Search Results (46)

Wounds, particularly chronic wounds, represent an increasing challenge for global health systems, affecting millions of people worldwide, and are often associated with persistent infections, biofilms, and multidrug-resistant microorganisms (MDRMs). In this context, the search for effective therapeutic alternatives has driven interest in photodynamic therapy (PDT), an approach in which light-excited photosensitizers promote the generation of reactive oxygen species (ROS) with antimicrobial and wound healing properties. Although first- and second-generation organic photosensitizers are widely used, they have significant limitations, including low aqueous solubility, self-aggregation, reduced photostability, and unsatisfactory ROS quantum yields. To overcome these drawbacks, various nanotechnology-based strategies have been explored. Among them, metallic nanoparticles stand out because they serve as carriers and exhibit intrinsic photosensitizing activity, high resistance to photobleaching, and remarkable extinction coefficients, which favor efficient singlet oxygen generation. Furthermore, metals such as gold and silver can enhance the performance of organic photosensitizers through a process known as metal-enhanced singlet oxygen generation, whereas others, such as copper, zinc, manganese, and magnesium, actively participate in biochemical events associated with the inflammatory and regenerative phases of wound healing. Considering these advances, this review compiles evidence published over the past five years regarding the use of metallic or metal-containing nanoparticles in PDT for acute and chronic wounds, with an emphasis on in vivo studies. In addition, we discuss the epidemiological and pathophysiological aspects of wounds and the intrinsic wound healing and antimicrobial properties of metallic compounds, thereby providing an integrated and up-to-date perspective. Full article

Photocatalysis is a process in which a material utilizes light energy to degrade contaminants through oxidation reactions that decompose impurities upon contact with its surface. Titanium dioxide is one of the most widely used semiconductor materials due to its abundance, chemical stability, and non-toxicity. However, its relatively wide bandgap restricts its photocatalytic activity to the ultraviolet region of the solar spectrum, limiting its overall efficiency under natural sunlight. The incorporation of copper nanoparticles into the TiO₂ matrix enhances light absorption by extending its activity into the visible range, thereby improving its energy conversion efficiency. In this study, undoped and Cu-doped TiO₂ powders were synthesized using the mechanochemical method. The characteristics of the prepared photocatalyst material were determined by XRD, SEM, absorbance, and chemical analysis. XRD analysis showed the formation of TiO₂ in its anatase and rutile phases. Sphere-like shapes with a size of 100 nm were inferred from SEM images. The photocatalytic tests revealed that the Cu-doped TiO₂ nanoparticles exhibited high photocatalytic activity in degrading contaminated water. This enhancement can be attributed to the formation of oxygen vacancies, which promote the photodegradation of organic compounds. Full article

The efficacy of X-ray-induced photodynamic therapy (X-PDT) for deep tumors is often hindered by conventional scintillators, typically rare-earth nanoparticles plagued by long-term toxicity and suboptimal scintillation yields. Here, we introduce a copper iodide (Cu-I) cluster, Cu₂I₂(PPh₃)₂(pz), composed of earth-abundant elements, as an efficient and biocompatible energy transducer for X-PDT. A theranostic nanoplatform, CuI@PcNP, was engineered by co-encapsulating the Cu-I cluster and a phthalocyanine photosensitizer (Pc4OH) within a 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-polyethylene glycol-2000 (DSPE-PEG2K) matrix, which confers excellent physiological stability. This nano-architecture ensures nanoscale proximity between the cluster (donor) and photosensitizer (acceptor), facilitating efficient (58%) Förster resonance energy transfer (FRET) while overcoming aggregation-induced quenching. Upon X-ray irradiation, the platform effectively converted X-rays to visible light, activating Pc4OH to generate potent reactive oxygen species (ROS) and inducing significant dose-dependent cytotoxicity in human hepatocellular carcinoma (HepG2) cells. In a murine hepatoma model, enabling image-guided X-PDT that resulted in a 77.4% tumor inhibition rate with negligible systemic toxicity. Collectively, this work pioneers the integration of phthalocyanine with Cu-I clusters, providing a stable and versatile nanoplatform for image-guided X-PDT. Full article

