Search Results (38)

Background/Objectives: Accurate patient-specific dosimetry is essential for optimizing radiopharmaceutical therapy (RPT), but current tools lack validation in clinically realistic conditions. This work aimed to develop a workflow for designing and fabricating patient-derived, organ-realistic RPT phantoms and evaluate their feasibility for commissioning patient-specific RPT radioactivity quantification. Methods: We used computed tomographic (CT) and magnetic resonance (MR) imaging of representative patients, computer-aided design, and in-house 3D printing technology to design and fabricate anthropomorphic kidney and parotid phantoms with realistic organ spacing, anatomically correct orientation, and surrounding tissue heterogeneities. We evaluated the fabrication process via geometric verification (i.e., volume comparisons) and leak testing (i.e., dye penetration tests). Clinical feasibility testing involved injecting known radioactivities of ¹⁷⁷Lu-PSMA-617 into the parotid and kidney cortex phantom chambers and acquiring SPECT/CT images. MIM SurePlan MRT SPECTRA Quant software (v7.1.2) reconstructed the acquired SPECT projections into a quantitative SPECT image and we evaluated the accuracy by region-based comparison to the known injected radioactivities and determined recovery coefficients for each organ phantom. Results: Phantom fabrication costs totaled < USD 250 and required <84 h. Geometric verification showed a slight systematic expansion (<10%) from the representative patient anatomy and leak testing confirmed watertightness of fillable chambers. Quantitative SPECT imaging systematically underestimated the injected radioactivity (mean error: −17.0 MBq; −13.2%) with recovery coefficients ranging from 0.82 to 0.93 that were negatively correlated with the surface-area-to-volume ratio. Conclusions: Patient-derived, 3D-printed fillable phantoms are a feasible, cost-effective tool to support commissioning and quality assurance for patient-specific RPT dosimetry. The results of this work will support other centers and clinics implementing patient-specific RPT dosimetry by providing the tools needed to comprehensively evaluate accuracy in clinically relevant geometries. Looking forward, widespread accurate patient-specific RPT dosimetry will improve our understanding of RPT dose response and enable personalized RPT dosing to optimize patient outcomes. Full article

Smart packaging materials (SPMs) combine the properties of intelligent and active packaging into a single system, enabling for the monitoring of the packaged product while enhancing its desired conditions. In this study, poly(lactic acid) (PLA) was used as the base polymer and functionalized with in situ synthesized gold nanoparticles (AuNPs) and methyl red (MR) as a pH-sensitive dye. Various additives, including poly(amic) acid (PAA), bromothymol blue (BB), 5-aminosalicylic acid (5AS), glutaraldehyde (GA), and silver and gold nanoparticles (AgNPs, Au NPs), were tested to optimize the SPMs. To evaluate their performance, the synthesized SPMs were characterized using UV-Vis spectroscopy, IR spectroscopy, SEM, microbiological assays, and mechanical tests. Our results revealed that PLA films containing AuNPs and MR exhibited excellent mechanical, chemical, and antimicrobial properties, making them highly suitable for smart packaging applications. In contrast, the addition of PAA disrupted film formation, while AgNPs and blueberry extracts increased the brittleness of the films, thereby limiting their practical use. Furthermore, BB was found to inhibit the in situ synthesis of AuNPs. A real-world application study demonstrated that cheddar cheese wrapped in the optimized PLA films remained unspoiled after 12 months of refrigeration. IR spectroscopy confirmed that no film components migrated into the cheese during the storage period. GA was identified as a critical component for maintaining the structural integrity of the films over the 12-month storage period. This is the first study to report on the development of PLA-based SPMs that incorporate AuNPs, MR, and GA, offering a promising solution for sustainable and intelligent food packaging. Full article

A water-soluble arene ruthenium metalla-rectangle (MR1) functionalized with boronic acid groups was used to host various fluorescent dyes (fluorescein, eosin Y, and erythrosin B). These simple host–guest systems partially quench the natural fluorescence of the dyes, which can be regained in the presence of saccharides, phosphorylated molecules, and other analytes. The intensity of the regained fluorescence is directly linked to the nature of the analyte, and it shows some dose–response relationships with saccharides and phosphorylated molecules that are not compatible with a displacement assay, thus suggesting an allosteric mechanism. Interestingly, when fluorescein is trapped by the metalla-rectangle in the presence of D-fructose, half of the maximum fluorescence intensity is recovered at a fructose concentration of 17.2 ± 4.7 μM, while, for D-glucose, a concentration of 50.6 ± 2.5 μM is required for the same effect. Indeed, all combinations of analyte–host–dye (seven analytes, one host, three dyes) show a unique dose–response relationship in water at pH 8.0. However, in the presence of naphthalene and pyrene, fluorescein⸦MR1 shows a different behavior, acting as an indicator displacement assay with the full recovery of fluorescence. All data were analyzed by unsupervised machine learning technologies (PCA and cluster analysis), suggesting that such systems with multiple analyte–response behaviors are offering new perspectives for the development of highly sensitive, easily tunable, water-soluble, fluorescent-based sensing arrays for biomolecules and other analytes. Full article

