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Toxicological Research Jul 2024Phthalates are extensively employed plasticizers crucial for conferring flexibility and plasticity to polyvinyl chloride. Phthalates, including DEHP...
Phthalates are extensively employed plasticizers crucial for conferring flexibility and plasticity to polyvinyl chloride. Phthalates, including DEHP (di(2-ethylhexyl)phthalate), present in diverse products, have been identified in fine dust and are capable of infiltrating the body, potentially posing health hazards. Importantly, melanocytes, existing at the basal layer of the epidermis, are susceptible to toxic substances. In our study, we employed the 3D human pigmented epidermis model, MelanoDerm™, along with the B16F10 murine melanoma cell line, to examine the influence of DEHP exposure on melanocytes. The exposure to low concentrations of DEHP (~ 5 μM), resulted in the extension of melanocyte dendrites, indicating the stimulation of melanocytes. Analysis of gene expression and protein profiles unveiled the up-regulation of MITF, Arpc2, and TRP1 genes subsequent to DEHP exposure, indicating alterations in cytoskeletal and melanosome-related genetic and protein components in melanocytes. Notably, increased pigmentation was observed in MelanoDerm™ following DEHP exposure. DEHP-stimulated reactive oxygen species generation appeared to be involved in these events since the antioxidant, ascorbic acid attenuated ROS generation and MITF upregulation. Collectively, our study demonstrated that DEHP exposure can induce cytoskeletal disturbance and skin pigmentation through oxidative stress.
PubMed: 38911535
DOI: 10.1007/s43188-024-00240-5 -
International Journal of Pharmaceutics Jun 2024In this work, feasibility of injection molding was demonstrated for manufacturing capsule shells. 600 µm-thick prototypes were successfully molded with...
In this work, feasibility of injection molding was demonstrated for manufacturing capsule shells. 600 µm-thick prototypes were successfully molded with pharmaceutical-grade low-viscosity polyvinyl alcohols (PVAs), possibly added with a range of different fillers. They showed reproducible weight and thickness (CV < 2 and 5, respectively), compliant behavior upon piercing (holes diameter analogous to the reference), tunable release performance (immediate and pulsatile), and moisture protection capability. To assess the latter, an on-line method relying on near infrared spectroscopy measurements was set-up and validated. Based on the data collected and considering the versatility IM would provide for product shape/thickness/composition, PVA-based molded shells could help widening the portfolio of ready-to-use capsules, representing an interesting alternative to those commercially available. Indeed, these capsules could be filled with various formulations, even those with stability issues, and intended either for oral administration or for pulmonary delivery via single-dose dry powder inhalers.
PubMed: 38909921
DOI: 10.1016/j.ijpharm.2024.124373 -
Supportive Care in Cancer : Official... Jun 2024
Topics: Humans; Pleural Effusion, Malignant; Pleurodesis; Povidone-Iodine; Doxycycline; Chest Tubes; Randomized Controlled Trials as Topic; Anti-Bacterial Agents
PubMed: 38909347
DOI: 10.1007/s00520-024-08670-5 -
International Journal of Biological... Jun 2024Cellulose nanocrystals (CNCs) have received immense interest lately as a potential nanomaterial because of their excellent mechanical and biological properties. This...
Cellulose nanocrystals (CNCs) have received immense interest lately as a potential nanomaterial because of their excellent mechanical and biological properties. This investigation aims to formulate a composite coating made of polyvinyl alcohol (PVA), CNCs, and a methanolic extract from the dried leaves and fruit of the fig tree (Ficus auriculata) (FAE). A sequential procedure to get CNCs included alkaline and acid hydrolysis, sonication, and suitable methods for purification. Analytical techniques like X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used to study the CNC-loaded films. Thermogravimetric analysis (TGA) of composites revealed superior thermal stability of the CNC-reinforced films versus control, evident from higher degradation temperatures, indicating desirable environmental resistance of proposed coatings for wood surfaces. The termite control was made more effective through synergistic use of a combination of CNCs, PVA, and FAE with proven insecticidal properties. The composite material was examined for its anti-termite resistance and termite mortality rate, and demonstrated that when used together, CNCs, PVA, and FAE were collectively and synergistically more effective at keeping termites away. The findings of this study demonstrate that the evolved composite could be used to develop anti-termite products that are environmentally benign and respond well. Synthesized composites also demonstrated significant antibacterial activity. Among all films, a combination of 0.7 % extract in PVA displayed excellent results with 26 and 28 mm diameter for growth inhibition zone for Gram-positive bacteria whereas 26 mm for both negative bacterial strains. The findings suggest a potential use of this composite as a sustainable, environmentally resistant, and eco-friendly alternative for termite/bacterial control in various building materials and wood preservation applications.
