Doxycycline Research Articles

Differential diagnosis and treatment protocols for desquamative gingivitis: A systematic review.

The occurrence of desquamation, shedding and erythema on marginal and attached gingiva is described as desquamative gingivitis (DG). Various autoimmune/dermatological disorders cause DG.The aim of the present systematic review was to gather information on all possible kinds of treatment for DG, based on specific DG diagnoses.The review was organized following the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) protocol. An electronic search was conducted in the PubMed, Scopus and Google Scholar databases, up to April 2022. Reviews, letters and studies with less than 2 participants were excluded.Fifteen publications matched the eligibility criteria: 6 case series; 5 clinical trials; 3 randomized clinical trials (RCTs), and 1 cohort study. A total of 330 patients were enrolled, mostly women (81.52%), with an average age of 57.6 years. Diagnostic characteristics corresponded to oral lichen planus (OLP) (n = 249), mucous membrane pemphigoid (MMP) (n = 30), pemphigus vulgaris (PV) (n = 19), plasma cell gingivitis (PCG) (n = 4), erythema multiforme (EM) (n = 1), and non-specified diseases (NSD) (n = 27). Oral lichen planus and MMP were eliminated using oral hygiene instructions with topical clobetasol and/or doxycycline monohydrate. Pemphigus vulgaris, PCG and EM were treated with topical clobetasol.To conclude, each DG case requires personalized treatment, depending on the diagnosis.

MiR126-mediated impaired vascular integrity in Rett syndrome.

Rett syndrome (RTT) is a neurodevelopmental disorder that is caused by mutations in melty-CpG binding protein 2 (MeCP2). MeCP2 is a non-cell type-specific DNA binding protein, and its mutation influences not only neural cells but also non-neural cells in the brain, including vasculature associated with endothelial cells. Vascular integrity is crucial for maintaining brain homeostasis, and its alteration may be linked to the pathology of neurodegenerative disease, but a non-neurogenic effect, especially the relationship between vascular alternation and Rett syndrome pathogenesis, has not been shown. Here, we recapitulate a microvascular network using Rett syndrome patient-derived induced pluripotent stem (iPS) cells that carry MeCP2[R306C] mutation to investigate early developmental vascular impact. To expedite endothelial cell differentiation, doxycycline (DOX)-inducible ETV2 expression vectors were inserted into the AAVS1 locus of Rett syndrome patient-derived iPS cells and its isogenic control by CRISPR/Cas9. With these endothelial cells, we established a disease microvascular network (Rett-dMVNs) and observed higher permeability in the Rett-dMVNs compared to isogenic controls, indicating altered barrier function by MeCP2 mutation. Furthermore, we unveiled that hyperpermeability is involved in the upregulation of miR126-3p in Rett syndrome patient-derived endothelial cells by microRNA profiling and RNAseq, and rescue of miR126-3p level can recover their phenotype. We discover miR126-3p-mediated vascular impairment in Rett syndrome patients and suggest the potential application of these findings for translational medicine.

Zwitterionic MOF-embedded alginate beads with polydopamine surface functionalization for efficient doxycycline removal: Optimization and mechanistic study

