-specific bioimaging and photodynamic therapy.


Assuntos
Neoplasias , Fotoquimioterapia , Fotoquimioterapia/métodos , Luz , Membrana Celular , Imagem Óptica , Oxigênio Singlete , Fármacos Fotossensibilizantes/farmacologia , Neoplasias/tratamento farmacológico
14.
Adv Mater ; 35(11): e2210161, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36504170

RESUMO

Tumor cells are dominant in the nutritional competition in the tumor microenvironment, and their metabolic abnormalities often lead to microenvironmental acidosis and nutrient deprivation, thereby impairing the function of immune cells and diminishing the antitumor therapeutic effect. Herein, a branched polymeric conjugate and its efficacy in attenuating the metabolic competition of tumor cells are reported. Compared with the control nanoparticles prepared from its linear counterpart, the branched-conjugate-based nanoparticles can more efficiently accumulate in the tumor tissue and interfere with the metabolic processes of tumor cells to increase the concentration of essential nutrients and reduce the level of immunosuppressive metabolites in the TME, thus creating a favorable environment for infiltrated immune cells. Its combined treatment with an immune checkpoint inhibitor (ICI) achieves an enhanced antitumor effect. The work presents a promising approach for targeting metabolic competition in the TME to enhance the chemo-immunotherapeutic effect against cancers.


Assuntos
Imunoterapia , Neoplasias , Humanos , Sistemas de Liberação de Medicamentos , Neoplasias/terapia , Microambiente Tumoral , Linhagem Celular Tumoral
15.
Bioact Mater ; 26: 102-115, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36875053

RESUMO

Cancer cells could be eradicated by promoting generation of excessive intracellular reactive oxygen species (ROS) via emerging nanomedicines. However, tumor heterogeneity and poor penetration of nanomedicines often lead to diverse levels of ROS production in the tumor site, and ROS at a low level promote tumor cell growth, thus diminishing the therapeutic effect of these nanomedicines. Herein, we construct an amphiphilic and block polymer-dendron conjugate-derived nanomedicine (Lap@pOEGMA-b-p(GFLG-Dendron-Ppa), GFLG-DP/Lap NPs) that incorporates a photosensitizer, Pyropheophorbide a (Ppa), for ROS therapy and Lapatinib (Lap) for molecular targeted therapy. Lap, an epidermal growth factor receptor (EGFR) inhibitor that plays a role in inhibiting cell growth and proliferation, is hypothesized to synergize with ROS therapy for effectively killing cancer cells. Our results suggest that the enzyme-sensitive polymeric conjugate, pOEGMA-b-p(GFLG-Dendron-Ppa) (GFLG-DP), releases in response to cathepsin B (CTSB) after entering the tumor tissue. Dendritic-Ppa has a strong adsorption capacity to tumor cell membranes, which promotes efficient penetration and long-term retention. Lap can also be efficiently delivered to internal tumor cells to play its role due to the increased vesicle activity. Laser irradiation of Ppa-containing tumor cells results in production of intracellular ROS that is sufficient for inducing cell apoptosis. Meanwhile, Lap efficiently inhibits proliferation of remaining viable cells even in deep tumor regions, thus generating a significant synergistic anti-tumor therapeutic effect. This novel strategy can be extended to the development of efficient membrane lipid-based therapies to effectively combat tumors.

16.
Adv Mater ; 35(23): e2300548, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36917817

RESUMO

Targeting metabolic vulnerability of tumor cells is a promising anticancer strategy. However, the therapeutic efficacy of existing metabolism-regulating agents is often compromised due to tolerance resulting from tumor metabolic plasticity, as well as their poor bioavailability and tumor-targetability. Inspired by the inhibitive effect of N-ethylmaleimide on the mitochondrial function, a dendronized-polymer-functionalized metal-phenolic nanomedicine (pOEG-b-D-SH@NP) encapsulating maleimide-modified doxorubicin (Mal-DOX) is developed to enable improvement in the overall delivery efficiency and inhibition of the tumor metabolism via multiple pathways. It is observed that Mal-DOX and its derived nanomedicine induces energy depletion of CT26 colorectal cancer cells more efficiently than doxorubicin, and shifts the balance of programmed cell death from apoptosis toward necroptosis. Notably, pOEG-b-D-SH@NP simultaneously inhibits cellular oxidative phosphorylation and glycolysis, thus potently suppressing cancer growth and peritoneal intestinal metastasis in mouse models. Overall, the study provides a promising dendronized-polymer-derived nanoplatform for the treatment of cancers through impairing metabolic plasticity.


Assuntos
Neoplasias Colorretais , Nanopartículas , Animais , Camundongos , Nanomedicina , Portadores de Fármacos/farmacologia , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Polímeros , Neoplasias Colorretais/tratamento farmacológico , Linhagem Celular Tumoral
17.
PeerJ Comput Sci ; 8: e942, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35494857

RESUMO

Random forwarding networks play a significant role in solving security and load balancing problems. As a random quantity easily obtained by both sender and receiver, the end-to-end delay of random forwarding networks can be utilized as an effective random source for cryptography-related applications. In this paper, we propose a mathematical model of Random forwarding networks and give the calculation method of end-to-end delay distribution. In exploring the upper limit of the randomness of end-to-end delay, we find that the end-to-end delay collision of different forwarding routes is the main reason for the decrease of end-to-end delay randomness. Some of these collisions can be optimized by better network deployment, while others are caused by some interesting network topology, which is unavoidable. For further analysis, we propose an algorithm to calculate the inevitable collision in random forwarding networks skillfully by using Symbol Matrix, and we give the optimal node forwarding strategy with the maximum randomness of the end-to-end delay for a given number of middle forwarding nodes and forwarding times. Finally, we introduce a specific application of generating symmetric keys by using the randomness of the end-to-end delay.

