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1.
Sci Total Environ ; 954: 176615, 2024 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-39349192

RESUMO

Microorganisms thriving in drinking water distribution system (DWDS) reduces biological stability of water, causing numerous threats to residents' drinking water safety. Traditional disinfection methods have intrinsic drawbacks, including microbial reactivation and byproduct formation, leading to waterborne diseases. Thus, effective disinfection techniques are required to ensure the microorganism's inactivation and enhance biological stability. Micro-nano bubbles (MNB) provide a promising result to these issues. This study simulates the hydraulic conditions of the tank of DWDS to investigate the enhancement of biological stability in the tank using MNBs with distinct gas sources. The analysis focused on water quality characteristics, biological stability indicators, and microbial community composition. The results showed that the dissolved gas method could generate abundant bubbles with a particle size below 1000 nm, with a concentration exceeding 106/mL in water. The particle size and Zeta potential of bubbles were crucial factors influencing in situ the ·OH generation; hence, the ·OH concentration was highly sensitive to changes in bubble size. In addition, MNBs inhibited the growth of target bacteria in water, degraded organic matter, and improved the biological stability of drinking water, reaching significant degradation rates for biodegradable dissolved organic carbon (42.74 %), assimilable organic carbon (49.49 %), and total bacteria (51.32 %). MNBs directly degraded organic matter in water by ·OH generation in situ, reducing the microbial nutrient source, thereby inhibiting microbial metabolism and activity, which induced optimum disinfection effects on Proteobacteria, Cyanobacteria, and Planctomycetota in water. In particular, the proposed experiment achieved a 100 % disinfection rate for Acinetobacter in Proteobacteria, disrupting metabolic intermediate functions with the microbial community after MNB treatment. Therefore, this study has demonstrated the potential of MNBs to enhance the biological stability of drinking water, improve water quality, and ensure residents' water health, providing valuable technical support for drinking water safety.

2.
Small ; : e2405649, 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39263810

RESUMO

Nitric oxide (NO), a key element in the regulation of essential biological mechanisms, presents huge potential as therapeutic agent in the treatment and prevention of chronic diseases. Metal-organic frameworks (MOFs) with open metal sites are promising carriers for NO therapies but delivering it over an extended period in biological media remains a great challenge due to i) a fast degradation of the material in body fluids and/or ii) a rapid replacement of NO by water molecules onto the Lewis acid sites. Here, a new ultra-narrow pores Fe bisphosphonate MOF, denoted MIP-210(Fe) or Fe(H2O)(Hmbpa) (H4mbpa = p-xylenediphosphonic acid) is described that adsorbs NO due to an unprecedented sorption mechanism: coordination of NO through the Fe(III) sites is unusually preferred, replacing bound water, and creating a stable interaction with the free H2O and P-OH groups delimiting the ultra-narrow pores. This, associated with the high chemical stability of the MOF in body fluids, enables an unprecedented slow replacement of NO by water molecules in biological media, achieving an extraordinarily extended NO delivery time over at least 70 h, exceeding by far the NO kinetics release reported with others porous materials, paving the way for the development of safe and successful gas therapies.

3.
Sci Rep ; 14(1): 18256, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39107368

RESUMO

The aim is to develop new fiber-reinforced polymer (FRP) water pipe by activating fiber glass (FG) by vinyltriethoxysilane (VS) getting vinylsilane-activated FG (AFG) for filling vinylester (VE) via continuous winding to make a novel VE-AFG composite. The novelty of this work is the activation of fiber glass by vinylsilane as a single filler in vinylester and compounding them via a two-dimensional continuous winding process for the first time. The crosslinking occurred in the AFG/VE/curing agent system after activation. The activated composites increased thermal stability; 25% VE-AGF increased the degradation temperatures at 10%, 25%, and 50% weight loss by 73.3%, 10%, and 7.2%. With the activated 20% composite, values of axial strength, hoop strength, and hardness were developed by 6.3%, 2%, and 8.7%, respectively. The decay resistance to different microorganisms was increased with VE-AFG composites as a result of a sharp decrease in biodegradability percentages. The activated composites are stable toward water absorption; the least percentage was recorded by 25% VE-AFG, which minimized the water absorptivity by more than 62%. The reported characterization sentence approves enhancement of thermal, physical, and mechanical stability of sustainable vinylester-fiber glass composites manufactured by continuous winding; this is recommended for application in water pipe systems.

