Light Irradiation In Presence Research Articles

Integrated photocatalysis adsorption processes for oxytetracycline removal: using volborthite and its composite with g-C3N4.

The photocatalytic-adsorption performance of the composites of volborthite (CuVA) and graphitic carbon nitride (g-C3N4) was studied in this work using oxytetracycline (OTC) as model pollutant under LED light irradiation. CuVA at different weight percentages (10, 30, 50), namely, C10, C30, and C50, were loaded onto graphitic carbon nitride using wet chemical method. The physical, chemical, and optical properties were evaluated via various analytical techniques. Through integrated adsorption-photocatalytic process, no significant photocatalytic reaction occurred in g-C3N4 and the composite even after 4h of irradiation. The setup was modified such that each run was conducted in the presence and absence of light. Aside from photolysis and g-C3N4, all composites performed better under the presence of light in which CuVA improved the most from ~ 50% down to ~ 20% of initial concentration. CuVA performed almost identically (80% removal of OTC) under the presence of light irradiation at ambient temperature (22°C) and in the dark at 32°C, confirming that temperature was the contributing factor to the improvement instead of light. CuVA exhibited excellent adsorption capacity of 171mg/g and adsorption rate of 90% towards the removal of highly concentrated OTC (100mg/L) under optimized parameters of pH 5.0 and at 42°C after 3h of adsorption process. Life cycle assessment revealed that close to 50% of fresh 100ppm OTC could be removed after five cycles without any desorption process.

Feasibility of UVA photocatalytic post-treatment of molasses wastewater: Effects on melanoidins removal, mineralization and oxidation of ammoniacal-nitrogen

The brown color of molasses wastewater is due to the presence of melanoidins which are toxic to human health and environment. In this study, combination of coagulation-flocculation process with UVA-photocatalytic degradation of raw and diluted molasses wastewater in the presence of zinc oxide (ZnO) and titanium dioxide (TiO2) as photocatalyst was investigated. The effect of various operating parameters, such as light irradiation, aeration, catalyst dosage and pH of molasses wastewater on the photocatalytic degradation process was examined. The pre-treated diluted molasses wastewater (2 DF) showed greater performance compared to pre-treated raw for both photocatalysts due to high penetration of light into the wastewater. The formation of •OH enhanced color intensity reduction rate of pre-treated raw and 2 DF molasses wastewater in the presence of light irradiation and aeration. The color removal efficiency of pre-treated raw and 2 DF molasses wastewater was better in alkaline medium (pH 10) when ZnO used as photocatalyst, meanwhile it achieved higher removal efficiency in acidic medium (pH 4) when TiO2 was used as photocatalyst. The mineralization and oxidation of ammoniacal-nitrogen of molasses wastewater showed enhanced performance in photocatalytic treatment.

Well-designed α-Fe2O3/ZnFe2O4 heterojunction for photocatalytic CO2 reduction to fuels

Spinel ZnFe2O4 photocatalyst has been widely applied in CO2 reduction due to its negative enough conduction band edge and relatively narrow band gap, which enable the generation of strong reduction electrons in the presence of light irradiation. Unfortunately, the catalytic performance of pure ZnFe2O4 was seriously hindered because of inefficient charge transfer. Here, Z-scheme α-Fe2O3/ZnFe2O4 heterojunctions were synthesized by coupling α-Fe2O3 nanosheets with spinel ZnFe2O4 nanoparticles and applied to the photoreduction of CO2. The α-Fe2O3/ZnFe2O4 heterojunctions realized high charge separation efficiency and strong redox ability. As a result, the CH4 generation rate of α-Fe2O3/ZnFe2O4 heterojunctions was 2.6 times higher than that of ZnFe2O4. This work exhibits a new strategy to design ZnFe2O4-based Z-scheme heterojunction for converting CO2 to hydrocarbon fuels.

