Study on aging behavior of polyethylene glycol under three wavelengths of ultraviolet light irradiation† † Electronic supplementary information (ESI) available. See DOI: https://doi.org/10.1039/d3ra06407g
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ABSTRACT:
SUBMITTER: Shang M
PROVIDER: S-EPMC10669924 | biostudies-literature | 2023 Nov
REPOSITORIES: biostudies-literature
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Project description:BackgroundMicroplastics (MPs), plastic particles < 5 mm in size, are prevalent in the environment, and human exposure to them is inevitable. To assess the potential risk of MPs on human health, it is essential to consider the physicochemical properties of environmental MPs, including polymer types, size, shape, and surface chemical modifications. Notably, environmental MPs undergo degradation due to external factors such as ultraviolet (UV) rays and waves, leading to changes in their surface characteristics. However, limited knowledge exists regarding the health effects of MPs, with a specific focus on their surface degradation. This study concentrates on cytotoxic MPs with surface degradation through UV irradiation, aiming to identify the mechanisms underlying their cell toxicity.ResultsPolyethylene (PE) and surface-degraded PE achieved through UV light irradiation were employed as model MPs in this study. We explored the impact of PE and degraded PE on cell death in murine macrophage cell line RAW264.7 cells and human monocyte cell line THP-1 cells. Flow cytometric analysis revealed that degraded PE induced programmed cell death without activating caspase 3, while non-degraded PE did not trigger programmed cell death. These findings suggest that degraded PE might induce programmed cell death through mechanisms other than caspase-driven apoptosis. To understand the mechanisms of cell death, we investigated how cells responded to degraded PE-induced cellular stress. Immunofluorescence and western blotting analyses demonstrated that degraded PE induced autophagosome formation and increased p62 expression, indicating inhibited autophagy flux after exposure to degraded PE. Furthermore, degraded PE exposure led to a decrease in acidic lysosomes, indicating lysosomal dysregulation. These results imply that degraded PE induces lysosomal dysfunction, subsequently causing autophagy dysregulation and cell death.ConclusionsThis study unveils that UV-induced degradation of PE results in cell death attributed to lysosomal dysfunction. The findings presented herein provide novel insights into the effects of surface-degraded MPs on biological responses.
| S-EPMC11473831 | biostudies-literature
Project description:Molecular dynamics (MD) simulations are reported for [polyethylene glycol (PEG)200], a polydisperse mixture of ethylene glycol oligomers with an average molar weight of 200 g·mol-1. As a first step, available force fields for describing ethylene glycol oligomers were tested on how accurately they reproduced experimental properties. They were found to all fall short on either reproducing density, a static property, or the self-diffusion coefficient, a dynamic property. Discrepancies with the experimental data increased with the increasing size of the tested ethylene glycol oligomer. From the available force fields, the optimized potential for liquid simulation (OPLS) force field was used to further investigate which adjustments to the force field would improve the agreement of simulated physical properties with experimental ones. Two parameters were identified and adjusted, the (HO)-C-C-O proper dihedral potential and the polarity of the hydroxy group. The parameter adjustments depended on the size of the ethylene glycol oligomer. Next, PEG200 was simulated with the OPLS force field with and without modifications to inspect their effects on the simulation results. The modifications to the OPLS force field significantly decreased hydrogen bonding overall and increased the propensity of intramolecular hydrogen bond formation at the cost of intermolecular hydrogen bond formation. Moreover, some of the tri- and more so tetraethylene glycol formed intramolecular hydrogen bonds between the hydroxy end groups while still maintaining strong intramolecular interactions with the ether oxygen atoms. These observations allowed the interpretation of the obtained RDFs as well as structural properties such as the average end-to-end distances and the average radii of gyration. The MD simulations with and without the modifications showed no evidence of preferential association of like-oligomers to form clusters nor any evidence of long-range ordering such as a side-by-side stacking of ethylene glycol oligomers. Instead, the simulation results support the picture of PEG200 being a random mixture of its ethylene glycol oligomer components. Finally, additional MD simulations of a binary mixture of tri-and hexaethylene glycol with the same average molar weight as PEG200 revealed very similar structural and physical properties as for PEG200.
