Biological Dyes Research Articles

Effect of Calcination Temperature on the Structure of Chitosan-Modified Montmorillonites and their Adsorption of Aflatoxin B1

AbstractChitosan (CTS) modified montmorillonite (Mnt) composites (CTS-Mnt), which have been widely reported for the adsorption of heavy-metal ions and biological dyes, have not been applied to the field of mycotoxin adsorption. The current study was focused on the preparation of CTS-Mnt by calcination as a mycotoxin adsorbent for the efficient removal of aflatoxin B1 (AFB1). The CTS-Mnt samples obtained were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and nitrogen adsorption/desorption analysis. The CTS-Mnt samples prepared at various calcination temperatures exhibited varying structural configurations, surface hydrophobicities, and texture properties. The results revealed that stable CTS-Mnt speciments, obtained at <350°C, displayed superior adsorption capacity for AFB1 from a simulated gastrointestinal tract, increasing from 0.51 mg/g of raw Mnt to 4.97 mg/g. With increased calcination temperature, the effect of pH on the adsorption process of AFB1 becomes negligible. This study demonstrates that the novel CTS-Mnt has tremendous potential as an AFB1 adsorbent.

Cellular Uptake and Intracellular Trafficking of Poly( N-(2-Hydroxypropyl) Methacrylamide).

Cellular uptake and intracellular trafficking of polymer conjugates or polymer nanoparticles is typically monitored using fluorescence-based techniques such as confocal microscopy. While these methods have provided a wealth of insight into the internalization and trafficking of polymers and polymer nanoparticles, they require fluorescent labeling of the polymer or polymer nanoparticle. Because in biological media fluorescent dyes may degrade, be cleaved from the polymer or particle, or even change uptake and trafficking pathways, there is an interest in fluorescent label-free methods to study the interactions between cells and polymer nanomedicines. This article presents a first proof-of-concept that demonstrates the feasibility of NanoSIMS to monitor the intracellular localization of polymer conjugates. For the experiments reported here, poly( N-(2-hydroxypropyl) methacrylamide)) (PHPMA) was selected as a prototypical polymer-drug conjugate. This PHPMA polymer contained a 19F-label at the α-terminus, which was introduced in order to allow NanoSIMS analysis. Prior to the NanoSIMS experiments, the uptake and intracellular trafficking of the polymer was established using confocal microscopy and flow cytometry. These experiments not only provided detailed insight into the kinetics of these processes but were also important to select time points for the NanoSIMS analysis. For the NanoSIMS experiments, HeLa cells were investigated that had been exposed to the PHPMA polymer for a period of 4 or 15 h, which was known to lead to predominant lysosomal accumulation of the polymer. NanoSIMS analysis of resin-embedded and microtomed samples of the cells revealed a punctuated fluorine signal, which was found to colocalize with the sulfur signal that was attributed to the lysosomal compartments. The localization of the polymer in the endolysosomal compartments was confirmed by TEM analysis on the same cell samples. The results of this study illustrate the potential of NanoSIMS to study the uptake and intracellular trafficking of polymer nanomedicines.

Applicability of biological dye tracer in strip biosensor for ultrasensitive detection of pathogenic bacteria

Here, a facile, label-free and sensitive lateral flow strip (LFS) biosensor for foodborne pathogens was established relying on the innovative introduction of Gram staining and the direct immunoreaction. Target bacteria can be directly marked with crystal violet (CV) by one-step staining which is superior to traditional signal marking techniques in LFS assay, and the method’s selectivity can be guaranteed by high-specificity monoclonal antibody. With Salmonella Enteritidis (S. Enteritidis) as a model target, this protocol can selectively detect 80 CFU mL−1S. Enteritidis within 11 min in the optimized conditions. Moreover, with Listeria monocytogenes as another model target, the biosensor shows a high universality for detections of both gram-negative and gram-positive bacteria. The unexpected applicability of biological dye tracer in strip biosensor reveals that the biological dye can be a potential tool serving as a universal signal tracer for pathogenic microorganisms in food safety monitoring and early clinical diagnosis.

Electrocomposite Developed with Chitosan and Ionic Liquids Using Screen-Printed Carbon Electrodes Useful to Detect Rutin in Tropical Fruits.