An Efficient Intercalation Supramolecular Structure for Photocatalytic CO2 Reduction to Ethylene Under Visible Light

AbstractPhotocatalytic CO2 reduction (CO2PR) into multi‐carbon products (especially C2H4) is a highly attractive route for global carbon cycle, however, which is seriously limited by sluggish C‐C coupling kinetics and competitive hydrogen evolution reaction (HER) and so on. Herein, the fabrication of a novel supramolecular assembly of NiAl‐Fe‐TCPP is reported by intercalating iron porphyrin (Fe‐TCPP) into NiAl‐layered double hydroxide (NiAl‐LDH), and the resultant NiAl‐Fe‐TCPP exhibit superior catalytic performance on CO2PR to C2H4 under visible light irradiation in presence of photosensitizer. A high C2H4 selectivity up to 93.4% in the carbon‐containing products with the production rate as high as 24.7 µmol h−1 can be achieved over NiAl‐Fe‐TCPP. The ex/in situ X–ray absorption spectoscopy (XAS) indicates that the electron transfer between NiAl‐LDH and Fe‐TCPP can promote the generation of low‐valence of Fe sites, resulting in the efficient production of C2H4. The spin‐polarized density functional theory (DFT) calculations find that the synergistic mechanism that CO2 molecules are activated to CO on NiAl‐LDH and then spilled to Fe‐TCPP and coupled to COCHO#, which is further reduced to C2H4, are feasible in the perspective of Gibbs free energy. Moreover, the strong host‐guest interactions between NiAl‐LDH and Fe‐TCPP lead to the promoted photocatalytic activity and superior cycle stability.

Multi-stimuli responsive carbazole-imidazole derivatives: Effect of phenyl substitution and UV light-oxygen induced photochemical transformation

New carbazole-imidazole derivatives, (3-(4,5-diphenyl-1H-imidazole-2-yl)-9-(3-methoxyphenyl)-9H-carbazole (Cz-DPIM)) and 9-(3-methoxyphenyl)-3-(1,4,5-triphenyl-1H-imidazole-2-yl)-9H-carbazole (Cz-TPIM) are synthesized and investigated the effect of phenyl substitution on the fluorescence and stimuli-induced fluorescence properties. Cz-DPIM exhibited relatively strong fluorescence in solution compared to Cz-TPIM (Quantum yield (Φf, compared to quinine sulphate standard) = 0.28 (Cz-DPIM) and 0.09 (Cz-TPIM)). In contrast, Cz-DPIM is weakly fluorescence in solid-state but Cz-TPIM showed strong fluorescence (Φf = 1.3% (Cz-DPIM) and 18.2% (Cz-TPIM)). Cz-TPIM displayed mechanoresponsive reversible fluorescence switching upon crushing and solvent fuming. Both Cz-DPIM and Cz-TPIM exhibited reversible halofluorochromsim upon exposure of trifluoroacetic acid (TFA) and ammonia (NH3). Interestingly, Cz-DPIM and Cz-TPIM exhibited photocleavage upon UV light irradiation in presence of oxygen in CH3CN and produced green emissive fluorescence product. The controlled studies revealed that the presence of oxygen is important for exhibiting photocleavage by UV light exposure and suggest potential use for oxygen sensing application. The UV light and oxygen induced photocleavage of Cz-DPIM and Cz-TPIM also demonstrated in thin films.

Optimization of Co3O4 surface sites for photo-ozone catalytic mineralization of dichloromethane

Obtaining high removal rate of chlorinated volatile organic compounds (CVOCs) and CO2 selectivity with a low ratio of O3/CVOC and energy consumption is challenging. Dodecylamine was used in this study to create active sites on Co3O4 for photo-ozone catalytic mineralization of dichloromethane (DCM). Amine-Co3O4-450 is a dodecylamine-modified sample with high density of Co3+, Co2+, and hydroxyl due to its nanosheet structure and exposed (112) facets. The optimized surface significantly enhanced the cleavage of the C–Cl bond at low temperatures. Photocatalysis primarily participated in the oxidation of intermediates following DCM dichlorination and significantly improved CO2 selectivity. The respective DCM removal rate and mineralization efficiency of Amine-Co3O4-450 with an O3/DCM molar ratio of 1.27 and one-sun irradiation were 14.9 and 15.0 times higher than the sum of those in the presence of light irradiation or O3 alone. This finding indicated that a strong synergistic effect exists between O3 and light.

