Search Results (132)

Background: While intravenous administration of nanoparticles (NPs) is effective for targeting the lungs and liver, directing them to other organs and tissues remains challenging. Methods: Here, we report alternative administration routes that improve organ-specific accumulation of poly (lactic-co-glycolic acid) (PLGA) NPs (100 nm, negatively charged) loaded with the near-infrared dye Cyanine 7 (Cy7). NP cytotoxicity was evaluated in HEK293, mMSCs, C2C12, L929, and RAW264.7 cells. Hemocompatibility was assessed using WBCs and RBCs. NPs were administered via the tail vein, carotid, renal, and femoral arteries in BALB/c mice. Administration safety was evaluated by laser speckle contrast imaging and histological analysis. NP biodistribution and accumulation were assessed using in vivo and ex vivo fluorescence tomography and confocal microscopy of cryosections. Results: PLGA-Cy7 NPs demonstrate low cytotoxicity even at high doses and exhibit good hemocompatibility. Administration of NPs through the mouse carotid, renal, and femoral arteries significantly increases accumulation in the target ipsilateral brain hemisphere (31.7-fold) and salivary glands (28.3-fold), kidney (13.7-fold), and hind paw (3.6-fold), respectively, compared to intravenous administration. Injection of NPs through arteries supplying the target organs and tissues does not result in significant changes in blood flow, morphological alterations, or irreversible embolization of vessels, provided the procedure is performed correctly and the optimal dosage is used. Conclusions: These results highlight the potential of intra-arterial delivery of NPs for organ-specific drug targeting, underscoring the synergistic impact of advances in materials science, minimally invasive endovascular surgery, and nanomedicine. Full article

We report that poly(vinyl alcohol) (PVA) matrices facilitate nanosecond photoinduced electron transfer (PET) from cyanine dyes to CaTiO₃ nanocrystals, yielding distinct radical cation excited-state absorption (ESA) with well-resolved D₀→D₁ and D₁→D₂ transitions. In dye-only PVA films, UV hole-burning produces a minority radical cation population, evidenced by a blue-shifted ESA band mirroring the D₁→D₂ manifold. Kinetic analysis of the ternary PVA–dye–CaTiO₃ system reveals a shared nanosecond decay (τ₂ ≈ 4–7 ns) for both oxide ESA and radical cation transitions, confirming coupled charge-separated states. These results establish orbital-level insight into how polymer matrices regulate PET and radical stabilization, providing a mechanistic foundation for programmable hybrid photonic devices. Full article

Using an environmentally friendly approach, we successfully synthesized an asymmetric monomethine cyanine dye, 7-chloro-1-ethyl-4-((3-ethylbenzo[d]thiazol-2(3H)-ylidene)methyl) quinolin-1-ium iodide, named CHLoris (CHL), via a modified Knoevenagel-type condensation. The reaction was carried out mechanochemically in an ethanol–water medium using 1-ethyl-2-methylbenzothiazolium iodide and 4,7-dichloro-1-ethylquinolin-1-ium iodide in the presence of sodium carbonate as a base and catalytic amounts of Hünig’s base. The UV/VIS absorption spectra of CHL in both the buffer solution and ethanol revealed the formation of aggregates in aqueous media. Density Functional Theory (DFT) and Time-Dependent DFT (TDDFT) calculations were employed to support the experimental findings further and provide insights into the self-association behavior of CHL in an aqueous solution. The photophysical properties of the dye were examined in the presence of DNA and RNA, and its performance was compared to that of the commercial dye Thiazole Orange (TO) under identical conditions. The results show that CHL is more sensitive towards RNA. Full article

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

IR-780 is a heptamethine cyanine dye that exhibits strong absorbance in the near-infrared region. Herein, we report IR-780 dye as a dual sensor for chromogenic cyanide detection and azide’s fluorogenic sensing in acetonitrile. Cyanide and hydroxide cause instant, dramatic color changes in the dye solution from green to yellow and dramatic spectral changes in the UV-Vis spectrum. The interaction of cyanide and hydroxide with the dye caused a dramatic decrease in the intensity of the strong absorption band at 780 nm and a concomitant band appearance at 435 nm. Other monovalent ions, including fluoride, chloride, bromide, iodide, dihydrogen phosphate, thiocyanate, acetate, and dihydrogen arsenate, caused no significant color or spectral changes. UV-Vis studies showed that the IR-780 dye is sensitive and selective to both ions. The detection limits for cyanide and azide are 0.39 µM and 0.50 µM, respectively. Interestingly, the IR-780 dye exhibited strong fluorescence at 535nm upon interaction with azide, while its initial emission at 809 nm was quenched. Both UV-Vis and fluorescence spectroscopy accomplished the detection of cyanide and azide using IR-780. Furthermore, the sensor’s effectiveness in fluorescence imaging of intracellular CN⁻ ions is demonstrated in live HeLa cells. 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