Communication devices are frequency-operating electronics equipment that utilizes analog modulation, frequency modulation, shortwave frequency, and even higher frequencies in telecommunications. We designed an antenna to transmit interfering frequencies for testing equipment and components based on the effects and conditions of achieving electromagnetic interference. Ansys 2024 was used to design the 35 to 4.4 GHz 2 × 2 patch antennas and simulate the response using a sample frequency of 35 MHz to determine the antenna’s polarization. The polarization was circular, in contrast to the results of the phases Phi and Theta observed in the radial field 3D polar plot, which are completely out of phase and different in magnitude by 5.4 in Phi and 5402.01 in Theta. The measurements from Ansys were congruent to the 2D model dimensions in AutoCAD 2024. The antenna was fabricated under a double-layered photosensitive FR-4 copper board. The antenna connected to the signal generator ADF 4351 effectively was interfered with by a frequency near the actual frequency with a maximum distance of 7.5 m in a room. The frequencies that interfered were from 91.5 to 102.7 MHz. Strong electromagnetic waves for interference disrupted frequency-operating devices due to high signal power achieving destructive interference. Full article

One of the most urgent threats to public health worldwide is the ongoing rise of multidrug-resistant (MDR) bacterial strains. Among the most critical pathogens are MDR-Klebsiella pneumoniae strains. The lack of new antibiotics has led to an increased need for non-antibiotic antimicrobial therapies. Photodynamic therapy (PDT) has become increasingly significant in treating MDR bacteria. PDT uses photosensitizer compounds (PS) that generate reactive oxygen species (ROS) when activated by light. These ROS produce localized oxidative stress, damaging the bacterial envelope. A downside of PDT is the limited bioavailability of PSs in vivo, which can be enhanced by conjugating them with carriers like nanoparticles (NPs). Zinc nanoparticles possess antibacterial properties, decreasing the adherence and viability of microorganisms on surfaces. The additive or synergistic effect of the combined NP-PS could improve phototherapeutic action. Therefore, this study evaluated the effectiveness of the copper(I)-based PS CuC1 compound in combination with Zinc Oxide NP, ZnONP, to inhibit the growth of both MDR and sensitive K. pneumoniae strains. The reduction in bacterial viability after exposure to a PS/NP mixture activated by 61.2 J/cm² of blue light photodynamic treatment was assessed. The optimal PS/NP ratio was determined at 2 µg/mL of CuC1 combined with 64 µg/mL of ZnONP as the minimum effective concentration (MEC). The bacterial gene response aligned with a mechanism of photooxidative stress induced by the treatment, which damages the bacterial cell envelope. Additionally, we found that the PS/NP mixture is not harmful to mammalian cells, such as Hep-G2 and HEK-293. In conclusion, the CuC1/ZnONP combination could effectively aid in enhancing the antimicrobial treatment of infections caused by MDR bacteria. Full article

W-Cu composites are widely used in the fields of switch contact materials and electronic packages because of their high hardness, high plasticity, and excellent thermal conductivity, while the traditional W-Cu composite preparation process is often accompanied by problems such as a long production cycle, difficulties in the processing of shaped parts, and difficulties in guaranteeing the uniformity. Therefore, this work developed a chemical plating technique to prepare W-20 wt.% Cu composite powder with a core–shell structure and used this powder as a raw material for powder metallurgy to solve the problem of inhomogeneity in the production of W-Cu composite by the conventional solution infiltration method. Moreover, the work also developed a high-temperature-resistant photosensitive resin, which was used as a raw material to prepare injection molds using photocuring to replace traditional steel molds. Compared to steel molds, which take about a month to prepare, 3D printed plastic molds take only a few hours, greatly reducing the production cycle. At the same time, 3D printing also provides the feasibility of the production of shaped parts. The injection molded blanks were degreased and sintered under different sintering conditions. The results show that the resultant chemically plated W-Cu composite powder has a uniform Cu coating on the surface, and the Cu forms a dense and uniform three-dimensional network in the scanning electron microscope images of each subsequent sintered specimen, while the photocuring-prepared molds were used to prepare the W-Cu shaped parts, which greatly shortened the production cycle. This preparation method enables rapid preparation of tungsten–copper composite-shaped parts with good homogeneity. Full article

