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The Journal of Physical Chemistry. B Jun 2024This study investigates the structural changes of cyclic polyethylene (PE) single chains during cooling through molecular dynamics simulations. The influence of...
This study investigates the structural changes of cyclic polyethylene (PE) single chains during cooling through molecular dynamics simulations. The influence of topological constraint on a ring is examined by comparing it with the results of its linear counterpart. A pseudo phase diagram of state transition for PE rings based on length and temperature is constructed, revealing a consistent chain-folding transition during cooling. The shape anisotropy of short crystallized cyclic chains exhibits oscillations with chain length, leading to a more pronounced odd-even effect in single cyclic chains compared with the linear ones. A honeycomb model is proposed to elucidate the odd-even effect of chain folding in crystalline structures of single linear and cyclic chains, and we discuss its potential to predict surface tension. Analyses of the tight folding model and the re-entry modes demonstrate that a cyclic chain possesses a shorter average crystalline stem length and a more compact folded structure than its linear counterpart. The findings highlight the impact of topological change on crystallization and the odd-even effect of chain length, providing valuable insights for understanding polymer crystallization with different topologies.
PubMed: 38941574
DOI: 10.1021/acs.jpcb.4c01143 -
ACS Nano Jun 2024Solid-state nanochannels (SSNs) have emerged as promising platforms for controlling ionic transport at the nanoscale. SSNs are highly versatile, and this feature can be...
Solid-state nanochannels (SSNs) have emerged as promising platforms for controlling ionic transport at the nanoscale. SSNs are highly versatile, and this feature can be enhanced through their combination with porous materials such as Metal-Organic Frameworks (MOF). By selection of specific building blocks and experimental conditions, different MOF architectures can be obtained, and this can influence the ionic transport properties through the nanochannel. Herein, we study the effects of confined synthesis of Zr-based UiO-66 MOF on the ion transport properties of single bullet-shaped poly(ethylene terephthalate) (PET) nanochannels. We have found that emerging textural properties from the MOF phase play a determinant role in controlling ionic transport through the nanochannel. We demonstrate that a transition from ion current saturation regimes to diode-like regimes can be obtained by employing different synthetic approaches, namely, counterdiffusion synthesis, where MOF precursors are kept separate and forced to diffuse through the nanochannel, and one-pot synthesis, where both precursors are placed at both ends of the channel. Also, by considering the dependence of the charge state of the UiO-66 MOF on the protonation degree, pH changes offered a mechanism to tune the iontronic output (and selectivity) among different regimes, including anion-driven rectification, cation-driven rectification, ion current saturation, and ohmic behavior. Furthermore, Poisson-Nernst-Planck (PNP) simulations were employed to rationalize the different iontronic outputs observed experimentally for membranes modified by different methods. Our results demonstrate a straightforward tool to synthesize MOF-based SSN membranes with tunable ion transport regimes.
PubMed: 38941562
DOI: 10.1021/acsnano.4c04435 -
Biological Trace Element Research Jun 2024Metals are used in orthopedic implants. The wear of arthroplasty implant can lead to the release of arthroprosthetic metals, both locally and systemically, after...
Metals are used in orthopedic implants. The wear of arthroplasty implant can lead to the release of arthroprosthetic metals, both locally and systemically, after migration into the organs. While the toxicity of metal-on-metal arthroplasty implants is well-known and monitored, the toxicity associated with metal-on-polyethylene (MoP) ones is not as comprehensively understood. This study aimed to investigate the release of metals from MoP arthroplasty implants and their impact on the tissue metal profile in autopsied individuals, comparing them to deceased controls without prostheses. High-resolution ICP-MS was employed to analyze 39 metals in the blood, urine, hair, organs, and periprosthetic tissue of 25 deceased individuals with arthroplasty implants and 20 control subjects (Prometox study, protocol ID: APHP180539, NCT03812627). Eight metals (beryllium, chromium, cobalt, lanthanum, molybdenum, nickel, tellurium, titanium) exhibited significant impacts in arthroplasty implant wearers across various organs. Increased concentrations of La and Be were observed, the origin of which could not be precisely defined within the scope of this study. Notably, the lungs emerged as the primary target organ for metallic ions contained in implants. This study suggests that MoP arthroplasty implants, even when functional and not visibly worn, release arthroprosthetic metals into the body, potentially causing disturbances. Furthermore, considering the presence of an arthroplasty implant in autopsy reports may be relevant, as the released metals could influence the tissue metal profile.
PubMed: 38941062
DOI: 10.1007/s12011-024-04278-2 -
Biomaterials Science Jun 2024PEGylation is currently used for the synthesis of stealth liposomes and to enhance the pharmacokinetic and biopharmaceutical properties of payloads. PEGylated dendron...
