Search Results (270)

Background/Objectives: Head and neck cancer (HNC) is the sixth most common cancer worldwide, with a high mortality, particularly from head and neck squamous cell carcinoma (HNSCC). Although some therapeutic strategies are available, they might cause severe side effects. For example, surgery may result in disfigurement and functional loss, severely impacting the patient’s quality of life. Thus, minimally invasive and more effective alternatives are needed. Gold nanoparticle (AuNP)-mediated photothermal therapy (PTT) is a promising approach for HNC, which relies on AuNP photothermal efficiency and tumor localization. This study aimed to synthesize and characterize AuNPs, evaluate their safety without laser activation, and assess their efficacy with laser activation. Methods and Results: Their physicochemical and photostability over three months and sterility were confirmed. In vitro safety was tested using human non-cancerous and HNC cell lines, while in vivo biocompatibility was evaluated in the hen’s egg chorioallantoic membrane (CAM) model, with no adverse effects observed. Upon laser activation, AuNPs reduced HNC cell viability by 50–70%, including HNSCC lines. In vivo biodistribution studies showed that AuNPs remained at the injection site for up to one month without toxicity. Conclusions: Overall, the developed AuNP formulation demonstrates stability, biocompatibility, and prolonged local retention, key attributes for effective and targeted PTT. These findings support the potential of AuNP-mediated photothermal therapy as a promising treatment modality for HNC, although further preclinical and clinical studies are needed to optimize treatment parameters. Full article

The excessive use of antibiotics and the rise in resistant strains have significantly contributed to increased mortality rates associated with tumors and infectious diseases, posing a severe threat to public health. Consequently, there is an urgent need to enhance detection and treatment strategies for critical diseases, including cancer and pathogenic microorganisms. Conjugated oligomers, formed by a limited number of repeating conjugated units linked through covalent bonds, exhibit a high potential for various applications in biological monitoring and disease diagnosis due to their controllable molecular weight, precise molecular structure, and excellent photostability. Therefore, it is particularly essential to design and optimize the structure of conjugated oligomers to improve their biocompatibility and therapeutic efficacy. In this review article, we summarize recent advancements in applying conjugated oligomers in imaging, cancer therapy, and antibacterial treatment. Furthermore, this article critically examines the challenges in their biological applications, underscoring the need for continued innovation. Full article

The increasing occurrence of antibiotics in water bodies all over the world has raised concerns because of the prospect that they might have genotoxic and antibiotic-resistant consequences in both people and aquatic creatures. In particular, it has been discovered that the construction of hybrid photocatalytic composite materials has greater antibiotic degradation efficiencies. The hybrid photocatalysts deliver improved photoabsorbance, charge separation, transfer, and redox characteristics, as well as enhanced photostability and rapid recovery, due to their optimal characteristic qualities, including superior structural, surface, and interfacial properties. Additionally, metal-based electrocatalysts have garnered notable attention in the field of water splitting as they are low-cost, standard and have the potential to be used in green and clean technology. MXene, a family of two-dimensional transition metal carbides and nitrides, was discovered in 2011 due to its high conductivity, large surface area, and abundance of catalytically active sites. By making hybrid structures of MXene with other materials, which have shown better electrocatalytic activity than pure MXenes. The two half-cell processes involved in water electrolysis are the oxygen generation at the anode site and the hydrogen production at the cathode site. This review paper provides a summary of the latest advancements in the design of several hybrid systems, catalysts and their effectiveness in degrading a range of newly discovered antibiotic pharmaceutical pollutants in aquatic settings, as well as recent developments on the use of MXenes and MXene-based hybrid structures such as OER, HER, and bifunctional electrocatalysts for general water splitting. Full article