Colloidal copper-based chalcogenide quantum dots (QDs), particularly lead-free CuInSe₂ systems, have emerged as promising photosensitizers for optoelectronic de-vices due to their high extinction coefficients and solution processability. In this work, we demonstrate a TiO₂ photodetector enhanced through interfacial engineering with the size of 9.88 ± 2.49 nm CuInSe₂ QD_s, synthesized via controlled thermal injection. The optimized device architecture combines a 160 nm TiO₂ active layer with 60 μm horizontal channel electrodes, achieving high performance metrics. The QD-sensitized device demonstrates an impressive switching ratio of approximately 10⁵ in the 405 nm wavelength, a significant 34-times increase in responsivity at a 2 V bias, and a detection rate of 4.17 × 10⁸ Jones. Due to the limitations imposed by the TiO₂ bandgap, the TiO₂ photodetector exhibits a negligible increase in photocurrent at 565 nm. The engineered type-II heterostructure enables responsivity enhancement across an extended spectral range through sensitization while maintaining equivalent performance characteristics at both 405 nm and 565 nm wavelengths. Furthermore, the sensitized architecture demonstrates superior response kinetics, enhanced specific detectivity, and exceptional operational stability, establishing a universal design framework for broadband photodetection systems. Full article

Background/Objectives: Radiotherapy is a widely applied first-line clinical treatment modality of cancer. Copper–cysteamine (Cu-Cy) nanoparticles represent a new type of photosensitizer that demonstrates significant anti-tumor potential by X-ray-induced photodynamic therapy. Iodide is a high-Z element with superior X-ray absorption ability and has the β-decay radiotherapeutic nuclide, ¹³¹I, which emits Cherenkov light. In this study we aimed to investigate the X-ray-induced photodynamic therapy potential of iodinated Cu-Cy (Cu-Cy-I) nanoparticles and also explore the local treatment efficacy of ¹³¹I-labeled Cu-Cy-I ([¹³¹I]Cu-Cy-I) nanoparticles. Methods: The synthesis of [¹³¹I]Cu-Cy-I nanoparticles was performed with [¹³¹I]I⁻ anions. The in vitro radiobiological effects on tumor cells incubated with Cu-Cy-I nanoparticles by X-ray irradiation were investigated. The in vivo tumor growth-inhibitory effects of the combination of Cu-Cy-I nanoparticles with X-ray radiotherapy and [¹³¹I]Cu-Cy-I nanoparticles were evaluated with 4T1 tumor-xenografted mice. Results: The in vitro experiment results indicated that the X-ray irradiation with the presence of Cu-Cy-I nanoparticles produced a higher intracellular reactive oxygen species (ROS) level and more DNA damage of 4T1 cells and showed a stronger tumor cell killing ability compared to X-ray irradiation alone. The in vivo experimental results with 4T1 breast carcinoma-bearing mice showed that the combination of an intratumoral injection of Cu-Cy-I nanoparticles and X-ray radiotherapy enhanced the tumor growth-inhibitory effect and prolonged the mice’s lives. Conclusions: Cu-Cy-I nanoparticles have good potential as new radiosensitizers to enhance the efficacy of external X-ray radiotherapy. However, the efficacy of local treatment with [¹³¹I]Cu-Cy-I nanoparticles at a low ¹³¹I dose was not verified. The effective synthesis of smaller sizes of nanoparticles is necessary for further investigation of the radiotherapy potential of [¹³¹I]Cu-Cy-I nanoparticles. Full article

Catheter-associated urinary tract infections (CAUTIs) present significant health risks in medical settings, necessitating innovative solutions to prevent bacterial colonization on catheter surfaces. This study introduces a novel polymeric coating with dual antifouling and light-activated bactericidal properties to enhance the bactericidal efficacy of urinary catheters. The coatings were synthesized using a one-step process involving pyrogallol chemistry to deposit a copolymer composed of zwitterionic sulfobetaine for antifouling and sodium copper chlorophyllin, a photosensitizer that generates reactive oxygen species under light exposure to effectively kill bacteria. We evaluated the antifouling properties, cytocompatibility, and bactericidal performance of the coatings under various light conditions. The results showed significant reductions in bacterial adhesion, with light activation further endowing the catheter with bactericidal effects. Additionally, light could be delivered through an optical fiber within the catheter lumen to target and kill bacteria. The innovative coating using light-activated bactericidal action offers a promising approach to preventing CAUTIs, representing a potential breakthrough in developing safer and more effective urinary catheters. Full article

