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1.
Sci Rep ; 14(1): 13051, 2024 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844516

RESUMO

In this work, the surface of polyvinyl chloride PVC sheet was modified by blending it with sunflower seed oil SSO to obtain PVC sheet/SSO films of ratios 100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 (v/v)% using the solution casting method. Various techniques were used to characterize the prepared films, besides the use of hemolysis assays and blood clot formation tests. FTIR spectra revealed that there was a good interaction between the PVC sheet and the oil. The dielectric measurement indicated that SSO addition enhanced the dielectric properties of the sheet. The study of dielectric relaxation times confirmed the interaction between SSO and the sheet. DC conductivity increased to 6 × 10-6 S/m, so it could be applied in antistatic applications. Also, SSO addition increased the value of the thermal stability. According to SEM micrographs, the film was roughened at a ratio of 60/40 and smoothed out at 50/50. This behavior was confirmed with roughness and contact angle measurement results, in which the film of ratio 60/40 had the highest value equal to (72.03°) and then decreased at 50/50 to (59.62°). These results were confirmed by XRD measurement as the crystallinity increased at the film ratio of 60/40 and decreased again at 50/50. Also, the ratio of 60/40 demonstrated a large decrease in thrombus weights along with a slight increase in hemolysis, which is within the acceptable range and has a high degree of biocompatibility, so this concentration is recommended to be used in blood bags applications.


Assuntos
Hemólise , Cloreto de Polivinila , Óleo de Girassol , Óleo de Girassol/química , Cloreto de Polivinila/química , Hemólise/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier , Humanos , Animais , Coagulação Sanguínea/efeitos dos fármacos , Propriedades de Superfície , Óleos de Plantas/química
2.
Environ Geochem Health ; 46(6): 193, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38696028

RESUMO

Microplastics (MPs) and copper (Cu) pollution coexist widely in cultivation environment. In this paper, polyvinyl chloride (PVC) were used to simulate the MPs exposure environment, and the combined effects of MPs + Cu on the germination of perilla seeds were analyzed. The results showed that low concentrations of Cu promoted seed germination, while medium to high concentrations exhibited inhibition and deteriorated the morphology of germinated seeds. The germination potential, germination index and vitality index of 8 mg • L-1 Cu treatment group with were 23.08%, 76.32% and 65.65%, respectively, of the control group. The addition of low concentration PVC increased the above indicators by 1.27, 1.15, and 1.35 times, respectively, while high concentration addition led to a decrease of 65.38%, 82.5%, and 66.44%, respectively. The addition of low concentration PVC reduced the amount of PVC attached to radicle. There was no significant change in germination rate. PVC treatment alone had no significant effect on germination. MPs + Cu inhibited seed germination, which was mainly reflected in the deterioration of seed morphology. Cu significantly enhanced antioxidant enzyme activity, increased reactive oxygen species (ROS) and MDA content. The addition of low concentration PVC enhanced SOD activity, reduced MDA and H2O2 content. The SOD activity of the Cu2+8 + PVC10 group was 4.05 and 1.35 times higher than that of the control group and Cu treatment group at their peak, respectively. At this time, the CAT activity of the Cu2+8 + PVC5000 group increased by 2.66 and 1.42 times, and the H2O2 content was 2.02 times higher than the control. Most of the above indicators reached their peak at 24 h. The activity of α-amylase was inhibited by different treatments, but ß-amylase activity, starch and soluble sugar content did not change regularly. The research results can provide new ideas for evaluating the impact of MPs + Cu combined pollution on perilla and its potential ecological risk.


Assuntos
Cobre , Germinação , Perilla , Cloreto de Polivinila , Sementes , Germinação/efeitos dos fármacos , Cobre/toxicidade , Sementes/efeitos dos fármacos , Perilla/efeitos dos fármacos , Microplásticos/toxicidade , Tamanho da Partícula , Espécies Reativas de Oxigênio/metabolismo , Malondialdeído/metabolismo , Poluentes do Solo/toxicidade
3.
ACS Appl Mater Interfaces ; 16(19): 24248-24260, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38693878