4.
Sci Total Environ ; 929: 172441, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38614327

RESUMO

Climate and time are among the most important factors driving soil organic carbon (SOC) stability and accrual in mineral soils; however, their relative importance on SOC dynamics is still unclear. Therefore, understanding how these factors covary over a range of soil developmental stages is crucial to improve our knowledge of climate change impact on SOC accumulation and persistence. Two chronosequences located along a climate gradient were investigated to determine the main interactions among time (age) and climate (precipitation and temperature) on SOC stability and stock with depth. Considering a common depth (0-15 or 0-30 cm), in the drier chronosequence, the older soil showed the highest SOC stock, while the younger exhibited the lowest carbon accumulation. Considering the whole profile, the SOC stock increased with age. In the wetter chronosequence, the younger soil showed the highest SOC stock considering a common depth, whereas, when the entire profile is taken into account, the older one accumulated 2-3 times more SOC than the others. In both chronosequences, significant stocks of SOC (∼42 %) were accumulated below 30 cm. Soil organic matter stability, assessed by thermal analysis and heterotrophic respiration, increases with depth and age only in the drier chronosequence. Soils from the wetter chronosequence were instead characterized by a greater quantity of labile and/or not-stabilized SOC; here, the amorphous Fe/Al-rich secondary mineral weathering products showed an essential predictor function of SOC storage, although they do not seem to be involved in SOC stabilization mechanisms. Otherwise, the interaction of SOC with fine particles, short-range order minerals, and organo-metal complexes represent the significant stabilization mechanisms in soils from drier climate. The results highlighted how the age factor plays an unassuming role in geochemical processes influencing SOC dynamics; however, climate determines different trajectories of soil development and SOC dynamics for a given soil age. Thus, soil age shows a key role in SOC stabilization especially in drier climatic conditions, while wetter conditions determine an accumulation of a higher yet more labile amount of SOC.

5.
J Environ Manage ; 355: 120493, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38452624

RESUMO

The present study aimed to narrow such gaps by applying nonlinear differential equations to biostability in drinking water. Biostability results from the integrated dynamics of nutrients and disinfectants. The linear dynamics of biostability have been well studied, while there remain knowledge gaps concerning nonlinear effects. The nonlinear effects are explained by phase plots for specific scenarios in a drinking water system, including continuous nutrient release, flush exchange with the adjacent environment, periodic pulse disinfection, and periodic biofilm development. The main conclusions are, (1) The correlations between the microbial community and nutrients go through phases of linear, nonlinear, and chaotic dynamics. Disinfection breaks the chaotic phase and returns the system to the linear phase, increasing the microbial growth potential. (2) Post-disinfection after multiple microbial peaks produced via metabolism can increase disinfection efficiency and decrease the risks associated with disinfectant byproduct risks. This can provide guidelines for optimizing the disinfection strategy, according to the long-term water safety target or a short management. Limited disinfection and ultimate disinfection may be more effective and have low chemical risk, facing longer stagnant conditions. (3) Periodic biofilm formation and biofilm detachment increase the possibility of uncertainty in the chaotic phase. For future study, nonlinear differential equation models can accordingly be applied at the molecular and ecological levels to further explore more nonlinear regulation mechanisms.