The adsorptive removal of amphoteric antibiotics like doxycycline (DOX) is a difficult task because of the electrostatic repulsion between these amphoteric molecules and adsorbents. For this purpose, a zwitter adsorbent was fabricated by incorporating zwitter ZIF-67/MIL-88A binary MOF into the matrix of alginate (Alg); in addition, the surface of the beads was modified by polydopamine (PDA). The batch experiments implied the super-high adsorption efficacy of ZIF-67/MIL-88A@Alg@PDA toward DOX attained 384.61 ± 5.08 mg/g at a neutral pH medium, 25 °C, and using 0.02 g. The isotherm analysis implied the physisorption of DOX onto ZIF-67/MIL-88A@Alg@PDA, while the kinetic analysis denoted the chemisorption of DOX. The results of XPS, Zeta potential, and Lab experiments identified the types of physical and chemical interactions between ZIF-67/MIL-88A@Alg@PDA and DOX. The durability of the ZIF-67/MIL-88A@Alg@PDA beads was inspected by the recycling test, clarifying that the DOX adsorption aptitude declined by 12.22 mg/g. In addition, the measured leaching concentrations of cobalt and iron from the leaching test were 0.008 and 0.098 mg/L. The ionic strength of ZIF-67/MIL-88A@Alg@PDA, implying an enhancement in the DOX removal (%) from 83.51 to 93.50 % by raising the NaCl concentration from 0.2 to 1.0 mol/L. Therefore, our study could provide a simple procedure to overcome the electrostatic repulsion that retard the adsorption process of the amphoteric drugs onto charged adsorbents with positive or negative charges. Additionally, this procedure could also generate an electrostatic interaction between the zwitter adsorbents and the amphoteric drugs at specific pH media when they are in a zwitterionic nature.

Adherence to Hygiene Protocols and Doxycycline Therapy in Ameliorating Lymphatic Filariasis Morbidity in an Endemic Area Post-Interruption of Disease Transmission in Ghana.

Filarial lymphedema (LE) remains a significant global problem despite the progress made toward elimination of lymphatic filariasis (LF). In Ghana, the main approach to LF is preventive chemotherapy, but this has minimal impact on individuals who have already developed LE. In 2018-2020, a 24-month randomized, double-blind, placebo-controlled trial was conducted to evaluate the efficacy of stringent hygiene measures using the Essential Package of Care with or without additional administration of doxycycline (DOX) to improve filarial leg LE. This study enrolled 356 participants with LE stages 1-3 from two districts in the Upper East Region of Ghana. In addition to regular training on appropriate care for their affected legs, participants were randomized to receive 6 weeks of either 200 mg/day DOX (n = 117), 100 mg/day DOX (n = 120), or matching placebo (n = 119). Participants were seen every 2 months, with clinical measurements done at 6, 12, 18, and 24 months to assess the status of affected legs. There was a trend toward later appearance of acute attacks after DOX, but surprisingly, DOX showed no effect on LE stage progression. In all groups, leg LE improvement was more common (DOX 200 mg: n = 23 [20%]; DOX 100 mg: n = 23 [19.5%]; placebo: n = 32 [27.4%]) than LE worsening (DOX 200 mg: n = 2 [1.7%]; DOX 100 mg: n = 3 [2.5%]; placebo: n = 2 [1.7%]). Overall, these data show a strong benefit from adherence to a strict hygiene protocol, with some added potential benefit for DOX in preventing acute attacks.

A smartphone-integrated bimetallic ratiometric fluorescent probe for specific visual detection of tetracycline antibiotics in food samples and latent fingerprinting

Designing and preparing highly sensitive and accurate fluorescent chemosensors for monitoring tetracycline antibiotics remains a challenge. Herein, a fluorescent chemosensor based on lanthanide metal-organic frameworks (Ln-MOFs) is proposed to realize high-precision monitoring by adjusting the ratio of lanthanide ions. Ln-MOFs with good aqueous stability were prepared by a solvothermal method using Eu3+, Tb3+ and the ligand 4,4′,4″-s-triazine-2,4,6-triyltribenzoic acid (H3TATB) in DMF/NMP/H2O. The Ln-MOFs could recognize oxytetracycline (OTC) and doxycycline (DOX), and the detection limits of OTC and DOX were as low as 8.6 and 4.8 nM, respectively. In particular, Eu(1.4 μM)-Tb-MOF sensors were used for visual detection of OTC and DOX in combination with smartphones with detection lines as low as 9.8 nM and 14.2 nM, respectively. Meanwhile, Eu-MOF, Tb-MOF and Eu(1.4 μM)-Tb-MOF can be used for latent fingerprint (LFP) visualization, demonstrating their potential applications in the field of criminal case investigation. The developed probes were successfully applied to determining OTC and DOX in milk, beef and pork with recoveries ranging from 92.0 % to 109.63 % and relative standard deviations (RSDs) ranging from 1.83 % to 4.56 %. Eu(1.4 μM)-Tb-MOF is believed to utilize its lanthanide metal ion coordination and photoinduced electron transfer (PET) mechanism to achieve highly selective and accurate OTC and DOX detection, which is supported by experimental and density functional theory (DFT) calculations.