| S-EPMC9923754 | biostudies-literature
Project description:To explore aggregate-induced emission (AIE) properties, this study adopts a one-pot hydrothermal route for synthesizing polyethylene glycol (PEG)-coated graphene quantum dot (GQD) clusters, enabling the emission of highly intense photoluminescence under blue light illumination. The hydrothermal synthesis was performed at 300 °C using o-phenylenediamine as the nitrogen and carbon sources in the presence of PEG. Three different solvents, propylene glycol methyl ether acetate (PGMEA), ethanol, and water, were used for dispersing the PEG-coated GQDs, where extremely high fluorescent emission was achieved at 530-550 nm. It was shown that the quantum yield (QY) of PEG-coated GQD suspensions is strongly dependent on the solvent type. The pristine GQD suspension tends to be quenched (i.e., QY: ~1%) when dispersed in PGMEA (aggregation-caused quenching). However, coating GQD nanoparticles with polyethylene glycol results in substantial enhancement of the quantum yield. When investigating the photoluminescence emission from PEG-coated GQD clusters, the surface tension of the solvents was within the range of from 26.9 to 46.0 mN/m. This critical index can be tuned for assessing the transition point needed to activate the AIE mechanism which ultimately boosts the fluorescence intensity. The one-pot hydrothermal route established in this study can be adopted to engineer PEG-coated GQD clusters with solid-state PL emission capabilities, which are needed for next-generation optical, bio-sensing, and energy storage/conversion devices.
| S-EPMC8225077 | biostudies-literature
Project description:RNA was isolated from material that had been subjected to immunoprecipitation (IP) from RKO cells that were either left untreated or irradiated with 20 J/m2 UVC and collected 1h later; IP assays were carried out using either an antibody recognizing RNA-binding protein TIAR, or using a control IgG1 antibody. RNA was reverse-transcribed in the presence of [alpha-33P]dCTP and the radiolabeled product used to hybridize human cDNA arrays. The experiment was repeated using three independent sample sets. The samples were numbered Tc-1, Tc-2, Tc-3, Tuv-1, Tuv-2, Tuv-3, IgG1c-1, IgG1c-2, IgG1c-3, IgG1uv-1, IgG1uv-2, and IgG1uv-3. ‘Tc’ denotes RNA from IP reactions using untreated cells and anti-TIAR antibody, ‘Tuv’ denotes RNA from IP reactions using UVC-treated cells and anti-TIAR antibody, ‘IgG1c’ denotes RNA from IP reactions using untreated cells and anti-IgG1 antibody, and ‘IgG1uv’ denotes RNA from IP reactions using UVC-treated cells and anti-IgG1 antibody. The numbers 1, 2 and 3 correspond to the three independent experimental datasets. Keywords = post-transcriptional / translation / nascent protein synthesis / stress response / ribonomics Keywords: ordered
2004-05-27 | GSE1433 | GEO