Assuntos
Desinfetantes , Água Potável , Purificação da Água , Cloro/química , Cloro/farmacologia , Desinfecção/métodos , Biofilmes , Purificação da Água/métodos
6.
Small ; 20(30): e2306257, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38377302

RESUMO

Due to the disadvantages of poor targeting, slow action, and low effectiveness of current commonly used cancer treatments, including surgery, chemotherapy, and radiotherapy, researchers have turned to DNA as a biomaterial for constructing drug delivery nanocarriers. DNA is favored for its biocompatibility and programmability. In order to overcome the limitations associated with traditional drug delivery systems (DDSs), researchers have developed smart-responsive DNA DDSs that can control drug release in response to specific physical or chemical stimuli at targeted sites. In this review, a summary of multiple targeted ligand structures is provided, various shapes of stable DNA nanomaterials, and different stimuli-responsive drug release strategies in DNA DDSs. Specifically, targeted cell recognition, in vivo stable transport, and controlled drug release of smart DDSs are focused. Finally, the further development prospects and challenges of clinical application of DNA nanomaterials in the field of smart drug delivery are discussed. The objective of this review is to enhance researchers' comprehension regarding the potential application of DNA nanomaterials in precision drug delivery, with the aim of expediting the clinical implementation of intelligent DDSs.


Assuntos
DNA , Sistemas de Liberação de Medicamentos , Neoplasias , Humanos , DNA/química , Sistemas de Liberação de Medicamentos/métodos , Neoplasias/tratamento farmacológico , Nanoestruturas/química , Animais
7.
Water Res ; 252: 121188, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38324987

RESUMO

Ensuring biological stability in drinking water distribution systems (DWDSs) is important to reduce the risk of aesthetic, operational and hygienic impairments of the distributed water. Drinking water after treatment often changes in quality during transport due to interactions with pipe-associated biofilms, temperature increases and disinfectant residual decay leading to potential biological instability. To comprehensively assess the potential for biological instability in a large chlorinated DWDS, a tool-box of bacterial biomass and activity parameters was applied, introducing bacterial community turnover times (BaCTT) as a direct, sensitive and easy-to-interpret quantitative parameter based on the combination of 3H-leucine incorporation with bacterial biomass. Using BaCTT, hotspots and periods of bacterial growth and potential biological instability could be identified in the DWDS that is fed by water with high bacterial growth potential. A de-coupling of biomass from activity parameters was observed, suggesting that bacterial biomass parameters depict seasonally fluctuating raw water quality rather than processes related to biological stability of the finished water in the DWDS. BaCTT, on the other hand, were significantly correlated to water age, disinfectant residual, temperature and a seasonal factor, indicating a higher potential of biological instability at more distant sampling sites and later in the year. As demonstrated, BaCTT is suggested as a novel, sensitive and very useful parameter for assessing the biological instability potential. However, additional studies in other DWDSs are needed to investigate the general applicability of BaCTT depending on water source, applied treatment processes, biofilm growth potential on different pipe materials, or size, age and complexity of the DWDS.


Assuntos
Desinfetantes , Água Potável , Purificação da Água , Áustria , Qualidade da Água , Bactérias , Biofilmes , Abastecimento de Água , Microbiologia da Água
8.
Int J Pharm ; 649: 123643, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38040395

RESUMO

The two anti-epidermal growth factor receptor monoclonal antibodies (mAbs) cetuximab and panitumumab are the pillars for the treatment of EGFR-positive, KRAS wild-type metastatic colorectal cancers. However, stability data of these mAbs are generally missing or incomplete. Here, we report for the first time an orthogonal analysis of the stability of cetuximab (Erbitux®) and panitumumab (Vectibix®), either undiluted vial leftovers or saline dilutions in polyolefin/polyamide infusion bags. All samples were stored at 2-8 °C protected from light, according to their summary of product characteristics (SmPCs). Alternatively, opened vials and preparations were maintained at 25 °C for 15 h, and then stored again at 2-8 °C protected from light to mimic a temporary interruption of the cold chain. Vial leftovers proved stable up to 180 days when stored according to their SmPCs, while compounded preparations in infusion bags maintained their physiochemical, biological and microbiological stability up to 30 days. Additionally, no changes were detected up to 30 days for the same samples undergoing a thermal excursion. Our results provide additional rationale to the SmPCs, crucial especially in the case of reassignment and pre-preparation of bags. This information will allow hospitals to achieve significant cost savings, and better organization of the entire therapeutic process.