AuQDs (Au quantum dots) are ultrasmall nanostructures that combine the size-tunable fluorescence and photostability of semiconductor quantum dots with the chemical stability, low toxicity, and versatile surface chemistry of gold nanoparticles. This unique combination endows AuQDs with exceptional biocompatibility and multifunctionality, making them ideal for biomedical applications such as cellular imaging, real-time tracking, targeted drug delivery, diagnostics, therapeutic monitoring, and biosensing. Various synthesis methods—including chemical reduction, hydrothermal, laser ablation, and microwave-assisted techniques—allow for precise control over size and surface properties, optimizing fluorescence and electronic behavior for high-resolution imaging and sensitive detection. Compared to traditional quantum dots, AuQDs offer enhanced safety and biocompatibility, while surpassing larger gold nanoparticles by enabling fluorescence-based imaging. Their surfaces can be functionalized with diverse ligands for targeted delivery and specific biological interactions. In summary, AuQDs are multifunctional nanoprobes that combine superior optical properties, chemical stability, and biocompatibility, making them powerful tools for advanced biomedical diagnostics, therapy, and biosensing. Full article

Thanks to their multiple outstanding features—such as high fluorescence quantum yield, good photostability, and excellent sensitivity—conjugated polymers (CPs) have emerged as a pioneering class of fluorescent materials for sensing applications, particularly in environmental and biological fields, for the detection of a wide range of environmental pollutants and bioactive compounds. The presence of delocalized π-electrons in the CP backbone significantly enhances sensing performance through a unique phenomenon known as the “molecular wire effect.” As a result, CP-based fluorescent sensors have been extensively developed and employed as exceptional tools for monitoring various analytes in environmental and biological contexts. A deep understanding of their unique properties, fabrication techniques, and recent innovations is essential for guiding the strategic development of advanced CP-based fluorescent sensors, particularly for future point-of-care applications. This study presents a critical review of the key characteristics of fluorescent sensors and highlights several common types of conjugated polymers (CPs) used in their design and fabrication. It summarizes and discusses the main sensing mechanisms, state-of-the-art applications, and recent innovations of CP-based fluorescent sensors for detecting target compounds in environmental and biological fields. Furthermore, potential strategies and future perspectives for designing and developing high-performance CP-based fluorescent sensors are emphasized. By consolidating current scientific evidence, this review aims to support the advancement of highly sensitive fluorescent sensors based on various CP nanoparticles for environmental and biological applications. Full article

This study employed a sol–gel route to fabricate mesoporous silica (MS) carriers capable of simultaneously encapsulating two widely utilized UV absorbers—benzophenone-3 (BP-3) and octyl methoxycinnamate (OMC)—resulting in the composite sunscreen agent S4M1B1. Comprehensive characterization using FTIR, TGA, UV–vis spectroscopy, DSC, SEM, and standard photoprotective indices (SPF and UVA-PF) confirmed the successful immobilization of both active ingredients within the MS porous structure, achieving a notably high loading of up to 72 wt%. Sunscreen formulations incorporating the encapsulated composite demonstrated superior photoprotective performance, exhibiting SPF and UVA-PF values approximately 40% higher than equivalent physical mixtures of the same actives. Additionally, the MS encapsulation significantly enhanced the photostability of BP-3 and OMC, effectively maintaining their UV-protective efficacy after prolonged simulated solar exposure. Franz glass diffusion cell assays further revealed that encapsulation markedly reduced the in vitro skin permeation of both BP-3 and OMC by over 55%, substantially diminishing transdermal absorption risks. The dual benefits of enhanced UV-protection efficiency and reduced dermal penetration underscore the composite’s potential as a safer and more effective active ingredient in cosmetic sunscreen products, with promising applications in advanced skincare and cosmeceutical formulations. Full article