RESUMO

Biomedical devices are vulnerable to infections and biofilm formation, leading to extended hospital stays, high expenditure, and increased mortality. Infections are clinically treated via the administration of systemic antibiotics, leading to the development of antibiotic resistance. A multimechanistic strategy is needed to design an effective biomaterial with broad-spectrum antibacterial potential. Recent approaches have investigated the fabrication of innately antimicrobial biomedical device surfaces in the hope of making the antibiotic treatment obsolete. Herein, we report a novel fabrication strategy combining antibacterial nitric oxide (NO) with an antibiofilm agent N-acetyl cysteine (NAC) on a polyvinyl chloride surface using polycationic polyethylenimine (PEI) as a linker. The designed biomaterial could release NO for at least 7 days with minimal NO donor leaching under physiological conditions. The proposed surface technology significantly reduced the viability of Gram-negative Escherichia coli (>97%) and Gram-positive Staphylococcus aureus (>99%) bacteria in both adhered and planktonic forms in a 24 h antibacterial assay. The composites also exhibited a significant reduction in biomass and extra polymeric substance accumulation in a dynamic environment over 72 h. Overall, these results indicate that the proposed combination of the NO donor with mucolytic NAC on a polymer surface efficiently resists microbial adhesion and can be used to prevent device-associated biofilm formation.


Assuntos
Acetilcisteína , Antibacterianos , Biofilmes , Escherichia coli , Óxido Nítrico , Staphylococcus aureus , Acetilcisteína/química , Acetilcisteína/farmacologia , Óxido Nítrico/química , Óxido Nítrico/metabolismo , Óxido Nítrico/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Biofilmes/efeitos dos fármacos , Polietilenoimina/química , Polietilenoimina/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Testes de Sensibilidade Microbiana , Cloreto de Polivinila/química , Doadores de Óxido Nítrico/química , Doadores de Óxido Nítrico/farmacologia
4.
Anal Methods ; 16(21): 3372-3384, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38747244

RESUMO

Microfluidic channels fabricated over fabrics or papers have the potential to find substantial application in the next generation of wearable healthcare monitoring systems. The present work focuses on the fabrication procedures that can be used to obtain practically realizable fabric-based microfluidic channels (µFADs) utilizing patterning masks and wax, unlike conventional printing techniques. In this study, comparative analysis was used to differentiate channels obtained using different masking tools for channel patterning as well as different wax materials as hydrophobic barriers. Drawbacks of the conventional tape and candle wax technique were noted and a novel approach was used to create microfluidic channels through a facile and simple masking technique using PVC clear sheets as channel stencils and beeswax as the channel barriers. The resulting fabric based microfluidic channels with varying widths as well as complex microchannel, microwell, and micromixer designs were investigated and a minimum channel width resolution of 500 µm was successfully obtained over cotton based fabrics. Thereafter, the PVC clear sheet-beeswax based microwells were successfully tested to confine various organic and inorganic samples indicating vivid applicability of the technique. Finally, the microwells were used to make a simple and facile colorimetric assay for glucose detection and demonstrated effective detection of glucose levels from 10 mM to 50 mM with significant color variation using potassium iodide as the coloring agent. The above findings clearly suggest the potential of this alternative technique for making low-cost and practically realizable fabric based diagnostic devices (µFADs) in contrast to the other approaches that are currently in use.


Assuntos
Cloreto de Polivinila , Têxteis , Ceras , Ceras/química , Cloreto de Polivinila/química , Colorimetria/métodos , Colorimetria/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Análise Custo-Benefício , Glucose/análise , Dispositivos Lab-On-A-Chip , Humanos , Desenho de Equipamento , Dispositivos Eletrônicos Vestíveis
5.
Ecotoxicol Environ Saf ; 278: 116422, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38705040

RESUMO

Although more attention has been paid to microplastics (MPs) pollution in environment, research on the synthetic influence of microplastic and heavy metals remains limited. To help fill this information gap, we investigated the adsorption behavior of virgin polyvinyl chloride microplastics (PVCMPs) (≤450 µm white spherical powder) on cadmium (II). The effects on seed germination, seedling growth, photosynthetic system, oxidative stress indicators of lettuce, and changes in Cd bioavailability were evaluated under Cd2+ (25 µmol/L), PVCMPs (200 mg/L), and PVCMP-Cd combined (200 mg/L + 25 µmol/L) exposures in hydroponic system. The results demonstrated that the PVCMPs effectively adsorbed Cd ions, which validated by the pseudo-second-order kinetic and the Langmuir isotherm models, indicating the sorption of Cd2+ on the PVCMPs was primary chemisorption and approximates monomolecular layer sorption. Compared to MPs, Cd significantly inhibits plant seed germination and seedling growth and development. However, Surprising improvement in seed germination under PVCMPs-Cd exposure was observed. Moreover, Cd2+ and MPs alone or combined stress caused oxidative stress with reactive oxygen species (ROS) including H2O2, O2- and Malondialdehyde (MDA) accumulation in plants, and substantially damaged to photosynthesis. With the addition of PVCMPs, the content of Cd in the leaves significantly (P<0.01) decreased by 1.76-fold, and the translocation factor and Cd2+removal rate in the water substantially (P<0.01) decreased by 6.73-fold and 1.67-fold, respectively in contrast to Cd2+ stress alone. Therefore, it is concluded the PVCMP was capable of reducing Cd contents in leaves, alleviating Cd toxicity in lettuce. Notably, this study provides a scientific foundation and reference for comprehending the toxicological interactions between microplastics and heavy metals in the environment.