Recent Developments in Nanoparticle-Based Photo-Immunotherapy for Cancer Treatment.

Phototherapy is an emerging approach for cancer treatment that is effective at controlling the growth of primary tumors. In the presence of light irradiation, photothermal and photodynamic agents that are delivered to tumor sites can induce local hyperthermia and the production of reactive oxygen species, respectively, that directly eradicate cancer cells. Nanoparticles, characterized by their small size and tunable physiochemical properties, have been widely utilized as carriers for phototherapeutic agents to improve their biocompatibility and tumor-targeted delivery. Nanocarriers can also be used to implement various codelivery strategies for further enhancing phototherapeutic efficiency. More recently, there has been considerable interest in augmenting the immunological effects of nanoparticle-based phototherapies, which can yield durable and systemic antitumor responses. This review provides an overview of recent developments in using nanoparticle technology to achieve photo-immunotherapy.

Rational design of Mg2Sn2O4/rGO/Ag nanocomposites with enhanced photocatalytic and antibacterial activities

A Mg2Sn2O4, Mg2Sn2O4/rGO and Mg2Sn2O4/rGO/Ag nanocomposites encompass a new brand of the nanocatalyst, which can be broad-minded to a professional photocatalyst via visible light because of this attractive photocatalytic activity by UV Visible spectroscopy. In particular, Mg2Sn2O4 nanoparticles enclose low bandgap energy consequently enhancing photocatalytic dye degradation. Herewith, these Mg2Sn2O4, Mg2Sn2O4/rGO and Mg2Sn2O4/rGO/Ag nanocomposites were prepared by a hydrothermal method. The Mg2Sn2O4, Mg2Sn2O4/rGO and Mg2Sn2O4/rGO/Ag nanocomposites were tested towards FT-IR, XRD, Raman, DRS UV–Visible spectroscopy and Scanning electron microscopy (SEM) analysis. In FT-IR spectroscopy investigations, Peaks 423 and 548 cm−1 is confirmed to the Mg–O–Mg (M-O-M) and O–Sn–O (O-M-O) groups. The 485, 658, and 750 cm−1 is can be assigned to the Sn–O modes and peaks 578 and 917 cm−1 is corresponds to Mg–O bonds, which was carried out by Raman spectroscopy analysis. The Mg2Sn2O4 nanoparticle's cubic phase of the crystal system was confirmed by XRD studies. Pure Mg2Sn2O4 nanoparticle's observed band gap energies values at 2.7eV. The crystal shape and sheets like morphology were determined by SEM analysis. Mg2Sn2O4, Mg2Sn2O4/rGO and Mg2Sn2O4/rGO/Ag nanocomposites were evaluated by photocatalytic activities under visible light irradiation in presence of Malachite Green dye (MG). Hence, Mg2Sn2O4/rGO/Ag nanocomposites have higher degradation efficiency when compare to the Mg2Sn2O4, Mg2Sn2O4/rGO nanocomposites. Moreover, the Mg2Sn2O4/rGO/Ag nanocomposites was tested to the antibacterial activity with Gram-positive Staphylococcus aureus (S. Aureus) and Gram-negative Salmonella Typhi (S. Typhi) bacteria. Finally, as proposed materials are enhanced to the antibacterial and photocatalytic activities.

Effective and reproducible biosynthesis of nanogold-composite catalyst for paracetamol oxidation.