Phthalocyanines (Pcs) are well-established photosensitizers in photodynamic therapy, valued for their strong light absorption, high singlet oxygen generation, and photostability. Recent advances have focused on covalently conjugating Pcs, particularly zinc phthalocyanines (ZnPcs), with a wide range of small bioactive molecules to improve selectivity, efficacy, and multifunctionality. These conjugates combine light-activated reactive oxygen species (ROS) production with targeted delivery and controlled release, offering enhanced treatment precision and reduced off-target toxicity. Chemotherapeutic agent conjugates, including those with erlotinib, doxorubicin, tamoxifen, and camptothecin, demonstrate receptor-mediated uptake, pH-responsive release, and synergistic anticancer effects, even overcoming multidrug resistance. Beyond oncology, ZnPc conjugates with antibiotics, anti-inflammatory drugs, antiparasitics, and antidepressants extend photodynamic therapy’s scope to antimicrobial and site-specific therapies. Targeting moieties such as folic acid, biotin, arginylglycylaspartic acid (RGD) and epidermal growth factor (EGF) peptides, carbohydrates, and amino acids have been employed to exploit overexpressed receptors in tumors, enhancing cellular uptake and tumor accumulation. Fluorescent dye and porphyrinoid conjugates further enrich these systems by enabling imaging-guided therapy, efficient energy transfer, and dual-mode activation through pH or enzyme-sensitive linkers. Despite these promising strategies, key challenges remain, including aggregation-induced quenching, poor aqueous solubility, synthetic complexity, and interference with ROS generation. In this review, the examples of Pc-based conjugates were described with particular interest on the synthetic procedures and optical properties of targeted compounds. Full article

We report the development of highly luminescent, bovine serum albumin (BSA)-stabilized gold–silver bimetallic nanoclusters (Au-AgNCs@BSA) as a novel platform for high-sensitivity, ratiometric intracellular temperature sensing. Precise and non-invasive temperature sensing at the nanoscale is crucial for applications ranging from intracellular thermogenesis monitoring to localized hyperthermia therapies. Traditional luminescent thermometric platforms often suffer from limitations such as high cytotoxicity and low photostability. Here, we synthesized Au-AgNCs@BSA via a one-pot aqueous reaction, achieving significantly enhanced photoluminescence quantum yields (PL QYs, up to 18%) and superior thermal responsiveness compared to monometallic counterparts. The dual-emissive Au-AgNCs@BSA exhibit a linear ratiometric fluorescence response to temperature fluctuations within the physiological range (20–50 °C), enabling accurate and concentration-independent thermometry in live cells. Time-resolved PL and Arrhenius analyses reveal two distinct emissive states and a high thermal activation energy (E_a = 199 meV), indicating strong temperature dependence. Silver doping increases radiative decay rates while maintaining low non-radiative losses, thus amplifying fluorescence intensity and thermal sensitivity. Owing to their small size, excellent photostability, and low cytotoxicity, these nanoclusters were applied to non-invasive intracellular temperature mapping, presenting a promising luminescent nanothermometer for real-time cellular thermogenesis monitoring and advanced bioimaging applications. Full article

The unique properties of phthalocyanines (Pcs), such as strong absorption, high photostability, effective singlet oxygen generation, low toxicity and biocompatibility, versatile chemical modifications, broad spectrum of antimicrobial activity, and synergistic effects with other treatment modalities, make them a preferred superior sensitizer in the field of antimicrobial photodynamic therapy. The photodynamic and sonodynamic activity of 3-(3-(diethylamino)phenoxy)propanoxy substituted silicon(IV) Pc were evaluated against bacteria and cancer cells. Stability and singlet oxygen generation upon light irradiation and ultrasound (1 MHz, 3 W) were assessed with 1,3-diphenylisobenzofuran. The phthalocyanine revealed high photostability in DMF and DMSO, although the singlet oxygen yields under light irradiation were low. On the other hand, the phthalocyanine revealed excellent sonostability and caused a high rate of DPBF degradation upon excitation by ultrasounds at 1 MHz. The silicon phthalocyanine presented significant bacterial reduction growth, up to 5 log against MRSA and S. epidermidis upon light excitation, whereas the sonodynamic effect was negligible. The phthalocyanine revealed high activity in both photodynamic and sonodynamic manner toward hypopharyngeal tumor (FaDu, 95% and 42% reduction, respectively) and squamous cell carcinoma (SCC-25, 96% and 62% reduction, respectively). The sensitizer showed ca. 30% aldehyde dehydrogenase inhibition in various concentrations and up to 85% platelet-activating factor acetylhydrolase for 0.25 μM, while protease-activated protein C was stimulated up to 66% for 0.75 μM. Full article

