-
Environment International Nov 2022Personal chemical exposure assessment is necessary to determine the frequency and magnitude of individual chemical exposures, especially since chemicals present in... (Review)
Review
Personal chemical exposure assessment is necessary to determine the frequency and magnitude of individual chemical exposures, especially since chemicals present in everyday environments may lead to adverse health outcomes. In the last decade, silicone wristbands have emerged as a new chemical exposure assessment tool and have since been utilized for assessing personal exposure to a wide range of chemicals in a variety of populations. Silicone wristbands can be powerful tools for quantifying personal exposure to chemical mixtures in a single sample, associating exposure with health outcomes, and potentially overcoming some of the challenges associated with quantifying the chemical exposome. However, as their popularity grows, it is crucial that they are used in the appropriate context and within the limits of the technology. This review serves as a guide for researchers interested in utilizing silicone wristbands as a personal exposure assessment tool. Along with briefly discussing the passive sampling theory behind silicone wristbands, this review performs an in-depth comparison of wristbands to other common exposure assessment tools, including biomarkers of exposure measured in biospecimens, and evaluates their utility in exposure assessments and epidemiological studies. Finally, this review includes recommendations for utilizing silicone wristbands to evaluate personal chemical exposure and provides suggestions on what research is needed to recognize silicone wristbands as a premier chemical exposure assessment tool.
Topics: Biomarkers; Environmental Monitoring; Knowledge; Silicones
PubMed: 36116363
DOI: 10.1016/j.envint.2022.107339 -
Journal of Biomedical Optics Oct 2002We investigate optoelectronic properties of integrated structures comprising semiconductor light-emitting materials for optical probes of microscopic biological systems....
We investigate optoelectronic properties of integrated structures comprising semiconductor light-emitting materials for optical probes of microscopic biological systems. Compound semiconductors are nearly ideal light emitters for probing cells and other microorganisms because of their spectral match to the transparency wavelengths of biomolecules. Unfortunately, the chemical composition of these materials is incompatible with the biochemistry of cells and related biofluids. To overcome these limitations, we investigate functionalized semiconductor surfaces and structures to simultaneously enhance light emission and the flow of biological fluids in semiconductor microcavities. We have identified several important materials problems associated with the semiconductor/biosystem interface. One is the biofluid degradation of electroluminescence by ionic diffusion into compound semiconductors. Ions that diffuse into the active region of a semiconductor light emitter can create point defects that degrade the quantum efficiency of the radiative recombination process. In this paper we discuss ways of mitigating these problems using materials design and surface chemistry, and suggest future applications for these materials.
Topics: Animals; Biocompatible Materials; Biotechnology; Cells, Cultured; Dimethylpolysiloxanes; Electronics, Medical; Humans; Materials Testing; Optics and Photonics; Prostheses and Implants; Rats; Semiconductors; Silicones; Spectrometry, Mass, Secondary Ion
PubMed: 12421120
DOI: 10.1117/1.1506931 -
Chemistry, An Asian Journal May 2022In this review, we describe recent progress on stimuli-responsive hybrid materials based on polyhedral oligomeric silsesquioxane (POSS) and their applications as a... (Review)
Review
In this review, we describe recent progress on stimuli-responsive hybrid materials based on polyhedral oligomeric silsesquioxane (POSS) and their applications as a chemical sensor. In particular, we explain the unique functions originating from molecular assembly concerning POSS-containing soft materials mainly from our studies. POSS has an inorganic cubic core composed of silicon-oxygen (Si-O) bonds and organic substituents at each vertex. Owing to intrinsic properties of POSS, such as high thermal stability, rigidity, and low chemical reactivity, various robust hybrid materials have been developed. From the numerous numbers of POSS hybrids, we herein focus on the environment-sensitive optical materials in which molecular assembly of POSS itself and functional units connected to POSS should be a key factor for expressing material properties. We also explain the mechanisms of chemical sensors originating from these stimuli-responsive optical properties. Stimuli-responsive excimer emission and pollutant detectors, nanoplastic sensors with the water-dispersive POSS networks, trans fatty acid sensors, turn-on luminescent sensors for aerobic condition and fluoride anion sensors are described. We also mention the mechanochromic polyurethane hybrids and the thermally-durable mechanochromic luminescent materials. The roles of the unique optical properties from soft materials composed of rigid POSS, which doesn't have significant light-absorption and emission properties in the visible region, are surveyed.