Noble-metal-free CO₂ reduction systems based on cobalt phthalocyanine (CoPc) and its derivatives have demonstrated remarkable photocatalytic performances; however, their structure-activity relationship with electronic tuning remains unexplored. Herein, we now provide a systematic study to investigate the electron effects of substituents on the CoPc family in photocatalytic CO₂ reduction, where a Cu(I) heteroleptic photosensitizer is utilized. The highest performance can be achieved using cobalt tetracarboxylphthalocyanine in light-driven CO₂-to-CO reduction, with a maximum turnover number of 2950 at 450 nm and an outstanding apparent quantum yield of 63.5% at 425 nm, over ten times the activity with the tetra-dimethylamino-substituted CoPc derivative. The favorable electron-withdrawing effects have been further verified by DFT calculations and cyclic voltammetry, which reduces the overpotential required for CO₂ reduction and decreases the Gibbs free energy of the catalyst active intermediates, particularly the CO-desorption energetics. Full article

Singlet oxygen (¹O₂) is known to have antibacterial activity; however, production can involve complex processes with expensive chemical precursors and/or significant energy input. Recent studies have confirmed the generation of ¹O₂ through the activation of photosensitizer molecules (PSs) with visible light in the presence of oxygen. Given the increase in the incidence of foodborne diseases associated with cross-contamination in food-processing industries, which is becoming a major concern, food-safe additives, such as chlorophyllins, have been studied for their ability to act as PSs. The fluorescent probe Singlet Oxygen Sensor Green (SOSG^®) was used to estimate ¹O₂ formation upon the irradiation of traditional PSs (rose bengal (RB), chlorin 6 (ce6)) and novel chlorophyllins, sodium magnesium (NaChl) and sodium copper (NaCuChl), with both simulated-solar and visible light. NaChl gave rise to a similar ¹O₂ production rate when compared to RB and ce6. Basic mixing was shown to introduce sufficient oxygen to the PS solutions, preventing the limitation of the ¹O₂ production rate. The NaChl-based inactivation of Gram-positive S. aureus and Gram-negative E. coli was demonstrated with a 5-log reduction with UV–Vis light. The NaChl-based inactivation of Gram-positive S. aureus was accomplished with a 2-log reduction after 105 min of visible-light irradiation and a 3-log reduction following 150 min of exposure from an initial viable bacterial concentration of 10⁶ CFU mL⁻¹. CHS-NaChl-based photosensitization under visible light enhanced Gram-negative E. coli inactivation and provided a strong bacteriostatic effect preventing E. coli proliferation. The difference in the ability of NaChl and CHS-NaChl complexes to inactivate Gram-positive and Gram-negative bacteria was confirmed to result from the cell wall structure, which impacted PS–bacteria attachment and therefore the production of localized singlet oxygen. Full article

Phototransistors are three-terminal photodetectors that usually have a higher photocurrent gain than photodiodes due to the amplification of the gate electrode. In this work, a broad spectral phototransistor based on copper phthalocyanine (CuPc) and a Cs₃Bi₂I₉ (CBI) heterojunction is fabricated by the full vacuum evaporation method. Due to the complementary UV–visible absorption of CuPc and CBI, the device exhibits superior performance under three different types of visible light illumination. The experimental results show that the structure of the organic/perovskite heterojunction active layer has the characteristics of good compatibility and a simple process. Meanwhile, by utilizing the superior light-absorption characteristics of perovskite materials and the strong exciton dissociation efficiency of a hetero-type heterojunction interface, the CuPc/CBI-PT exhibits a higher photoresponsivity, photosensitivity, specific detection rate, and lower operating voltage than the CuPc reference device. The stability test shows that the CuPc/CBI-PT can still obtain a 0.73 A/W photoresponsivity under 660 nm light illumination after being stored in the air for 360 h without any packaging. This indicates that the organic/perovskite heterojunction PT may be a good choice for the preparation of high-performance photodetectors. Full article