Luminescent metal–organic frameworks (MOFs) are used for the detection of organophosphorus pesticides (OPs) due to their large surface area and pore volume as well as their special optical properties. However, most self-luminescent MOFs are not only complex to synthesize and unstable in water but also feature a “turn-off” sensing system, which has highly restricted their practical applications in OP detection. Herein, a “turn-on” fluorescence sensor based on the guest-induced luminescence MOF Ru(bpy)₃²⁺@UiO-66 was constructed, which realized the sensitive detection of OPs through a dual-enzyme system for the first time. Compared with self-luminescent MOFs, Ru(bpy)₃²⁺@UiO-66 was not only more easily synthesized but also had higher chemical and photostability in water. In this strategy, by means of the hydrolysis of AChE and ChOx, H₂O₂ will be produced, which can oxidize Fe²⁺ to Fe³⁺, thereby quenching the fluorescence of Ru(bpy)₃²⁺@UiO-66. In the presence of OPs, the activity of AChE can be inhibited, resulting in the inability to generate H₂O₂ and Fe³⁺, which will turn on the fluorescence signal of Ru(bpy)₃²⁺@UiO-66. As a result, the Ru(bpy)₃²⁺@UiO-66 sensing system not only had high sensitivity for OPs detection but also possessed a satisfactory detection recovery rate for parathion-methyl in real samples, which provides a new approach for OP detection in food safety as well as environmental monitoring. Full article

In this study, we synthesized novel donor–π–acceptor (D–π–A) functional dyes bearing a carbonyl-bridged bithiophene as a π-conjugated spacer and evaluated the absorption and fluorescence properties as well as the photostability. The developed dyes 1-CO–3-CO possess an N,N-diphenylaminophenyl electron donor unit and an electron acceptor unit such as a formyl group (1-CO), an (N,N-diethylthiobarbituryl)methylene moiety (2-CO), or a (3-dicyanomethylidene-1-indanon-2-yl)methylene moiety (3-CO). The absorption spectra of 1-CO–3-CO in dichloromethane at room temperature showed absorption maxima at 569 nm, 631 nm, and 667 nm, respectively, and the stronger acceptors in 2-CO and 3-CO led to enhancement of the ICT character. In addition, 2-CO and 3-CO had a second absorption band in the visible region, showing panchromatic absorption properties. Electrochemical analyses of the developed dyes revealed that the carbonyl bridging group in the π-spacer contributes to stabilization of the frontier orbitals such as the highest occupied and lowest unoccupied molecular orbitals (HOMO and LUMO, respectively), in comparison with the referential dyes bearing a dibutylmethylene-bridged bithiophene spacer, 1-CBu₂–3-CBu₂. The HOMO/LUMO stabilization brought about high photostability in the doped poly(methyl methacrylate) film. Full article

Background/Objectives: This study aims to present a strategic approach to enhancing the photostability and antioxidative resilience of curcumin and capsaicin by integrating selected natural stabilizers within a nanoemulsion-based delivery system. Methods: Coffee extract (Coffea arabica Linn.), along with its active components and vitamin E-containing natural oils, was assessed in terms of improving the photostabilizing and antioxidative retention abilities of curcumin and capsaicin. An optimized ratio of the active mixture was then loaded into a nanoformulation. Results: The analysis of active contents with validated high-performance liquid chromatography (HPLC), ferric reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays confirmed the stabilization enhancement after irradiation with UV and white light for 72,000–84,000 lux hours. The optimized combination of coffee extract with turmeric and chili mixtures loaded into the optimized nanoemulsion enhanced the half-lives (T_1/2) of curcumin and capsaicin by 416% and 390%, respectively. The interactions of curcumin and capsaicin with caffeine and chlorogenic acid were elucidated using computational calculations. Interaction energies (E_int), HOMO-LUMO energy gap (HLG) analysis, and global reactivity descriptors revealed hydrogen bonding interactions be-tween capsaicin and chlorogenic acid, as well as between curcumin and caffeine. Conclusions: By leveraging the synergistic antioxidative properties of coffee extract and vitamin E within a nanoemulsion matrix, this study overcomes the intrinsic stability limitations of curcumin and capsaicin, offering a robust platform for future pharmaceutical and nutraceutical applications. Full article

