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Sensors and Actuators. B, Chemical Mar 2023Rapid, sensitive, and specific detection of the severe acute respiratory syndrome coronavirus (SARS-CoV)- 2 during early infection is pivotal in controlling the spread...
Rapid, sensitive, and specific detection of the severe acute respiratory syndrome coronavirus (SARS-CoV)- 2 during early infection is pivotal in controlling the spread and pathological progression of Coronavirus Disease 2019 (COVID-19). Thus, highly accurate, affordable, and scalable point-of-care (POC) diagnostic technologies are necessary. Herein, we developed a rapid and efficient self-directed molecular diagnostic (SdMDx) system for SARS-CoV-2. This system combines the sample preparation step, including virus enrichment and extraction processes, which involve dimethyl suberimidate dihydrochloride and diatomaceous earth functionalized with 3-aminopropyl(diethoxy)methylsilane, and the detection step using loop-mediated isothermal amplification-lateral flow assay (LAMP-LFA). Using the SdMDx system, SARS-CoV-2 could be detected within 47 min by hand without the need for any larger instruments. The SdMDx system enabled detection as low as 0.05 PFU in the culture fluid of SARS-CoV-2-infected VeroE6 cells. We validated the accuracy of the SdMDx system on 38 clinical nasopharyngeal specimens. The clinical utility of the SdMDx system for targeting the S gene of SARS-CoV-2 showed 94.4% sensitivity and 100% specificity. This system is more sensitive than antigen and antibody assays, and it minimizes the use of complicated processes and reduces contamination risks. Accordingly, we demonstrated that the SdMDx system enables a rapid, accurate, simple, efficient, and inexpensive detection of SARS-CoV-2 at home, in emergency facilities, and in low-resource sites as a pre-screening platform and POC testing through self-operation and self-diagnosis.
PubMed: 36570722
DOI: 10.1016/j.snb.2022.133193 -
Insects Feb 2020Western flower thrips (WFT), Frankliniella occidentalis (Pergande), is a highly invasive pest which is harmful to many cash crops globally and resistant to various...
The Time-Concentration-Mortality Responses of Western Flower Thrips, Frankliniella occidentalis, to the Synergistic Interaction of Entomopathogenic Fungus Metarhizium flavoviride, Insecticides, and Diatomaceous Earth.
Western flower thrips (WFT), Frankliniella occidentalis (Pergande), is a highly invasive pest which is harmful to many cash crops globally and resistant to various insecticides. Entomopathogenic fungi (EPF), as biological control agents, have demonstrated a good control effect on WFT. The aim of this study was to evaluate the synergistic and pathogenicity efficacy of the fungal strain WSWL51721 when distributed with diatomaceous earth (DE) and the active ingredient imidacloprid using four bioassay methods against adult and second instar larvae of WFT. The data of the four bioassays have been fitted to the time-concentration-mortality (TCM) model. The corrected mortality ranges of WFT adults were 75-100%, 82.69-100%, 78.85-100%, and 92.31-100%, and the corrected mortality ranges of WFT second instar larvae were 72.22-100%, 85.19-100%, 77.77-100%, and 100% in the four bioassays at concentrations of 1.2 × 10 to 1.2 × 10 conidia/mL, respectively. At 1.2 × 10 conidia/mL, assays 2 ( with DE), 3 ( with imidacloprid), and 4 ( with DE and imidacloprid) had the shortest median lethal time (LT), compared with that of assay 1 ( alone) for adults at 2.26 d, 2.06 d, and 1.53 d, and second instar larvae at 2.45 d, 1.70 d, and 1.41 d, respectively. The median lethal concentration (LC) in the four bioassays decreased within 3-10 days of inoculation. On the third day, it was found that the lowest median lethal concentrations in assays 2, 3, and 4 were 1.58 × 10, 1.13 × 10, and 3.39 × 10 conidia/mL, respectively, which were significantly different from that in assay 1 for the adults. For the second instar larvae, assays 2, 3, and 4 also had the lowest lethal concentrations and were significantly different from those of assay 1. There were significant differences in sporulation between adults and second instar larvae under the four bioassays. Our results indicate that assays 2 ( with DE), 3 ( with imidacloprid), and 4 ( with DE and imidacloprid) demonstrate synergistic effects on the control of both adult and second instar larvae of WFT under laboratory conditions.
PubMed: 32024074
DOI: 10.3390/insects11020093 -
Marine Drugs Aug 2023Diatom microalgae are a natural source of fossil biosilica shells, namely the diatomaceous earth (DE), abundantly available at low cost. High surface area, mesoporosity...