Chemodynamic therapy (CDT) alone cannot achieve sufficient therapeutic effects due to the excessive glutathione (GSH) and hypoxia in the tumor microenvironment (TME). Developing a novel strategy to improve efficiency is urgently needed. Herein, we prepared a copper silicate nanoplatform (CSNP) derived from colloidal silica. The Cu(II) in CSNP can be reduced to Cu(I), which cascades to induce a subsequent CDT process. Additionally, benefiting from GSH depletion and oxygen (O₂) generation under 660 nm laser irradiation, CSNP exhibits both Fenton-like and hypoxia-alleviating activities, contributing to the effective generation of superoxide anion radical (^•O₂⁻) and hydroxyl radical (^•OH) in the TME. Furthermore, given the suitable band-gap characteristic and excellent photochemical properties, CSNP can also serve as an efficient type-I photosensitizer for photodynamic therapy (PDT). The synergistic CDT/PDT activity of CSNP presents an efficient antitumor effect and biosecurity in both in vitro and in vivo experiments. The development of an all-in-one nanoplatform that integrates Fenton-like and photosensing properties could improve ROS production within tumors. This study highlights the potential of silicate nanomaterials in cancer treatment. Full article

In recent years, the utilization of extremophile microorganisms for the synthesis of metal nanoparticles, featuring enhanced properties and diverse compositions, has emerged as a sustainable strategy to generate high-quality nanomaterials with unique characteristics. Our study focuses on the biosynthesis of Cu-In-S (CIS) nanoparticles, which has garnered considerable attention in the past decade due to their low toxicity and versatile applications in biomedicine and solar cells. Despite this interest, there is a notable absence of reports on biological methods for CIS nanoparticle synthesis. In this research, three yeast species were isolated from soil samples in an extreme Antarctic environment—Union Glacier, Ellsworth Mountains. Among these isolates, Filobasidium stepposum demonstrated the capability to biosynthesize CIS nanoparticles when exposed to copper sulfate, indium chloride, glutathione, and cysteine. Subsequent purification and spectroscopic characterization confirmed the presence of characteristic absorbance and fluorescence peaks for CIS nanoparticles at 500 and 650 nm, respectively. Transmission electron microscopy analysis revealed the synthesis of monodisperse nanoparticles with a size range of 3–5 nm. Energy dispersive X-ray spectroscopy confirmed the composition of the nanoparticles, revealing the presence of copper, indium, and sulfur. The copper/indium ratio ranged from 0.15 to 0.27, depending on the reaction time. The biosynthesized CIS nanoparticles showed higher photostability than biomimetic nanoparticles and demonstrated successful application as photosensitizers in quantum dot-sensitized solar cells (QDSSC), achieving a conversion efficiency of up to 0.0247%. In summary, this work presents a cost-effective, straightforward, and environmentally friendly method for CIS nanoparticle synthesis. Furthermore, it constitutes the first documented instance of a biological procedure for producing these nanoparticles, opening avenues for the development of environmentally sustainable solar cells. Full article

Candida albicans is a clinically significant opportunistic fungus that is generally treated with antifungal drugs such as itraconazole and fluconazole. However, the recent emergence of fungal resistance has made treatment increasingly difficult. Therefore, novel antifungal treatment methods are urgently required. Hexanol ethosome photodynamic therapy (HE-PDT) is a method that uses photosensitizers (PS), such as hexanol ethosome, to exert antifungal effects, and can be used to treat resistant fungal strains. However, due to the high dose of PS required for antifungal treatment, excess photosensitizers may remain. Furthermore, once exposed to light, normal tissues or cells are damaged after photodynamic therapy, which limits the clinical application of HE-PDT. Therefore, improving the efficacy without increasing the dose is the key to this treatment. In this study, the antifungal effect of copper sulfate combined with HE-PDT was investigated, and its mechanism was explored. The results suggested that exogenous copper sulfate significantly increased the antifungal effect of HE-PDT by enhancing the rate of C. albicans inhibition, increasing reactive oxygen species (ROS) accumulation, increasing the rate of apoptosis, and altering the mitochondrial membrane potential (MMP) and ATP concentration, which is related to the downregulation of apoptosis-inducing factor (AIF1) expression. In conclusion, copper sulfate combined with photodynamic therapy significantly inhibited the activity of C. albicans by inducing apoptosis. The combined approach reported herein provides new insights for future antifungal therapy. Full article