Topics: Organosilicon Compounds; Polyurethanes
PubMed: 35322576
DOI: 10.1002/asia.202200144 -
The Plant Journal : For Cell and... Apr 2016Traditional method of Agrobacterium-mediated transformation through the generation of tissue culture had limited success for Setaria viridis, an emerging C4 monocot...
Traditional method of Agrobacterium-mediated transformation through the generation of tissue culture had limited success for Setaria viridis, an emerging C4 monocot model. Here we present an efficient in planta method for Agrobacterium-mediated genetic transformation of S. viridis using spike dip. Pre-anthesis developing spikes were dipped into a solution of Agrobacterium tumefaciens strain AGL1 harboring the β-glucuronidase (GUS) reporter gene driven by the cauliflower mosaic virus 35S (CaMV35S) promoter to standardize and optimize conditions for transient as well as stable transformations. A transformation efficiency of 0.8 ± 0.1% was obtained after dipping of 5-day-old S3 spikes for 20 min in Agrobacterium cultures containing S. viridis spike-dip medium supplemented with 0.025% Silwet L-77 and 200 μm acetosyringone. Reproducibility of this method was demonstrated by generating stable transgenic lines expressing β-glucuronidase plus (GUSplus), green fluorescent protein (GFP) and Discosoma sp. red fluorescent protein (DsRed) reporter genes driven by either CaMV35S or intron-interrupted maize ubiquitin (Ubi) promoters from three S. viridis genotypes. Expression of these reporter genes in transient assays as well as in T1 stable transformed plants was monitored using histochemical, fluorometric GUS activity and fluorescence microscopy. Molecular analysis of transgenic lines revealed stable integration of transgenes into the genome, and inherited transgenes expressed in the subsequent generations. This approach provides opportunities for the high-throughput transformation and potentially facilitates translational research in a monocot model plant.
Topics: Acetophenones; Agrobacterium tumefaciens; Genes, Reporter; Organosilicon Compounds; Plant Leaves; Plants, Genetically Modified; Promoter Regions, Genetic; Reproducibility of Results; Seedlings; Seeds; Setaria Plant; Transformation, Genetic; Transgenes
PubMed: 26932666
DOI: 10.1111/tpj.13148 -
The Annals of Thoracic Surgery Jan 2006
Topics: Chest Tubes; Dimethylpolysiloxanes; Drainage; Equipment Design; Humans; Pliability; Research Design; Silicones; Thoracostomy; Treatment Outcome
PubMed: 16368395
DOI: 10.1016/j.athoracsur.2005.07.066 -
International Journal of Nanomedicine 2023The respiratory system is intensely damaged by acute lung injury (ALI). The anti-inflammatory effects of tetramethylpyrazine (TMP) against ALI have been confirmed, but...
BACKGROUND
The respiratory system is intensely damaged by acute lung injury (ALI). The anti-inflammatory effects of tetramethylpyrazine (TMP) against ALI have been confirmed, but it exhibits a short half-life. miR-194-5p could directly target Rac1, but the internalization rate of miRNA cells was low.
PURPOSE
To explore the potential of the soft mesoporous organic silica nanoplatform (NPs) as carriers for delivery of TMP and miR-194-5p through the tail vein.
METHODS
NPs@TMP and NPs@PEI@miR-194-5p were added to the HUVEC cell-lines, in vitro, to observe the cell uptake and cytotoxic effects. In vivo experiments were conducted by injecting fluorescently labeled NPs through the tail vein and tracking distribution. Therapeutic and toxic side-effects were analyzed systemically.