This work reports the development of a composite of the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BP4) and chitosan (CS) described in previous reports through a new method using cyclic voltammetry with 10 cycles at a scan rate of 50.0 mV s−1. This method is different from usual methods such as casting, deposition, and constant potential, and it allows the development of an electroactive surface toward the oxidation of rutin by stripping voltammetry applied to the detection in tropical fruits such as orange, lemon, and agraz (Vaccinium meridionale Swartz), with results similar to those reported in previous studies. In addition, the surface was characterized by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and Raman spectroscopy. The limit of detection was 0.07 µmol L−1 and the relative standard deviation (RSD) of 10 measurements using the same modified electrode was 0.86%. Moreover, the stability of the sensor was studied for six days using the same modified electrode, where the variation of the signal using a known concentration of rutin (RT) was found to be less than 5.0%. The method was validated using a urine chemistry control spiked with known amounts of RT and possible interference was studied using ten substances including organic and biological compounds, metal ions, and dyes. The results obtained in this study demonstrated that this electrodeveloped composite was sensitive, selective, and stable.

Anthocyanins Immobilization on Titania Nanotubes and Its Characterization through Cyclic Voltammetry: Preliminary Results

Titania nanotubes grown on titanium through the electrochemical anodization are an attractive nanostructure due to their applicability in areas such as photocatalysis, dye-sensitized solar cells, sensors, etc. Nanotubes functionalization with nanoparticles or different molecules is becoming a common practice that can either aid or enhance their performance in a variety of applications. Dyes have been used in solar cells and photocatalysis to sensitize the semiconductor and, biological dyes such as anthocyanins have been tested for these purposes due to their low cost and environmentally friendly nature (1). In this work, titania nanotubes electrodes were functionalized with anthocyanins in order to test their performance as sensitizers for photoelectrocatalytic purposes. Anthocyanins alcoholic extract has been obtained from hibiscus flower (Hibiscus sabdariffa L) and immobilized on titania nanotubes (TiO2 Nts ) grown from 2 cm2 titania plates (TiO2 Nts/Ti) by anodization at 30 V in a glycerol:water (2:1) solution containing sodium fluoride and sodium sulfate. Anthocyanins immobilization was achieved through immersion for 48 h of the TiO2/Ti plates in the alcoholic extract at O°C. The antioxidant activity from both, the as-extracted and the immobilized, anthocyanins was tested by the ABTS assay. This essay showed that a 1:100 dilution from the extract had an antioxidant activity of 550 μTrolox while the immobilized anthocyanins had a higher antioxidant activity of 699 μTrolox (2). Electrochemical techniques have gained importance in the study of nanostructured materials especially in the field of surface characterization. Within this work, cyclic voltammetry was used to determine surface characteristics from the bare TiO2 nanotubes and from the nanotubes functionalized with anthocyanins. Through cyclic voltammetry in a pH 7.00 1.0 M buffer phosphate it was possible to confirm TiO2 Nts functionalization with anthocyanins as it can be seen from the change in the voltamperogram´s shape for the bare nanotubes and after functionalization with anthocyanins (Figure 1). Cyclic voltammetry on anthocyanins-TiO2-Nts electrode showed two oxidation peaks at -0.390 V and -0.096 V (vs. mercurous sulfate electrode) which can be attributed to the delphinidin-3-O-glucoside (3), the main anthocyanin found in Hibiscus sabdariffa L (4). Complementary results concerning these electrodes performance will be presented at the conference. References Zyoud, A., Zaatar, N., Saadeddin, I., Helal, M.H., Campet, G., Hakim, M., Park, D., Hilal, H. 2011. Alternative natural dyes in water purification: Anthocyanin as TiO2-sensitizer in methyl orange photo-degradation. Solid State Sciences, 13: 1268-1275.Pérez‐Jiménez, J., & Saura‐Calixto, F. (2008). Anti‐oxidant capacity of dietary polyphenols determined by ABTS assay: a kinetic expression of the results. International journal of food science & technology, 43(1), 185-191. Janeiro, P., Oliveira-Brett, A. M. 2007. Redox behavior of anthocyanins present in Vitis vinifera L. Electroanalysis. 19(17): 1779-1786.Galicia-Flores, L. A., Salinas-Moreno, Y., Espinoza- García, B. M. y Sánchez-Feria, C. 2008. Caracterización fisicoquímica y actividad antioxidante de extractos de jamaica (Hibiscus sabdariffa L) nacional e importada. Revista Chapingo Serie Horticultura. 14(2):121-129. Figure 1