Assuntos
Cádmio , Germinação , Hidroponia , Lactuca , Microplásticos , Estresse Oxidativo , Poluentes Químicos da Água , Lactuca/efeitos dos fármacos , Lactuca/crescimento & desenvolvimento , Lactuca/metabolismo , Cádmio/toxicidade , Microplásticos/toxicidade , Germinação/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Fotossíntese/efeitos dos fármacos , Adsorção , Cloreto de Polivinila , Espécies Reativas de Oxigênio/metabolismo
6.
Sci Total Environ ; 933: 173032, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38734099

RESUMO

Ferroptosis is frequently observed in fibrosis and diseases related to iron metabolism disorders in various mammalian organs. However, research regarding the damage mechanism of ferroptosis in the female reproductive system of avian species remains unclear. In this study, Muscovy female ducks were divided into three groups which were given purified water, 1 mg/L polyvinyl chloride microplastics (PVC-MPs) and 10 mg/L PVC-MPs for two months respectively, to investigate the ferroptosis induced by PVC-MPs caused ovarian tissue fibrosis that lead to premature ovarian failure. The results showed that the high accumulation of PVC-MPs in ovarian tissue affected the morphology and functional activity of ovarian granulosa cells (GCs) and subsequently caused the follicular development disorders and down-regulated the immunosignaling of ovarian steroidogenesis proteins 3ß-hydroxysteroid dehydrogenase (3ß-HSD), 17ß-hydroxysteroid dehydrogenase (17ß-HSD), CYP11A1 cytochrome (P450-11A1) and CYP17A1 cytochrome (P450-17A1) suggested impaired ovarian function. In addition, PVC-MPs significantly up-regulated positive expression of collagen fibers, significantly increased lipid peroxidation and malondialdehyde (MDA) level, along with encouraged overload of iron contents in the ovarian tissue were the characteristics of ferroptosis. Further, immunohistochemistry results confirmed that immunosignaling of ferroptosis related proteins Acyl-CoA synthetase (ACSL4), Cyclooxygenase 2 (COX2) and ferritin heavy chain 1 (FTH1) were significantly increased, but solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase (GPX4) were decreased by PVC-MPs in the ovarian tissue. In conclusion, our study demonstrates that PVC-MPs induced ferroptosis in the ovarian GCs, leading to follicle development disorders and ovarian tissue fibrosis, and ultimately contributing to various female reproductive disorders through regulating the proteins expression of ferroptosis.


Assuntos
Patos , Ferroptose , Microplásticos , Ovário , Cloreto de Polivinila , Animais , Feminino , Ferroptose/efeitos dos fármacos , Cloreto de Polivinila/toxicidade , Ovário/efeitos dos fármacos , Microplásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Células da Granulosa/efeitos dos fármacos , Células da Granulosa/metabolismo
7.
Waste Manag ; 183: 21-31, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38714119

RESUMO

Poly(vinyl chloride) (PVC) is one of the most widely used plastics. However, a major challenge in recycling PVC is that there is no economical method to separate and remove its toxic phthalate plasticizers. This research made a breakthrough by extracting PVC with liquefied dimethyl ether (DME) and successfully separating the plasticizer components. Nearly all (97.1 %) of the di(2-ethylhexyl) phthalate plasticizer was extracted within 30 min by passing liquefied DME (285 g) through PVC at 25 °C. The compatibility of PVC with organic solvents, including liquefied DME, was derived theoretically from their Hansen solubility parameters (HSP), and actual dissolution experiments were conducted to determine the optimal PVC solvents. A liquefied DME mixture was used to dissolve PVC, and the extract was diluted with ethanol to precipitate the dissolved PVC. We demonstrated that liquefied DME is a promising method for producing high quality recycled products and that the process retains the fundamental properties of plasticizers and PVC without inducing degradation or depolymerization. Because of its low boiling point, DME can be easily separated from the solute after extraction, allowing for efficient reuse of the solvent, extracted plasticizer, and PVC. DME does not require heat and produces little harmful wastewater, which significantly reduces the energy consumption of the plasticizer additive separation process.