18.
J Agric Food Chem ; 70(23): 6943-6962, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35666880

RESUMO

The extensive use of high-concentration copper (Cu) in feed additives, fertilizers, pesticides, and nanoparticles (NPs) inevitably causes significant pollution in the ecological environment. This type of chain pollution begins with animal husbandry: first, Cu accumulation in animals poisons them; second, high Cu enters the soil and water sources with the feces and urine to cause toxicity, which may further lead to crop and plant pollution; third, this process ultimately endangers human health through consumption of livestock products, aquatic foods, plants, and even drinking water. High Cu potentially alters the antibiotic resistance of soil and water sources and further aggravates human disease risks. Thus, it is necessary to formulate reasonable Cu emission regulations because the benefits of Cu for livestock and plants cannot be ignored. The present review evaluates the potential hazards and benefits of high Cu in livestock, the environment, the plant industry, and human health. We also discuss aspects related to bacterial and fungal resistance and homeostasis and perspectives on the application of Cu-NPs and microbial high-Cu removal technology to reduce the spread of toxicity risks to humans.


Assuntos
Gado , Poluentes do Solo , Animais , Cobre/toxicidade , Homeostase , Humanos , Plantas , Solo , Água
19.
Acta Biomater ; 143: 320-332, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35235863

RESUMO

In this study, we developed an enzyme- and pH-responsive dendronized poly(oligo-(ethylene glycol) methacrylate) (pOEGMA)-doxorubicin (DOX) polymeric prodrug, which combined the pOEGMA structure with a degradable peptide dendron. The introduction of the dendron in the prodrug hindered the entanglement of brush oligo-(ethylene glycol) (OEG) chains, allowed the prodrug to possess dual stimuli-responsiveness, and mediated self-assembly of the polymeric prodrug to form stable nanoparticles (NPs). Brush conformation of polyethylene glycol (PEG) side chains endowed the NPs with long-term circulation with a half-life of 16.0 h. The dual-responsive dendritic structure enhanced cellular uptake of NPs and facilitated drug release in response to overexpressed cathepsin B and an acidic pH in the tumor microenvironment, resulting in an enhanced therapeutic effect with a tumor inhibition rate of 72.9% for 4T1 tumor-bearing mice. The NPs were demonstrated to possess great hemocompatibility and biosafety. Therefore, this strategy could provide great insight for the design of poly(oligo-(ethylene glycol) methacrylate)-based copolymers as drug delivery carriers. STATEMENT OF SIGNIFICANCE: We propose a dual-stimuli-responsive dendronized strategy for improving the cancer therapeutic effect of the poly(oligo-(ethylene glycol) methacrylate) (pOEGMA)-based drug conjugates. The introduction of the functional dendron promotes self-assembly of the polymeric prodrug into nanoparticles, hindering the entanglement of brush oligo-(ethylene glycol) (OEG) chains in the conjugated drugs. The obtained poly OEGMA-GFLG-Dendron-NH-N=DOX nanoparticles maintains long circulation, while addresses the drug release issue due to the presence of high-density PEG. The drug delivery system exhibits a high therapeutic potentcy with negligible side effects.


Assuntos
Nanopartículas , Neoplasias , Pró-Fármacos , Animais , Doxorrubicina/química , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Etilenoglicol , Metacrilatos/química , Metacrilatos/farmacologia , Camundongos , Nanopartículas/química , Neoplasias/tratamento farmacológico , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Polímeros/química , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Microambiente Tumoral
20.
Adv Sci (Weinh) ; 9(30): e2201903, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36057998

RESUMO

Amorphization and crystalline grain boundary engineering are adopted separately in improving the catalytic kinetics for water electrolysis. Yet, the synergistic effect and advance in the cooperated form of crystalline/amorphous interfaces (CAI) have rarely been elucidated insightfully. Herein, a trimetallic FeCo(NiS2 )4 catalyst with numerous CAI (FeCo(NiS2 )4 -C/A) is presented, which shows highly efficient catalytic activity toward both hydrogen and oxygen evolution reactions (HER and OER). Density functional theory (DFT) studies reveal that CAI plays a significant role in accelerating water electrolysis kinetics, in which Co atoms on the CAI of FeCo(NiS2 )4 -C/A catalyst exhibit the optimal binding energy of 0.002 eV for H atoms in HER while it also has the lowest reaction barrier of 1.40 eV for the key step of OER. H2 O molecules are inclined to be absorbed on the interfacial Ni atoms based on DFT calculations. As a result, the heterostructural CAI-containing catalyst shows a low overpotential of 82 and 230 mV for HER and OER, respectively. As a bifunctional catalyst, it delivers a current density of 10 mA cm-2 at a low cell voltage of 1.51 V, which enables it a noble candidate as metal-based catalysts for water splitting. This work explores the role of CAI in accelerating the HER and OER kinetics for water electrolysis, which sheds light on the development of efficient, stable, and economical water electrolysis systems by facile interface-engineering implantations.


Assuntos
Ferro , Água , Água/química , Cinética , Eletrólise , Cobalto , Hidrogênio/química , Oxigênio
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