Two new asymmetric monomethine cyanine dyes, featuring dimethoxy quinolinium or methyl quinolinium end groups and benzothiazole or methyl benzothiazole end groups were synthesized. The chemical structures of the two dyes—(E)-6,7-dimethoxy-1-methyl-4-((3-methylbenzo[d]thiazol-2(3H)-ylidene)methyl)quinolin-1-ium iodide (3a) and (E)-4-((3,5-dimethylbenzo[d]thiazol-2(3H)-ylidene)methyl)-1,2-dimethylquinolin-1-ium iodide (3b)—were confirmed through NMR spectroscopy and MALDI-TOF mass spectrometry. A new methodology was developed to study monocationic dyes in the absence of a matrix and cationizing compounds in MALDI-TOF mass experiments. The newly synthesized dyes contain hydrophobic functional groups attached to the chromophore, enhancing their affinity for the hydrophobic regions of nucleic acids within the biological matrix. The dyes’ photophysical properties were investigated in aqueous solutions and DMSO, as well as in the presence of nucleic acids. The dyes exhibit notable aggregachromism in both pure aqueous and buffered solutions. The observed aggregation phenomena were further elucidated using computational methods. Fluorescence titration experiments revealed that upon contact with nucleic acids, the dyes exhibit bioaggregachromism–aggregachromism on the surfaces of the respective biomolecular matrix (RNA or DNA). This bioaggregachromism was further confirmed by CD spectroscopy. Given the pronounced aggregachromism detected, we conclude that the dyes investigated in this study are highly suitable for use as fluorogenic probes in biomolecular recognition techniques. The unique absorption and fluorescence spectra of these dyes make them promising fluorogenic markers for various bioanalytical methods related to biomolecular recognition. Full article

Perovskite solar cell (PSC) technology holds great promise with continuously improving power conversion efficiency; however, the use of metal electrodes hinders its commercialization and the development of tandem designs. Although single-walled carbon nanotubes (SWCNTs), as one-dimensional materials, have the potential to replace metal electrodes in PSCs, their poor conductivity still limits their application. In this study, the near-infrared (NIR)-absorbing anionic heptamethine cyanine dye-doped SWCNTs functioned in a dual role as an efficient charge-selective layer and electrode in PSCs. Benefiting from the improvement in conductivities and matched energy level of doped-SWCNT, the dual-role SWCNT electrodes applied to PSCs achieved a better performance than the undoped PSCs with a higher short circuit current (J_SC) and fill factor (FF). Full article

The development of fluorescence-based methods for bioassays and medical diagnostics requires the design and synthesis of specific markers to target biological microobjects. However, biomolecular recognition in real cellular systems is not always as selective as desired. A new concept for creating fluorescent biomolecular probes, utilizing a fluorogenic dye and biodegradable, biocompatible nanomaterials, is demonstrated. The synthesis of a new dicationic asymmetric monomethine cyanine dye with benzo[d]thiazolium-N-propionamide and chloroquinoline end groups is presented. The photophysical properties of the newly synthesized dye were examined through the combined application of spectroscopic and theoretical methods. The applicability of the dye as a fluorogenic nucleic acid probe was proven by UV-VIS spectroscopy and fluorescence titration. The dye–nucleic acid interaction mode was investigated by UV-Vis and CD spectroscopy. The newly synthesized dicationic dye, like other similar fluorogenic structures, limited permeability, which restricts its use as a probe for RNA and DNA. To enhance cellular delivery, we utilized a patented technology that employs solid, insoluble lipid nanoparticles. This method ensures the complete introduction of the dye into cells while minimizing activity outside the cells. In our study involving two human cell lines, we observed improved penetration through the cell membrane and distinctive selectivity in visualizing nucleic acids within the cytoplasm and nucleus. Full article

