Search Results (81)

Fluorescent dyes, such as cyanine dyes, are widely used in fluorescence-imaging-guided tumor therapy due to their high absorbance and fluorescence quantum yield. However, challenges persist in optimizing the performance of fluorescent nanoparticles, particularly due to the aggregation-caused quenching (ACQ) effect of cyanine dyes. Here, a novel counterion construction strategy is introduced using cyanine dye as a model ACQ dye. Through dynamic-controlled flash nanoprecipitation, fluorescent nanoparticles (CyINPs) with tunable structures are developed, investigating the effects of various factors, including counterions, block copolymers, and dye concentrations, on CyINPs’ stability and fluorescence enhancement. The optimized CyINPs with good water solubility show a 21-fold increase in fluorescence intensity and a 3.5-fold increase in encapsulation efficiency compared to CyINPs prepared by a thermodynamic-driven method. Under the efforts of polymers and counterions, dyes are separated, which reduces the impact of the ACQ effect and results in stronger fluorescence intensity, providing insights into improving nanoparticle biocompatibility and energy utilization efficiency. Full article

Photosensitizers with high singlet oxygen (¹O₂) generation capacity under near-infrared (NIR) irradiation are essential and challenging for photodynamic therapy (PDT). A simple yet effective molecular design strategy is realized to construct 1 + 1 > 2 photosensitizers with synergistic effects by covalently integrating iridium complexes with cyanine via ether linkages, as well as introducing aldehyde groups to suppress non-radiative decay, named CHO−Ir−Cy. It is demonstrated that CHO−Ir−Cy successfully maintains the NIR absorption and emission originated from cyanine units and high ¹O₂ generation efficiency from the iridium complex part, which gives full play to their respective advantages while compensating for shortcomings. Density functional theory (DFT) calculations reveal that CHO−Ir−Cy exhibits a stronger spin–orbit coupling constant (ξ (S1, T1) = 9.176 cm⁻¹) and a reduced energy gap (ΔE = −1.97 eV) between triplet excited states (T₁) and first singlet excited states (S₁) compared to parent Ir−Cy or Cy alone, directly correlating with its enhanced ¹O₂ production. Remarkably, CHO−Ir−Cy demonstrates superior cellular internalization in 4T1 murine breast cancer cells, generating substantially elevated ¹O₂ yields compared to individual Ir−Cy/Cy under 808 nm laser irradiation. Such enhanced reactive oxygen species production translates into effective cancer cell ablation while maintaining favorable biocompatibility, significant phototoxicity and negligible dark toxicity. This molecular engineering strategy overcomes the inherent NIR absorption limitation of traditional iridium complexes and ensures their own high ¹O₂ generation ability through dye–metal synergy, establishing a paradigm for designing metal–organic photosensitizers with tailored photophysical properties for precision oncology. Full article

Background/Objectives: Targeted and non-targeted fluorescent molecular probes (FMPs) can be used intra-operatively to visualise tumour tissue. Multiple probes have been clinically approved for fluorescence-guided surgery (FGS) in adult oncology, and the translation of these technologies to paediatric neuroblastoma may provide novel strategies for optimising tumour resection whilst minimising morbidity. We aimed to identify clinically approved FMPs with potential utility for FGS in neuroblastoma. Methods: A systematic review of the literature was performed in accordance with the PRISMA guidelines (PROSPERO CRD42024541623). PubMed and Web of Science databases were searched to identify studies investigating clinically approved FGS probes and/or their targets in the context of neuroblastoma. Pre-clinical and clinical studies looking at human neuroblastoma were included. The primary outcomes were that the FGS probe was tested in patients with neuroblastoma, the probe selectively accumulated in neuroblastoma tissue, or that the target of the probe was selectively over-expressed in neuroblastoma tissue. Results: Forty-two studies were included. Four were clinical studies, and the remainder were pre-clinical studies using human neuroblastoma cell lines, human tumour tissue, or xenograft models using human neuroblastoma cells. The only FMP clinically evaluated in neuroblastoma is indocyanine green (ICG). FMP targets that have been investigated in neuroblastoma include poly-ADP ribose polymerase (PARP) (targeted by PARPiFL), endothelial growth factor receptor (EGFR) (targeted by Panitumumab-IRDye800CW, Cetuximab-IRDye800CW, Nimotuzumab-IRDye800CW and QRHKPRE-Cy5), vascular endothelial growth factor receptor (VEGFR) (targeted by Bevacizumab IRDye800CW), and proteases such as cathepsins and matrix metalloproteinases that activate the fluorescent signal of FMPs, such as LUM015 and AVB-620. Of the clinical studies included, all were found to have a high risk of bias. Conclusions: ICG is the only clinically approved fluorescent dye currently used for FGS in neuroblastoma; however, studies suggest that its ability to recognise neuroblastoma tissue is inconsistent. There are several clinically approved FMPs, or FMPs in clinical trials, that are used in adult oncology surgery that have targets expressed in neuroblastoma. Further research should validate these probes in neuroblastoma to enable their rapid translation into clinical practice. Full article

