Cancer Cell-Specific and Laser-Activatable NanoSeeds for Targeted Photothermal Ablation of Triple-Negative Breast Cancer

This investigation reports the quality-by-design (QbD) assisted novel templated approach for developing cancer cell-specific and laser-activatable nanoseeds (AuraTherm) for targeted photothermal ablation of triple-negative breast cancer (TNBC). AuraTherm was nanometric in size as characterized by SEM, TEM and particle analysis (80.28 ± 2.56 nm; −21.80 ± 0.17 mV) with hemocompatibility and neutrality towards blood components. AuraTherm showed reversible photothermal effect (ΔT: 37 ± 1.2°C → 49.4 ± 1.5°C; 15 min; 2.4 W cm⁻²) employing near-infrared 808 nm laser (NIR-808). The targeted cytosolic localization led to a significant anticancer activity as evaluated using apoptosis assay, cell cycle analysis, Intracellular ROS generation assay, cellular uptake and receptor binding assay. The NIR-808 laser-responsive photothermal ablation of cancer cell was found to be more effective compared to without NIR-808 laser-treated counterparts, suggesting the fundamental role of photothermal ablation in the treatment of TNBC.     

Treatment of Malignant Melanoma by High-Peak-Power 1064 nm Irradiation Followed by Photodynamic Therapy

Irradiation of B16 pigmented melanoma subcutaneously transplanted in C57 mice with a single 650 mj pulse (10 ns) of 1064 nm light from a Q-switched Nd: YAG laser caused instantaneous bleaching of the pigmented tissue. Visual and histological examination of the resulting gray-colored tumor revealed the breakdown of melanosomes with no detectable alteration of the normal and tumor-overlying skin. Histological examination of the irradiated tumor showed some degree of vascular damage; the depth of the photodamage was not affected by the successive delivery of three consecutive light pulses. The bleached tumor grew at a modestly slower rate but the high-peak-power (HPP) laser treatment did not affect the tumor concentration of a photodynamic sensitizer Si(IV)-naphthalocyanine (isoBO-SiNc) intravenously injected 24 h before Nd : YAG irradiation. Treatment of the B16 pigmented melanoma by photodynamic therapy (PDT: 1 mg/kg isoBO-SiNc, 300 mW/cm², 520 J/cm²) from a 774 nm diode laser immediately after the 1064 nm irradiation resulted in a 16 day delay of tumor regrowth, which was markedly longer than the delay (ca 6 days) obtained after PDT under identical conditions without the preirradia-tion. Thus, pretreatment of pigmented tumors with HPP 1064 nm light appears to enhance their susceptibility to conventional PDT. The tumor response was further enhanced by repeating the combined HPP/PDT treatment at an interval of 10 days (regrowth delay: 27 days), as well as by applying hyperthermia immediately after HPP/PDT (regrowth delay: ca 34 days).     

Charge Transfer Metal-Organic Framework Containing Redox-Active TTF/NDI Units for Highly Efficient Near-Infrared Photothermal Conversion

Metal-organic frameworks (MOFs), as a class of new inorganic-organic hybrid crystal materials, could have important applications in near-infrared (NIR) photothermal conversion. Herein, a new charge-transfer MOF (Co-MOF) with mixed ligands of H₄TTFTB and bpmNDI incorporating redox-active tetrathiafulvalene/naphthalene diimide (TTF/NDI) units into one system is reported. Due to the presence of TTF/NDI oxidative and reductive couples, stable radicals can be observed in the MOF. In addition, charge transfer from the electron donor (TTF) to the acceptor (NDI) results in a broad absorption in the NIR region. The Co-MOF exhibited an efficient photothermal effect induced by irradiation with a NIR laser. Under the 808 nm laser (0.7 W cm⁻²) illumination, the temperature of the Co-MOF increased from room temperature to 201 °C in only 10 s. Furthermore, a series of polydimethylsiloxane (PDMS) films doped with trace amounts of Co-MOF showed efficient NIR photothermal conversion. When a Co-MOF@PDMS (0.6 wt %) film is irradiated by 808 nm laser with power of 0.5 W cm⁻², it′s temperature can reach a plateau at 62 °C from 20 °C within 100 s. Our experimental results from the Co-MOF@PDMS film demonstrate that the effectiveness and feasibility of the material is promising for photothermal applications.     