Assuntos
Dietilexilftalato , Éteres Metílicos , Plastificantes , Cloreto de Polivinila , Reciclagem , Cloreto de Polivinila/química , Dietilexilftalato/química , Reciclagem/métodos , Éteres Metílicos/química , Éteres Metílicos/análise , Solventes/química , Ácidos Ftálicos/química
8.
Chemosphere ; 359: 142283, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38734251

RESUMO

Polyvinyl chloride (PVC), known for its chemical stability and flame-retardant qualities, has many uses in various fields, such as pipes, electric wires, and cable insulation. Research has established its potential recovery as a fluidic fuel through pyrolysis, but the use of PVC pyrolysis oil, which is tainted by chlorine, is constrained by its low heat value and harmful environmental effects. This study engineered a layered double hydroxide (LDH) to tackle these challenges. The LDH facilitated dechlorination during PVC pyrolysis and bolstered thermal stability via cross-linking. During pyrolysis with LDH, PVC was transformed into carbon-rich precursors to sorbents. Chemical activation of these residues using KOH created sorbents with a specific surface area of 1495.4 m2 g⁻1, rendering them hydrophilic. These resulting sorbents displayed impressive adsorption capabilities, removing up to 486.79 mg g⁻1 of methylene blue and exhibiting the simultaneous removal of cations and anions.


Assuntos
Corantes , Hidróxidos , Cloreto de Polivinila , Cloreto de Polivinila/química , Hidróxidos/química , Adsorção , Corantes/química , Corantes/isolamento & purificação , Compostos de Potássio/química , Poluentes Químicos da Água/química , Azul de Metileno/química , Pirólise
9.
J Chem Phys ; 160(14)2024 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-38591687

RESUMO

The pervasive presence of nanoplastics (NPs) in the environment has gained increasing attention due to their accumulation in living organisms. These emerging contaminants inevitably interact with extracellular polymeric substances along respiratory or gastrointestinal tracts, and diverse organic coating on the surface of NPs, known as bio- or eco-corona, is formed. Although its impact on altering the NP properties and potential cell internalization has been extensively examined, studies on its role in NP partitioning in the cell membrane are elusive yet. In this work, molecular dynamics is used to investigate the formation of chitosan (CT) corona centered on a polyvinyl chloride (PVC) nanoparticle and the uptake of the resulting complex onto lipid membranes. Coarse-grained models compatible with the newly developed Martini 3.0 force field are implemented for the two polymers employing the atomistic properties as targets in the parameterization. The reliability of the coarse-grained polymer models is demonstrated by reproducing the structural properties of the PVC melt and of solvated CT strands, as well as by determining the conformation adopted by the latter at the NP surface. Results show that the spontaneous binding of CT chains of high and intermediate protonation degrees led to the formation of soft and hard corona that modulates the interaction of PVC core with model membranes. The structural changes of the corona adsorbed at the lipid-water interface enable a subsequent transfer of the NP to the center of the saturated lipid membranes and a complete or partial transition to a snorkel conformation depending on the hydrophilic/hydrophobic balance in the CT-PVC complex. Overall, the computational investigation of the coarse-grained model system provides implications for understanding how the eco-corona development influences the uptake and implicit toxicology of NPs.


Assuntos
Bicamadas Lipídicas , Nanopartículas , Bicamadas Lipídicas/química , Cloreto de Polivinila , Reprodutibilidade dos Testes , Nanopartículas/química , Carboidratos
10.
J Med Case Rep ; 18(1): 155, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38581068

RESUMO

BACKGROUND: S-lon® (S) is a locally produced polyvinyl chloride-based solvent cement. It is a clear, slightly viscous liquid. Other constituents include 1-cyclohexanone, 3-butanone, and 1-acetone. It is used ubiquitously for building construction in Sri Lanka. Although the clinical effects of the compound have not yet been ascertained, the constituents have been implicated in neurotoxicity, respiratory tract, eye and skin irritation, and delayed liver and renal injury. CASE DESCRIPTION: A 42-year-old South Asian male presented following self-ingestion of S. His vital parameters were stable and initially managed symptomatically. A few hours later, he developed central nervous system depression and stridor requiring elective intubation. Examination of the upper airway revealed inflammation and edema. He was sedated and ventilated, and intravenous dexamethasone was administered. Attempts at removal of the nasogastric tube after extubation on day 3 failed. The patient had to be reintubated and sedated owing to extreme agitation not responding to routine doses of sedatives. The nasogastric tube had been amalgamated after reacting with S, forming a solid clump, later found after removal. The posterior pharynx and nasopharynx were packed and later removed before extubation. The patient made a full recovery and was transferred to the ward on day 5. CONCLUSION: Ingestion of a sufficient quantity of S could result in gut absorption with central nervous system depression, coma, and even death. No antidote is available for toxicity, and management is largely supportive. As witnessed in our patient, chemical laryngitis and upper airway inflammation may lead to upper airway obstruction. Chemical reactions with medical equipment may lead to unforeseen outcomes.