Nanostructured NiCo2S4 immobilized on nickel foam as recyclable catalyst for activating peroxymonosulfate toward doxycycline degradation: Performance and mechanism

The existing powder catalysts used in sulfate radical-based advanced oxidation processes (SR-AOPs) commonly suffer from severe limitation due to the difficulty of recycling and inadequate exposure of the active site. In this work, spinel sulfide (NiCo2S4) was uniformly grown on 3D nickel foam (NF) through a one-step hydrothermal route for the activation of peroxymonosulfate (PMS) toward highly efficient degradation of doxycycline (DOX). Due to the synergistic effect of Ni and Co in the NiCo2S4, the NiCo2S4/NF (0.6 g/L) combined with PMS (3.0 mmol L-1) can promote a nearly complete degradation (98.2 %) toward 0.3 mmol/L DOX within 6 min. Density functional theory (DFT) calculations illustrated that the NiCo2S4/NF can adsorb PMS through a unique Ni-S-Co structure and “conducting bridge” mode of NF, accelerating the electron transfer from NiCo2S4/NF to PMS and the subsequent O-O bond cleavage. Especially, the Co/Ni dual-site enhanced the adsorption of PMS and promotes electron transfer to form surface-activated PMS complex (catalyst-PMS*), leading to the generation of surface-bound reactive oxygen species (ROS) on the NiCo2S4 surface. Quenching experiments and ESR tests demonstrated that radicals such as SO4•-, 1O2, •OH and surface-bound ROS play a vital role in DOX degradation. Moreover, the potential mechanism and pathway of DOX degradation are reasonably deduced by investigating and analyzing the intermediates with liquid chromatography-mass spectromsetry (LC-MS). Consequently, this study provides a deep insight on the systhsis of spinel sulfide and its intrinsic mechanism of PMS activation toward organic contaminant degradation.

Antibiotic Therapy in Asthma as One of First Step Treatment, a Phase 3 Randomized Clinical Trial

Background: Focus of this study was on subjects suffering from new onset asthma, but actually, they may involve with an infection. Objectives: The target of this study was to determine the frequency of total control of asthma in new onset asthma. Methods: this is a phase 3 randomized clinical trial. The participants were 50 new onset asthma, who feel suffering from respiratory infection, however the physician diagnosis was asthma according to wheezy chest, spirometry and clear chest roentgenogram. Age less than 18 years and pregnant women were excluded. The subjects were randomly divided into two groups, doxycycline hyclate and the placebo arms. The drugs were repacked in similar in shape container. Primary endpoint was time to first recurrence. Secondary endpoints were frequency of total control of asthma, dyspnea, cough, asthma control test (ACT) score, FEV1, FEV1/FVC, eosinophil and neutrophil in blood and sputum. Results: The difference of clinical findings between two groups before the trial were not significant. Ten percent reported acute attack of asthma during last two months. Treatment with Doxycyline revealed significant improvement of clinical findings, asthma attack and ACT score after two months of treatment, however, complete resolution of clinical findings were significantly higher in Doxycyline group compare to placebo. Clinical findings and FEV1 percent predicted in Doxycyline group T2low asthma group showed significant improvement which were not depicted in T2high group. Eighteen months follow up of the subjects showed complete resolution of asthma symptoms in 12 (48%) on Doxycyline group, which was significantly higher than control group (5 (20%). Time to first exacerbation in doxycycline group was 13.6±5.64 months which was significantly longer than control group (7.49±6.95, P=0.002). Time to first exacerbation in CRP positive was significantly longer (13.64±5.35 months) than CRP negative subjects (9.67±7.76 months, P=0.02). Conclusion: Doxycycline is an effective antibiotic for preventing recurrence of asthma, in selected new subjects who suspicious for respiratory infection.