Currently, several organic dyes found in wastewater cause severe contamination problems for flora, fauna, and people in direct contact with them. This research proposes an alternative for the degradation of polluting dyes using ZnO nanoparticles (NPs) synthesized by an ecological route using leaf and root extracts of Ambrosia ambrosioides as a reducing agent (with a weight/volume ratio = 4%). Scanning Electron Microscopy (SEM) was used to determine the morphology, showing an agglomeration of cluster-shaped NPs. Using Transmission Electron Microscopy (TEM), different sizes of NPs ranging from 5 to 56 nm were observed for both synthesized NPs. The composition and structure of the nanomaterial were analyzed by infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), showing as a result that the NPs have a wurtzite-like crystalline structure with crystallite sizes around 32–37 nm for both samples. Additionally, the bandgap of the NPs was calculated using Ultraviolet Visible Spectroscopy (UV–Vis), determining values of 2.82 and 2.70 eV for the NPs synthesized with leaf and root, respectively. Finally, thermogravimetric analysis demonstrated that the nanoparticles contained an organic part after the green synthesis process, with high thermal stability for both samples. Photocatalytic analysis showed that these nanomaterials can degrade four dyes under UV irradiation, reaching 90% degradation for methylene blue (MB), methyl orange (MO) and Congo red (CR) at 60, 100 and 60 min, respectively, while for methyl red (MR) almost 90% degradation was achieved at 140 min of UV irradiation. These results demonstrate that it is effective to use Ambrosia ambrosioides root and leaf extracts as a reducing agent for the formation of ZnO NPs, also evidencing their favorable application in the photocatalytic degradation of these four organic dyes. Full article

This work focused on the decolorization of methyl red (MR) from an aqueous solution utilizing Rumex abyssinicus-derived biochar (RAB). RAB was prepared to involve unit operations such as size reduction, drying, and carbonization. The pyrolysis of the precursor material was carried out at a temperature of 500 °C for two hours. After that, the prepared RAB was characterized by the pH point of zero charge (pHpzc), the Brunauer–Emmett–Teller (BET) method, Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared (FTIR) spectroscopy. On the other hand, a batch adsorption experiment of MR removal onto RAB was conducted, considering four operating parameters: pH, contact time, adsorbent dose, and initial dye concentration. The characterization of the adsorbent material revealed a porous and heterogeneous surface morphology during SEM, a specific surface area of 45.8 m²/g during the BET method, the presence of various functional groups during FTIR, and a pHpzc of 6.2. The batch adsorption experiment analysis results revealed that a maximum removal efficiency of 99.2% was attained at an optimum working condition of pH 6, contact time of 40 min, initial dye concentration of 70 mg/L and adsorbent dosage of 0.2 g/100 mL. Furthermore, Freundlich isotherm (R² = 0.99) and pseudo-second-order kinetics (R² = 0.99) models confirmed the heterogeneous surface interaction and chemisorption nature. Generally, this study highlighted that RAB could be a potential adsorbent for the detoxification of MR-containing industrial effluents. Full article

Hollow mesoporous hydroxyapatite (HM-HAP) composites coated with titania are prepared to increase the stability and catalytic performance of titania for azo dyes present in the wastewater system. In this work, HM-HAP particles were first synthesized by a hydrothermal method utilizing the CaCO₃ core as a template and then coated with titania to form TiO₂/HM-HAP composites. Utilizing SEM, XRD, XPS, BET, FTIR, EDS, UV–vis DRS spectroscopy, and point of zero charge (PZC) analysis, the coating morphological and physicochemical parameters of the produced samples were analyzed. The photocatalytic efficiency of the synthesized coated composites was assessed by the degradation of methyl red (MR) dye in water. The results indicated that TiO₂/HM-HAP particles could efficiently photodegrade MR dye in water under UV irradiation. The 20% TiO₂/HM-HAP coating exhibited high catalytic performance, and the degradation process was followed by the pseudo-first-order (PFO) kinetic model with a rate constant of 0.033. The effect of pH on the degradation process was also evaluated, and the maximum degradation was observed at pH 6. The analysis of degraded MR dye products was investigated using LC-MS and FTIR analysis. Finally, a good support material, HM-HAP for TiO₂ coatings, which provides a large number of active adsorption sites and has catalytic degradation performance for MR dye, was revealed. Full article