Assuntos
Edema , Cloreto de Polivinila , Humanos , Masculino , Adulto , Antídotos , Inflamação , Solventes
11.
J Hazard Mater ; 470: 134278, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38631247

RESUMO

Resuspension caused by human walking activities is an important source of indoor bioaerosols and has been associated with health effects such as allergies and asthma. However, it is unknown whether inhalation of resuspended bioaerosols is an important exposure pathway for airborne infection. Also, crucial factors influencing the resuspension of settled microbes have not been quantified. In this study, we experimentally investigated the resuspension of culturable bacteria from human-stepping on polyvinyl chloride (PVC) flooring under different conditions. We determined the bacterial resuspension emission factor (ER), a normalized resuspension parameter for the ratio of resuspended mass in the air to the mass of settled particles, for two common bacteria, Escherichia coli and Salmonella enterica. The investigation involved varying factors such as microbial surface-attached durations (0, 1, 2, and 3 days), the absence or presence of nutrients on flooring surfaces, and changes in relative humidity (RH) (35%, 65%, and 85%). The results showed that, in the absence of nutrients, the highest ER values for E. coli and S. enterica were 3.8 × 10-5 ± 5.2 × 10-6 and 5.3 × 10-5 ± 6.0 × 10-6, respectively, associated with surface-attached duration of 0 days. As the surface-attached duration increased from 0 to 3 days, ER values decreased by 92% and 84% for E. coli and S. enterica, respectively. In addition, we observed that ER values decreased with the increasing RH, which is consistent with particle adhesion theory. This research offers valuable insights into microbial resuspension during human walking activities and holds the potential for assisting in the assessment and estimation of risks related to human exposure to bioaerosols.


Assuntos
Escherichia coli , Umidade , Caminhada , Humanos , Pisos e Cobertura de Pisos , Salmonella enterica , Aerossóis , Poluição do Ar em Ambientes Fechados , Microbiologia do Ar , Cloreto de Polivinila/química , Nutrientes
12.
J Hazard Mater ; 470: 134167, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38598880

RESUMO

This study investigated the leaching of phthalate and non-phthalate plasticizers from polyvinyl chloride microplastics (MPs) into sediment and their degradation over a 30-d period via abiotic and biotic processes. The results showed that 3579% of plasticizers were released into the sediment from the MPs and > 99.9% degradation was achieved. Although a significantly higher degradation was found in plasticizer-added microcosms under biotic processes (overall, 94%), there was a noticeable abiotic loss (72%), suggesting that abiotic processes also play a role in plasticizer degradation. Interestingly, when compared with the initial sediment-water partitioning for plasticizers, the partition constants for low-molecular-weight compounds decreased in both microcosms, whereas those for high-molecular-weight compounds increased after abiotic degradation. Furthermore, changes in the bacterial community, abundance of plasticizer-degrading bacterial populations, and functional gene profiles were assessed. In all the microcosms, a decrease in bacterial community diversity and a notable shift in bacterial composition were observed. The enriched potential plasticizer-degrading bacteria were Arthrobacter, Bacillus, Desulfovibrio, Desulfuromonas, Devosia, Gordonia, Mycobacterium, and Sphingomonas, among which Bacillus was recognized as the key plasticizer degrader. Overall, these findings shed light on the factors affecting plasticizer degradation, the microbial communities potentially involved in biodegradation, and the fate of plasticizers in the environment.


Assuntos
Bactérias , Sedimentos Geológicos , Microplásticos , Ácidos Ftálicos , Plastificantes , Cloreto de Polivinila , Poluentes Químicos da Água , Cloreto de Polivinila/química , Plastificantes/metabolismo , Sedimentos Geológicos/microbiologia , Sedimentos Geológicos/química , Ácidos Ftálicos/metabolismo , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo , Bactérias/metabolismo , Bactérias/classificação , Biodegradação Ambiental
13.
Water Sci Technol ; 89(8): 2105-2117, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38678412