Photobiomodulation Enhances Cisplatin Cytotoxicity in a Culture Model with Oral Cell Lineages

Cisplatin plays a central role in cancer chemotherapy, but resistance to this drug remains a major obstacle in treatment. Drawbacks related to cisplatin failure may be associated with cell energy metabolism. This study investigated whether photobiomodulation (PBM) can potentiate the effects of cisplatin on keratinocytes (HaCat) and cancer cells (SCC25 and HN12). Cells were treated with laser (GaAlAs; 660 nm; 60 mW; 0.33 J; 2.14 W cm⁻²; 11.7 J cm⁻² and 6 s) and cisplatin (7.8 μg mL⁻¹) to evaluate cell viability, Ki-67, VEGF, TGF-β1, EGF expression and ROS production. Observations were validated in the SCC25 cell lineage, where the type of cell death (necrosis/apoptosis) and the amount of ATP were assessed. Cell lineages showed increased sensitivity to cisplatin associated with PBM (Cis-PBM). Ki-67 was augmented in all cell lineages treated with Cis-PBM when compared to cisplatin alone (Cis). Cis or Cis-PBM significantly decreased VEGF expression in cancer cells, while no changes were seen in the expression of TGF-β1 or EGF compared to control. ROS levels were similar in the Cis and Cis-PBM groups. Cells treated with Cis-PBM died by apoptosis, leading to greater consumption of ATP. These observations suggest that PBM may potentiate the effects of cisplatin, leading to increased drug cytotoxicity and enhanced cell death.     

Two-Photon-Induced CO-Releasing Molecules as Molecular Logic Systems in Solution,Polymers, and Cells

Phototherapeutic applications of carbon monoxide (CO)-releasing molecules are limited because they require harmful UV and blue light for activation. We describe two-photon excitation with NIR light (800 nm)-induced CO-release from two Mn^I tricarbonyl complexes bearing 1,8-naphthalimide units ( 1 , 2 ). Complex 2 behaves as a logic OR gate in solution, nonwovens, and in HeLa cells. CO release, indicated by fluorescence enhancement, was detected in solution, nonwoven, and HeLa cells by single- (405 nm) and two-photon (800 nm) excitation. The photophysical properties of 1 and 2 have been measured and supported by DFT and TDDFT quantum chemical calculations. Both photoCORMs are stable in the dark in solution and noncytotoxic, leading to promising applications as phototherapeutics with NIR light.     

Nd3+-Sensitized Upconversion Metal–Organic Frameworks for Mitochondria-Targeted Amplified Photodynamic Therapy

Herein, we report the design and synthesis of a mitochondria-specific, 808 nm NIR light-activated photodynamic therapy (PDT) system based on the combination of metal–organic frameworks (MOFs) and upconversion photochemistry with an organelle-targeting strategy. The system was synthesized through the growth of a porphyrinic MOF on Nd³⁺-sensitized upconversion nanoparticles to achieve Janus nanostructures with further asymmetric functionalization of the surface of the MOF domain. The PDT nanoplatform allows for photosensitizing with 808 nm NIR light, which could effectively avoid the laser-irradiation-induced overheating effect. Furthermore, mitochondria-targeting could amplify PDT efficacy through the depolarization of the mitochondrial membrane and the initiation of intrinsic apoptotic pathway. This work sheds light on the hybrid engineering of MOFs to combat their current limitations for PDT.     

Nd3+‐Sensitized Upconversion Metal–Organic Frameworks for Mitochondria‐Targeted Amplified Photodynamic Therapy

Herein, we report the design and synthesis of a mitochondria‐specific, 808 nm NIR light‐activated photodynamic therapy (PDT) system based on the combination of metal–organic frameworks (MOFs) and upconversion photochemistry with an organelle‐targeting strategy. The system was synthesized through the growth of a porphyrinic MOF on Nd³⁺‐sensitized upconversion nanoparticles to achieve Janus nanostructures with further asymmetric functionalization of the surface of the MOF domain. The PDT nanoplatform allows for photosensitizing with 808 nm NIR light, which could effectively avoid the laser‐irradiation‐induced overheating effect. Furthermore, mitochondria‐targeting could amplify PDT efficacy through the depolarization of the mitochondrial membrane and the initiation of intrinsic apoptotic pathway. This work sheds light on the hybrid engineering of MOFs to combat their current limitations for PDT.     

