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An algorithmic approach to single probe Cherenkov removal in pulsed X-ray beams
摘要： Purpose: The removal of Cherenkov light in an optical dosimetry system is an important process to ensure accurate dosimetry without compromising spatial resolution. Many solutions have been presented in the literature, each with advantages and disadvantages. We present a methodology to remove Cherenkov light from a scintillator fibre optic dosimeter in a pulsed megavoltage X-ray beam using the temporal waveform across the pulse. Methods: A sample waveform of Cherenkov light can be measured by exposing only the fibre to the beam. By assuming that the Cherenkov waveform closely matches the intensity of incident radiation, this waveform can be convoluted with the instantaneous scintillation response function to generate an expected scintillation signal. By finding the least-squares fit between these two functions and the experimental data, the estimated Cherenkov contribution can be subtracted off the net signal. This can be applied for arbitrarily complex Cherenkov waveforms (within the 2 ns timing resolution of the data acquisition), and in fact the results suggest more fluctuations in the waveforms provide a better fit to data. Results: Four beam profiles for different field sizes and energies were found with this method. They closely matched references data measured with ionisation chamber with average differences across the beam no more than 4%. Noisy waveforms are assumed to be the primary cause of differences between the analysed scintillator and IC results. We propose methods for improving the results and optimising the data acquisition and analysis processes. Conclusions: These results demonstrate that it is possible and effective with a single probe to use function-fitting of expected data to experimental to remove a complicated Cherenkov signal from the net light signal in pulsed-beam optical dosimetry.
关键词： x-ray,scintillators,fiber-optic dosimetry,microbeam radiation therapy
更新于2025-09-23 15:23:52
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High Photosensitized Singlet Oxygen Generating Zinc and Chloroindium Phthalocyanines Bearing (4-isopropylbenzyl)oxy Groups as Potential Agents for Photophysicochemical Applications
摘要： In this study, novel phthalonitrile derivatives (1 and 2) and their peripherally and non-peripherally tetra (4-isopropylbenzyl)oxy-substituted zinc and chloroindium phthalocyanine complexes (3-6) have been prepared for the first time. The synthesized phthalonitrile derivatives and phthalocyanine complexes were characterized spectroscopically. Not only the chloroindium phthalocyanines but also zinc phthalocyanines are essentially free from aggregation in THF at the studied micromolar concentration. The purpose is to compare the effects of two types of substitution on the phthalocyanines to be used as sensitizers in photodynamic therapy (PDT). Photophysical and photochemical properties of all phthalocyanines are investigated and the results showed that the peripheral phthalocyanines more effectively photooxidize DPBF through singlet oxygen. The photochemical results showed that both ZnPc (3 and 5) and InPc (4 and 6) can be used as sensitizers in PDT because of their very high singlet oxygen quantum yields (range from 0.80 to 0.97).
关键词： Singlet Oxygen,Photosensitizer,Phthalocyanines,Photodynamic Therapy
更新于2025-09-23 15:23:52
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SwissKnife-Inspired Multifunctional Fluorescence Probes for Cellular Organelle Targeting Based on Simple AIEgens
摘要： Facile, efficient and mass production of aggregation-induced emission (AIE) luminogens (AIEgens) with excited-state intramolecular proton transfer (ESIPT) characteristics was achieved by one-step condensation reaction of 2-(hydrazonomethyl)phenol with benzaldehydes. The function of as-prepared AIEgens could be tuned easily by varying the functional group carrying on the phenyl ring of benzaldehyde just like Swiss knife handle. The suitable distance and angle of intramolecular hydrogen bond in these AIEgens endowed them with ESIPT properties, intense solid-state luminescence and large Stokes shifts (155?169 nm). These AIEgens could not only serve as biological probes showing specific targeting to lipid droplets, endoplasmic reticulum and lysosomes, respectively, but also generate reactive oxygen species upon visible light irradiation to make them promise for photodynamic therapy.
关键词： Fluorescence probes,Aggregation-induced emission,Excited-state intramolecular proton transfer,Photodynamic therapy,Organelle-targeting
更新于2025-09-23 15:23:52
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Chlorin e6 and halogen light as a sebostatic photomedicine modulates linoleic acid-induced lipogenesis
摘要： Introduction Backgrounds: Chlorin e6-mediated photodynamic therapy (Ce6-PDT) showed anti-microbial and anti-inflammatory effects on acne vulgaris model previously. Excess sebum production in sebocytes is a crucial cause of acne. However, information on the effect of Ce6-PDT associated with lipogenesis in sebocytes has not been reported so far. Methods: The oil red O staining, triglyceride assay and cholesterol assay were used to investigate lipid synthesis in human sebocytes. The expressions of various molecular signals associated with lipogenesis were examined by western blot analysis. Results: Ce6-PDT reduced the lipid content of cultured sebocytes. The inactivation of Akt, mTOR, Raptor, PPARγ and C/EBPα, as well as the activation of AMPK, were revealed to be the molecular signals associated with sebostatic modulation by Ce6-PDT. Conclusion: Ce6-PDT using halogen light exerts anti-lipogenesis in sebocytes and may be utilized for the treatment of acne vulgaris.