Diatom microalgae are a natural source of fossil biosilica shells, namely the diatomaceous earth (DE), abundantly available at low cost. High surface area, mesoporosity and biocompatibility, as well as the availability of a variety of approaches for surface chemical modification, make DE highly profitable as a nanostructured material for drug delivery applications. Despite this, the studies reported so far in the literature are generally limited to the development of biohybrid systems for drug delivery by oral or parenteral administration. Here we demonstrate the suitability of diatomaceous earth properly functionalized on the surface with -octyl chains as an efficient system for local drug delivery to skin tissues. Naproxen was selected as a non-steroidal anti-inflammatory model drug for experiments performed both in vitro by immersion of the drug-loaded DE in an artificial sweat solution and, for the first time, by trans-epidermal drug permeation through a 3D-organotypic tissue that better mimics the in vivo permeation mechanism of drugs in human skin tissues. Octyl chains were demonstrated to both favour the DE adhesion onto porcine skin tissues and to control the gradual release and the trans-epidermal permeation of Naproxen within 24 h of the beginning of experiments. The evidence of the viability of human epithelial cells after permeation of the drug released from diatomaceous earth, also confirmed the biocompatibility with human skin of both Naproxen and mesoporous biosilica from diatom microalgae, disclosing promising applications of these drug-delivery systems for therapies of skin diseases.
Topics: Humans; Animals; Swine; Diatoms; Microalgae; Naproxen; Diatomaceous Earth; Drug Delivery Systems; Anti-Inflammatory Agents, Non-Steroidal
PubMed: 37623719
DOI: 10.3390/md21080438 -
Marine Drugs Apr 2023Colorectal cancer is among the most prevalent and lethal cancers globally. To address this emergency, countries have developed diffuse screening programs and innovative... (Review)
Review
Colorectal cancer is among the most prevalent and lethal cancers globally. To address this emergency, countries have developed diffuse screening programs and innovative surgical techniques with a consequent decrease in mortality rates in non-metastatic patients. However, five years after diagnosis, metastatic CRC is still characterized by less than 20% survival. Most patients with metastatic CRC cannot be surgically treated. For them, the only option is treatment with conventional chemotherapies, which cause harmful side effects in normal tissues. In this context, nanomedicine can help traditional medicine overcome its limits. Diatomite nanoparticles (DNPs) are innovative nano-based drug delivery systems derived from the powder of diatom shells. Diatomite is a porous biosilica largely found in many areas of the world and approved by the Food and Drug Administration (FDA) for pharmaceutical and animal feed formulations. Diatomite nanoparticles with a size between 300 and 400 nm were shown to be biocompatible nanocarriers capable of delivering chemotherapeutic agents against specific targets while reducing off-target effects. This review discusses the treatment of colorectal cancer with conventional methods, highlighting the drawbacks of standard medicine and exploring innovative options based on the use of diatomite-based drug delivery systems. Three targeted treatments are considered: anti-angiogenetic drugs, antimetastatic drugs, and immune checkpoint inhibitors.
Topics: Animals; Nanomedicine; Diatoms; Diatomaceous Earth; Drug Delivery Systems; Nanoparticles; Colorectal Neoplasms; Antineoplastic Agents
PubMed: 37233460
DOI: 10.3390/md21050266 -
Foods (Basel, Switzerland) Sep 2020In large-sized breweries, rough beer clarification is still carried out using Kieselguhr filters notwithstanding their environmental and safety implications. The main...
In large-sized breweries, rough beer clarification is still carried out using Kieselguhr filters notwithstanding their environmental and safety implications. The main aim of this work was to test an innovative rough beer clarification and stabilization process involving enzymatic treating with Brewers Clarex, centrifuging, rough filtering across 1.4-μm ceramic hollow-fiber membrane at 30 °C, and fine filtering through 0.45-μm cartridge filter. When feeding an enzymatically-pretreated and centrifuged rough beer with permanent haze (H) of 2 or 14 European Brewery Convention unit (EBC-U), its primary clarification under periodic CO backflushing yielded a permeate with turbidity of 1.0-1.5 EBC-U at a high permeation flux (2.173 ± 51 or 593 ± 100 L m h), much greater than that typical of powder filters. The final beer was brilliant (H = 0.57 ± 0.08 EBC-U) with almost the same colloidal stability of the industrial control and an overall log reduction value (~5.0 for the selected beer spoilage bacterium or 7.6 for the brewing yeast) in line with the microbial effectiveness of current sterilizing membranes. It was perceived as significantly different in flavor and body from the industrial control at a probability level of 10% by a triangle sensory test, as more likely related to the several lab-scale beer-racking steps used than to the novel process itself.