PEGylation is currently used for the synthesis of stealth liposomes and to enhance the pharmacokinetic and biopharmaceutical properties of payloads. PEGylated dendron phospholipids can decrease the detachment of polyethylene glycol (PEG) from the liposomal surface owing to an increased hydrophobic anchoring effect on the phospholipid bilayer of liposomes and thus generating super stealth liposomes that are suitable for the systemic delivery of anticancer drugs. Herein, doxorubicin hydrochloride-loaded super stealth liposomes were studied for the treatment of breast cancer lung metastasis in an animal model. The results demonstrated that the super stealth liposomes had suitable physicochemical properties for administration and could significantly increase the efficacy of doxorubicin in breast cancer lung metastasis tumor-bearing mice compared to the free drug. The super stealth liposomes also increased doxorubicin accumulation inside the tumor tissue. The permanence of PEG on the surface of the super stealth liposomes favored the formation of a depot of therapeutic nanocarriers inside the tumor tissue by improving their permanence after stopping treatment. The doxorubicin-loaded super stealth liposomes increased the survival of the mouse tumor model. These promising results demonstrate that the doxorubicin-loaded super stealth liposomes could be an effective nanomedicine to treat metastatic breast cancer.
PubMed: 38940612
DOI: 10.1039/d4bm00478g -
ACS Applied Materials & Interfaces Jun 2024Membranous nephropathy (MN) is a common immune-mediated glomerular disease that requires the development of safe and highly effective therapies. Celastrol (CLT) has...
Membranous nephropathy (MN) is a common immune-mediated glomerular disease that requires the development of safe and highly effective therapies. Celastrol (CLT) has shown promise as a therapeutic molecule candidate, but its clinical use is currently limited due to off-target toxicity. Given that excess levels of reactive oxygen species (ROS) contributing to podocyte damage is a key driver of MN progression to end-stage renal disease, we rationally designed ROS-responsive cationic polymeric nanoparticles (PPS-CPNs) with a well-defined particle size and surface charge by employing poly(propylene sulfide)-polyethylene glycol (PPS-PEG) and poly(propylene sulfide)-polyethylenimine (PPS-PEI) to selectively deliver CLT to the damaged glomerulus for MN therapy. Experimental results show that PPS-CPNs successfully crossed the fenestrated endothelium, accumulated in the glomerular basement membrane (GBM), and were internalized by podocytes where rapid drug release was triggered by the overproduction of ROS, thereby outperforming nonresponsive CLT nanotherapy to alleviate subepithelial immune deposits, podocyte foot process effacement, and GBM expansion in a rat MN model. Moreover, the ROS-responsive CLT nanotherapy was associated with significantly lower toxicity to major organs than free CLT. These results suggest that encapsulating CLT into PPS-CPNs can improve efficacy and reduce toxicity as a promising treatment option for MN.
PubMed: 38940537
DOI: 10.1021/acsami.4c04345 -
Advanced Science (Weinheim,... Jun 2024Zinc anodes of zinc metal batteries suffer from unsatisfactory plating/striping reversibility due to interfacial parasitic reactions and poor Zn mass transfer kinetics....
Zinc anodes of zinc metal batteries suffer from unsatisfactory plating/striping reversibility due to interfacial parasitic reactions and poor Zn mass transfer kinetics. Herein, methoxy polyethylene glycol-phosphate (mPEG-P) is introduced as an electrolyte additive to achieve long anti-calendar aging and high-rate capabilities. The polyanionic of mPEG-P self-assembles via noncovalent-interactions on electrode surface to form polyether-based cation channels and in situ organic-inorganic hybrid solid electrolyte interface layer, which ensure rapid Zn mass transfer and suppresses interfacial parasitic reactions, realizing outstanding cycling/calendar aging stability. As a result, the Zn//Zn symmetric cells with mPEG-P present long lifespans over 9000 and 2500 cycles at ultrahigh current densities of 120 and 200 mA cm, respectively. Besides, the coulombic efficiency (CE) of the Zn//Cu cell with mPEG-P additive (88.21%) is much higher than that of the cell (36.4%) at the initial cycle after the 15-day calendar aging treatment, presenting excellent anti-static corrosion performance. Furthermore, after 20-day aging, the Zn//MnO cell exhibits a superior capacity retention of 89% compared with that of the cell without mPEG-P (28%) after 150 cycles. This study provides a promising avenue for boosting the development of high efficiency and durable metallic zinc based stationary energy storage system.
PubMed: 38937993
DOI: 10.1002/advs.202404513 -
Journal of Separation Science Jun 2024Short-chain fatty acids (SCFAs) are organic acids with carbon atoms less than six, released through fermentation products by intestinal microbiome, having multiple...
Short-chain fatty acids (SCFAs) are organic acids with carbon atoms less than six, released through fermentation products by intestinal microbiome, having multiple physiological activities. Considering weak acidity and high volatility, derivatization or liquid-liquid extraction is essential, which is time consuming. Headspace-solid-phase dynamic extraction (HS-SPDE) coupled with gas chromatography-mass spectrometry is automated and effortless to determine SCFAs in rat feces. The extraction procedure is performed by aspirating and discharging the headspace cyclically through a steel needle, coated with an inner polyethylene glycol sorbent. The key parameters of SPDE were optimized including coating type, incubation time and temperature, and number of extraction strokes. Besides, salting-out was conducted. Then, a method by HS-SPDE-GC-MS was established and validated. It only took 3-min incubation time, 4.5 min extraction time, and 13 min chromatographic separation in a run. The recovery, linearity, limit of quantification, and stability were evaluated. Then, the proposed method was applied to analyze rat feces including 18 rats with liver injury and 23 normal controls. Mann-Whitney U test indicated that the concentrations of six SCFAs in normal rat feces were higher than those with liver injury. This method provides a choice for fast, solvent-free, automated, and high-throughput analysis of SCFAs.