Production of Ligninolytic Enzymes from Penicillium Sp. and Its Efficiency to Decolourise Textile Dyes

Background:The present study discussed the bio decolourization of synthetic textile dyes using extracellular crude laccase from an Ascomycetes fungusPenicilliumsp. Laccase based decolourization is found to be potentially advantageous to bioremediation technologies.Methods:In this study, the production of laccase was observed for 7 days of incubation under shaking conditions. Maximum laccase production was secreted by fungal strain on the 6thday of incubation under submerged fermentation. Incubation of fungal mycelium and culture filtrate as crude enzyme obtained fromPenicilliumsp. with textile dyes - Indigo, Reactive black-5, Acid blue -1 and Vat brown -5 on solid PDA medium and liquid PDA broth showed effective biological dye decolourisation.Result:Solid state dye decolourisation had shown 45%, 25%, 50% and 72% colour removal of dyes - Indigo, Reactive black-5, Acid blue -1 and Vat brown -5 whereas maximum decolourization of same dyes of 45%, 20%, 48%, and 75% was obtained in liquid state with crude enzyme within 3h.Conclusion:The results had shown the potential dye decolourisation capacity of thePenicilliumsp. extracellular crude laccase and pave a way to apply this strain on an industrial scale.

Evans Blue Dye: A Revisit of Its Applications in Biomedicine.

Evans blue (EB) dye has owned a long history as a biological dye and diagnostic agent since its first staining application by Herbert McLean Evans in 1914. Due to its high water solubility and slow excretion, as well as its tight binding to serum albumin, EB has been widely used in biomedicine, including its use in estimating blood volume and vascular permeability, detecting lymph nodes, and localizing the tumor lesions. Recently, a series of EB derivatives have been labeled with PET isotopes and can be used as theranostics with a broad potential due to their improved half-life in the blood and reduced release. Some of EB derivatives have even been used in translational applications in clinics. In addition, a novel necrosis-avid feature of EB has recently been reported in some preclinical animal studies. Given all these interesting and important advances in EB study, a comprehensive revisiting of EB has been made in its biomedical applications in the review.

Aerobic Biodegradation Characteristic of Different Water-Soluble Azo Dyes.

This study investigated the biodegradation performance and characteristics of Sudan I and Acid Orange 7 (AO7) to improve the biological dye removal efficiency in wastewater and optimize the treatment process. The dyes with different water-solubility and similar molecular structure were biologically treated under aerobic condition in parallel continuous-flow mixed stirred reactors. The biophase analysis using microscopic examination suggested that the removal process of the two azo dyes is different. Removal of Sudan I was through biosorption, since it easily assembled and adsorbed on the surface of zoogloea due to its insolubility, while AO7 was biodegraded incompletely and bioconverted, the AO7 molecule was decomposed to benzene series and inorganic ions, since it could reach the interior area of zoogloea due to the low oxidation-reduction potential conditions and corresponding anaerobic microorganisms. The transformation of NH3-N, SO42− together with the presence of tryptophan-like components confirm that AO7 can be decomposed to non-toxic products in an aerobic bioreactor. This study provides a theoretical basis for the use of biosorption or biodegradation mechanisms for the treatment of different azo dyes in wastewater.

Rapid Synthesis of Pure and Doped ZnS Quantum Dots for Photocatalytic Degradation of Biological Dye Pollutants

Rapid Synthesis of Pure and Doped ZnS Quantum Dots for Photocatalytic Degradation of Biological Dye Pollutants

Laurdan and Di-4-ANEPPDHQ probe different properties of the membrane

Lipid packing is a crucial feature of cellular membranes. Quantitative analysis of membrane lipid packing can be achieved using polarity sensitive probes whose emission spectrum depends on the lipid packing. However, detailed insights into the exact mechanisms that cause the changes in the spectra are necessary to interpret experimental fluorescence emission data correctly. Here, we analysed frequently used polarity sensitive probes, Laurdan and di-4-ANEPPDHQ, to test whether the underlying physical mechanisms of their spectral changes are the same and, thus, whether they report on the same physico-chemical properties of the cell membrane. Steady-state spectra as well as time-resolved emission spectra of the probes in solvents and model membranes revealed that they probe different properties of the lipid membrane. Our findings are important for the application of these dyes in cell biology.