Pharmaceutical products are some of the most serious emergent pollutants in the environment, especially nowadays of the COVID-19 pandemic. In this study, nanogold-composite was prepared, and its catalytic activity for paracetamol degradation was investigated. Moreover, for the first time, recycled waste diatomite earth (WDE) from beer filtration was used for reproducible gold nanoparticle (Au NPs) preparation. We studied Au NPs by various psychical-chemical and analytical methods. Transmission and scanning electron microscopy were used for nanogold-composite morphology, size and shape characterization. Total element concentrations were determined using inductively coupled plasma mass and X-ray fluorescence spectrometry. X-ray powder diffraction analysis was used for crystal structure characterization of samples. Fourier transform infrared spectrometer was used to study the chemical changes before and after Au NP formation. The results revealed that the WDE served as both a reducing and a stabilizing agent for crystalline spherical 30 nm Au NPs as well as acting as a direct support matrix. The kinetics of paracetamol degradation was studied by high-performance liquid chromatography with a photodiode array detector. The conversion of paracetamol was 62% and 67% after 72 h in the absence or presence of light irradiation, respectively, with 0.0126 h−1 and 0.0148 h−1 reaction rate constants. The presented study demonstrates the successful use of waste material from the food industry for nanogold-composite preparation and its application as a promising catalyst in paracetamol removal.Graphical abstract Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-022-21868-6.

An Effective Photocatalytic Degradation of Industrial Pollutants through Converting Titanium Oxide to Magnetic Nanotubes and Hollow Nanorods by Kirkendall Effect.

Controlling of morphology from nanoparticles to magnetic nanotubes and hollow nanorods are interesting for developing the photo-active materials and their applications in the field of photocatalysis and decontamination of aquatic effluents. In the current study, titanium dioxide nanoparticles and nanocomposites were prepared by different techniques to produce various morphologies. The nanoparticles of pure titanium dioxide were prepared by sol-gel technique. Magnetic nanotubes and hollow nanorods were prepared by combining titanium with di- and tri-valent iron through two stages: urea hydrolysis and solvent thermal technique. According to the Kirkendall effect, magnetic nanotubes were fabricated by unequal diffusion of Fe2+, Fe3+ and Ti4+ inside the nanocomposite to produce maghemite-titanian phase. In the same trend, hollow nanorods were synthesized by limited diffusion of both trivalent iron and tetravalent titanium producing amorphous structure of titanium iron oxides. The magnetic and optical properties showed that these nanotubes and hollow nanorods are magnetically active and optically more effective compared with titanium dioxide nanoparticles. Therefore, the Naphthol green B dye completely disappeared after 45 min of UV light irradiation in presence of the hollow nanorods. The kinetic study confirmed the high performance of the hollow nanorods for the photocatalytic degradation of Naphthol green B compared with titanium dioxide nanoparticles.

Photodynamic therapy initiated immunotherapy of self-delivery re-educator by inducing immunogenic cell death and macrophage polarization

Immunotherapy is a promising clinical treatment strategy against malignant tumor metastasis, however, it often shows an inadequate efficacy owing to the immunosuppressive tumor microenvironment (ITM). Herein, we develop a self-delivery re-educator to induce immunogenic cell death (ICD) and macrophage polarization for photodynamic therapy (PDT) and immunotherapy against breast cancer. To be specific, the self-delivery re-educator (designated as PyroR) is prepared by the self-assembly of the photosensitizer pyropheophorbide-a (Pyro) and TLR agonist resiquimod (R848). Without any carriers, nanosized PyroR exhibits high drug contents and could avoid the side effects raised by excipients. After intravenous administration, PyroR could generate a lot of reactive oxygen species (ROS) for PDT against primary tumor in the presence of light irradiation. Meanwhile, PDT triggered ICD cascade would promote dendritic cells (DCs) maturation and activate cytotoxic T lymphocytes (CTLs) for immunotherapy against distant and metastatic tumors. More importantly, R848 is able to polarize macrophages from M2 to M1 phenotype, which would improve the ITM to enhance antitumor immunity. Consequently, the PDT-initiated immunotherapy of PyroR demonstrates significant inhibition effects on primary, distant and metastatic tumors while causes a minimal system toxicity. This self-delivery re-educating strategy would shed light on constructing carrier-free nanomedicine for treatment of malignant tumors.