Background: A phthalimide-functionalized heptamethine cyanine dye, named Ph790H, is used for targeted photothermal cancer therapy in vivo. We highlight that the chemical structure of Ph790H is newly designed and synthesized for the first time in this study. Objectives: By possessing a rigid chloro-cyclohexenyl ring in the heptamethine cyanine backbone, the bifunctional near-infrared (NIR) fluorescent dye Ph790H can be preferentially accumulated in tumor without the need for additional targeting ligands, which is defined as the “structure-inherent tumor targeting” concept. Methods: The phototherapeutic effect of Ph790H is evaluated in HT-29 human colorectal cancer xenografts to be used as a cancer-targeting photothermal agent. Results: The results reveal that the Ph790H shows enhanced tumor accumulation in HT-29 xenografts 48 h post-injection with a high tumor-to-background ratio. After determination of the optimal timing for photothermal therapy (PTT), the HT-29 tumor-possessing nude mice pretreated with Ph790H are subsequently irradiated with an 808 nm NIR laser for 5 min. The tumor-targeted PTT treatment can efficiently inhibit the tumor development compared with that of control groups. Moreover, no tumor regrowth or Ph790H-induced mortality occurs after the treatment of Ph790H and laser irradiation during a period of monitoring. Conclusions: Therefore, this work demonstrates that the bifunctional phototheranostic agent Ph790H can be utilized for targeted cancer imaging and fluorescence-guided phototherapy simultaneously. Full article

Photodynamic therapy (PDT) is a minimally invasive treatment that elicits tumor apoptosis using laser light exclusively applied to the tumor site. IR-783, a heptamethine cyanine (HMC) dye, impedes the proliferation of breast cancer cells, even without light. Although studies have investigated the efficacy of IR-783 in cell and animal studies, its efficacy in clinical settings remains unknown. Therefore, we aimed to determine the efficacy of PDT using IR-783 liposomes. An HMC dye, excited by long-wavelength infrared light and with high tissue permeability, was used for PDT after liposomization to enhance tumor tissue accumulation. PDT was performed using IR-783 in two patients with either tongue or breast cancer, one each. IR-783 liposomes inhibited cell proliferation in tongue cancer cells even when not excited by light. Tumor size was markedly reduced in both cases, with no significant adverse events. Furthermore, the patient with tongue cancer exhibited improved respiratory, swallowing, and speech functions, which were attributed not only to the shrinkage of the tumor but also to the improvement in airway narrowing. In conclusion, PDT using IR-783 liposomes effectively reduces tumor size in tongue and breast cancers. Full article

Cancer treatment remains a significant challenge, with chemotherapy still being one of the most common therapeutic approaches. Based on our initial studies of symmetric monomethine cyanine dyes, which showed potential against colorectal cancer, this study explored several asymmetric cyanines, aiming to develop more potent and selective antitumor agents, particularly against colorectal cancer. In pursuit of this goal, we have designed, synthesized, and structurally characterized twelve new cyanine dyes. Their antiproliferative effects were then investigated in vitro against both tumor and non-tumor cell lines. Notably, the two most promising dyes in terms of potency and selectivity against Caco-2 colorectal cancer cells were derived from the combination of N-methylbenzoxazole and N-methylquinoline (dye 5), as well as N-ethylbenzothiazole and N-ethyl-6-nitrobenzothiazole (dye 10). The potential mechanisms behind their antiproliferative action were also explored, revealing that both dyes penetrate cells and localize within the cytoplasm and nucleus. Furthermore, dye 5 was found to slightly induce apoptosis without causing significant cell cycle arrest, in contrast to dye 10, which increased the number of cells in the G0/G1 phase. Interestingly, both dyes exhibited marked topoisomerase II inhibitory effects, particularly cyanine 5, which may further explain their antiproliferative activity. Additionally, drug-likeness properties were predicted for both dyes. Overall, cyanine 5 emerged as the most promising candidate for further investigation as a potential treatment for colorectal cancer. Full article

The purpose of this research is to design nanocomposite materials for biomedical applications. New conjugates of PEG derivatives of RGD peptides and magnetic nanoparticles, based on Fe₃O₄ (MNPs) with silica coating covalently labelled with fluorescent dye Cyanine5, were obtained. It was shown that a higher loading level of RGD peptides occurred in the case of MNPs with SiO₂/aminopropylsilane coating, synthesised using N-(phosphonomethyl)iminodiacetic acid (PMIDA) as a surfactant. To confirm the structure and chemical purity of the new RGD-PEG conjugate, a number of methods were used, including ¹H NMR, HRMS, and RP-HPLC. The characterisation of MNPs was carried out using the following physical methods: TEM, FTIR, EDX, CHN analysis, DLS, fluorescence spectrometry, vibration magnetometry, and relaxometry. Samples obtained from PMIDA-stabilised MNPs contained a greater amount of the peptide and possessed better hydrodynamic characteristics than samples obtained from non-stabilised MNPs. A comparative study of the MNP cytotoxicity was carried out towards 4T1 and MDA-MB231 cell lines (MTT test), and the possibility of cell labelling was assessed. The cellular uptake was more efficient for nanoconjugates obtained without PMIDA. The data obtained can be used for the design of materials for cell labelling and visualisation. Full article