Project description:Untreated or 20 J/m2 UVC treated RKO cells were collected and RNA from either whole-cell lysates or from polysomal fractions was extracted at 0 (untreated), 3, 6, and 12 h after treatment. RNA from whole-cell lysates or each of 11 polysomal fraction was reverse-transcribed in the presence of [α-33P]dCTP and the radiolabeled product used to hybridize human cDNA arrays. The experiment was repeated using three independent sample sets. The samples were named T-c-A, T-c-B, T-c-C, T-3h-A, T-3h-B, T-3h-C, T-6h-A, T-6h-B, T-6h-C, T-12h-A, T-12h-B, T-12h-C, P-c-1-A, P-c-2-A, P-c-3-A, P-c-4-A, P-c-5-A, P-c-6-A, P-c-7-A, P-c-8-A, P-c-9-A, P-c-10-A, P-c-11-A, P-c-1-B, P-c-2-B, P-c-3-B, P-c-4-B, P-c-5-B, P-c-6-B, P-c-7-B, P-c-8-B, P-c-9-B, P-c-10-B, P-c-11-B, P-c-2-C, P-c-3-C, P-c-4-C, P-c-5-C, P-c-6-C, P-c-7-C, P-c-8-C, P-c-9-C, P-c-10-C, P-c-11-C, P-3h-1-A, P-3h-2-A, P-3h-3-A, P-3h-4-A, P-3h-5-A, P-3h-6-A, P-3h-7-A, P-3h-8-A, P-3h-9-A, P-3h-10-A, P-3h-11-A, P-3h-1-B, P-3h-2-B, P-3h-3-B, P-3h-4-B, P-3h-5-B, P-3h-6-B, P-3h-7-B, P-3h-8-B, P-3h-9-B, P-3h-10-B, P-3h-11-B, P-3h-1-C, P-3h-2-C, P-3h-3-C, P-3h-4-C, P-3h-6-C, P-3h-7-C, P-3h-8-C, P-3h-9-C, P-3h-10-C, P-3h-11-C, P-6h-1-A, P-6h-2-A, P-6h-3-A, P-6h-4-A, P-6h-5-A, P-6h-6-A, P-6h-7-A, P-6h-8-A, P-6h-9-A, P-6h-10-A, P-6h-11-A, P-6h-1-B, P-6h-2-B, P-6h-3-B, P-6h-4-B, P-6h-5-B, P-6h-6-B, P-6h-7-B, P-6h-8-B, P-6h-9-B, P-6h-10-B, P-6h-11-B, P-6h-1-C, P-6h-2-C, P-6h-3-C, P-6h-4-C, P-6h-5-C, P-6h-6-C, P-6h-7-C, P-6h-8-C, P-6h-9-C, P-6h-10-C, P-6h-11-C, P-12h-1-A, P-12h-2-A, P-12h-3-A, P-12h-4-A, P-12h-5-A, P-12h-6-A, P-12h-7-A, P-12h-8-A, P-12h-9-A, P-12h-10-A, P-12h-11-A, P-12h-1-B, P-12h-2-B, P-12h-3-B, P-12h-4-B, P-12h-5-B, P-12h-6-B, P-12h-7-B, P-12h-8-B, P-12h-9-B, P-12h-10-B, P-12h-11-B, P-12h-1-C, P-12h-2-C, P-12h-3-C, P-12h-6-C, P-12h-7-C, P-12h-8-C, P-12h-9-C, P-12h-10-C, P-12h-11-C. ‘T’ represents total RNA, ‘P’ represents RNA from polysomes fractions, ‘c’ represents RNA from untreated cells, ‘3h’ represents RNA from cells collected 3 h after UVC treatment, ‘6h’ represents RNA from cells collected 6 h after UVC treatment, ‘12h’ represents RNA from cells collected 12 h after UVC treatment. The numbers 1-11 correspond to the each polysomal fraction. The letters A, B and C correspond to the three independent experimental datasets. Keywords = post-transcriptional / translation / nascent protein synthesis / stress response / ribonomics Keywords: ordered
2004-06-02 | GSE1440 | GEO
Project description:The emergence of fluorescent graphene quantum dots (GQDs) is expected to enhance the usefulness of quantum dots (QDs), in terms of their unique luminescence, photostability, low toxicity, chemical resistance, and electron transport properties. Here we prepared blue-photoluminescent polyethylene glycol GQDs (PEG-GQDs) through PEG surface passivation. The photoluminescence (PL) quantum yield (QY) of PEG-GQDs with 320 nm excitation was about 4.9%, which was higher than that of pure GQDs. The as-fabricated PEG-GQDs with high QY were then used as light-emitting diode (PGQD-LED) emitters, in which the GQDs were incorporated into polymeric host layers in a multilayer electroluminescent device; blue emission with a luminance exceeding 800 cd m-2 was achieved, thus demonstrating the potential of PEG-GQDs as emitters in electroluminescence applications. Furthermore, the fluorescence mechanism of PEG-GQDs was investigated and proved that the origin of strong fluorescence of PEG-GQDs is associated with the luminescence from intrinsic states. The highly fluorescent PEG-GQDs will allow new devices, such as multicolor LEDs, to be developed with extraordinary properties, by tailoring the intrinsic and extrinsic states.