Assuntos
Antineoplásicos , Neoplasias Colorretais , Humanos , Panitumumabe/uso terapêutico , Cetuximab , Neoplasias Colorretais/tratamento farmacológico , Anticorpos Monoclonais , Solução Salina
9.
ACS Nano ; 17(18): 17996-18007, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37713675

RESUMO

The stability of the core can significantly impact the therapeutic effectiveness of liposome-based drugs. While the spherical nucleic acid (SNA) architecture has elevated liposomal stability to increase therapeutic efficacy, the chemistry used to anchor the DNA to the liposome core is an underexplored design parameter with a potentially widespread biological impact. Herein, we explore the impact of SNA anchoring chemistry on immunotherapeutic function by systematically studying the importance of hydrophobic dodecane anchoring groups in attaching DNA strands to the liposome core. By deliberately modulating the size of the oligomer that defines the anchor, a library of structures has been established. These structures, combined with in vitro and in vivo immune stimulation analyses, elucidate the relationships between and importance of anchoring strength and dissociation of DNA from the SNA shell on its biological properties. Importantly, the most stable dodecane anchor, (C12)9, is superior to the n = 4-8 and 10 structures and quadruples immune stimulation compared to conventional cholesterol-anchored SNAs. When the OVA1 peptide antigen is encapsulated by the (C12)9 SNA and used as a therapeutic vaccine in an E.G7-OVA tumor model, 50% of the mice survived the initial tumor, and all of those survived tumor rechallenge. Importantly, the strong innate immune stimulation does not cause a cytokine storm compared to linear immunostimulatory DNA. Moreover, a (C12)9 SNA that encapsulates a peptide targeting SARS-CoV-2 generates a robust T cell response; T cells raised from SNA treatment kill >40% of target cells pulsed with the same peptide and ca. 45% of target cells expressing the entire spike protein. This work highlights the importance of using anchor chemistry to elevate SNA stability to achieve more potent and safer immunotherapeutics in the context of both cancer and infectious disease.


Assuntos
COVID-19 , Ácidos Nucleicos , Animais , Camundongos , Lipossomos , SARS-CoV-2 , DNA , Imunização
10.
Water Res ; 245: 120598, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37722140

RESUMO

Ion exchange resins (IEX) are used in drinking water utilities to remove natural organic matter (NOM) from surface water; however, the disposal of used brine can be a major drawback. Recently, biological ion exchange (BIEX) has been proposed as an alternative to biological activated carbon (BAC) for removing natural organic matter (NOM). The present study is, to the best of our knowledge, the first attempt to use a hybrid BIEX and BAC (BIEX+BAC) system for drinking water treatment. The removal of NOM, assimilable organic carbon, and trihalomethane formation potential was investigated by operating four columns comprising IEX, BIEX, BAC, and BIEX+BAC with 18,000 bed volumes. The BIEX+BAC system was the most effective at removing dissolved organic carbon (59.9%). Based on fluorescence excitation-emission matrix spectroscopy, the BIEX+BAC column showed the maximum removal rates in all peak regions of T1, T2, and A. Using liquid chromatography-organic carbon detection, resin-containing columns were found to effectively remove humic substances, which are the principal precursors of trihalomethanes. The lowest potential for trihalomethane formation was observed in BIEX+BAC. BIEX+BAC also had the highest assimilable organic carbon removal efficiency (61.2%) followed by BIEX (52.3%), BAC (49.5%), and IEX (47.1%). The BIEX+BAC hybrid was found to be the most effective method for removing NOM fractions and reducing the formation of disinfection byproducts.