PubMed: 38908623
DOI: 10.1016/j.ijbiomac.2024.133338 -
International Journal of Biological... Jun 2024Electromagnetic hydrogels have attracted significant attention due to their vast potential in soft robotics, biomedical engineering, and energy harvesting. To facilitate...
Bridging papermaking and hydrogel production: Nanoparticle-loaded cellulosic hollow fibers with pitted walls as skeleton materials for multifunctional electromagnetic hydrogels.
Electromagnetic hydrogels have attracted significant attention due to their vast potential in soft robotics, biomedical engineering, and energy harvesting. To facilitate future commercialization via large-scale industrial processes, we present a facile concept that utilizes the specialized knowledge of papermaking to fabricate hydrogels with multifunctional electromagnetic properties. The principles of papermaking wet end chemistry, which involves the handling of interactions among cellulosic fibers, fines, polymeric additives, and other components in aqueous systems, serves as a key foundation for this concept. Our methodology exploits the unique hierarchically pitted and hollow tube-like structures of papermaking grade cellulosic fibers with discernible pits, enabling the incorporation of magnetite nanoparticles through lumen loading. By combining microscale softwood-derived cellulosic fibers with additives, including polyvinyl alcohol and borax, we achieve dynamic covalent interactions that transform the cellulosic fiber slurry into an impressive hydrogel. The cellulosic fibers act as a skeleton, providing structural support within the hydrogel framework. In accordance with our concept, the typical hydrogel exhibits combined attributes, including electrical conductivity, self-healing properties, pH responsiveness, and dynamic rheologic behavior. Our approach not only yields hydrogel with interesting properties but also aligns with the forefront of advanced cellulosic material applications. These materials hold the promise in remote strain sensing devices, electromagnetic navigation systems, contactless toys, and flexible electronic devices. The concept and findings of the current work may shed light on materials innovation based on traditional pulp and paper processes. Furthermore, the facile processes involved in hydrogel formation can serve as valuable tools for chemistry and materials education, providing easy demonstrations of principles for university students at different levels.
PubMed: 38908622
DOI: 10.1016/j.ijbiomac.2024.133280 -
Methods in Molecular Biology (Clifton,... 2024Polymeric delivery systems could enable the fast- and low-side-effect transport of various RNA classes. Previously, we demonstrated that polyvinylamine (PVAm), a...
Polymeric delivery systems could enable the fast- and low-side-effect transport of various RNA classes. Previously, we demonstrated that polyvinylamine (PVAm), a cationic polymer, transfects many kinds of RNAs with high efficiency and low toxicity both in vitro and in vivo. The modification of poly lactic-co-glycolic acid (PLGA) with cartilage-targeting peptide (CAP) enhances its stiffness and tissue-specific delivery of RNA to overcome the avascular nature of articular cartilage. Here we describe the protocol to use PVAm as an RNA carrier, and further, by modifying PVAm with PLGA and CAP, the corresponding co-polymer could be applied for functional RNA delivery for osteoarthritis treatment.
Topics: Polyvinyls; Animals; Polylactic Acid-Polyglycolic Acid Copolymer; Humans; Lactic Acid; Transfection; Gene Transfer Techniques; Polyglycolic Acid; Drug Carriers; RNA, Small Interfering; Osteoarthritis
PubMed: 38907928
DOI: 10.1007/978-1-0716-3918-4_22 -
Biomedical Physics & Engineering Express Jul 2024In this study tissue equivalency of the polymeric materials was investigated by comparing with ICRP 110 Male Adult Computational Phantom tissues. For this purpose,... (Comparative Study)
Comparative Study
In this study tissue equivalency of the polymeric materials was investigated by comparing with ICRP 110 Male Adult Computational Phantom tissues. For this purpose, radiological properties of polyamide (PA), high density polyethylene (HDPE), ultra-high molecular weight polyethylene (UHMWPE), polypropylene (PP), polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), polyoxymethylene (POM) and polyurethane foam (PU FOAM) were evaluated in the diagnostic energy range (15-150 keV). The radiological properties of the materials and ICRP 110 Male and Female Adult Computational Phantom tissues were calculated with Phy-X/PSD software. No major differences were seen except for sex-specific organs, and comparisons were made using an adult male phantom. To confirm the results experimentally, a chest phantom was designed with the polymeric materials. The phantom was scanned by Siemens SOMATOM Edge CT device with tube voltage of 120 kVp and Hounsfield Unit (HU) values were measured. In addition, HU values were calculated using theoretical relationships and significant agreement was obtained between measured and calculated HUs. It was determined that PA, PP, UHMWPE and HDPE were equivalent to muscle and adipose tissue, PVC and PTFE were equivalent to mineral bone, PET and POM were equivalent to spongiosa bone and PU FOAM was equivalent to lung tissue.
