Recent development of nanomaterials-based PDT to improve immunogenic cell death.

被引量：- 发表：1970

Design and synthesis of a 2,5-Diarylthiophene chromophore for enhanced near-infrared two-photon uncaging efficiency of calcium ions.

The design and synthesis of two-photon-responsive chromophores have recently garnered significant attention owing to their potential applications in materials and life sciences. In this study, a novel π-conjugated system, 2-dimethylaminophenyl-5-nitrophenylthiophene derivatives, featuring a thiophene unit as the π-linker between the donor (NMe2C6H4-) and acceptor (NO2C6H4-) units was designed, synthesized, and applied for the development of two-photon-responsive chromophores as a photoremovable protecting group in the near-infrared region. Notably, the positional effect of the nitro group (NO2), meta versus para position, was observed in the uncaging process of benzoic acid. Additionally, while the para-isomer exhibited a single fluorescence peak, a dual emission was detected for the meta-isomer in polar solvents. The caged calcium ion (Ca2+) incorporating the newly synthesized thiophene unit exhibited a sizable two-photon absorption cross-section value (σ2 = 129 GM at 830 nm). Both one-photon and two-photon photoirradiation of caged calcium ions successfully released calcium ions, indicating the potential utility of 2,5-diarylthiophene derivatives in future biological studies.

被引量：- 发表：1970

The effect of fluence rate and wavelength on the formation of protoporphyrin IX photoproducts.

Photodynamic diagnosis and therapy (PDD and PDT) are emerging techniques for diagnosing and treating tumors and malignant diseases. Photoproducts of protoporphyrin IX (PpIX) used in PDD and PDT may be used in the diagnosis and treatment, making a detailed analysis of the photoproduct formation under various treatment and diagnosis conditions important.Spectroscopic and mass spectrometric analysis of photoproduct formation from PpIX dissolved in dimethyl sulfoxide were performed under commonly used irradiation conditions for PDD and PDT, i.e., wavelengths of 405 and 635 nm and fluence rates of 10 and 100 mW/cm2. Irradiation resulted in the formation of hydroxyaldehyde photoproduct (photoprotoporphyrin; Ppp) and formyl photoproduct (product II; Pp II) existing in different quantities with the irradiation wavelength and fluence rate. Ppp was dominant under 635 nm irradiation of PpIX, with a fluorescence peak at 673 nm and a protonated monoisotopic peak at m/z 595.3. PpIX irradiation with 405 nm yielded more Pp II, with a fluorescence peak at 654 nm. A higher photoproduct formation was observed at a low fluence rate for irradiation with 635 nm, while irradiation with 405 nm indicated a higher photoproduct formation at a higher fluence rate.The photoproduct formation with the irradiation conditions can be exploited for dosimetry estimation and may be used as an additional photosensitizer to improve the diagnostics and treatment efficacies of PDD and PDT. Differences in environmental conditions of the present study from that of a biological environment may result in a variation in the photoproduct formation rate and may limit their clinical utilization in PDD and PDT. Thus, further investigation of photoproduct formation rates in more complex biological environments, including in vivo, is necessary. However, the results obtained in this study will serve as a basis for understanding reaction processes in such biological environments.

被引量：- 发表：1970

On the glow of cremated remains: long-lived green photo-luminescence of heat-treated human bones.

The long-lived green luminescence of human bone (that has been heated to 600 °C for a short duration) is attributed to a carbon quantum dot material (derived from collagen) encapsulated and protected by an inorganic matrix (derived from bone apatite) and is more intense in dense rigid and crystalline parts of (healthy) human bones. The strong collagen-apatite interaction results (upon decomposition) in a protective inorganic environment of the luminescent centers allowing long-lived triplet-based emission of a carbon (quantum) dot-like material at room temperature, as well as resilience against oxidation between 550 and 650 °C. The graphitic black phase (obtained upon heating around 400 °C) is a precursor to the luminescent carbon-based material, that is strongly interacting with the crystalline inorganic matrix. Human bone samples that have been heated to 600 °C were subjected to steady-state and time-resolved spectroscopy. Excitation-emission matrix (EEM) luminescence spectroscopy revealed a broad range of excitation and emission wavelengths, indicating a heterogeneous system with a broad density of emissive states. The effect of low temperature on the heat-treated bone was studied with Cryogenic Steady State Luminescence Spectroscopy. Cooling the bone to 80 K leads to a slight increase in total emission intensity as well as an intensity increase towards to red part of the spectrum, incompatible with a defect state model displaying luminescent charge recombination in the inorganic matrix. Time-resolved spectroscopy with an Optical Multichannel Analyzer (OMA) and Time Correlated Single Photon Counting (TCSPC) of these samples showed that the decay could be fitted with a multi-exponential decay model as well as with second-order decay kinetics. Confocal Microscopy revealed distinct (plywood type) structures in the bone and high intensity-fast decay areas as well as a spatially heterogeneous distribution of green and (fewer) red emissive species. The use of the ATTO 565 dye aided in bone-structure visualization by chemical adsorption. Conceptually our data interpretation corresponds to previous reports from the material science field on luminescent powders.

被引量：1 发表：1970

Photodegradation of tylosin tartrate by advanced oxidation processes.

被引量：- 发表：1970