Process analytical technology based quality assurance of API concentration and fiber diameter of electrospun amorphous solid dispersions

In this study, a novel quality assurance system was developed utilizing Process analytical technology (PAT) tools and artificial intelligence (AI). Our goal was to monitor the critical quality attributes (CQAs) like drug concentration, morphology and fiber diameter of electrospun amorphous solid dispersion (ASD) formulations with fast at-line techniques. Doxycycline-hyclate (DOX), a tetracycline-type antibiotic was used as a model drug with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) as the matrix excipient. The water-based formulations were electrospun with high-speed electrospinning (HSES). Raman and NIR sensors and machine vision-based color measurement techniques were employed to accurately determine the drug concentration. Given that morphology can influence the solubility of the drug, a convolutional neural network (CNN)-based AI model was developed to examine this property and detect manufacturing defects. Additionally, the diameter of electrospun fibrous samples was measured using camera images and a trained AI model, enabling rapid analysis of fiber diameter with results similar to that of scanning electron microscopy (SEM). These methods and models demonstrate potential in-line analytical tools, offering rapid, cheap and non-destructive analysis of ASD formulations.

Magnetic solid-phase extraction of amoxicillin and doxycycline from water and urine samples based on cetylpyridinium chloride-modified Fe3O4 nanoparticles followed by spectrophotometric determination.

This research describes an easy, rapid, and inexpensive magnetic solid-phase extraction (MSPE) approach employing Fe3O4 magnetic nanoparticles modified with cetylpyridinium chloride (Fe3O4@CPC/MNPs) for extracting amoxicillin (AMX) and doxycycline (DOX) after derivatization with 4-chloroaniline as a color reagent. The azo-coupling of AMX and DOX with the color reagent in the alkaline medium caused yellow and yellow-orange azo dyes with maximum absorption wavelengths of 435 and 438 nm, respectively. The UV-Vis spectroscopy was utilized to determine the target analyte after the extraction procedure. Good linearities (R2 > 0.99) in the concentration ranges of 0.03-4.50 and 0.05-6.00µg/mL were obtained for AMX and DOX, respectively. The experimental detection limits of AMX and DOX were obtained as 0.01 and 0.02 µg/mL, respectively. The developed approach was effectively applied to pre-concentrate and quantify AMX and DOX in environmental water and urine samples.

Ratiometric fluorescence sensing and discrimination of tetracycline analogs by using coumarin-embedded Eu-MOF nanosensor

As widely used antibiotics, tetracycline residues exist in food and environmental media, which pose certain hidden dangers and negative effects on public health. Therefore, the sensing and discrimination of tetracycline analogs (TCs) have great significance for improving food safety and preventing environmental pollution. Herein, a 7-hydroxycoumarin-3-carboxylic acid-embedded Eu-MOF (HC@Eu-MOF) material was constructed and then developed for the detection of TCs. Upon addition of TCs, the synthesized sensor displays opposite fluorescence changes at two different wavelengths due to the simultaneous presence of the inner filter effect (IFE) and the antenna effect (AE), and achieves a stable ratio signal response within 90 s. In addition, six important tetracycline analogs, including chlortetracycline (CTC), oxytetracycline (OTC), tetracycline (TC), metacycline (MC), doxycycline (DC) and demeclocycline (DMC) can be discriminated with 100 % accuracy through the principal component analysis even in extremely complicated mixtures. Further, a smartphone-assisted portable device was applied for visual sensing of TCs. The as-developed platform possessed the characteristics of simple synthesis, fast response, high sensitivity, and high stability, which further lays a further foundation for the on-site visual detection and discrimination of TCs in real samples.