| S-EPMC9055582 | biostudies-literature
Project description:We have studied copolymer dendrimer structure: carbosilane dendrimers with terminal phenylbenzoate mesogenic groups attached by poly(ethylene) glycol (PEG) spacers. In this system PEG spacers are additional tuning to usual copolymer structure: dendrimer with terminal mesogenic groups. The dendrimer macromolecules were investigated in a dilute chloroform solution by (1)H NMR methods (spectra and relaxations). It was found that the PEG layer in G = 5 generations dendrimer is "frozen" at high temperatures (above 260 K), but it unexpectedly becomes "unfrozen" at temperatures below 250 K (i.e., melting when cooling). The transition between these two states occurs within a small temperature range (~10 K). Such a behavior is not observed for smaller dendrimer generations (G = 1 and 3). This effect is likely related to the low critical solution temperature (LCST) of PEG and is caused by dendrimer conformations, in which the PEG group concentration in the layer increases with growing G. We suppose that the unusual behavior of PEG fragments in dendrimers will be interesting for practical applications such as nanocontainers or nanoreactors.
| S-EPMC4823654 | biostudies-literature
Project description:RNA was isolated from material that had been subjected to immunoprecipitation (IP) from RKO cells that were either left untreated or irradiated with 20 J/m2 UVC and collected 1h later; IP assays were carried out using either an antibody recognizing RNA-binding protein TIAR, or using a control IgG1 antibody. RNA was reverse-transcribed in the presence of [alpha-33P]dCTP and the radiolabeled product used to hybridize human cDNA arrays. The experiment was repeated using three independent sample sets. The samples were numbered Tc-1, Tc-2, Tc-3, Tuv-1, Tuv-2, Tuv-3, IgG1c-1, IgG1c-2, IgG1c-3, IgG1uv-1, IgG1uv-2, and IgG1uv-3. âTcâ denotes RNA from IP reactions using untreated cells and anti-TIAR antibody, âTuvâ denotes RNA from IP reactions using UVC-treated cells and anti-TIAR antibody, âIgG1câ denotes RNA from IP reactions using untreated cells and anti-IgG1 antibody, and âIgG1uvâ denotes RNA from IP reactions using UVC-treated cells and anti-IgG1 antibody. The numbers 1, 2 and 3 correspond to the three independent experimental datasets. Keywords = post-transcriptional / translation / nascent protein synthesis / stress response / ribonomics Keywords: ordered
2010-06-09 | E-GEOD-1433 | biostudies-arrayexpress
Project description:The deep ultraviolet photochemistry of aqueous pyruvate is believed to have been essential to the origin of life, and near ultraviolet excitation of pyruvate in aqueous aerosols is assumed to contribute significantly to the photochemistry of the Earth's atmosphere. However, the primary photochemistry of aqueous pyruvate is unknown. Here we study the susceptibility of aqueous pyruvate to photodissociation by deep ultraviolet and near ultraviolet irradiation with femtosecond spectroscopy supported by density functional theory calculations. The primary photo-dynamics of the aqueous pyruvate show that upon deep-UV excitation at 200 nm, about one in five excited pyruvate anions have dissociated by decarboxylation 100 ps after the excitation, while the rest of the pyruvate anions return to the ground state. Upon near-UV photoexcitation at a wavelength of 340 nm, the dissociation yield of aqueous pyruvate 200 ps after the excitation is insignificant and no products are observed. The experimental results are explained by our calculations, which show that aqueous pyruvate anions excited at 200 nm have sufficient excess energy for decarboxylation, whereas excitation at 340 nm provides the aqueous pyruvate anions with insufficient energy to overcome the decarboxylation barrier.
| S-EPMC10912111 | biostudies-literature
Project description:Tuning of the photoluminescence property of carbon nanodots is realized by surface modification through ultraviolet light irradiation. The photoluminescence of the processed carbon nanodots in the visible region is weakened while that in the ultraviolet region increases significantly. Fourier transform infrared spectroscopy and X-ray photo-electron spectroscopy reveal that the number of surface functional groups decrease significantly after ultraviolet light processing. By examining the electron donating and accepting properties, we confirm that the surface of the carbon nanodots is photoreduced by ultraviolet light, causing a decrease in the number of functional groups as well as emission in the visible region. The temporal behavior of the photoluminescence reveals that the increase of the emission in the ultraviolet region originates from the increased intrinsic state emission of the carbon nanodots.
| S-EPMC9063684 | biostudies-literature