RESUMO

Photodynamic processes have found widespread application in therapies. These processes involve photosensitizers (PSs) that, when excited by specific light wavelengths and in the presence of molecular oxygen, generate reactive oxygen species (ROS), that target cells leading to inactivation. Photodynamic action has gained notable attention in environmental applications, particularly against pathogens and antibiotic-resistant bacteria (ARB) that pose a significant challenge to public health. However, environmental matrices frequently encompass additional contaminants and interferents, including microplastics (MPs), which are pollutants of current concern. Their presence in water and effluents has been extensively documented, highlighting their impact on conventional treatment methods, but this information remains scarce in the context of photodynamic inactivation (PDI) setups. Here, we described the effects of polyvinyl chloride (PVC) microparticles in PDI targeting Staphylococcus aureus and its methicillin-resistant strain (MRSA), using curcumin as a PS under blue light. The presence of PVC microparticles does not hinder ROS formation; however, depending on its concentration, it can impact bacterial inactivation. Our results underscore that PDI remains a potent method for reducing bacterial concentrations in water and wastewater containing ARB, even in highly contaminated scenarios with MPs.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Microplásticos , Cloreto de Polivinila , Staphylococcus aureus , Cloreto de Polivinila/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos da radiação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química
14.
Environ Pollut ; 349: 123994, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38636835

RESUMO

Microplastics (MPs) pollution and their impact on plants have become a global threat, but their effect at the molecular level remains scarce. This study aims to gain insight into the effects of polyvinylchloride microplastic (PVC-MP) on tomato plants at the genetic and protein levels. In this study, we found that increasing concentrations of PVC-MP (2.5, 5,7.5, and 10% w/w) in the soil did not cause any phytotoxic (chlorosis or necrosis) symptoms but it did result in a dose-dependent reduction in plant growth-related parameters, such as height, leaf area, stem diameter, and plant fresh and dry weight. Additionally, the number of secondary roots was reduced while the primary roots were elongated. Furthermore, PVC-MP also caused a significant decrease in light-harvesting pigments chlorophylls, and carotenoids while increasing the level of reactive oxygen species (ROS) and lipid peroxidation in plants. Microscopic analysis of the roots revealed the uptake of PVC-MP of size less than 10 µm. Micro- and macro-element analysis showed changes in concentrations of Ca, Cu, Fe, Mg, Mn, Ni, and Zn, upon PVC-MP exposure. Results from western blotting and q-PCR showed that higher doses of PVC-MP significantly reduced the CO2-fixing enzyme RuBisCO and D1 proteins of PSII at both protein and transcript levels. These findings suggest that lower levels of light-harvesting pigments, D1 protein, RuBisCO, and modulation of nutrient absorption are among the factors responsible for growth suppression in tomato plants upon exposure to PVC-MP. As tomato plants are economically significant crops, an increase in PVC-MP in agricultural fields may have a detrimental influence on crop production, resulting in economic loss.


Assuntos
Microplásticos , Fotossíntese , Cloreto de Polivinila , Poluentes do Solo , Solanum lycopersicum , Solanum lycopersicum/efeitos dos fármacos , Solanum lycopersicum/crescimento & desenvolvimento , Solanum lycopersicum/metabolismo , Poluentes do Solo/toxicidade , Poluentes do Solo/metabolismo , Fotossíntese/efeitos dos fármacos , Microplásticos/toxicidade , Nutrientes/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Clorofila/metabolismo , Espécies Reativas de Oxigênio/metabolismo
15.
Sci Total Environ ; 927: 172395, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38608882

RESUMO

PVC microplastics (PVC-MPs) are environmental pollutants that interact with cadmium (Cd) to exert various biological effects. Ducks belong to the waterfowl family of birds and therefore are at a higher risk of exposure to PVC-MPs and Cd than other animals. However, the effects of co-exposure of ducks to Cd and PVC-MPs are poorly understood. Here, we used Muscovy ducks to establish an in vivo model to explore the effects of co-exposure to 1 mg/L PVC-MPs and 50 mg/kg Cd on duck pancreas. After 2 months of treatment with 50 mg/kg Cd, pancreas weight decreased by 21 %, and the content of amylase and lipase increased by 25 % and 233 %. However, exposure to PVC-MPs did not significantly affect the pancreas. Moreover, co-exposure to PVC-MPs and Cd worsened the reduction of pancreas weight and disruption of pancreas function compared to exposure to either substance alone. Furthermore, our research has revealed that exposure to PVC-MPs or Cd disrupted mitochondrial structure, reduced ATP levels by 10 % and 18 %, inhibited antioxidant enzyme activity, and increased malondialdehyde levels by 153.8 % and 232.5 %. It was found that exposure to either PVC-MPs or Cd can induce inflammation and fibrosis in the duck pancreas. Notably, co-exposure to PVC-MPs and Cd exacerbated inflammation and fibrosis, with the content of IL-1, IL-6, and TNF-α increasing by 169 %, 199 %, and 98 %, compared to Cd exposure alone. The study emphasizes the significance of comprehending the potential hazards linked to exposure to these substances. In conclusion, it presents promising preliminary evidence that PVC-MPs accumulate in duck pancreas, and increase the accumulation of Cd. Co-exposure to PVC-MPs and Cd disrupts the structure and function of mitochondria and promotes the development of pancreas inflammation and fibrosis.