PubMed: 32899206
DOI: 10.3390/foods9091228 -
Biomaterials Advances Jul 2024Engineering of scaffolds for bone regeneration is often inspired by the native extracellular matrix mimicking its composite fibrous structure. In the present study, we...
Engineering of scaffolds for bone regeneration is often inspired by the native extracellular matrix mimicking its composite fibrous structure. In the present study, we used low loadings of diatomite earth (DE) biosilica to improve the bone regeneration potential of gelatin electrospun fibrillar microenvironments. We explored the effect of increasing the DE content from 1 % to 3 % and 5 %, respectively, on the physico-chemical properties of the fibrous scaffolds denoted FG_DE1, FG_DE3, FG_DE5, regarding the aqueous media affinity, stability under simulated physiological conditions, morphology characteristics, and local mechanical properties at the surface. The presence of biosilica generated composite structures with lower swelling degrees and higher stiffness when compared to gelatin fibers. Increasing DE content led to higher Young modulus, while the stability of the protein matrix in PBS, at 37 °C, over 21 was significantly decreased by the presence of diatomite loadings. The best preosteoblast response was obtained for FG_DE3, with enhanced mineralization during the osteogenic differentiation when compared to the control sample without diatomite. 5 % DE in FG_DE5 proved to negatively influence cells' metabolic activity and morphology. Hence, the obtained composite microfibrillar scaffolds might find application as osteoblast-responsive materials for bone tissue engineering.
Topics: Gelatin; Osteoblasts; Tissue Scaffolds; Tissue Engineering; Animals; Diatomaceous Earth; Osteogenesis; Cell Differentiation; Mice; Bone Regeneration; Cell Line; Cellular Microenvironment; Microfibrils; Extracellular Matrix
PubMed: 38796956
DOI: 10.1016/j.bioadv.2024.213894 -
The Science of the Total Environment Mar 2021Polymer injection is used in enhanced oil recovery (EOR) when an oil field ages and the pressure in the reservoir decreases, or for oil fields with heavy oil. By polymer...
Polymer injection is used in enhanced oil recovery (EOR) when an oil field ages and the pressure in the reservoir decreases, or for oil fields with heavy oil. By polymer injection, the viscosity of the water injected for pressure support is increased by mixing with a high concentration of a polymer solution. Polymers used in EOR operations are often high molecular weight polyacrylamides, including anionic polyacrylamide (APAM), which may subsequently enter the marine environment with produced water releases. Since seawater (SW) contains mineral particles (MPs) in low concentrations, and polymers like APAM are known to flocculate MPs, we investigated if APAM at different concentrations (0.5-10 mg/L) would attach and flocculate MPs, when these occurred in concentrations relevant for oceanic SW (1 mg/L). Two types of MPs, diatomaceous earth and kaolin, were exposed to fluorescence-tagged APAM (APAM-TAG). A low-energy carousel system with natural seawater (SW) was used for incubation of MPs and APAM-TAG at a temperature relevant for the Norwegian Continental Shelf (13 °C). Attachment to MPs and aggregates of these were analysed by fluorometry and fluorescence microscopy. Particle analyses showed that only minor fractions of the MPs aggregated. When samples were separated in steel filter with a mesh size of 20 μm, APAM-TAG was mainly measured in the flow-through fraction (<20 μm), and the results therefore showed that the polymer mainly remained in the water-phase, or was attached to small particles (<20 μm). For the small fraction of APAM attaching to aggregated MPs, attraction to kaolin was higher than to diatomaceous earth, and fluorescence microscopy analyses confirmed the presence of fluorescent particles at the higher APAM concentrations. MPs at concentrations relevant for oceanic SW are therefore not expected to significantly contribute to sedimentation of APAM dissolved in the water column.
PubMed: 33333302
DOI: 10.1016/j.scitotenv.2020.143888 -
Environmental Research Jan 2020To ameliorate adsorbent recovery by an external magnetic field, naturally occurring diatomaceous earth (DE) was modified with iron-oxide, characterized and applied for...