Photodynamic actinometry using microspheres: concept, development and responsivity

Photodynamic therapy (PDT) relies on three main ingredients, oxygen, light and photoactivating compounds, although the PDT response is definitively contingent on the site and level of reactive oxygen species (ROS) generation. This study describes the development of a novel, fluorescent-based actinometer microsphere system as a means of discerning spatially resolved dosimetry of total fluence and ROS production. Providing a high resolution, localized, in situ measurement of fluence and ROS generation is critical for developing in vivo PDT protocols. Alginate-poly-L-lysine-alginate microspheres were produced using ionotropic gelation of sodium alginate droplets, ranging from 80 to 200 microm in diameter, incorporating two dyes, ADS680WS (ADS) and Rhodophyta-phycoerythrin (RPE), attached to the spheres' inside and outside layers, respectively. To test the responsivity and dynamic range of RPE for ROS detection, the production of ROS was initiated either chemically using increasing concentrations of potassium perchromate or photochemically using aluminum tetrasulphonated phthalocyanine. The generation of singlet oxygen was confirmed by phosphorescence at 1270 nm. The resulting photodegradation and decrease in fluorescence of RPE was found to correlate with increased perchromate or PDT treatment fluence, respectively. This effect was independent of pH (6.5-8) and could be inhibited using sodium azide. RPE was not susceptible to photobleaching with light alone (670 nm; 150 Jcm(-2)). ADS, which absorbs light between 600 and 750 nm, showed a direct correlation between radiant exposure (670 nm; 0-100 Jcm(-2)) and diminished fluorescence. Photobleaching was independent of irradiance (10-40 mW cm(-2)). We propose that actinometer microspheres may provide a means for obtaining high spatial resolution information regarding delivered PDT dose within model systems during investigational PDT development and dosimetric information for clinical extracorporeal PDT as in the case of ex vivo bone marrow purging.     

Synthesis and study of a novel hybrid UV photoinitiator: p-benzoyldiphenyliodonium hexafluorophosphate (PhCOPhI+PhPF)

A novel hybrid photoinitiator, p-benzoyldiphenyliodonium hexafluorophosphate (PhCOPhI⁺PhPF⁻₆), was synthesized, characterized, and studied. It absorbs UV light not only below 300 nm, but above 300 nm as well. When exposed to UV light, it undergoes an asymmetrical photocleavage to produce cation-radicals and radicals which could induce cationic and radical polymerizations respectively. Compared with the simple iodonium salt PhI⁺PhPF⁻₆, and bimolecular sensitization system PhCOPh/PhI⁺PhPF⁻₆, the covalently bonded photosensitization system PhCOPhI⁺PhPF⁻₆ is much more efficient as a photoinitiator. Oxygen has a small negative effect on the cationic polymerization photoinitiated by PhCOPhI⁺PhPF⁻₆, while isopropanol has a small positive influence only in argon atmosphere. © 1996 John Wiley & Sons, Inc.     

Promoting near-infrared photocatalytic activity of carbon-doped carbon nitride via solid alkali activation

Ultrabroad spectral absorption is required for semiconductor photocatalysts utilized for solar-to-chemical energy conversion. The light response range can be extended by element doping, but the photocatalytic performance is generally not enhanced correspondingly. Here we present a solid alkali activation strategy to synthesize near-infrared (NIR) light-activated carbon-doped polymeric carbon nitride (A-cPCN) by combining the copolymerization of melamine and 1,3,5-trimesic acid. The prepared A-cPCN is highly crystalline with a narrowed bandgap and enhanced efficiency in the separation of photogenerated electrons and holes. Under irradiation with NIR light (780 nm ≥ λ ≥ 700 nm), A-cPCN shows an excellent photocatalytic activity for H₂ generation from water with rate of 165 µmol g⁻¹ h⁻¹, and the photo-redox activity for H₂O₂ production (109 µmol g⁻¹ h⁻¹) from H₂O and O₂, whereas no observed photocatalytic activity over pure PCN. The NIR photocatalytic activity is due to carbon doping, which leads to the formation of an interband level, and the alkali activation that achieved shrinking the transfer distance of photocarriers. The current synergistic strategy may open insights to fabricate other carbon-nitrogen-based photocatalysts for enhanced solar energy capture and conversion.     