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers worldwide due to its resistance to conventional therapies that is attributed to its dense and acidic tumor microenvironment. Chemotherapy based on gemcitabine usually lacks efficacy due to poor drug penetration and the metabolic characteristics of the cells adapted to grow at a more acidic pH_e, thus presenting a more aggressive phenotype. In this context, photodynamic therapy (PDT) offers a promising alternative since it generally does not suffer from the same patterns of cross-resistance observed with chemotherapy drugs. In the present work, a novel bromine-substituted heptamethine-cyanine dye (BrCY7) was synthesized, loaded into PEG-PLGA NPs, and tested on the pancreatic ductal adenocarcinoma cell line cultured under physiological (PANC-1 CT) and acidic (PANC-1 pH selected) conditions, which promotes the selection of a more aggressive phenotype. The cytotoxicity of BrCY7-PEG-PLGA is dose-dependent, with an IC₅₀ of 2.15 µM in PANC-1 CT and 2.87 µM in PANC-1 pH selected. Notably, BrCY7-PEG-PLGA demonstrated a phototoxic effect against PANC-1 pH selected cells but not on PANC-1 CT, which makes these findings particularly relevant since PANC-1 pH selected cells are more resistant to gemcitabine as compared with PANC-1 CT cells. Full article

Global knockout (KO) of the Lrrk1 gene in mice causes severe osteopetrosis because of the failure of osteoclasts to resorb bone. The molecular mechanism of LRRK1 regulation of osteoclast function is not fully understood. Here, we performed a 2D DIGE phosphor-proteomics analysis to identify potential LRRK1 targets in osteoclasts. Splenocytes from Lrrk1 KO and wild-type (WT) mice were differentiated into osteoclasts for protein extraction. Lysates from Lrrk1 KO and WT cells were labeled with Cy3- and Cy5-dye, respectively. Labeled proteins were mixed and analyzed on the same 2D SDS PAGE for protein profiling. The same amounts of cellular protein were also labeled with Cy3-dye and ran on a 2D SDS PAGE. The gels were then stained using Pro-Q^® Diamond Phosphoprotein Gel Stain for phosphoprotein profiling. Differentially phosphorylated protein spots between the two types of cells were collected, digested with trypsin, and identified by mass spectrometry. Seventeen phosphoproteins were identified, six of which are known to be involved in endosome/lysosome sorting, vacuolar protection, and trafficking. While five of these proteins (SNX2, VPS35, VTA1, CFL1, and CTSA) were significantly hypophosphorylated, SNX3 was hyperphosphorylated in LRRK1-deficient osteoclasts. The downregulation of VSP35 and CFL1 phosphorylation in LRRK1-deficient cells was validated by Phos-tag SDS PAGE analysis. Our results indicate that LRRK1 signaling regulates osteoclast function via modulating VPS35 and CFL1 phosphorylation critical for endosome/lysosome trafficking and dynamic cytoskeleton arrangement in osteoclasts. Full article

Fe³⁺-reducing agents have been used to enhance Fenton process efficiency in degrading dyes commonly found in textile wastewater. The present work consisted of evaluating the effect of two compounds that reduce Fe³⁺, cysteine (Cys) and hydroxylamine (HA), on the oxidative decolorization of Rhodamine B dye by homogeneous Fenton processes, Fe²⁺/H₂O₂ and Fe³⁺/H₂O₂. The kinetics of the reactions were analyzed to better interpret the decolorization data. Due to the addition of the two reducing agents and the increase in temperature, there were increases in decolorization and the values of the reaction rate constants. The first-order reaction kinetic model was the one that best fit the experimental data. Comparing the two reducers, Cys was more effective. As an example, for reactions initially containing Fe²⁺ in just 20 min and at a temperature of 30 °C, the HA and Cys reducers increased the decolorization from 33% to 48% and 64%, respectively. It was possible to verify a decrease in the activation energy (Ea) due to the presence of the two reducing agents, but more significantly for reactions containing Fe³⁺. The values of Ea to Fe³⁺/H₂O₂, Fe³⁺/H₂O₂/Cys, and Fe³⁺/H₂O₂/HA were 85.7, 52.2, and 50.9 kJ∙mol⁻¹, respectively. This way, it can be inferred that the two reducers decreased the energy barrier to enhance the Fenton-based oxidation of Rhodamine B. Full article