Biological textile dye removal mechanism of direct blue 15 (DB15) by anoxic/oxic-SBR system

Biological textile dye removal mechanism of direct blue 15 (DB15) by anoxic/oxic-SBR system

Enhancement of coherent optical signal from tissue phantom by gold nanorods in near-infrared range

To investigate gold nanorods as a contrast agent to enhance signal to noise ratio(SNR) and contrast of spectroscopic optical coherence tomography imaging of the turbid tissue sample, suspensions of silica coated plasmon resonant gold nanorods (GNRs) and biological dye(India ink) were used in gelatin-based phantoms. With the same background scattering condition caused by TiO2 microspheres, samples of single and double layers were fabricated and test. By comparison of the signal to noise ratio and slop of the depth-dependent signal, some different properties appeared between nanoparticle and biological dye. Unlike simple absorption of ink, GNRs have narrow absorption peak and scattering property which will enhance backscattering in the area of aggregation. A 10dB enhancement of SNR has been observed in double-layer sample. GNRs tend to gather around interface of two layers and generate the photon-thermal effect that also enhance the signal intensity.

Контрастирующие вещества для хромовитрэктомии

One of the most difficult tasks for surgeons and one of the main components of success of surgical treatment is a safe removal of transparent vitreous body, and structures of the vitreoretinal interface (VI): translucent, internal limiting membrane (ILM), epiretinal membranes during subtotal vitrectomy. Biological and synthetic dyes are used for intra-operative visualization of vitreous body, highlighting its native structures and pathologically changed sites. The peak of development of the intravitreal injection of dyes was the appearance of a new surgical approach – chromovitrectomy, in 2000. Its essence consists in the injection of intraoperative dyes for contrast enhancement of structures of the posterior segment of the eye. This technique provides a better intra-operative visualization of vitreous body and the VI, a more thorough removal of the cortical vitreous layers, simplifies the peeling of ILM and epiretinal membranes, reducing the risk of iatrogenic damage to the retina. However, contrast agents have a number of side effects, and as a result, many discrepancies regarding the potential toxicity and safety of use of these substances remains. Despite the large accumulated in this field experience, a number of issues associated with the properties of intravitreal dyes, their interaction with the surrounding anatomical structures, side effects of these substances remain unresolved until now. It should provide adequate color difference between the stained ILM/ERM and the normal retina. Other favorable characteristics are: rapid elimination from vitreous cavity, photochemical stability, solubility in balanced salt solution, absence of toxicity and an adequate light absorption profile. Also, numerous dyes have been applied in experimental settings with promising or devastating results. This article highlights the major clinical and experimental results of currently used novel vital dyes. The aim of this article is to present the current state-of-theart in regard to the application of vital dyes during vitreoretinal surgery to overview the current literature regarding the properties of dyes, techniques of application, indications, and complications in chromovitrectomy, the surgical recommendations to minimize the risk of toxic effects.

Investigation of enhanced biological dye removal of colored wastewater in a lab-scale biological activated carbon process

In this study, the influence of bacteria and activated carbon adjacent was investigated on treatment and decolorization of synthetic wastewater in a Biological Activated Carbon process. Pseudomonas putida was selected as a bacterial strain capable of degrading aromatic compounds and Acid Blue 92 was used as model azo dye. The optimum conditions for environmental factors affecting decolorization of azo dye was achieved from series of batch experiments. At 25 °C and pH7 the highest efficiency was obtained. At concentration of 20 mg L−1 in batch process, more than 90 % of Acid Blue 92 was reduced in color within just 3 h under optimum conditions. Dual-beam UV–Visible spectrometry and plate assay confirmed biodegradation of the dye by P.putida. The optimum values were then used for continues process. It was found that flow rate and thereby retention time has a critical role in biofilter efficiency. A lab-scale submerged downflow GAC column was sustained by bacterial strain to form the biofilter. About 70 % decolorization was obtained in continuous biological activated carbon process within 2 h with 60 mL h−1 flow rate while adsorption of dye reached the equilibrium and no further dye removal observed. Our results suggest the potential use of P. putida in azo dye decolorization. The combination of activated carbon adsorption and biodegradation by bacterial strains capable of degrading xenobiotic proved to be a promising technique for treatment of dye-contaminated wastewater.