Iron oxide nanoparticles were synthesized by co-precipitation using three different iron salt stoichiometric mole ratios. Powder X-ray diffraction patterns revealed the inverse cubic spinel structure of magnetite iron oxide. Transmission electron microscopic images showed Fe₃O₄ nanoparticles with different shapes and average particle sizes of 5.48 nm for Fe₃O₄-1:2, 6.02 nm for Fe₃O₄-1.5:2, and 6.98 nm for Fe₃O₄-2:3 with an energy bandgap of 3.27 to 3.53 eV. The as-prepared Fe₃O₄ nanoparticles were used as photocatalysts to degrade brilliant green (BG), rhodamine B (RhB), indigo carmine (IC), and methyl red (MR) under visible light irradiation. The photocatalytic degradation efficiency of 80.4% was obtained from Fe₃O₄-1:2 for brilliant green, 61.5% from Fe₃O₄-1.5:2 for rhodamine B, and 77.9% and 73.9% from Fe₃O₄-2:3 for both indigo carmine and methyl red. This indicates that Fe₃O₄-2:3 is more efficient in the degradation of more than one dye. This study shows that brilliant green degrades most effectively at pH 9, rhodamine B degrades best at pH 6.5, and indigo carmine and methyl red degrade most efficiently at pH 3. Recyclability experiments showed that the Fe₃O₄ photocatalysts can be recycled four times and are photostable. Full article

Ionizing radiation covers a broad spectrum of applications. Since radioactive/radiation pollution is directly related to radiation risk, radiation levels should be strictly controlled. Different detection methods can be applied for radiation registration and monitoring. In this paper, radiation-induced variations in the optical properties of silver-enriched PVA-based hydrogel films with and without azo dye (Toluidine blue O, TBO, and Methyl red, MR) additives were investigated, and the feasibility of these free-standing films to serve as radiation detectors/exposure indicators was assessed. AgNO₃ admixed with PVA gel was used as a source for the radiation-induced synthesis of silver nanoparticles (AgNPs) in irradiated gel films. Three types of sensors were prepared: silver-enriched PVA films containing a small amount of glycerol (AgPVAGly); silver-enriched PVA films with toluidine blue adducts (AgPVAGlyTBO); and silver-enriched PVA films with methyl red additives (AgPVAGlyMR). The selection of TBO and MR was based on their sensitivity to irradiation. The irradiation of the samples was performed in TrueBeam2.1 (VARIAN) using 6 MeV photons. Different doses up to 10 Gy were delivered to the films. The sensitivity of the films was assessed by analyzing the characteristic UV-Vis absorbance peaks on the same day as irradiation and 7, 30, 45, 90, and 180 days after irradiation. It was found that the addition of azo dyes led to an enhanced radiation sensitivity of the AgNPs containing films (0.6 Gy⁻¹ for AgPVAGlyTBO and 0.4 Gy⁻¹ for AgPVAGlyMR) irradiated with <2 Gy doses, indicating their applicability as low-dose exposure indicators. The irradiated films were less sensitive to higher doses. Almost no dose fading was detected between the 7th and 45th day after irradiation. Based on the obtained results, competing AgNP formation and color-bleaching effects in the AgPVAGly films with dye additives are discussed. Full article

The advancement of stem cell therapy has offered transformative therapeutic outcomes for a wide array of diseases over the past decades. Consequently, stem cell tracking has become significant in revealing the mechanisms of action and ensuring safe and effective treatments. Fluorescence stands out as a promising choice for stem cell tracking due to its myriad advantages, including high resolution, real-time monitoring, and multi-fluorescence detection. Furthermore, combining fluorescence with other tracking modalities—such as bioluminescence imaging (BLI), positron emission tomography (PET), photoacoustic (PA), computed tomography (CT), and magnetic resonance (MR)—can address the limitations of single fluorescence detection. This review initially introduces stem cell tracking using fluorescence imaging, detailing various labeling strategies such as green fluorescence protein (GFP) tagging, fluorescence dye labeling, and nanoparticle uptake. Subsequently, we present several combinations of strategies for efficient and precise detection. Full article