In this study, an electrochemical approach was utilized to degrade the anionic Chlorazol Yellow (CY) dye in an aqueous solution using a lead oxide-modified stainless steel electrode (denoted as PbO₂-SS). The fabrication of this electrode involved scanning a clean stainless steel (denoted as SS) plate within a range of −1.0 V to +1.0 V against Ag/AgCl (saturated KCl) for three cycles at a scan rate of 0.1 V s⁻¹ in a 0.1 M Pb(NO₃)₂ solution. Analysis via X-ray photoelectron spectroscopy (XPS) confirmed successful fabrication, with Pb⁴⁺ being the predominant species observed in the XPS spectra. Additionally, scanning electron microscopy (SEM) imaging of the fabricated electrode revealed the deposition of PbO₂ in a flower-like, nanostructured form on the SS surface. To provide a cost-effective method for dye treatment, the PbO₂-SS anode was utilized to oxidize chloride ions (Cl⁻) into hypochlorite ions (ClO⁻), which subsequently oxidized CY molecules. Optimization of parameters such as the voltage, supporting electrolytes, and solution pH was conducted to determine the most effective degradation conditions. The method achieved a degradation efficiency of approximately 97% over a wide pH range within 20 min, indicating its applicability across various pH conditions. Consequently, this technique presents a promising approach for the treatment of industrial wastewater. Full article

Sulfonated indocyanines 3 and 5 (sCy3, sCy5) are widely used to label biomolecules. Their high molar absorption coefficients and lack of spectral overlap with biopolymers make them ideal as linker components for rapid assessment of bioconjugate stoichiometry. We recently found that the determination of the sCy3:sCy5 molar ratio in a conjugate from its optical absorption spectrum is not straightforward, as the sCy3:sCy5 absorbance ratio at the maxima tends to be larger than expected. In this work, we have investigated this phenomenon in detail by studying the spectral properties of a series of sCy3-sCy5 conjugates in which the dyes are separated by linkers of various lengths, including DNA duplexes. It was found that when sCy3 and sCy5 are located in close proximity, they consistently exhibit an “abnormal” absorbance ratio. However, when the two dyes are separated by long rigid DNA-based spacers, the absorbance ratio becomes consistent with their individual molar absorption coefficients. This phenomenon should be taken into account when assessing the molar ratio of the dyes by UV-Vis spectroscopy. Full article

Acrylamide (ACR) is a low-molecular weight, non-aromatic reagent, widely used in industry, such as in the manufacture of paper, textiles, plastics, cosmetics, and dyes. ACR is formed during the cooking of starchy food and its toxicity results mainly by conferring oxidative stress by elevating reactive oxygen species (ROS). To identify potential antidotes for ACR toxicity, we evaluated the efficacy of several thiol-based molecules known for ROS-scavenging, disulfide-reducing properties, and inhibition of oxidative stress-induced activation of the mitogen-activated protein kinases (MAPKs): the extracellular-signal-regulated-kinases (ERK1/2), p38-mitogen-activated-protein-kinases (p38^MAPK), and c-Jun-N-terminal-kinases (JNKs). We established a reproducible assay testing N-acetylcysteine (NAC), AD4/NACA, and the N-and C-blocked tri- and tetra-thioredoxin-mimetic (TXM) peptides, in PC12 cells. Our results demonstrate that these compounds exhibited high efficacy in suppressing ACR-induced MAPK activation, either prior to or subsequent to ACR exposure. The inhibition by single cysteine (Cys) residue, NAC and AD4/NACA (NAC-amide), 2 Cys peptides TXM-CB30, AcDCys-Gly-DCysNH₂, TXM-CB20, AcCys-Gly-CysNH₂, SuperDopa (SD, Ac-CysL-Levodopa-CysNH₂, TXM-CB13, AcCys-Met-Lys-CysNH₂, and a 3-Cys peptide, TXM-CB16, AcCys-γGlu-Cys-CysNH₂ was dose-dependent and potency displayed a direct correlation with the number of Cys residues. Cellular proteolysis of SD, which consists of levodopa flanked by two Cys, may suppress the manifestation of Parkinson’s disease (PD)-like symptoms mediated by chronic ACR exposure not only through lowering oxidative stress but also by replenishing cellular levels of dopamine. Overall, these results could advance the clinical application of TXM peptides as potential treatments for acute and/or chronic exposure to ACR and show promise as antidotes for preventing ACR-triggered PD-like neurotoxic symptoms. Full article