Developing an efficient approach for preparation of high-performance visible-light assisted ethanol electro-oxidation materials based on Pd, Pt and Pd–Pt nanoparticles supported on iron doped titania nanotube films

Electrochemical anodization and electrodeposition have been used to synthesize highly ordered iron doped titania nanotubes (FeT) loaded with palladium (Pd), platinum (Pt) and Pt–Pd nanoparticles, followed by characterization by FE-SEM and XRD analyses. Higher photoelectrocatalytical activity is shown by the electrodeposited nanotube samples compared with undeposited-FeT sample under identical conditions, according to the photoelectrochemical experiments. The electrochemical behavior of the synthetic electrodes was studied by investigation of ethanol electrocatalytic oxidation in an alkaline medium in the absence or presence of light irradiation. The results of electrochemical studies indicated that Pt–Pd/FeT/Ti was more catalytically active than Pt/FeT/Ti and Pd/FeT/Ti in ethanol electrooxidation in alkaline media both in the dark and under light irradiation. Furthermore, the catalytic activities of nanotube based catalysts were considerably enhanced under light irradiation due to the interaction of electrocatalysis and photocatalysis. The peak current density of ethanol oxidation using sample FeT2 under light irradiation is about 1.45 times the corresponding value in the dark.

Synthesis and characterization of chitosan-supported Fe2O3 nanohybrids for rapid sonophotocatalytic degradation of 2,4,6-trichlorophenol.

The present study reports the design of heterogeneous photocatalytic system using Fe2O3 with chitosan (CS) as a matrix for the sonophotocatalytic degradation of 2,4,6-trichlorophenol (2,4,6-TCP). CS was chosen as a polymer matrix as it is abundant in nature, eco-friendly, and can be easily processed into microparticles, nanofibers, as well as nanoparticles and shows the tendency of adhesion towards a vast range of solid substrates besides serving as a chelating agent toward metallic oxides. The nanohybrids were characterized via Fourier transformation infrared spectrum (FT-IR), X-ray diffraction (XRD), scanning electron microscopy coupled with electron dispersive spectrum (SEM-EDS), thermogravimetric analysis (TGA), and UV-visible diffuse reflectance (UV-Vis-DRS) analyses. Infrared spectroscopy (IR) studies confirmed synergistic interaction between Fe2O3 and CS. The XRD measurements confirmed the crystalline morphology while SEM revealed formation of rod-like structures. The TGA studies confirmed higher thermal stability of CS/Fe2O3 as compared to pure CS. The optical band gap for CS and CS/Fe2O3 was calculated to be 3 eV and 2.25 eV, respectively, from diffuse reflectance spectral (DRS) studies. Rapid photocatalytic degradation of 2,4,6-TCP was observed under UV light irradiation in presence of CS and CS/Fe2O3 nanohybrids which revealed 83.19% and 95.20% degradation within a short span of 60 min. The degraded fragments were identified using liquid chromatography-mass spectrometry (LC-MS). The present study on the development of ecofriendly nanohybrid photocatalyst is expected to provide experimental basis for the future development of CS-based photocatalysts which can be easily processed into membranes/filters for the industrial scale degradation of toxic organic pollutants.

Efficient synthesis of a new heterogeneous gold nanocatalyst stabilized by di-alkyne ligand and its applications for photocatalytic dye degradation and transfer hydrogenation reaction