Impaired learning and memory in male mice induced by sodium arsenite was associated with MMP-2/MMP-9-mediated blood-brain barrier disruption and neuronal apoptosis

Arsenic is a widespread environmental contaminant known to accumulate in the brain, leading to cognitive impairment. However, the exact mechanisms by which arsenic causes cognitive deficits remain unclear. The present study aims to discover whether the destruction of the blood-brain barrier (BBB) mediated by matrix metalloproteinases 2 and matrix metalloproteinases 9 (MMP-2 and MMP-9) and subsequent neuronal apoptosis are involved in arsenic-induced cognitive impairment. Ninety male mice were given 0, 25, and 50 mg/L NaAsO2 in drinking water and 30 mg/kg doxycycline hyclate (DOX, an inhibitor of MMPs) gavage for 12 weeks to observe the alterations in learning and memory of mice, the morphology of hippocampal neurons, as well as the BBB permeability and ultrastructure, the localization and expression of tight junction proteins, MMP-2, and MMP-9. Our findings indicated that arsenic exposure induced learning and memory impairment in mice, accompanied by neuronal loss and apoptosis. Furthermore, arsenic exposure increased hematogenous IgG leakage into the brain, disrupted the tight junctions, reduced the expression of Claudin5, Occludin, and ZO1 in the endothelial cells, and increased the expression of MMP-2 and MMP-9 in the endothelial cells and astrocytes. Finally, DOX intervention preserved BBB integrity, alleviated hippocampal neuronal apoptosis, and improved cognitive impairment in mice caused by arsenic exposure. Our research demonstrates that cognitive disfunction in mice induced by arsenic exposure is associated with MMP-2 and MMP-9-mediated BBB destruction and neuronal apoptosis. The current investigation provides new insights into mechanisms of arsenic neurotoxicity and suggests that MMP-2 and MMP-9 may serve as potential therapeutic targets for treating arsenic-induced cognitive dysfunction in the future.

Three-dimensional gel network structure of agarose interlayer dispersed Pd nanoparticles in copper foam electrode for electrocatalytic degradation of doxycycline hydrochloride

In this study, we successfully prepared palladium/agarose/copper foam (Pd/AG/CF) composite electrodes by utilizing the three-dimensional network structure agarose (AG), a green material derived from biomass, and homogeneously immobilizing palladium (Pd) atoms on a copper foam (CF) substrate through a facile route. The electrode showed excellent performance in the electrocatalytic degradation of doxycycline (DOX), with a high DOX degradation rate of 92.19 % in 60 min. In-depth studies revealed that palladium can form metal-metal interactions with the CF substrates, which enhances the electron transfer on the catalyst surface. In addition, the introduction of agarose effectively prevented the agglomeration of palladium nanoparticles. In addition, the hydroxyl functional groups in the molecular structure of agarose facilitate interactions between water molecules and the electrode interface through the formation of hydrogen bonds, thereby further enhancing the efficiency of the electrocatalytic reaction. In addition to good stability and reusability. Microbial toxicity test results show that the degraded wastewater has minimal impact on the environment. Also, possible degradation pathways of DOX were explored in this study. Finally, a novel continuous flow reactor was designed, featuring a unique design that ensures full contact between wastewater and the composite electrodes, thereby achieving continuous and efficient treatment of antibiotic wastewater.

Assessing the structural, antibacterial, and dissolution properties of 1:1 doxycycline/β-cyclodextrin complexes

A 1:1 β-cyclodextrin (βCD) inclusion complex with doxycycline (DO) as the guest molecule was prepared using kneading (KN) and coprecipitation (CoP) methods, along with a physical mixture (PM) . The complex was characterized through FTIR, ¹H NMR, UV–Vis spectroscopy, and DSC analysis. Semi-empirical quantum mechanical calculations confirmed the inclusion of DO within βCD's hydrophobic cavity. The formation constant, determined by a modified Benesi-Hildebrand equation at 25 °C, was 116.22 M⁻¹ for the βCD-DO complex. Dissolution studies revealed that the CoP method significantly enhanced DO's dissolution kinetics compared to the KN, PM methods, and free DO, highlighting CoP's effectiveness. Molecular docking indicated a stable βCD-DO complex, with binding energies from -5.9570 to -6.1423 kcal/mol, driven by hydrophilic and hydrophobic interactions. Antibacterial testing against E. coli, P. aeruginosa, S. aureus, B. cereus, and B. subtilis showed CoP had the highest efficacy, with MIC values of 5–10 µg/ml and MBC values of 10–20 µg/ml, better than KN, DO, and βCD.