The development of biomaterials with gradient surface modification capable of spatially controlled cell adhesion and migration is of great importance for tissue engineering and regeneration. In this study, we proposed a method for the covalent modification of PLA-based materials with a cationic polypeptide (polylysine, PLys) via a thiol-ene click reaction carried out under a light gradient. With this aim, PLA-based films were fabricated and modified with 2–aminoethyl methacrylate (AEMA) as a double bond source. The latter was introduced by reacting pre-formed and activated surface carboxyl groups with the amino group of AEMA. The success of the modification was confirmed by ¹H NMR, Raman and X-ray photoelectron spectroscopy data. A further photoinduced thiol-ene click reaction in the presence of a photosensitive initiator as a radical source was further optimized using cysteine. For grafting of PLys via the thiol-ene click reaction, PLys with a terminal thiol group was synthesized by ring-opening polymerization using Cys(Acm) as an amine initiator. Deprotection of the polypeptide resulted in the formation of free thiol groups of Cys-PLys. Successful gradient grafting of Cys-PLys was evidenced by covalent staining with the fluorescent dye Cy3-NHS. In addition, PLys gradient-dependent adhesion and migration of HEK 293 cells on PLys-PLA-based surfaces was confirmed. Full article

The first example of sonodynamic therapy (SDT) with a cyanine dye–antibody conjugate is reported. The aim of this study was to evaluate the sonodynamic efficacy of a trastuzumab-guided diiodinated heptamethine cyanine-based sensitizer, 2ICy7–Ab, versus its non-iodinated counterpart, Cy7–Ab, in a human epidermal growth factor receptor 2-positive (HER2+) xenograft model. In addition, the combined sonodynamic and photodynamic (PDT) effects were investigated. A single intravenous injection of 2ICy7–Ab followed by sonication or combined sonication and photoirradiation in mice resulted in complete tumor growth suppression compared with the nontreated control and showed no detectable toxicity to off-target tissues. In contrast, Cy7–Ab provided only a moderate therapeutic effect (~1.4–1.6-fold suppression). SDT with 2ICy7–Ab resulted in a 3.5-fold reduction in tumor volume within 45 days and exhibited 13-fold greater tumor suppression than PDT alone. In addition, 2ICy7–Ab showed more durable sonostability than photostability. The sonotoxicity of the iodinated versus noniodinated counterparts is attributed to the increased generation of hydroxyl radicals, superoxide, and singlet oxygen. We observed no significant contribution of PDT to the efficacy of the combined SDT and PDT, indicating that SDT with 2ICy7–Ab is superior to PDT alone. These new findings set the stage for the application of cyanine–antibody conjugates for fluorescently monitored targeted sonodynamic treatment of cancer. Full article

Super-resolution single-molecule localization microscopy (SMLM) of presynaptic active zones (AZs) and postsynaptic densities contributed to the observation of protein nanoclusters that are involved in defining functional characteristics and in plasticity of synaptic connections. Among SMLM techniques, direct stochastic optical reconstruction microscopy (dSTORM) depends on organic fluorophores that exert high brightness and reliable photoswitching. While multicolor imaging is highly desirable, the requirements necessary for high-quality dSTORM make it challenging to identify combinations of equally performing, spectrally separated dyes. Red-excited carbocyanine dyes, e.g., Alexa Fluor 647 (AF647) or Cy5, are currently regarded as “gold standard” fluorophores for dSTORM imaging. However, a recent study introduced a set of chemically modified rhodamine dyes, including CF583R, that promise to display similar performance in dSTORM. In this study, we defined CF583R’s performance compared to AF647 and CF568 based on a nanoscopic analysis of Bruchpilot (Brp), a nanotopologically well-characterized scaffold protein at Drosophila melanogaster AZs. We demonstrate equal suitability of AF647, CF568 and CF583R for basal AZ morphometry, while in Brp subcluster analysis CF583R outperforms CF568 and is on par with AF647. Thus, the AF647/CF583R combination will be useful in future dSTORM-based analyses of AZs and other subcellularly located marker molecules and their role in physiological and pathophysiological contexts. Full article