Self-emulsifying solid nanodispersion technology is emerging as an attractive strategy to prepare new eco-friendly and efficient nano-formulations due to its simple, energy efficient and easy scale-up process. However, it is still unknown whether this technology can be employed to cope with the drawbacks of botanical insecticides including poor water solubility, rapid photodegradation and limited targeting efficiency. In this study, rotenone (Rot) was selected as a model of botanical insecticides, and its solid nanodispersion (Rot–SND) was prepared by a self-emulsifying method combined with parameter optimization. Our target nano-formulation, consisting of 5% Rot, 20% surfactant complexes of 8% Ethylan 992 and 12% EL–80, and 75% lactose, exhibited excellent storage stability and significantly improved the pseudo-solubility of Rot by at least 250 times. The average particle size and polydispersity index (PDI) of Rot–SND were determined to be 101.19 nm and 0.21, respectively. Rot–SND displayed smaller contact angles and greater retention on both cucumber and cabbage leaves than those of a commercial emulsifiable concentrates (ECs). Rot–SND was also more resistant to photodegradation, with a degradation rate reduced by 27.01% as compared with the ECs. In addition, the toxicity of Rot–SND towards Aphis gossypii was 3.01 times that of the ECs, with a median lethal concentration (LC₅₀) of 1.45 µg a.i./mL. Under the field conditions, Rot–SND showed a prolonged duration for A. gossypii control, with a significantly higher control efficacy (88.10%) on the 10th day than that of the ECs (77.02%). Moreover, a 2.34-fold decline in the toxicity towards nontarget mosquito larvae was observed for Rot–SND as compared with the EC. Overall, for the first time, our results indicate the role of Rot–SND as an eco-friendly and efficient way to improve the solubility, foliar affinity, photostability, bioactivity and eco-safety of Rot. This research also provided a feasible strategy to prepare more eco-friendly botanical pesticide formulations of high efficiency. Full article

Optical oxygen sensors have attracted considerable attention owing to their high sensitivity, rapid response, and broad applicability. However, their test results may be affected by fluctuations in the pump light source and instability of the detection equipment. In this study, the intrinsic luminescence of pine wood was utilized as the reference signal, and the luminescence of platinum(II) octaethylporphyrin (PtOEP) was employed as the oxygen indication signal, to fabricate a dual-signal ratiometric oxygen sensor PtOEP/PDMS@Pine. The ratio of the luminescence of pine wood to that of PtOEP was defined as the optical parameter (OP). OP increased linearly with oxygen concentration ([O₂]) in the range of 10–100 kPa, and a calibration curve was obtained. The sensor exhibits excellent anti-interference capabilities, effectively resisting fluctuations from laser sources and detection equipment. It also displays stable hydrophobicity with a contact angle of 118.3° and maintains excellent photostability under continuous illumination. The sensor exhibited long-term stability within 90 days and robust recovery performance during cyclic tests, wherein the response time and recovery time were determined to be 1.4 s and 1.7 s, respectively. Finally, the effects of temperature fluctuations and photobleaching on the sensor’s performance have been effectively corrected, enabling accurate oxygen concentration measurements in complex environments. Full article

Morin is a natural flavonoid with potent antioxidant activity, yet its clinical and nutraceutical applications remain limited due to poor aqueous solubility and low bioavailability. This study explores the interaction of morin with bovine serum albumin (BSA) and the development of BSA-based nanoparticles as a delivery platform. Fluorescence spectroscopy confirmed the formation of a stable 1:1 morin–BSA complex, governed by hydrophobic interactions, with a binding constant (Ka) of 1.87 × 10⁵ L·mol⁻¹. Binding conferred enhanced photostability, as BSA attenuated morin degradation under oxidative stress conditions. BSA nanoparticles prepared by desolvation encapsulated morin with high monodispersity and encapsulation efficiencies up to 26%. Co-encapsulation with ellagic acid or tocopherol succinate improved loading capacity but reduced morin release, suggesting intermolecular stabilization. Release studies in simulated intestinal fluid showed controlled diffusion, while compatibility assays in milk-based food matrices confirmed colloidal stability in whole and reduced-fat milk. These findings support BSA–morin nanoparticles as a promising system for the oral delivery and functional food incorporation of polyphenolic antioxidants. Full article