Selective decomposition of proteins by photocatalytic Ti(IV)-doped calcium hydroxyapatite particles from mixed-protein systems

The decomposition of protein molecules from a mixed-protein solution on the surface of calcium hydroxyapatite (CaHap) and Ti(IV)-doped CaHap (TiHap) particles with a Ti/(Ca + Ti) atomic ratio (X _Ti) of 0.10 and 0.20 under UV irradiation of 365 nm in wavelength was investigated. Acidic bovine serum albumin (BSA) and basic lysozyme (LSZ) were employed as a model of pathogenic proteins. The photocatalytic activities of TiHap particles were estimated from the decomposition of BSA and LSZ from the BSA (2.5 mg/cm³)–LSZ(1.0 mg/cm³) mixture under 1 mW/cm² UV irradiation dispersed in a 10-mL quartz tube. No change in BSA concentration by UV irradiation was observed for all the unheated original CaHap and TiHap particles without and with low photocatalytic activities, respectively. Similar results were observed for the systems that employed heat-treated particles endowed a high photocatalytic activity by heat treatment at 650 °C for 1 h. On the other hand, a selective photocatalytic decomposition was observed for the LSZ, i.e., only LSZ molecules were decomposed completely from the BSA (2.5 mg/cm³)–LSZ(1.0 mg/cm³) mixture by using heat-treated TiHap particles with X _Ti?=?0.10 and 0.20. This selective decomposition by TiHap particles was interpreted by higher adsorption affinity of positively charged LSZ to highly negatively charged TiHap together with low molecular weight and rigid structure of LSZ molecules.     

Visible-Light Augmented Lithium Storage Capacity in a Ruthenium(II) Photosensitizer Conjugated with a Dione-Catechol Redox Couple

Controlling redox activity of judiciously appended redox units on a photo-sensitive molecular core is an effective strategy for visible light energy harvesting and storage. The first example of a photosensitizer - electron donor coordination compound in which the photoinduced electron transfer step is used for light to electrical energy conversion and storage is reported. A photo-responsive Ru-diimine module conjugated with redox-active catechol groups in [Ru(II)(phenanthroline-5,6-diolate)₃]⁴⁻ photosensitizer can mediate photoinduced catechol to dione oxidation in the presence of a sacrificial electron acceptor or at the surface of an electrode. Under potentiostatic condition, visible light triggered current density enhancement confirmed the light harvesting ability of this photosensitizer. Upon implementation in galvanostatic charge-discharge of a Li battery configuration, the storage capacity was found to be increased by 100 %, under 470 nm illumination with output power of 4.0 mW/cm⁻². This proof-of-concept molecular system marks an important milestone towards a new generation of molecular photo-rechargeable materials.     

Detection of active oxidative species in TiO2 photocatalysis using the fluorescence technique

The active oxidative species (mainly corresponding to hydroxyl radicals (· OH)) produced on TiO₂ film photocatalyst in aerated aqueous solution have been quantitatively investigated by measuring the fluorescence derived by the reaction with either coumarin or terephthalic acid. Upon UV light illumination, coumarin in aqueous solution and terephthalic acid in NaOH solution were converted on the TiO₂ film photocatalyst to highly fluorescent hydroxy products. Analysis of the resultant hydroxy compounds provides sensitive and specific monitoring of the generated active oxidative species. The rate of active species formation could be determined by the time dependence of the increase in concentration of the resultant hydroxy products. Using this fluorescence method, the effect of light intensity on the generation efficiency of active oxidative species was examined. The obtained results show that the efficiency of active oxidative species formation is constant at the UV intensity from 50 μW cm⁻² to 15 mW cm⁻², which is consistent with the results for · OH detection reported recently by the use of other techniques.     