A major challenge in improving the overall efficiency of dye-sensitized solar cells is improving the optoelectronic properties of small molecule acceptors. This work primarily investigated the effects of conjugation in nitriles incorporated as acceptor moieties into a newly designed series of D-A-A dyes. Density functional theory was employed to specifically study how single–double and single–triple conjugation in nitriles alters the optical and electronic properties of these dyes. The Cy-4c dye with a highly conjugated nitrile unit attained the smallest band gap (1.80 eV), even smaller than that of the strong cyanacrylic anchor group (2.07 eV). The dyes lacking conjugation in nitrile groups did not contribute to the LUMO, while LUMOs extended from donors to conjugated nitrile components, facilitating intramolecular charge transfer and causing a strong bind to the film surface. Density of state analysis revealed a considerable impact of conjugated nitrile on the electronic properties of dyes through an effective contribution in the LUMO, exceeding the role of the well-known strong 2,1,3-benzothiadiazole acceptor unit. The excited state properties and the absorption spectra were investigated using time-dependent density functional theory (TD-DFT). Conjugation in the nitrile unit caused the absorption band to broaden, strengthen, and shift toward the near-infrared region. The proposed dyes also showed optimum photovoltaic properties; all dyes possess high light-harvesting efficiency ($LHE$) values, specifically 96% for the dyes Cy-3b and Cy-4c, which had the most conjugated nitrile moieties. The dyes with higher degrees of conjugation had longer excitation lifetime values, which promote charge transfer by causing steady charge recombination at the interface. These findings may provide new insights into the structure of conjugated nitriles and their function as acceptor moieties in DSSCS, which may lead to the development of extremely effective photosensitizers for solar cells. Full article

Zeolitic imidazolate framework-8 (ZIF-8) nanoparticles (NPs) are gaining traction in tumor theranostics for their effectiveness in encapsulating both imaging agents and therapeutic drugs. While typically, similar hydrophilic molecules are encapsulated in either pure aqueous or organic environments, few studies have explored co-encapsulation of chemotherapeutic drugs and imaging agents with varying hydrophilicity and, consequently, constructed multifunctional ZIF-8 composite NPs for acid-responsive, near-infrared fluorescence imaging/chemotherapy combined tumor theranostics. Here, we present a one-pot method for the synthesis of uniform Cy5.5&DOX@ZIF-8 nanoparticles in mixed solvents, efficiently achieving simultaneous encapsulation of hydrophilic doxorubicin (DOX) and hydrophobic Cyanine-5.5 (Cy5.5). Surface decoration with dextran (Dex) enhanced colloidal stability and biocompatibility. The method significantly facilitated co-loading of Cy5.5 dyes and DOX drugs, endowing the composite NPs with notable fluorescent imaging capabilities and pH-responsive chemotherapy capacities. In vivo near-infrared fluorescence (NIRF) imaging in A549 tumor-bearing mice demonstrated significant accumulation of Cy5.5 at tumor sites due to enhanced permeability and retention (EPR) effects, with fluorescence intensities approximately 48-fold higher than free Cy5.5. Enhanced therapeutic efficiency was observed in composite NPs compared to free DOX, validating tumor-targeted capability. These findings suggest ZIF-8-based nanomedicines as promising platforms for multifunctional tumor theranostics. Full article

Colorectal tumorigenesis involves the development of aberrant crypt foci (ACF) or preneoplastic lesions, representing the earliest morphological lesion visible in colon cancer. The purpose of this study was to determine changes in protein expression in carcinogen-induced ACF as they mature and transform into adenomas. Protein expression profiles of azoxymethane (AOM)-induced F344 rat colon ACF and adenomas were compared at four time points, 4 (control), 8, 16, and 24 weeks post AOM administration (n = 9/group), with time points correlating with induction and transformation events. At each time point, micro-dissected ACF and/or adenoma tissues were analyzed across multiple quantitative two-dimensional (2D-DIGE) gels using a Cy-dye labeling technique and a pooled internal standard to quantify expression changes with statistical confidence. Western blot and subsequent network pathway mapping were used to confirm and elucidate differentially expressed (p ≤ 0.05) proteins, including changes in vinculin (Vcl; p = 0.007), scinderin (Scin; p = 0.02), and profilin (Pfn1; p = 0.01), By determining protein expression changes in ACF as they mature and transform into adenomas, a “baseline” of altered regulatory proteins associated with adenocarcinoma development in this model has been elucidated. These data will enable future studies aimed at biomarker identification and understanding the molecular biology of intestinal tumorigenesis and adenocarcinoma maturation under varying intestinal conditions. Full article