RESULTS
In vitro study exhibited that NPs have no toxic effect on HUVECs within the experimental parameters and have excellent cellular uptake. The IVIS Spectrum Imaging System shows that NPs accumulate mainly in the lungs. NPs@TMP treatment can improved oxidative stress and inflammation levels in ALI mice and inhibited the TLR4/NLRP3/caspase 1 pathway. NPs@PEI@miR-194-5p can inhibit the Rac1/ZO-1/occludin pathway and improved endothelial cell permeability in ALI mice. The co-treatment of NPs@TMP and NPs@PEI@miR-194-5p can significantly improved the survival rates of the mice, reduced pulmonary capillary permeability and improved pathological injury in ALI mice.
INNOVATION
This study combined traditional Chinese medicine, bioinformatics, cellular molecular biology and nanobiomedicine to study the pathogenesis and treatment of ALI. The rate of cellular internalization was improved by changing the shape and hardness of nanoparticles. NPs@TMP and NPs@PEI@miR-194-5p combined application can significantly improve the survival condition and pathological injury of mice.
CONCLUSION
NPs loaded with TMP and miR-194-5p showed a greater therapeutic effect in ALI mice.
Topics: Animals; Humans; Mice; Acute Lung Injury; Human Umbilical Vein Endothelial Cells; Lipopolysaccharides; Lung; MicroRNAs; Organosilicon Compounds; Pyrazines
PubMed: 38026537
DOI: 10.2147/IJN.S420802 -
Scientific Reports Jun 2019Cotton fabrics are functionalized with a binary solution of fluorine-free organosilanes and "encapsulated" with silver nanoparticles to achieve both superhydrophobic and...
Cotton fabrics are functionalized with a binary solution of fluorine-free organosilanes and "encapsulated" with silver nanoparticles to achieve both superhydrophobic and antimicrobial properties. Derived from cellulose, cotton is one of the most abundant biologically generated materials and has been used in a wide variety of consumer goods. Nonetheless, cotton fabrics are not waterproof and prone to microbial contamination. Herein we report the rapid functionalization of cotton fabrics with a binary hexane solution of methyltrichlorosilane (MTS) and octadecyltrichlorosilane (OTS) at low concentration (0.17% v/v) followed by coating with colloidal silver nanoparticles (AgNP). The combined effects of binary silanization and AgNP encapsulation produced a surface that has remarkable water contact angle of 153 ± 2° and antimicrobial properties (against gram-negative Escherichia coli). The superior performance of the modified cotton fabrics produced with fluorine-free organosilanes and silver nanoparticles augments the potential of improving the functionality of abundant biopolymers to be waterproof and contamination-resistant.
Topics: Anti-Bacterial Agents; Cotton Fiber; Escherichia coli; Hydrophobic and Hydrophilic Interactions; Metal Nanoparticles; Organosilicon Compounds; Silver
PubMed: 31235747
DOI: 10.1038/s41598-019-45622-0 -
Molecules (Basel, Switzerland) Sep 2018Understanding the mechanism of molecular self-assembly to form well-organized nanostructures is essential in the field of supramolecular chemistry. Particularly,... (Review)
Review
Understanding the mechanism of molecular self-assembly to form well-organized nanostructures is essential in the field of supramolecular chemistry. Particularly, amphiphilic copolymers incorporated with polyhedral oligomeric silsesquioxanes (POSSs) have been one of the most promising materials in material science, engineering, and biomedical fields. In this review, new ideas and research works which have been carried out over the last several years in this relatively new area with a main focus on their mechanism in self-assembly and applications are discussed. In addition, insights into the unique role of POSSs in synthesis, microphase separation, and confined size were encompassed. Finally, perspectives and challenges related to the further advancement of POSS-based amphiphilics are discussed, followed by the proposed design considerations to address the challenges that we may face in the future.