Assuntos
Cádmio , Patos , Microplásticos , Estresse Oxidativo , Pâncreas , Animais , Cádmio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Pâncreas/efeitos dos fármacos , Microplásticos/toxicidade , Fibrose , Cloreto de Polivinila/toxicidade , Poluentes Químicos da Água/toxicidade
16.
Biomacromolecules ; 25(4): 2621-2634, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38457653

RESUMO

Postpolymerization modification of highly defined "scaffold" polymers is a promising approach for overcoming the existing limitations of controlled radical polymerization such as batch-to-batch inconsistencies, accessibility to different monomers, and compatibility with harsh synthesis conditions. Using multiple physicochemical characterization techniques, we demonstrate that poly(2-vinyl-4,4-dimethyl azlactone) (PVDMA) scaffolds can be efficiently modified with a coumarin derivative, doxorubicin, and camptothecin small molecule drugs. Subsequently, we show that coumarin-modified PVDMA has a high cellular biocompatibility and that coumarin derivatives are liberated from the polymer in the intracellular environment for cytosolic accumulation. In addition, we report the pharmacokinetics, biodistribution, and antitumor efficacy of a PVDMA-based polymer for the first time, demonstrating unique accumulation patterns based on the administration route (i.e., intravenous vs oral), efficient tumor uptake, and tumor growth inhibition in 4T1 orthotopic triple negative breast cancer (TNBC) xenografts. This work establishes the utility of PVDMA as a versatile chemical platform for producing polymer-drug conjugates with a tunable, stimuli-responsive delivery.


Assuntos
Lactonas , Neoplasias , Polímeros , Humanos , Distribuição Tecidual , Polímeros/química , Polivinil/química , Cloreto de Polivinila , Doxorrubicina/farmacologia
17.
Int J Biol Macromol ; 266(Pt 1): 131190, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38552689

RESUMO

In this study, new, functional hydroxyapatite-lignin hybrid systems were designed and characterized. The efficacy of the mechanical method utilized to obtain these systems was confirmed by Fourier transform infrared spectroscopy. The hybrid materials were also noted for their good electrokinetic stability and thermal stability. The introduction of 2.5 to 10 wt% hydroxyapatite-lignin systems into an unplasticized PVC blend using a two-step kneading and pressing method resulted in composites with relatively homogeneous distribution, as confirmed by SEM observations. The processing properties of the filler-containing blends were investigated using plastographometric analysis and MFR tests. The introduction of a lignin-predominant hybrid system into the PVC matrix results in a significant improvement of thermal stability, softening temperature, and tensile strength, while maintaining sufficient impact strength for numerous applications. Hybrid materials containing higher amounts of added lignin are promising materials with bacteriostatic properties. This can be utilized to stabilize and prevent the deposition of microorganisms, as well as the formation of biofilms, on material surfaces, thereby limiting the spread of pathogens. New eco-composites based on PVC and a hybrid filler containing lignin show promise in producing components with surfaces resistant to bacterial colonization. Hence, these materials could be used in medical and hospital equipment.


Assuntos
Durapatita , Lignina , Cloreto de Polivinila , Lignina/química , Durapatita/química , Cloreto de Polivinila/química , Resistência à Tração , Temperatura , Espectroscopia de Infravermelho com Transformada de Fourier
18.
Int J Biol Macromol ; 263(Pt 2): 130511, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38423443

RESUMO

The mechanical properties of ionic conductive hydrogels (ICHs) are generally inadequate, leading to their susceptibility to breakage under external forces and consequently resulting in the failure of flexible electronic devices. In this work, a simple and convenient strategy was proposed based on the synergistic effect of ion cross-linking and salting out, in which the hydrogels consisting of polyvinyl alcohol (PVA) and xanthan gum (XG) were immersed in zinc sulfate (ZnSO4) solution to obtain ICHs with exceptional mechanical properties. The salt-out effects between PVA chains and SO42- ions along with the cross-linked network of XG chains and Zn2+ ions contribute to the desirable mechanical properties of ICHs. Notably, the mechanical properties of ICHs can be adjusted by changing the concentration of ZnSO4 solution. Consequently, the optimum fracture stress and the fracture energy can reach 3.38 MPa and 12.13 KJ m-2, respectively. Moreover, the ICHs demonstrated a favorable sensitivity (up to 2.05) when utilized as a strain sensor, exhibiting an accurate detection of human body movements across various amplitudes.