A new form of carbon-based ligand supported robust heterogeneous gold nanocatalyst was synthesized and its potential catalytic applications are demonstrated. The high yield (> 90%) synthesis procedure involves ligand exchange between hydrophilic polyvinylpyrrolidone polymer stabilized gold nanoparticles (Au:PVP) with a di-alkyne ligand (1,4-Diethynylbenzene). The ultrasmall stabilized gold nanoparticles (1.8 ± 0.3 nm) are bonded to di-alkyne ligand through acetylenic carbon atom (≡C-Au) with an electronically conjugated 3D network. The synthesized material (Au-P1) was meticulously characterized using several spectroscopic and microscopic techniques, e.g., Fourier transform infrared spectroscopy (FTIR), optical absorption spectroscopy (UV-Vis), powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscope (TEM) and thermogravimetric analysis (TGA). The Au nanocatalyst showed good photocatalytic activity for degradation of several organic dye molecules in aqueous phase under visible light irradiation in presence of oxidizing agent (H2O2). The proposed mechanism involves dye absorption on ligand surface through π-π interaction followed by transfer of electron from excited dye molecules to gold core through electronically conjugated ligand for generation of reactive oxygen species (·OH). The catalyst has also been demonstrated for transfer hydrogenation of organic carbonyl and nitro functional groups (>C=O, -NO2) with potassium formate (HCOOK) as hydrogen source in water. The catalyst could be recovered by simple filtration, and it was reused up to five cycles for both of these catalytic transformations with complete retention of its catalytic activity.

Highly efficient activation of peroxymonosulfate by Co3O4/Bi2WO6 p-n heterojunction composites for the degradation of ciprofloxacin under visible light irradiation

Photocatalytic technology assisted via peroxymonosulfate (PMS) has good potential in water treatment. In this study, the Co3O4/Bi2WO6 composite was constructed via an in-situ calcination process and used to activate PMS for the degradation of ciprofloxacin (CIP) under visible light irradiation. The obtained 5 wt% Co3O4/Bi2WO6(CBWO-2) can highly effectively remove 86.2% CIP within 5 min visible light irradiation in presence of PMS. The excellent degradation performance of Co3O4/Bi2WO6/PMS system can be attributed to the synergistic effect between p-n heterojunction and PMS activation. The conduction band and valence band deviation between Co3O4 and Bi2WO6 were calculated by XPS techniques. Besides, DFT calculations were performed to further confirm the internal structure between Co3O4 and Bi2WO6. This work not only provides an approach to fabricate heterostructures but also indicated that Co3O4/Bi2WO6/PMS/Vis system is a potential environment remediation alternative for the efficient removal of recalcitrant organic compounds from wastewaters.

Engineering spin polarization in a driven multistranded magnetic quantum network

Possible engineering of spin polarization through a multistranded magnetic quantum network in the presence of light irradiation is reported. Each site of the network is associated with a net magnetic moment which provides a spin-dependent scattering via spin-spin exchange interaction, yielding a finite spin polarization across the network. The quantum system is described within a tight-binding framework where the irradiation effect is incorporated through Floquet-Bloch prescription. The spin-polarization coefficient, measured by determining spin-dependent transmission probabilities following the Green's function formalism, shows several atypical features with irradiation parameters. Apart from getting a high degree of spin polarization, a complete phase reversal can be achieved. These two issues are extremely important in designing efficient spin-based electronic devices. A detailed mathematical description is given to decouple the Hamiltonian of a generalized multistranded magnetic ladder into distinct one-dimensional lattices in separate spin subspaces for any arbitrary orientation of local spin, which clearly illustrates the allowed energy spin subbands. Effects of system size and uncorrelated disorder on spin polarization are critically examined. Finally, we discuss the possible experimental realization of our magnetic quantum systemto regulate the degree and phase of spin polarization by irradiating a magnetic sample, and thus we believe that the present analysis may provide a route of engineering spin-dependent electron transfer through a spin-polarized device.

Conjugated BODIPY Oligomers with Controllable Near-Infrared Absorptions as Promising Phototheranostic Agents through Excited-State Intramolecular Rotations