Fabrication of Multi-pore Structure Cu,N-codoped Porous Carbon-based Catalyst and its Oxygen Reduction Reaction Catalytic Performance for Microbial Fuel Cell

The development of a non-noble metal cathode ORR catalyst with low cost, high activity and high stability has become an inevitable trend in MFC. The purpose of this study is to develop an efficient and stable Cu, N-codoped porous carbons catalysts with multi-pore structure for MFC. Herein, Cu, N-codoped porous carbons materials (Cu−NC−T) with high N content and multi-pore structure were successfully developed by co-pyrolysis with MOF-199 and melamine. By contrast, Cu-doped porous carbon (Cu−C−T) without melamine was synthesized using MOF-199 as template. The results showed that Cu−NC−T possessed a rough octahedral crystal with a unique multi-mesopore structure with pore centers of 3.4 nm and 11.2 nm, respectively. Owing to high N content, abundantly exposed Cu−N_x active sites and the multi-pore structure, Cu−NC−800 had a pronounced electrochemical ORR activity in neutral solution (onset potential and limiting current density were 0.161 V and −6.256 mA ⋅ cm⁻²), which were slightly lower than 20 wt % Pt/C (0.189 V and −6.479 mA ⋅ cm⁻²). Moreover, the MFC with Cu−NC−800 showed a power density of 662.8±3.6 mW ⋅ m⁻², which was higher than that of Cu−C−800 (425.7±3.9 mW ⋅ m⁻²) and was slightly lower than that 20 wt % Pt/C (815.0±6.2 mW ⋅ m⁻²). The output voltage of MFC with Cu−NC−T had no obvious decreasing trend in 30 days, demonstrating that the Cu−NC−T had great stability.     

Optimizing the Photovoltaic Performance of Organic Solar Cells for Indoor Light Harvesting

Organic solar cells (OSCs) harvesting indoor light are highly promising for emerging technologies, such as internet of things. Herein, the photovoltaic performance of PTB7-Th:PC₇₁BM solar cells constructed using “optimized (with 1,8-diiodooctane (DIO))” and “non-optimized (without DIO)” processing conditions are compared for indoor and outdoor applications. We find that in comparison to the “optimized” solar cell, the “non-optimized” solar cell is less efficient under simulated solar light illumination (100 mW cm⁻², spectral range 350–1100 nm), owing to significant bimolecular charge carrier recombination losses. However, under simulated indoor illumination (3.28 mW cm⁻², spectral range 400–700 nm), bimolecular recombination losses are effective suppressed, thus the power conversion efficiency of the solar cell without DIO was increased to 14.7 %, higher than that of the solar cell with DIO (14.2 %). These results suggest that the common strategy used to optimize the OSCs could be undesired for indoor OSCs. We demonstrate that the efforts for realizing the desired “morphology” of the active layer for the outdoor OSCs may be unnecessary for indoor OSCs, allowing us to realize high-efficiency indoor OSCs using a non-halogenated solvent.     

Au/La2Ti2O7 Nanostructures Sensitized with Black Phosphorus for Plasmon‐Enhanced Photocatalytic Hydrogen Production in Visible and Near‐Infrared Light

Efficient utilization of solar energy is a high‐priority target and the search for suitable materials as photocatalysts that not only can harvest the broad wavelength of solar light, from UV to near‐infrared (NIR) region, but also can achieve high and efficient solar‐to‐hydrogen conversion is one of the most challenging missions. Herein, using Au/La₂Ti₂O₇ (BP‐Au/LTO) sensitized with black phosphorus (BP), a broadband solar response photocatalyst was designed and used as efficient photocatalyst for H₂ production. The optimum H₂ production rates of BP‐Au/LTO were about 0.74 and 0.30 mmol g⁻¹ h⁻¹ at wavelengths longer than 420 nm and 780 nm, respectively. The broad absorption of BP and plasmonic Au contribute to the enhanced photocatalytic activity in the visible and NIR light regions. Time‐resolved diffuse reflectance spectroscopy revealed efficient interfacial electron transfer from excited BP and Au to LTO which is in accordance with the observed high photoactivities.     

Synergistic Photobactericidal Activity Based on Ultraviolet‐A Irradiation and Ferulic Acid Derivatives