Topics: Phantoms, Imaging; Humans; Male; Polymers; Female; Adult; Tomography, X-Ray Computed; Materials Testing; Polyethylenes
PubMed: 38906123
DOI: 10.1088/2057-1976/ad5a9d -
Indian Journal of Ophthalmology Jul 2024
Topics: Humans; Povidone-Iodine; Ophthalmic Solutions; COVID-19; Anti-Infective Agents, Local; SARS-CoV-2; Conjunctivitis
PubMed: 38905467
DOI: 10.4103/IJO.IJO_2666_23 -
Analytical Chemistry Jul 2024A simple, sustainable, and sensitive monitoring approach of micro/nanoplastics (MNPs) in aqueous samples is crucial since it helps in assessing the extent of...
Monitoring Poly(methyl methacrylate) and Polyvinyl Dichloride Micro/Nanoplastics in Water by Direct Solid-Phase Microextraction Coupled to Gas Chromatography-Mass Spectrometry.
A simple, sustainable, and sensitive monitoring approach of micro/nanoplastics (MNPs) in aqueous samples is crucial since it helps in assessing the extent of contamination and understanding the potential risks associated with their presence without causing additional stress to the environment. In this study, a novel strategy for qualitative and quantitative determination of MNPs in water by direct solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was proposed for the first time. Spherical poly(methyl methacrylate) (PMMA) and irregularly shaped polyvinyl dichloride (PVDC) were used to evaluate the feasibility and performance of the proposed method. The results demonstrated that both PMMA and PVDC MNPs were efficiently extracted by the homemade SPME coating of nitrogen-doped porous carbons (N-SPCs) and exhibited sufficient thermal decomposition in the GC-MS injection port. Excellent extraction performances of N-SPCs coating for MNPs are attributed to hydrophobic cross-linking, electrostatic forcing, hydrogen bonding, and pore trapping. Methyl methacrylate was identified as the marker for PMMA, while 1,3-dichlorobenzene and 1,3,5-trichlorobenzene were the indicators for PVDC. Under the optimal extraction and decomposition conditions, the proposed method exhibited ultrahigh sensitivity, with a limit of detection of 0.0041 μg/L for PMMA and 0.0054 μg/L for PVDC. Notably, a programmed temperature strategy for the GC-MS injector was developed to discriminate and eliminate the potential interferences of intrinsic indicator compounds. Owing to the integration of sampling, extraction, injection, and decomposition into one step by SPME, the proposed method demonstrates exceptional sensitivity, eliminating the necessity for complex sample pretreatment procedures and the use of organic solvents. Finally, the proposed method was successfully applied in the determination of PMMA and PVDC MNPs in real aqueous samples.
PubMed: 38902946
DOI: 10.1021/acs.analchem.4c01900 -
Langmuir : the ACS Journal of Surfaces... Jul 2024The structure-property relationship of poly(vinyl chloride) (PVC)/CaCO nanocomposites is investigated by all-atom molecular dynamics (MD) simulations. MD simulation...
The structure-property relationship of poly(vinyl chloride) (PVC)/CaCO nanocomposites is investigated by all-atom molecular dynamics (MD) simulations. MD simulation results indicate that the dispersity of nanofillers, interfacial bonding, and chain mobility are imperative factors to improve the mechanical performance of nanocomposites, especially toughness. The tensile behavior and dissipated work of the PVC/CaCO model demonstrate that 12 wt % CaCO modified with oleate anion and dodecylbenzenesulfonate can impart high toughness to PVC due to its good dispersion, favorable interface interaction, and weak migration of PVC chains. Under the guidance of MD simulation, we experimentally prepared a transparent PVC/CaCO nanocomposite with good mechanical properties by polymerization of monodispersed CaCO in vinyl chloride monomers. Interestingly, experimental tests indicate that the optimum toughness of a nanocomposite (a 368% increase in the elongation at break and 204% improvement of the impact strength) can be indeed realized by adding 12 wt % CaCO modified with oleic acid and dodecylbenzenesulfonic acid, which is remarkably consistent with the MD simulation prediction. In short, this work provides a proof-of-concept of using MD simulation to guide the experimental synthesis of PVC/CaCO nanocomposites, which can be considered as an example to develop other functional nanocomposites.
PubMed: 38902198
DOI: 10.1021/acs.langmuir.4c01435