Constructing interfacial electric field with rich oxygen vacancy modulated heterojunction FeVO4-MgZnAl LDH for enhanced photocatalytic degradation of doxycycline

FeVO4 nanorods were synthesized and integrated with plate-like MgZnAl layered double hydroxide (MZA LDH) using a combination of sonochemical coprecipitation and hydrothermal methods. The resulting FeVO4-MgZnAl LDH nanocomposites (NCs) were engineered to enhance photocatalytic performance through an S-scheme charge transfer mechanism. These NCs exhibited exceptional photocatalytic activity, achieving 93.7 % degradation of doxycycline (DXY) which is significantly outperforming its counterparts, FeVO4 (29.8 %) and MgZnAl LDH (49.8 %). Detailed analysis using scavenging tests and electron spin resonance (ESR) analysis confirmed that the photoexcited charges follow the S-scheme pathway, leading to the generation of hydroxyl (•OH) and superoxide (O2•⁻) radicals. This mechanism remarkedly improves the catalytic efficiency of FeVO4-MZA NCs with a kinetic rate constant of 4–9 times higher than those of its individual components. The photocatalyst's were comprehensively characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–visible diffuse reflectance spectroscopy (UV–vis-DRS), photoluminescence (PL) spectroscopy, and electrochemical impedance spectroscopy (EIS). The FeVO₄-MZA NCs demonstrated remarkable stability and reusability, indicating their suitability for large-scale water treatment applications. Additionally, the non-toxic nature of FeVO4-MZA NCs, coupled with effective charge carrier separation and reduced recombination rates, establishes them as highly efficient photocatalysts for the removal of pharmaceutical contaminants from aquatic systems and paves a way for manufacturing innovation.

Bifunctional Pt-loaded steel slag matrix composites for the detection and degradation of tetracycline antibiotics

In this paper, a method for the simultaneous detection and degradation of tetracycline antibiotics (TCs) in water was investigated. Calcium silicate hydrate (CSH), FeO and calcium aluminate hydrate (CAH) were isolated from steel slag as carriers for Pt monomers. The produced Pt-modified modified steel slag (ALANH-Pt) possessed both peroxidase activity and photocatalytic properties. As a result, a sensitive and selective colorimetric sensor was exploited on the basis of ALANH-Pt for tetracycline (TC), oxytetracycline (OTC), and doxycycline (DOX), which exhibited a detection limit (LOD) of 1.696 μM, 0.999 μM and 3.607 μM, respectively. In addition, the degradation rate for TCs could be achieved 82 % within 60 min. The possible mechanisms of detection and degradation are discussed based on ESR spectroscopy, revealing the generation of hydroxyl radicals (OH), superoxide radicals (O2−) and holes (h+). The degradation pathway of TC was inferred by HPLC-MS. The selectivity of the colorimetric sensing platform and the application of the bifunctional ALANH-Pt to real water samples were investigated. This work provides a new idea that allows for the simultaneous detection and degradation of TCs, and offers a new approach to the utilization of steel slag.

Microbiological and Analytical Evaluation of Semi-Solid Formulations of Doxycycline Hyclate under Accelerated Stability Conditions