Ultraviolet‐A (UV‐A)‐mediated bactericidal activity was enhanced by combined treatment with trans‐ferulic acid (trans‐FA, compound 1 ) or its derivatives. Derivative compounds 4 and 10 contain a phenyl group or an l ‐tyrosine HCl tert‐butyl ester, respectively, linked to the carboxyl group of trans‐FA. Of the three compounds, 10 exhibited the highest synergistic activity in a photobactericidal assay based on treating Escherichia coli with a derivative compound and UV‐A irradiation (wavelength 350–385 nm). Inactivation of viable cells at a 4.9 J cm^?2 UV‐A fluence increased from 1.90 to 5.19 logs in the presence of 10 (100 μm ); a 4.95‐log inactivation was achieved with 10 (5 μm ) and a 7.4 J cm^?2 UV‐A fluence. Addition of antioxidants significantly suppressed photosynergistic bactericidal activity, suggesting that reactive oxygen species (ROS) are involved in the combined bactericidal mechanism. Flow cytometry revealed that combined treatment with UV‐A and compound 10 , which showed the highest photobactericidal activity, generates an excess of oxidative radicals in bacterial cells. The bactericidal activity of compound 10 may be due to electrostatic interaction between the molecule's cationic moiety and the cell surface, followed by amplification of ROS generation in the cells.     

Raman spectrometry and neural networks for the classification of wood types—1

In this work the coupling of near infrared (NIR) Fourier-transform (FT) Raman spectroscopy and neural computing for spectral feature extraction and classification of woods is reported. A NIR FT-Raman spectrometer operating at 1064 nm was used for all measurements; particular attention was paid to the effects of sample fluorescence and heating. It was demonstrated that fluorescence rejection is accomplished only for the lighter colored woods and that fluorescence was found to be severe for 10 of the 71 woods studied in this work even using excitation at 1064 nm. It was further found that hardwoods were no more or less susceptible to sample heating than softwoods. Feed-forward neural networks were used to extract the principal features of wood spectra at resolutions of 4, 8 and 16 cm⁻¹ and to classify spectra as either temperate hardwoods or temperate softwoods. Neural networks were constructed using zero and two processing elements in the hidden layer. It was shown that neural networks with two hidden processing elements perform near optimally, since each hidden layer processing element may function as either a hardwood or softwood feature detector. This work represents the first time that FT-Raman spectroscopy and neural network technology have been coupled for spectral feature extraction and classification.     

Calix[5]phyrin for Fluoride Ion Sensing with Visible and Near Infrared Optical Responses

Fluoride (F⁻) ion sensing is an important topic due to its roles in health, medical, and environmental sciences. In this regard, colorimetric sensors with a near infrared (NIR) optical response are useful in biological systems because they can avoid interference from endogenous chromophores. Although calix[n]phyrins are highly attractive as sensors with the NIR optical response, studies on calix[n]phyrins are still limited owing to their intrinsic instability against ambient light and air. In this study, we report the synthesis and characterization of a new calix[5]phyrin bearing one sp³‐hybridized carbon atom as a π‐expanded calix[n]phyrin. Upon addition of tetrabutylammonium fluoride, the calix[5]phyrin exhibited distinct NIR absorptions at 908 and 1064 nm as well as a visible color change. Importantly, it revealed an excellent selectivity for F⁻ ion. These results demonstrate that calix[5]phyrins are promising colorimetric and NIR sensors of F⁻ ion.     

Effects of 660‐nm and 780‐nm Laser Therapy on ST88‐14 Schwann Cells

The aim of the present study was to evaluate the comparative effects of red (660‐nm) and near‐infrared (780‐nm) low‐level laser therapy (LLLT) on viability, mitochondrial activity, morphology and gene expression of growth factors on Schwann cells (SC). ST88‐14 cells were grown in RPMI 1640 with 10 mM of HEPES, 2 mM of glutamine, 10% fetal bovine serum and 1% antibiotic‐antimycotic solution at 37°C in humidified atmosphere of 5% CO₂. Cells were detached with trypsin and centrifugated at 231 g for 5 min at 10°C, and the pellet (8 × 10⁴ cells/tube) was irradiated at the bottom of 50 ml polypropylene tube with a Twin‐Laser system (660 and 780 nm, 40 mW, 1 mW cm^?2, 3.2 and 6.4 J, 80 and 160 J cm^?2 with 80 and 160 s). After 1, 3 and 7 days, the analysis was performed. After irradiation, the SC increase mitochondrial activity, gene expression of the neural growth factors NGF and BDNF, and cell migration and increase the G2/M cells. SC showed neuronal morphology, normal F‐actin cytoskeleton organization and positive labeling for S100. PBM increased metabolic activity, mitosis and gene expression when irradiated with red and infrared LLLT. An increase in cell migration was obtained when irradiated with infrared LLLT.