Assuntos
Hidrogéis , Polissacarídeos Bacterianos , Álcool de Polivinil , Humanos , Etanol , Cloreto de Sódio , Condutividade Elétrica , Íons , Poli A , Cloreto de Polivinila
19.
Environ Pollut ; 346: 123543, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38367691

RESUMO

The study focused on detecting and characterizing microplastics in outdoor and indoor air in Ranchi, Jharkhand, India during post-monsoon (2022) and winter (2023). Stereo microscopic analysis showed that plastic fibres had a dominant presence, fragments were less abundant, whereas fewer films could be detected in indoor and outdoor air. The atmospheric deposition of microplastics outdoors observed 465 ± 27 particles/m2/day in PM10 and 12104 ± 665 and 13833 ± 1152 particles/m2/day in PM2.5 in quartz and PTFE, respectively during the post-monsoon months. During winter, microplastic deposition rates in PM10 samples were found to be 689 ± 52 particles/m2/day and 19789 ± 2957 and 30087 ± 13402 in quartz and PTFE particles/m2/day respectively in PM2.5. The mean deposition rate in indoor environment during post-monsoon was 8.3 × 104 and 1.03 × 105 particles/m2/day in winter. During the post-monsoon period in PM10, there were fibres from 7.7 to 40 µm and fragments from 2.3 µm to 8.6 µm. Indoor atmospheric microplastics, fibres ranged from 1.2 to 47 µm and fragments from 0.9 to 16 µm present respectively during the post-monsoon season. Fibres and fragment sizes witnessed during winter were 3.6-6.9 µm and 2.3-34 µm, respectively. Indoor air films measured in the range of 4.1-9.6 µm. Fourier transform infrared analysis showed that outdoor air contained polyethylene, polypropylene, Polystyrene, whereas indoor air had polyvinyl chloride. Polyethylene mainly was present in outdoor air, with lesser polypropylene and polystyrene than indoors, where polyvinyl chloride and polyethylene were in dominant proportions. Elemental mapping of outdoor and indoor air samples showed the presence of elements on the microplastics. The HYSPLIT models suggest that the particles predominantly were coming from North-West during the post-monsoon season. Principal component analysis indicated wind speed and direction influencing the abundance of microplastics. Microplastics concentration showed strong seasonal influence and potential to act as reservoir of contaminants.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Poluição do Ar em Ambientes Fechados/análise , Poluentes Atmosféricos/análise , Microplásticos/análise , Plásticos/análise , Monitoramento Ambiental , Polipropilenos/análise , Poliestirenos/análise , Cloreto de Polivinila/análise , Quartzo , Índia , Polietileno/análise , Material Particulado/análise , Politetrafluoretileno
20.
Sci Rep ; 14(1): 4962, 2024 02 29.
Artigo em Inglês | MEDLINE | ID: mdl-38424121

RESUMO

Microplastics are exotic pollutants and are increasingly detected in soil, but it remains poorly understood how microplastics impact soil and plant systematically. The present study was conducted to evaluate the effects of polyvinyl chloride microplastics (PVC-MPs) on wheat seedlings performance and soil properties. Under the stress of PVC-MPs, no new substance and functional groups were generated in soil by X-ray diffraction and the fourier transform infrared spectroscopy analyses, whereas the diffraction and characteristic peaks and of soil was affected by PVC-MPs. Wheat seedlings shoot biomass and soil nitrate nitrogen were significantly inhibited by PVC-MPs. Chlorophylls were not significant affected by PVC-MPs. Superoxide dismutase, catalase, and peroxidase activities in wheat seedlings increased, while malondialdehyde and proline contents decreased significantly. Redundancy analysis displayed that wheat seedlings traits can be largely explained by soil nitrate nitrogen. Our results indicate that PVC-MPs have more significant influence on soil structure than on soil substance composition. Moreover, even though antioxidant enzyme activities were improved to respond the stress of PVC-MPs, wheat seedlings are not severely impacted by PVC-MPs. Besides, soil nitrate nitrogen is the main factor on wheat seedlings performance and wheat seedlings are prone to ensure the root growth under the stress of PVC-MPs.


Assuntos
Microplásticos , Plásticos , Plásticos/farmacologia , Triticum , Nitratos/farmacologia , Plântula , Cloreto de Polivinila , Solo/química , Antioxidantes/farmacologia
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