الدوكسيسكلين هايكلات هو مضاد حيوي واسع الطيف ينتمي لعائلة التتراسيكلينات، يستخدم بشكل واسع في معالجة العديد من الأمراض الالتهابيًة، ويعتبر الخط العلاجي الأوًل في تدبير الحالات المتوسطة إلى الشديدة من حب الشًباب. تم في هذا البحث صياغة أربع صيغ نصف صلبة للدوكسيسيكلين (F2,F1 كصيغ هلاميًة، F3,F4 كصيغ مرهميًة)، ثم عُرّضت الصيغ السابقة إلى شروط ثبات مسرًعة في حاضنات الثبات لمدة ثلاثة أشهر. تم تقييم الصيغ المحضرة باستخدام طرق ميكروبيولوجيًة وتحليلية وذلك خلال شهر وثلاثة أشهر. استخدمت طريقة الانتشار على الآغار لتقييم الفعاليًة المضادة للجراثيم وذلك على نوعين من الجراثيم، العنقوديات المذهًبة والزائفة الزنجاريًة. بينما استخدم HPLC كطريقة تحليل كمية وكيفية لمقايسة الصيغ. أجريت مقارنة بين نتائج المقايسة الميكروبيولوجيًة والمقايسة التحليلية لتقييم الفعاليًة. أظهرت النتائج أن الصيغ المرهميّة F3,F4 أكثر ثباتاً من الصيغ الهلاميّة F1,F2، حيث بلغت النسبة المئوية للدوكسيسيكلين % 93و%91 للصيغة F3,F4 على التوالي وذلك عند الحفظ بدرجة حرارة الغرفة بعد شهر واحد. بينما بلغت النسبة%90 و65% للصيغ الهلاميّةF2,F1 عند الحفظ في نفس الشروط السابقة. أظهرت نتائج قياس الفعاليًة المضادة للجراثيم أن الصيغة المرهميًة F4 امتلكت أكبر قطر تثبيط جرثومي ويقدر بحوالي 31 ملم للعنقوديات المذهبة و26 ملم لـلزوائف الزنجارية وذلك بعد حفظ الصيغة لمدة ثلاثة أشهر عند درجة الحرارة 25ºم. وبالتالي حافظت الصيغ على فعاليتها على الرغم من التخرّب الكيميائي البنيوي للحاصل للدوكسيسيكلين. تعود هذه الفعالية إلى حقيقة أن نواتج التخرب لا تزال محافظة على الموقع البنيوي الفعًال والمسؤول عن إعطاء الفعاليًة المضادة للجراثيم.

Efficient synthesis of multifunctional α-Fe2O3 QDs/TS-1 as an artificial nanozyme for simultaneous colorimetric detection and photodegradation of tetracyclines

In this study, a multifunctional catalyst was developed innovatively by loading α-Fe2O3 quantum dots (QDs) onto Titanium Silicalite-1 (TS-1), creating an artificial nanozyme capable of simultaneously detecting, adsorbing, and photodegrading tetracyclines (TCs) in water. The catalyst demonstrated a limit of detection (LOD) as low as 19.7 μg/L for oxytetracycline (OTC), 23.1 μg/L for doxycycline (DOX), and 35.9 μg/L for tetracycline (TC). The peroxidase-mimic activity of the nanozyme, which was enhanced by TCs and caused a visible color change in 3,3′,5,5′-tetramethylbenzidine (TMB), was thoroughly investigated using DFT calculations. Additionally, the artificial nanozyme exhibited exceptional adsorption capabilities and photocatalytic activity under solar light irradiation, achieving a total removal rate of about 70 %. The underlying mechanism was also studied. This research provided valuable insights for the scalable production of multifunctional catalysts, thereby advancing the practical application of “integration of diagnosis and treatment” strategies for managing and controlling TCs in the environment.

Construction of scheelite CaWO4 with natural diatomite for boosted photocatalytic degradation of tetracycline and doxycycline antibiotics under natural conditions