To ameliorate adsorbent recovery by an external magnetic field, naturally occurring diatomaceous earth (DE) was modified with iron-oxide, characterized and applied for adsorption of carbamazepine (CBZ) from synthetic wastewater using batch equilibration method. The fabricated adsorbent was characterized using XRF, XRD, SEM-EDX, FT-IR, BET surface area analysis, VSM and pH of point of zero charge (pH) determination. The adsorption rate was described by the pseudo-first-order (PFO) model suggesting a physisorption controlled rate-determining step. Equilibrium adsorption data were fitted to linear and nonlinear isotherm models, viz Langmuir and Freundlich models, and were best described by Freundlich nonlinear equations implying heterogeneous multilayer adsorption. The best-fitting kinetic and isotherm model was determined using four mathematical error functions. The thermodynamic parameters, namely enthalpy (ΔH = -26.4 kJ mol), Gibbs free energy (ΔG = -2.22 kJ mol at 298 K), entropy (ΔS = -34.0 kJ mol), indicated that the adsorption was a spontaneous, exothermic, and physical process. The adsorption mechanism is postulated to involve cation-π interactions. Modified diatomaceous earth is a potentially excellent, low-cost, and novel sorbent for CBZ adsorption with 88% removal in 180 min and provides a possible alternative adsorbent for wastewater treatment.
Topics: Adsorption; Carbamazepine; Diatomaceous Earth; Ferric Compounds; Hydrogen-Ion Concentration; Kinetics; Spectroscopy, Fourier Transform Infrared; Thermodynamics; Water Pollutants, Chemical
PubMed: 31732171
DOI: 10.1016/j.envres.2019.108898 -
Insects Jul 2022Cases of Lyme disease in humans are on the rise in the United States and Canada. The vector of the bacteria that causes this disease is the blacklegged tick, . Current...
Cases of Lyme disease in humans are on the rise in the United States and Canada. The vector of the bacteria that causes this disease is the blacklegged tick, . Current control methods for mainly involve chemical acaricides. Unfortunately, ticks are developing resistance to these chemicals, and more and more, the public prefers non-toxic alternatives to chemical pesticides. We discovered that volcanic glass, Imergard WP, and other industrial minerals such as Celite 610 were efficacious mechanical insecticides against mosquitoes, filth flies, and agricultural pests. In this report, when 6-10- and 50-70-day old unfed nymphs were dipped for 1-2 s into Celite, the time to 50% mortality (LT) was 66.8 and 81.7 min, respectively, at 30 °C and 50% relative humidity (RH). The LT was actually shorter at a higher 70% RH, 43.8 min. Scanning electron microscopy showed that the ticks were coated over most of their body surface, including partial to almost total coverage of the opening to their respiratory system. The other mechanical insecticide, Imergard, had similar efficacy against blacklegged unfed nymphs with an LT at 30 °C and 50% RH of 70.4 min. Although more research is needed, this study suggests that industrial minerals could be used as an alternative to chemical pesticides to control ticks and Lyme disease.
PubMed: 35893027
DOI: 10.3390/insects13080672 -
Scientific Reports Sep 2020The early diagnosis and monitoring of cancers are key factors in effective cancer treatment. Particularly, the separation of biomolecules is an essential step for both...
The early diagnosis and monitoring of cancers are key factors in effective cancer treatment. Particularly, the separation of biomolecules is an essential step for both diagnostic and analytical purposes. However, the current techniques used to isolate biomolecules are intensive, laborious, and require multiple instruments as well as repeated sample preparations to separate each biomolecule. Thus, an efficient separation system that can simultaneously separate biomolecules from scarce samples is highly desirable. Hence, in this study, we developed a biosilica-based syringe filtration system for the efficient separation of biomolecules from cancer samples using amine-modified diatomaceous earth (AD) with dimethyl 3,3'-dithiobispropionimidate (DTBP). The syringe filter can be an efficient and rapid tool for use in various procedures without complex instruments. The DTBP-based AD system was combined with the syringe filter system for nucleic acid and protein separation from various cancer cells. We demonstrated the efficacy of the DTBP-based AD in a single-filter system for the efficient separation of DNA and proteins within 40 min. This DTBP-based AD syringe filter system showed good rapidity, efficiency, and affordability in the separation of biomolecules from single samples for the early diagnosis and clinical analysis of cancers.
Topics: Biosensing Techniques; DNA, Neoplasm; Diatomaceous Earth; Humans; Imidoesters; Neoplasm Proteins; Neoplasms; Tumor Cells, Cultured
PubMed: 32973156
DOI: 10.1038/s41598-020-72913-8