11.
ACS Appl Mater Interfaces ; 15(39): 45616-45625, 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37729491

RESUMO

Carbon dots are emerging fluorescent nanomaterials with unique physical and chemical properties and a wide range of applications. Herein, we have designed and successfully synthesized thermally stable green emissive nitrogen-doped carbon dots (NCDs) with a photoluminescent quantum yield of 11.32% through facile solvent-free carbonization. NCDs demonstrated zero thermal quenching upon various temperatures modulating from 20 to 80 °C. The green emissive NCDs perform very stably even after heating them at 80 °C for 1 h. The thermal stability mechanism demonstrates that C═O and C═N functional groups control the particle aggregation and protect the fluorescent hub from photo-oxidation and thermal oxidation. Highly biocompatible CDs exhibit bright, stable, and multicolor emissions in T-ca cells under hot circumstances (25-45 °C). Additionally, NCDs offer long-term stability in the biosystem, as evidenced by the fact that the cell retains its brightness about 70% after prolonging the incubation time to 8 days. Furthermore, the fluorescent NCDs are utilized as in vivo imaging agents in the hot environment as they display bright and thermally stable imaging (27-45 °C) under 488 nm excitation. The results confirmed that the produced thermally stable NCDs could be used in biology and related medical fields that require hot environment imaging.

12.
Gels ; 9(8)2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37623088

RESUMO

Metallogels represent a class of composite materials in which a metal can be a part of the gel network as a coordinated ion, act as a cross-linker, or be incorporated as metal nanoparticles in the gel matrix. Cellulose is a natural polymer that has a set of beneficial ecological, economic, and other properties that make it sustainable: wide availability, renewability of raw materials, low-cost, biocompatibility, and biodegradability. That is why metallogels based on cellulose hydrogels and additionally enriched with new properties delivered by metals offer exciting opportunities for advanced biomaterials. Cellulosic metallogels can be either transparent or opaque, which is determined by the nature of the raw materials for the hydrogel and the metal content in the metallogel. They also exhibit a variety of colors depending on the type of metal or its compounds. Due to the introduction of metals, the mechanical strength, thermal stability, and swelling ability of cellulosic materials are improved; however, in certain conditions, metal nanoparticles can deteriorate these characteristics. The embedding of metal into the hydrogel generally does not alter the supramolecular structure of the cellulose matrix, but the crystallinity index changes after decoration with metal particles. Metallogels containing silver (0), gold (0), and Zn(II) reveal antimicrobial and antiviral properties; in some cases, promotion of cell activity and proliferation are reported. The pore system of cellulose-based metallogels allows for a prolonged biocidal effect. Thus, the incorporation of metals into cellulose-based gels introduces unique properties and functionalities of this material.

13.
Waste Manag ; 167: 74-80, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37245398

RESUMO

The biological stability of organic materials predicts their performance when used as either a soil improver or as an ingredient in growing media. CO2 release in a static measurement and O2 consumption rate (OUR) were compared for seven groups of growing media components. The ratio between CO2 release and OUR was matrix-specific. This ratio was highest for plant fibers high in C:N and with a high risk of N immobilization, intermediate for wood fiber and woody composts, and lowest for peat and other compost types. The effect of variable test conditions in the OUR setup was assessed for plant fibers, where addition of mineral N and/or nitrification inhibitor had no effect on the OUR measurements. Testing at 30 °C instead of 20 °C resulted in higher OUR values as expected, but did not change the effect of mineral N dose. A strong increase in the CO2 flux was measured when plant fibers were mixed with mineral fertilizer; in contrast, addition of mineral N or fertilizer before or during the OUR test had no effect. The present experimental setup did not allow for differentiation between a higher CO2 release as a result of increased microbial respiration after adding mineral N versus an underestimation of stability due to N limitation in the dynamic OUR setup. Results indicate that type of material, C:N ratio and risk of N immobilization all appear to affect the OUR results. The OUR criteria may therefore require clear differentiation based on the different materials used in horticultural substrates.