Recently, the production of new photocatalytic materials has attracted considerable attention as a promising strategy to mitigate anthropogenic environmental degradation. In this study, cement paste composites (water/cement ratio = 0.5) were prepared using a coating based on nanoparticles of SnO₂ (SnO₂/cement paste) and SnO₂ decorated with Ag₂O (Ag₂O-decorated SnO₂/cement paste) for photocatalytic applications. These coatings were prepared in this study by using the hydrothermal method as the strategy. Thus, photocatalyst efficiency was evaluated through the degradation of methylene blue (MB) and methyl red (MR) as cationic and anionic dyes, respectively, and the simultaneous degradation of MB/MR (1:1 v/v) dyes. Moreover, the photocatalytic mechanism was investigated in the presence of scavengers. Notably, an increase in pH in the range of 2–6 resulted in selective degradation of the MB/MR dye mixtures. Overall, the photocatalytic performance of these materials provides a novel platform technology focused on advanced civil engineering applications, which consequently facilitates the mitigation of various environmental problems. Full article

For the first time, cobalt ferrite spinel (CoFe₂O₄) was used as a catalyst in the Fenton process for Remazol Red RR dye degradation in water. CoFe₂O₄ was synthesized via gel combustion using tris(hydroxymethyl)aminomethane as an alternative fuel in one step with a ratio of Ψ = 0.8. Its structural, surface optics, magnetic properties, and the optimal conditions of the Fenton reagents for dye degradation were evaluated. The saturation magnetization and remanence (Ms and Mr, respectively) for the as-prepared powder were 65.7 emu/g and 30.4 emu/g, respectively, and the coercivity (Hc) was 1243 Oe, indicating its ferromagnetic nature and suitability as a magnetic catalyst. Red Remazol RR dye degradation tests were performed using the Fenton process to evaluate the influence of the catalyst dosage and H₂O₂ concentration. The tests were performed in a batch reactor in the dark with constant agitation for 24 h. The best result was obtained using 1 g/L of catalyst with a dye degradation of 80.6%. The optimal concentration of H₂O₂ (1.0 M) resulted in 96.5% dye degradation. Nanoparticle recyclability testing indicated that the material could be satisfactorily reused as a catalyst for at least three cycles. The potential use of the CoFe₂O₄ synthesized in this study as a catalyst for dye degradation by the Fenton process was demonstrated. Full article

The present work elucidates the fabrication of Barium Lanthanum Oxide nanosheets (BaLa₂O₄ NSs) via a simple one-pot precipitation method. The acquired results show an orthorhombic crystal system with an average crystallite size of 27 nm. The morphological studies revealed irregular-shaped sheets stacked together in a layered structure, with the confirmation of the precursor elements. The diffused reflectance studies revealed a strong absorption between 200 nm and 350 nm, from which the band-gap energy was evaluated to be 4.03 eV. Furthermore, the fluorescence spectrum was recorded for the prepared samples; the excitation spectrum shows a strong peak at 397 nm, attributed to the ⁴F_7/2→⁴G_11/2 transition, while the emission shows two prominent peaks at 420 nm (⁴G_7/2→⁴F_7/2) and 440 nm (⁴G_5/2→⁴F_7/2). The acquired emission results were utilized to confirm the color emission using a chromaticity plot, which found the coordinates to be at (0.1529 0.1040), and the calculated temperature was 3171 K. The as-prepared nanosheets were utilized in detecting latent fingerprints (LFPs) on various non-porous surfaces. The powder-dusting method was used to develop latent fingerprints on various non-porous surfaces, which resulted in detecting all the three ridge patterns. Furthermore, the as-synthesized nanosheets were used to degrade methyl red (MR) dye, the results of which show more than 60% degradation at the 70th minute. It was also found that there was no further degradation after 70 min. All the acquired results suggest the clear potential of the prepared BaLa₂O₄ NSs for use in advanced forensic and photocatalytic applications. Full article