Effect of ZnO nanoparticles on biodegradation and biotransformation of co-substrate and sulphonated azo dye in anaerobic biological sulfate reduction processes

In recent years, rapid increase of nanomaterial applications exposed the wastewater treatment plants to the new challenges. Potential effects of nanoparticles (NPs) on biological sulfate reduction and dyes biodegradation in biological wastewater treatment systems still need to be investigated. This study explored the effects of zinc oxide nanoparticles (ZnO-NPs) on sulfate reducing bacteria (SRB) culture treating textile wastewater. Batch reactor studies were performed by exposing the mixed SRB culture to different initial ZnO-NPs concentrations. Increasing ZnO-NPs concentrations from 0 to 200 mg l−1 inhibited the reactor performance by decreasing COD, sulfate, and color removal efficiencies from 54.4%, 78.1%, and 95.4% to 30.1%. 44.0%, and 80.0%, respectively. Moreover, dye biotransformation was also adversely affected in the presence of ZnO-NPs as revealed by the increase in total aromatic amines formation and the decrease in activities of various oxido-reductive enzymes such as veratryl alcohol oxidase, lignin peroxidase, and azo reductase.

Investigation on the uptake and release ability of β-cyclodextrin functionalized Fe3O4 magnetic nanoparticles by methylene blue

β-cyclodextrin functionalized magnetic nanoparticles (β-CD-MNPs) having a core–shell structure were fabricated with a layer-by-layer method by combining 3-aminopropyl triethoxysilane coated magnetic Fe3O4 nanoparticles (AP-MNPs) with 6-O-toluenesulfonyl-β-cyclodextrin (6-TsO-β-CD) at 70 °C. The characterization by transmission electron microscopy revealed β-CD-MNPs having an average diameter of 12 ± 2 nm and an average hydrodynamic diameter of 56.8 nm in aqueous solution by dynamic light scattering. The β-CD grafting was confirmed by Fourier-Transformed Infrared spectroscopy, and the amount of β-CD grafted on MNPs was determined as 60 mg/g by thermogravimetric analysis. The uptake and release ability of β-CD-MNPs was investigated using methylene blue (MB) as a biological staining dye by spectrophotometric method. The results showed that the uptake and release were greatly influenced by the pH value of dye solution, with a maximum loading capacity of 78.4 mg/g under pH = 8 at 25 °C, and the release was easily achieved at 73% within the first hour at physiological condition. The adsorption isotherms were examined by Langmuir and Freundlich models, and the satisfactory fitting to the Langmuir model suggested the adsorption on β-CD-MNPs as a mono-layer coverage.

N-Doped Ordered Mesoporous Carbon Originated from a Green Biological Dye for Electrochemical Sensing and High-Pressure CO2 Storage.

Herein, a series of nitrogen-doped ordered mesoporous carbons (NOMCs) with tunable porous structure were synthesized via a hard-template method with a green biological dye as precursor, under various carbonization temperatures (700-1100 °C). Compared with the ordered mesoporous silica-modified and unmodified electrodes, the use of electrodes coated by NOMCs (NOMC-700-NOMC-1100) resulted in enhanced signals and well-resolved oxidation peaks in electrocatalytic sensing of catechol and hydroquinone isomers, attributable to NOMCs' open porous structures and increased edge-plane defect sites on the N-doped carbon skeleton. Electrochemical sensors using NOMC-1000-modified electrode were fabricated and proved feasible in tap water sample analyses. The NOMCs were also used as sorbents for high-pressure CO2 storage. The NOMC with the highest N content exhibits the best CO2 absorption capacities of 800.8 and 387.6 mg/g at 273 and 298 K (30 bar), respectively, which is better than those of other NOMC materials and some recently reported CO2 sorbents with well-ordered 3D porous structures. Moreover, this NOMC shows higher affinity for CO2 than for N2, a benefit of its higher nitrogen content in the porous carbon framework.