Assuntos
Compostagem , Solo , Dióxido de Carbono , Madeira , Taxa Respiratória , Fertilizantes , Minerais , Oxigênio
14.
Chemosphere ; 321: 138049, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36746252

RESUMO

This study comprehensively investigates the quality of drinking water produced by novel advanced treatment encompassing 1 kDa hollow fiber nanofiltration (HFNF) - Biological Activated Carbon Filtration (BACF) from (reservoir) surface water, and compares this with drinking water after conventional 'CSF' pretreatment (coagulation - flocculation - sedimentation - media filtration - UV-disinfection) - BACF. The objective of HFNF - BACF treatment is to enhance the drinking water's quality in increased biological stability, reduced concentrations of organic micropollutants (OMP), and improvement in other chemical-physical parameters, whilst maintaining sufficient hardness to avoid subsequent remineralization. For this study a large suite of quality parameters was extensively monitored in pilot plants during nearly two years, enabling the incorporation of seasonal effects. HFNF - BACF treatment accomplished a similarly high level of biological stability as regrowth-free drinking waters (total organic carbon (DOC) 0.6 mg/L, assimilable organic carbon (AOC) 4 µg/L Ac-C and <1 µg/L biopolymer-C, total microbial growth potential (MGP) as BPC14 50 ng d/L and as BGP 170 × 103 cells/mL), unlike the conventional treatment (1.9 mg/L, 10 µg/L, 9 µg/L, 130 ng d/L and 170 × 103 cells/mL, respectively) where regrowth occurred in its distribution network. Average OMP removal, including perfluoro-alkyl substances (PFAS), by HFNF - BACF (54%) was higher than conventional treatment (37%). This improvement was mainly attributable to rejection in the HFNF membrane step, indicating that the DOC concentration after HFNF pretreatment was not yet sufficiently low to eliminate competitive adsorption and/or preloading in the BACF (confirmed by laboratory experiments). The advanced treatment also performed better in turbidity, particulates and most trace metals. Importantly, hardness retention by HFNF was only moderate, rendering remineralization unnecessary. Overall, this study demonstrates the superior performance in water quality of advanced HFNF - BACF treatment compared to conventional treatment.


Assuntos
Água Potável , Poluentes Químicos da Água , Purificação da Água , Carvão Vegetal , Filtração , Qualidade da Água , Poluentes Químicos da Água/análise
15.
Anal Chim Acta ; 1245: 340847, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36737134

RESUMO

Fluorescent carbon dots have been highly reported nanomaterials in recent times because of their excellent physio-chemical properties and various field of applications. Herein, a one-step hydrothermal approach was used to synthesize high biocompatible nitrogen and sulfur co-doped carbon dots, and examined their chemical sensing (Hg2+) and biological imaging properties. The N,S-CDs exhibited blue light, demonstrating a high quantum yield of up to 44.5% and excitation-independent fluorescent characteristics. Cytotoxicity was observed by CCK-8 assay using T-ca cells as a target source. Cell viability was recorded over 80% even after 7 days of treatment with a concentration up to 400 µg/mL, indicating low-toxicity of N,S-CDs. Notably, the bright blue fluorescence of N,S-CDs was quenched by introducing toxic Hg2+ ions into the solution. The detection limit was calculated to be about ∼3.5 nM, which is quite impressive compared to previous reports. Because of their low-toxicity, nano-size, and environment friendly properties, N,S-CDs could be excellent fluorescent agents for bio-imaging applications. The biological stability of fluorescent N,S-CDs was tested over time, and the findings were significant even after 8 days of incubation with T-ca cells. Because of good biocompatibility and bright fluorescence, N,S-CDs were suitable for in vivo imaging.