Topics: Animals; Gas Chromatography-Mass Spectrometry; Feces; Rats; Fatty Acids, Volatile; Solid Phase Extraction; Male; Rats, Sprague-Dawley
PubMed: 38937913
DOI: 10.1002/jssc.202400032 -
Dental Materials : Official Publication... Jun 2024Evaluate a new light-cured material with better properties for vital pulp therapy.
OBJECTIVES
Evaluate a new light-cured material with better properties for vital pulp therapy.
METHODS
Light-cured resin materials consisted of polyethylene glycol (600) diacrylate mixed with different ratios of TCP to HA. In addition to the temperature change (n = 5 for each subgroup) were tested, cell viability and Alizarin Red Staining (ARS) assay were also tested in vitro on human dental pulp cells (n = 6 for each subgroup). Lastly, the material was then compared with Biodentine and control groups in the molars of Wistar rats in vivo for histology assessment.
RESULTS
The temperature change for the new materials were under 5 degrees Celsius. For the in vitro assessments, there was no significant difference on day 3 and day 7 for cell viability test. ARS assay showed significantly higher mineralized nodule formation when treated without induction medium for Group D and Biodentine on day 10 compared to Group C and control. On the contrary, Biodentine and control groups treated with induction medium showed significant higher mineralization than the new materials. Histology assessments demonstrated higher mineralized content in Group D and Biodentine on week 3 and week 6. The inflammatory cells in the dental pulp complex of the Biodentine group resolved on week 6 while the inflammation resolved in Group D on week 3.
SIGNIFICANCE
The new material exhibits low heat production, low cytotoxicity, and good calcium ion release capability. Compared to traditional materials, it has shorter setting time and better aesthetic outcomes, making it highly suitable for use in vital pulp therapy.
PubMed: 38937202
DOI: 10.1016/j.dental.2024.06.009 -
Chemical Reviews Jun 2024A powerful toolbox is needed to turn the linear plastic economy into circular. Development of materials designed for mechanical recycling, chemical recycling, and/or... (Review)
Review
A powerful toolbox is needed to turn the linear plastic economy into circular. Development of materials designed for mechanical recycling, chemical recycling, and/or biodegradation in targeted end-of-life environment are all necessary puzzle pieces in this process. Polyesters, with reversible ester bonds, are already forerunners in plastic circularity: poly(ethylene terephthalate) (PET) is the most recycled plastic material suitable for mechanical and chemical recycling, while common aliphatic polyesters are biodegradable under favorable conditions, such as industrial compost. However, this circular design needs to be further tailored for different end-of-life options to enable chemical recycling under greener conditions and/or rapid enough biodegradation even under less favorable environmental conditions. Here, we discuss molecular design of the polyester chain targeting enhancement of circularity by incorporation of more easily hydrolyzable ester bonds, additional dynamic bonds, or degradation catalyzing functional groups as part of the polyester chain. The utilization of polyester circularity to design replacement materials for current volume plastics is also reviewed as well as embedment of green catalysts, such as enzymes in biodegradable polyester matrices to facilitate the degradation process.
PubMed: 38936815
DOI: 10.1021/acs.chemrev.4c00032 -
The Science of the Total Environment Jun 2024Nanoplastics (NPs) present a hidden risk to organisms and the environment via migration and enrichment. Detecting NPs remains challenging because of their small size,...
Nanoplastics (NPs) present a hidden risk to organisms and the environment via migration and enrichment. Detecting NPs remains challenging because of their small size, low ambient concentrations, and environmental variability. There is an urgency to exploit detection approaches that are more compatible with real-world environments. Herein, this study provides a surface-enhanced Raman spectroscopy (SERS) technique for the in situ reductive generation of silver nanoparticles (Ag NPs), which is based on photoaging-induced modifications in NPs. The feasibility of generating Ag NPs on the surface of NPs was derived by exploring the photoaging mechanism, which was then utilized to SERS detection. The approach was applied successfully for the detection of polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET) NPs with excellent sensitivity (e.g., as low as 1 × 10 mg/mL for PVC NPs, and an enhancement factor (EF) of up to 2.42 × 10 for small size PS NPs) and quantitative analytical capability (R > 0.95579). The method was successful in detecting NPs (PS NPs) in lake water. In addition, satisfactory recoveries (93.54-105.70 %, RSD < 12.5 %) were obtained by spiking tap water as well as lake water, indicating the applicability of the method to the actual environment. Therefore, the proposed approach offers more perspectives for testing real environmental NPs.
PubMed: 38936740
DOI: 10.1016/j.scitotenv.2024.174249