Topics: Organosilicon Compounds; Polymers
PubMed: 30262758
DOI: 10.3390/molecules23102481 -
Chemosphere Mar 2024Dimethylsilanediol (DMSD) is the degradation product of methylsiloxane polymers and oligomers such as volatile cyclic methylsiloxanes (cVMS). To better understand the...
Dimethylsilanediol (DMSD) is the degradation product of methylsiloxane polymers and oligomers such as volatile cyclic methylsiloxanes (cVMS). To better understand the environmental fate of this key degradation product, we conducted a three-part study on the movement of DMSD in soil. The objective of this third and final study was to determine the fate of DMSD in soil-plant systems under constant irrigation. Soil columns were constructed using two soils with the upper 20 cm layers spiked with C-labeled DMSD. Corn seedlings were transplanted into the soil columns and placed in a field plot underneath a transparent cover that prevented rainwater from reaching the soil columns while allowing soil water to be volatilized freely. The soil-plant columns were regularly irrigated with known amounts of DMSD-free plant growth solution to sustain the plant growth. At pre-determined time intervals (15-67 days), the plant and soil columns were sectioned and the distribution of Corganosilicon species in the soil profile and plant parts was determined using a combination of Liquid Scintillation Counting and High-Performance Liquid Chromatography-Flow Scintillation Analysis, while soil water loss was determined gravimetrically. It was found that the majority (>92 %) of DMSD initially spiked into the soil was removed from the soil-plant systems. Although DMSD was transported from the soil to the plant, it was subsequently volatilized from the plant via transpiration, with only a small fraction (∼5%) remaining at the conclusion of the experiments. In addition, little non-extractable DMSD was found in the top layer of soil in the soil-plant systems, suggesting that the air-drying of soil is a necessary pre-condition for the formation of such non-extractable silanol residue on topsoil.
Topics: Soil; Organosilicon Compounds; Water; Water Pollutants, Chemical; Soil Pollutants
PubMed: 38354863
DOI: 10.1016/j.chemosphere.2024.141454 -
Clinical and Experimental Dermatology Aug 2011Photodynamic therapy (PDT) has been shown to be effective in the treatment of malignancies of a variety of organ systems, including the lungs, bladder,... (Review)
Review
BACKGROUND
Photodynamic therapy (PDT) has been shown to be effective in the treatment of malignancies of a variety of organ systems, including the lungs, bladder, gastrointestinal tract and skin. Cutaneous lesions serve as ideal targets of PDT because of the accessibility of the skin to light. To achieve optimum results, the photosensitizer must be delivered effectively into the target layers of the skin within a practical timeframe, via noninvasive methods.
AIM
To determine whether topical application of a second-generation photosensitizer, silicon phthalocyanine (Pc) 4 [SiPc(OSi(CH3)2 (CH2)3 N(CH3)2)(OH)], results in effective penetration of the skin barrier.
METHODS
Penetration of Pc 4 was evaluated using standard Franz-type vertical diffusion cell experiments on surrogate materials (silicone membranes) and laser-scanning confocal microscopy of normal skin biopsy samples from human volunteers.
RESULTS
The Franz diffusion data indicate that Pc 4 formulated in an ethanol/propylene glycol solution (70/30%, v/v) can penetrate the membrane at a flux that is appreciable and relatively invariant. Using the same formulation, Pc 4 uptake could be detected in human skin via laser-scanning confocal microscopy.
CONCLUSION
After topical application, Pc 4 is absorbed into the epidermis in as little as 1 h, and the absorption increased with increasing time and dose. Pc 4 can be effectively delivered into human skin via topical application. The data also suggest that the degree of penetration is time- and dose-dependent.
Topics: Administration, Topical; Adult; Diffusion Chambers, Culture; Female; Humans; Indoles; Male; Membranes, Artificial; Microscopy, Confocal; Organosilicon Compounds; Photochemotherapy; Photosensitizing Agents; Skin; Young Adult
PubMed: 21623875
DOI: 10.1111/j.1365-2230.2010.03989.x