Assuntos
Mercúrio , Pontos Quânticos , Carbono/toxicidade , Carbono/química , Pontos Quânticos/toxicidade , Pontos Quânticos/química , Nitrogênio/química , Enxofre/química , Corantes Fluorescentes/toxicidade , Corantes Fluorescentes/química , Mercúrio/toxicidade
16.
Prep Biochem Biotechnol ; 53(7): 849-859, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36508334

RESUMO

The antimicrobial peptide was considered an important target for developing novel antibacterial drugs. However, the unstable biological activity and the low antibacterial activity are challenges for the application of recombinant proteins. In this study, the fusion peptide of Melittin-Thanatin (MT) was designed and produced, and its derivative sequence (MT-W) was obtained by replacing three glycines (Gly, G) with tryptophan (Trp, W). The MT-W peptide were synthesized in Bacillus subtilis WB700 by EDDIE self-cleavage protein fusion. Compared with MT, MT-W exhibited 2-4 times higher antibacterial rate against Escherichia coli K88. In addition, MT-W showed lower cytotoxicity (IC50 > 300 mg·L-1) to the red blood cell, and more stable biological activities under the conditions of different temperatures (20, 30, 40, 50, 60, 70, 80, and 90 °C), pH values (2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, and 9.0) and different proteases. Especially, MT-W showed a broader antibacterial effect on three drug-resistant strains than florfenicol and oxytetracycline calcium. In conclusion, compared with MT, the MT-W showed increased antibacterial activity, stability, lower cytotoxicity, and broader antimicrobial effect. Therefore, it would become a promising alternative to conventional antibiotics.


Assuntos
Meliteno , Triptofano , Meliteno/farmacologia , Meliteno/genética , Triptofano/genética , Glicina/farmacologia , Proteínas Recombinantes/genética , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Mutação , Testes de Sensibilidade Microbiana
17.
Cell Tissue Res ; 392(1): 113-133, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35796874

RESUMO

Prion diseases are a group of inevitably fatal neurodegenerative disorders affecting numerous mammalian species, including humans. The existence of heritable phenotypes of disease in the natural host suggested that prions exist as distinct strains. Transmission of sheep scrapie to rodent models accelerated prion research, resulting in the isolation and characterization of numerous strains with distinct characteristics. These strains are grouped into categories based on the incubation period of disease in different strains of mice and also by how stable the strain properties were upon serial passage. These classical studies defined the host and agent parameters that affected strain properties, and, prior to the advent of the prion hypothesis, strain properties were hypothesized to be the result of mutations in a nucleic acid genome of a conventional pathogen. The development of the prion hypothesis challenged the paradigm of infectious agents, and, initially, the existence of strains was difficult to reconcile with a protein-only agent. In the decades since, much evidence has revealed how a protein-only infectious agent can perform complex biological functions. The prevailing hypothesis is that strain-specific conformations of PrPSc encode prion strain diversity. This hypothesis can provide a mechanism to explain the observed strain-specific differences in incubation period of disease, biochemical properties of PrPSc, tissue tropism, and subcellular patterns of pathology. This hypothesis also explains how prion strains mutate, evolve, and adapt to new species. These concepts are applicable to prion-like diseases such as Parkinson's and Alzheimer's disease, where evidence of strain diversity is beginning to emerge.


Assuntos
Doenças Priônicas , Príons , Scrapie , Humanos , Animais , Ovinos , Scrapie/patologia , Fenótipo , Mutação , Doenças Priônicas/genética , Mamíferos
18.
Polymers (Basel) ; 14(21)2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36365681