“Salivary gland cellular architecture in the Asian malaria vector mosquito Anopheles stephensi”

BackgroundAnopheles mosquitoes are vectors for malaria, a disease with continued grave outcomes for human health. Transmission of malaria from mosquitoes to humans occurs by parasite passage through the salivary glands (SGs). Previous studies of mosquito SG architecture have been limited in scope and detail.MethodsWe developed a simple, optimized protocol for fluorescence staining using dyes and/or antibodies to interrogate cellular architecture in Anopheles stephensi adult SGs. We used common biological dyes, antibodies to well-conserved structural and organellar markers, and antibodies against Anopheles salivary proteins to visualize many individual SGs at high resolution by confocal microscopy.ResultsThese analyses confirmed morphological features previously described using electron microscopy and uncovered a high degree of individual variation in SG structure. Our studies provide evidence for two alternative models for the origin of the salivary duct, the structure facilitating parasite transport out of SGs. We compare SG cellular architecture in An. stephensi and Drosophila melanogaster, a fellow Dipteran whose adult SGs are nearly completely unstudied, and find many conserved features despite divergence in overall form and function. Anopheles salivary proteins previously observed at the basement membrane were localized either in SG cells, secretory cavities, or the SG lumen. Our studies also revealed a population of cells with characteristics consistent with regenerative cells, similar to muscle satellite cells or midgut regenerative cells.ConclusionsThis work serves as a foundation for linking Anopheles stephensi SG cellular architecture to function and as a basis for generating and evaluating tools aimed at preventing malaria transmission at the level of mosquito SGs.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-1229-z) contains supplementary material, which is available to authorized users.

Intravascular ultrasonic–photoacoustic (IVUP) endoscope with 2.2-mm diameter catheter for medical imaging

Intravascular ultrasound (IVUS) imaging is extremely important for detection and characterization of high-risk atherosclerotic plaques as well as gastrointestinal diseases. Recently, intravascular photoacoustic (IVPA) imaging has been used to differentiate the composition of biological tissues with high optical contrast and ultrasonic resolution. The combination of these imaging techniques could provide morphological information and molecular screening to characterize abnormal tissues, which would help physicians to ensure vital therapeutic value and prognostic significance for patients before commencing therapy. In this study, integration of a high-frequency IVUS imaging catheter (45MHz, single-element, unfocused, 0.7mm in diameter) with a multi-mode optical fiber (0.6mm in core diameter, 0.22 NA), an integrated intravascular ultrasonic–photoacoustic (IVUP) imaging catheter, was developed to provide spatial and functional information on light distribution in a turbid sample. Simultaneously, IVUS imaging was co-registered to IVPA imaging to construct 3D volumetric sample images. In a phantom study, a polyvinyl alcohol (PVA) tissue-mimicking arterial vessel phantom with indocyanine green (ICG) and methylene blue (MB) inclusion was used to demonstrate the feasibility of mapping the biological dyes, which are used in cardiovascular and cancer diagnostics. For the ex vivo study, an excised sample of pig intestine with ICG was utilized to target the biomarkers present in the gastrointestinal tumors or the atherosclerotic plaques with the proposed hybrid technique. The results indicated that IVUP endoscope with the 2.2-mm diameter catheter could be a useful tool for medical imaging.

Photocytotoxicity of a cyanine dye with two chromophores toward melanoma and normal cells

BackgroundDue to high optical absorption, triplet quantum yield and affinity to biological structures bichromophoric cyanine dyes (BCDs) can be considered promising sensitizers for application in photodynamic therapy (PDT). In this work, we report on the study of the BCD photocytotoxicity toward melanoma and normal cells in comparison with that of commercial photosensitizer Photogem®. MethodsThe cytotoxic and phototoxic effects were measured by standard tests of cell viability. The drug uptake was obtained by the flow cytometry and optical absorption techniques. The BCD intracellular distribution was obtained by the fluorescence image microscopy using specific organelle markers. ResultsBoth drugs demonstrated increased cytotoxicity under irradiation, while in darkness their cytotoxic effect at concentrations lower than 20μM after 24h of incubation did not exceed 20%. For 5h of incubation, BCD photocytotoxicity in relation to melanoma cells reached 100% already at concentrations below 5μM, while for normal cells the effect did not exceed 70% even for the 20μM concentration. It is shown that BCD penetrates into the cells and is located predominantly in perinuclear cytoplasmic structures. ConclusionsThe BCD photosensitizing characteristics appear more adequate for application in PDT than that of the actually applied commercial photosensitizer Photogem®. Higher light absorption by BCD in the near IR region and its preferential localization in mitochondria can explain its high photocytotoxicity. General significanceBCD can be considered as a new promising photosensitizer class for cancer PDT.