Fabrication of efficient and recyclable catalysts with natural supporting materials is still a challenge in the field of photocatalysis. In the present work, scheelite type calcium tungstate was successfully constructed with natural diatomite via in-situ co-precipitation method for effective photocatalytic degradation of tetracycline (TC) and doxycycline (DC) antibiotics. The as-synthesized photocatalysts were characterized by SEM-EDX, TEM, BET, XRD, XRF, XPS, FTIR, UV–vis DRS, PL and EIS techniques. The morphological and physiochemical analyses confirmed the successful hybridization of CaWO4 with natural diatomite. The optical, photoluminescence and electrochemical tests confirmed that the composite material displayed narrower band gap energy, lower recombination rate and facilitated separation of photogenerated carriers. After construction of CaWO4 with the diatomite structure, the TC and DC decomposition efficiencies were found 4.70 and 2.54 times higher than that of the pristine sample, respectively. Furthermore, the composite catalyst showed superior degradation performances (91.8 % for TC and 90.7 % for DC) in the presence of hydrogen peroxide as a Fenton-agent. The enhanced photocatalytic performance was assigned to the increased specific surface area and pore volume, decreased band gap energy, limited recombination rate of photoinduced carriers, decreased charge transfer resistance as well as the abundant of hydroxyl radicals. The degradation reaction was found to be mainly driven by photogenerated holes and superoxide radicals. The CWO@DT/Vis/Fenton catalytic system exhibited good performance at near-neutral pH, also the composite catalyst was sufficiently utilized in the presence of co-existing anions. Furthermore, the photocatalytic efficiency was also tested under natural sunlight irradiation and the TC degradation remained 71.4 % after four cycles, indicating the outstanding feature of the composite catalyst in outdoor process conditions. Under these circumstances, the present work demonstrated the utilization potential of natural diatomite for effective photocatalytic remediation of antibiotic molecules under natural sunlight irradiation.

Enhanced Tribodegradation of a Tetracycline Antibiotic by Rare-Earth-Modified Zinc Oxide.

Tribocatalysis is an emerging advanced oxidation process that utilizes the triboelectric effect, based on friction between dissimilar materials to produce charges that can initiate various catalytic reactions. In this study, pure and rare-earth-modified ZnO powders (La2O3, Eu2O3, 2 mol %) were demonstrated as efficient tribocatalysts for the removal of the tetracycline antibiotic doxycycline (DC). While the pure ZnO samples achieved 49% DC removal within 24 h at a stirring rate of 100 rpm, the addition of Eu2O3 increased the removal efficiency to 67%, and La2O3-modified ZnO powder exhibited the highest removal efficiency, reaching 80% at the same stirring rate. Additionally, increasing the stirring rate to 300 and 500 rpm led to 100% DC removal in the ZnO/La case within 18 h, with the pronounced effect of the stirring rate confirming the tribocatalytic effect. All tribocatalysts exhibited excellent recycling properties, with less than a 3% loss of activity over three cycles. Furthermore, a scavenger assay confirmed the importance of superoxide radical generation for the overall reaction rate. The results of this investigation indicate that the rare-earth-modified ZnO tribocatalysts can effectively utilize mechanical energy to decompose pollutants in contaminated water.

Eu(III)-functionalized metal–organic framework as a visual ratiometric fluorescence sensor for rapid discrimination and detection of multiple tetracyclines in agricultural products

The misuse of oxytetracycline (OTC), doxycycline (DOX), tetracycline (TC), and chlortetracycline (CTC) poses a serious threat to human health and it calls for rapid and visual methods. In this study, a novel ratio fluorescent sensor was constructed by simply combining Eu(III) with IRMOF-3. Spectral characterization and DFT theoretical calculations revealed different mechanism of interactions between the MOF-based sensor and different tetracyclines in detail. PCA analysis amplified these differences, enabling the simultaneous identification and differentiation of individual, binary or ternary mixtures of multiple tetracyclines. Subsequently, a rapid fluorescence sensing method (<5 min) for detecting OTC, DOX, TC, and CTC was established with low detection limits of 70, 75, 40, and 168 nM, respectively, which are all below the maximum residue limits by the European Union and the U.S. Food and Drug Administration regulations. A portable visual test strip was also conducted based smartphone with low detection limits of 1 μM, exhibiting an obvious color spectrum transition from blue to purple and finally to pink. Furthermore, the sensor was applied successful to pig feed, milk and veterinary drugs. The results showed good agreement with HPLC-MS/MS analysis.