RESUMO

The biodegradable dissolved organic carbon (BDOC) in micro-polluted water sources affects the drinking water quality and safety in the urban water supply. The conventional technology of "coagulation-sedimentation-filtration" in a water plant located in the lower reaches of the Yangtze River removed dissolved organic carbon (DOC) with a molecular weight (MW) > 30 kDa effectively, but the BDOC elimination only ranged 27.4−58.1%, due to their predominant smaller MW (<1 kDa), leading to a high residual BDOC of 0.22−0.33 mg/L. To ensure the biological stability of drinking water, i.e., the inability to support microbial growth (BDOC < 0.2 mg/L), a pilot-scale ultrafiltration process (UF, made of aromatic polyamide with MW cut-off of 1 kDa) was operated to remove BDOC as an advanced treatment after sand-filtration. Results showed the membrane flux decreased with the increase in the influent BDOC concentration and decrease in operating pressure. With an operating pressure of 0.25 MPa, the BDOC removal by UF reached 80.7%, leading to a biologically stable BDOC concentration of 0.08 mg/L. The fouling of the membrane was mainly caused by organic pollution. The H2O2−HCl immersion washing method effectively cleaned the membrane surface fouling, with a recovery of membrane flux of 98%.

19.
Water Res ; 221: 118734, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35714469

RESUMO

Possibility of human exposure to microplastics (MPs) in water environment has been escalating, and subsequent challenges of MPs to biostability and biosafety in drinking water deserve more attention, especially in stagnant water. The present study explored the integrated impacts of MPs and chlorine on disinfection kinetics, microbial growth, and microbial community formation in drinking water, by setting MPs or microplastic-biofilm (MP-BM) under different disinfection conditions. The following were the primary conclusions: (1) The presence of MP and MP-BM led to the deterioration of water indices (especially turbidity) when chlorine was less than 1 mg/L. (2) MP/MP-BM accelerated the decay of disinfectants and MP-BM consumed more rapidly. Meanwhile, chlorine contributed to the level of BRP, ranging from 4.78 × 105 CFU/mL to 1.42 × 107 CFU/mL. (3) MP/MP-BM and chlorine integrally shaped microbial communities in water samples and biofilm samples. Microbial dissimilarity between isolated and hybrid MP-BM indicated manners of microbial field or non-contact communication. Microbial abundance and OPs were effectively controlled when chlorine was over 1 mg/L. (4) According to time-lag differential equations simulation, impulsive chlorination contributed to controlling microbial risks and DBPs induced by MP/MP-BM and water stagnation.


Assuntos
Desinfetantes , Água Potável , Microbiota , Poluentes Químicos da Água , Purificação da Água , Cloretos , Cloro/farmacologia , Desinfetantes/farmacologia , Desinfecção , Água Potável/análise , Halogênios , Humanos , Microplásticos , Plásticos , Poluentes Químicos da Água/análise
20.
Colloids Surf B Biointerfaces ; 215: 112524, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35500532

RESUMO

The rapid development of colloid chemistry has raised the possibility of using nanocarriers for the targeted delivery and the controlled drug release at predictable locations to reduce side effects and enhance therapeutic efficacy. In the present work, we focused on the influence of temperature and pH upon in vitro controlled phytochemical/dye-release from a modified bilosome. Drug molecules can affect the properties of nanocarriers, so the effect of encapsulated bioactive compounds on nanoparticle structure has been investigated. The self-assembly process of bioinspired components (i.e., phospholipids, bile salts, and cholesterol), and biocompatible polymeric triblock materials, made it possible to receive structures with a size below 100 nm, demonstrated good capacity for active cargo encapsulation. Differential scanning calorimetry studies showed the possibility of the payloads' interaction with the bilosomes structure. A highly lipophilic compound, such as curcumin, can weaken hydrophobic interactions between the acyl chains of phospholipids, leading to a more flexible membrane. The in vitro release profiles have proved that both solubilities of the therapeutic substances and various environmental conditions affect the release rate of the hybrid cargo. Overall, the obtained double-loaded bilosomes represent a promising bioinspired nanoplatform for oral, intravenous, and topical drug delivery in future biomedical applications.


Assuntos
Materiais Biocompatíveis , Sistemas de Liberação de Medicamentos , Portadores de Fármacos , Liberação Controlada de Fármacos , Concentração de Íons de Hidrogênio , Fosfolipídeos , Temperatura
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