In this paper, Au nanocages (AuNCs) loaded with the MRI contrast agent gadolinium (Gd) and capped with the tumor-targeting gene survivin (Sur–AuNC•Gd–Cy7 nanoprobes) were designed and applied as a targeted imaging agent for pancreatic cancer. With its capacity to transport fluorescent dyes and MR imaging agents, the gold cage is an outstanding platform. Furthermore, it has the potential to transport different drugs in the future, making it a unique carrier platform. The utilization of Sur–AuNC•Gd–Cy7 nanoprobes has proven to be an effective means of targeting and localizing survivin-positive BxPC-3 cells within their cytoplasm. By targeting survivin, an antiapoptotic gene, the Sur–AuNC•Gd–Cy7 nanoprobe was able to induce pro-apoptotic effects in BxPC-3 pancreatic cancer cells. The biocompatibility of AuNCs•Gd, AuNCs•Gd–Cy7 nanoparticles, and Sur–AuNC•Gd–Cy7 nanoprobes is evaluated through the hemolysis rate assay. The stability of AuNCs•Gd, AuNCs•Gd–Cy7 nanoparticles, and Sur–AuNC•Gd–Cy7 nanoprobes was evaluated by determining their hydrodynamic dimensions following storage in different pH solutions for a corresponding duration. Excellent biocompatibility and stability of the Sur–AuNC•Gd–Cy7 nanoprobes will facilitate their further utilization in vivo and in vitro. The surface-bound survivin plays a role in facilitating the Sur–AuNC•Gd–Cy7 nanoprobes’ ability to locate the BxPC-3 tumor. The probe was modified to incorporate Gd and Cy7, thereby enabling the simultaneous utilization of magnetic resonance imaging (MRI) and fluorescence imaging (FI) techniques. In vivo, the Sur–AuNC•Gd–Cy7 nanoprobes were found to effectively target and localize survivin-positive BxPC-3 tumors through the use of MRI and FI. After being injected via the caudal vein, the Sur–AuNC•Gd–Cy7 nanoprobes were found to accumulate effectively in an in situ pancreatic cancer model within 24 h. Furthermore, these nanoprobes were observed to be eliminated from the body through the kidneys within 72 h after a single injection. This characteristic is crucial for a diagnostic agent. Based on the aforementioned outcomes, the Sur–AuNC•Gd–Cy7 nanoprobes have significant potential advantages for the theranostic treatment of pancreatic cancer. This nanoprobe possesses distinctive characteristics, such as advanced imaging abilities and specific drug delivery, which offer the possibility of enhancing the precision of diagnosis and efficacy of treatment for this destructive illness. Full article

Photocatalytic degradation technology has developed rapidly in the treatment of organic pollutants due to its high efficiency, mild reaction conditions and easy control. In this paper, a series of heterogeneous photocatalysts, BWZ-en-R (BWZ = [BW₁₁Z(H₂O)O₃₉]⁷⁻, Z = Zn, Cd, Mn, en = ethylenediamine, R = Merrifield resin), were prepared by using ethanediamine as a linker to immobilize Keggin-type transition elements substituting tungstoborates on Merrifield resin and characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The photocatalytic properties of BWZ-en-R (Z = Zn, Cd, Mn) for the degradation of methyl red (MR) were investigated. The results show that the BWZ-en-R (Z = Zn, Cd, Mn) photocatalysts exhibited high photodegradation ability for MR under the irradiation of ultraviolet light, and were easily separated from the reaction media. The maximum degradation rate (%) of MR (40 mL, 25 μM, pH = 2) reached 96.4% for the BWMn-en-R photocatalyst (40 mg) after being irradiated for 30 min, making this a promising photocatalyst candidate for dye degradation. Moreover, the influences of some factors, such as the Z-substituted elements in the BWZ, the BWZ-en-R dosage and the MR initial concentration, on the photocatalytic degradation rate of MR were also examined. Full article

Probiotic bacteria can be introduced to stresses during the culturing phase as an alternative to the use of protectants and coating substances during drying. Accurate enumeration of the bacterial count in a probiotic formulation can be provided using imaging flow cytometry (IFC). IFC overcomes the weak points of conventional, commonly used flow cytometry by combining its statistical power with the imaging content of microscopy in one system. Traditional flow cytometers only collect the fluorescence signal intensities, while IFC provides many more steps as it correlates the data on the measured parameters of fluorescence light with digitally processed images of the analyzed cells. As an alternative to standard methods (plate cell counts and traditional flow cytometry) IFC provides additional insight into the physiology and morphology of the cell. The use of complementary dyes (RedoxSensorTM Green and propidium iodide) allows for the designation of groups based on their metabolic activity and membrane damage. Additionally, cell sorting is incorporated to assess each group in terms of growth on different media (MRS-Agar and MRS broth). Results show that the groups with intermediate metabolic activity and some degree of cellular damage correspond with the description of viable but nonculturable cells. Full article