Conjugated molecules with coplanar strong donor and acceptor (D-A) units have been widely used in the design of near-infrared (NIR) photothermal agents to increase an absorption band through intramolecular charge transfer and to control intramolecular motions in aggregated states. However, such conjugated D-A systems have strong dipolar moments and intermolecular interactions, which may inhibit other channels of photothermal conversion and are often susceptible to nucleophiles, especially in the presence of light irradiation. Now, we report a molecular guideline to develop novel NIR organic photothermal nanoagents based on conjugated boron dipyrromethene (BODIPY) oligomers. This oligomerization is helpful not only for their tunable NIR absorptions in the ground state with distinctly redshifted absorption maxima up to 1002 nm and high extinction coefficients but also for their highly efficient photothermal conversion because of the possible motion of the BODIPY motifs around the ethene linked group in the excited state. These oligomers were fabricated as ultra-photostable nanoagents for multiple imaging-guided phototherapies, which efficiently accumulated in tumors, and gave complete tumor ablation with NIR laser irradiation. This strategy of "ground-state conjugation, excited-state rotation" provides a novel guideline to develop advanced theranostic molecules with NIR absorption.

Favorable thermoelectric performance in a Rashba spin-orbit coupled ac-driven graphene nanoribbon

A possible route is given to achieve enhanced thermoelectric (TE) performance in a spin-orbit (SO) coupled graphene nanoribbon (GNR). The GNR is irradiated with a suitable polarized light so that the transmission function can have asymmetry around the chemical potential, which is the key requirement to enhance the TE performance. The interplay between SO coupling and irradiation on the nature of transmission function is critically investigated. Astounding TE results are obtained in the presence of light irradiation without modifying the other physical parameters of the system. The thermopower is enhanced significantly and at the same time, a considerable suppression in the thermal conductance is observed which yields favorable energy conversion. We discuss thermoelectric properties for the unpassivated and passivated GNRs as well. Both zigzag and armchair GNRs are taken into account, and finally, the results are studied by varying their widths in a wide range. Enhancing the thermoelectric performance by means of irradiation in a SO coupled system is completely new and has not been explored so far to the best of our concern, and might be applicable as well in other such topological systems.

Near-infrared dual-functional AIEgens for lipid droplets imaging in multispecies and photodynamic therapy

Lipid droplets (LDs) are important organelles with hydrophobic structure that not only served the function of lipid storage in cells but also participate in the regulation of numerous metabolic processes. Broad visualization of LDs with high brightness is important for biological applications. In this study, three novel facile near-infrared aggregation-induced emission (AIE) fluorescent bioprobes based on triphenylamine-pyridine building block were designed and synthesized. These AIEgens block exhibits tunable D-D-π-A (D: donor, A: acceptor) structure with twisted intramolecular charge transfer (TICT) characteristics. These bioprobes can highly light up LDs in the living cells, model animal zebrafish and shelled sunflower seed. More importantly, these probes can effectively produce reactive oxygen species (ROS) in the presence of light irradiation, leading to the apoptosis of cancer cells. This study exhibits promising applications in photodynamic therapy through targeting LDs.

Development and in vitro evaluation of BSA-coated liposomes containing Zn (II) phthalocyanine-containing ferrocene groups for photodynamic therapy of lung cancer

The aim of our study was to discover an alternative active substance to tyrosine kinase inhibitors such as erlotinib (Erlo) used in lung cancer treatment and to develop an appropriate and efficient formulation for oral administration of the substance. Newly synthesized zinc (II) phthalocyanine bearing ferrocene groups (Pc-Zn) was chosen as a model drug due to its use in photodynamic therapy. Pc-Zn increased the amount of nicked form (Form II) by 22.90% and decreased the amount of supercoiled form (Form I) by 77.10% in DNA cleavage studies using plasmid pBR322 DNA in the presence of light and oxygen. Liposome formulations containing Pc-Zn (Pc-Zn Lip) or Erlo (Erlo Lip) had small particle size as 450.5±32.4 nm and 187.2±1.6 nm, respectively and coating with bovine serum albumin (BSA) had not significantly changed particle sizes. Pc-Zn loaded liposomes had significantly (p <0.001) cytotoxic effect under light irradiation than Erlo loaded liposomes. Coating with BSA had no significant effect on the cytotoxicity of the formulations. As a result, it was observed that Pc-Zn was more cytotoxic in the presence of light irradiation than Erlo. However, there was no significant difference in cytotoxic effects between the BSA-coated and non-coated Pc-Zn/Erlo formulations.