关键词： Sebocytes,Anti-lipogenesis,Photodynamic therapy,Halogen light,Ce6
更新于2025-09-23 15:23:52
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Porphyrin–High-Density Lipoprotein: A Novel Photosensitizing Nanoparticle for Lung Cancer Therapy
摘要： Background. We have developed ultrasmall porphyrin–high-density lipoprotein (HDL) nanoparticles (<20 nm), called “porphyrinHDL,” that have a high density of porphyrin molecules and dissociate rapidly upon tumor cell accumulation to become ?uorescent and photoactive. This is introduced as a novel activatable photosensitizer for image-guided photodynamic therapy (PDT). Here, we report the studies of these nanoparticles targeted to scavenger receptor class B type I (SR-BI) expressed on lung cancer cells as a ?rst step toward development of a minimally invasive treatment for peripheral lung cancer and metastatic lymph nodes of advanced lung cancer. Methods. The in vitro uptake of porphyrinHDL and the corresponding PDT ef?cacy were evaluated in both SR-BI–positive and SR-BI–negative lung cancer cell lines. A clinically relevant orthotopic lung cancer model in mice was used to examine ?uorescence activation and quanti?cation of uptake in tumor. In addition, we investigated the effect of porphyrinHDL-mediated PDT. Results. PorphyrinHDL promoted proper intracellular uptake in the H460 human lung cancer cell line. When irradiated with a 671-nm PDT laser, porphyrinHDL produced signi?cant therapeutic effectiveness in vitro. After systemic administration in mice with orthotopic lung cancer xenografts, porphyrinHDL demonstrated selective accumulation and photoactivation in tumor with signi?cantly enhanced disease-to-normal tissue contrast. Moreover, porphyrinHDL-PDT signi?cantly induced cell apoptosis in lung tumors (73.2%) without toxicity in normal tissues or damage to adjacent critical structures. Conclusions. SR-BI–targeted porphyrinHDL-mediated PDT of lung cancer is selective and effective in vitro and in vivo. These initial proof-of-principle studies suggest the potential of a “smart” PDT approach for highly selective tumor ablation.
关键词： Nanoparticles,PorphyrinHDL,Lung cancer,Scavenger receptor class B type I,Photodynamic therapy
更新于2025-09-23 15:23:52
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Mesoporous silica-coated gold nanoframes as drug delivery system for remotely controllable chemo-photothermal combination therapy
摘要： Tumor cells experience higher chemotherapy stress under condition of elevated temperature. As a result, developing novel nanoagents that integrates chemotherapy and thermotherapy holds great promise in biomedicine. Herein, utilizing spatially confined galvanic replacement method, we fabricated a yolk-shell Au@mSiO2 nanoframes with Au NPs and mesoporous silica as yolk and shell, respectively, to sever as an excellent drug nanocarrier with effective photothermal conversion efficiency. Taking full advantage of the high temperature response of the Au@mSiO2 nanoframes, the phase change material 1-tetradecanol (TD) was creatively employed as gatekeepers, intelligently controlling the release of loaded agents. Then, the actively targeted Alanine-Alanine-Asparagine, legumain-recognizable oligopeptides was decorated on the surface of the prepared nanoframes. Upon exposure to near-infrared light, the GC-PtAu@mSiO2-TD nanoframes not only exhibited a high localized temperature response, but also triggered the quick release of loaded cargos, and thus improved the chemotherapeutic efficacy. The in vitro cytotoxicity studies indicated the remarkable synergistic effects. Meanwhile, the laser confocal studies and flow cytometry showed the oligopeptides facilitated the intracellular uptake of GC-PtAu@mSiO2-TD nanoframes in MGC-803 cells. Our study highlighted the great potential of the GC-PtAu@mSiO2-TD nanoframes in drug delivery and the combination of chemotherapy and photothermal therapy.
关键词： Cisplatin,Mesoporous silica-gold nanoframes,Phase-change materials,Photothermal therapy,Controlled release
更新于2025-09-23 15:23:52
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Pd nanoparticle-decorated hydroxy boron nitride nanosheets as a novel drug carrier for chemo-photothermal therapy
摘要： A multi-stimuli responsive nanoagent, hydroxy boron nitride nanosheets and Pd nanohybrids (Pd@OH-BNNS), was studied. The well-dispersed hydroxy boron nitride nanosheets were prepared via a facile thermal substitution approach. Pd@OH-BNNS was endowed with a photothermal property after in situ formation of Pd nanoparticles on the surface of the nanosheets. Pd@OH-BNNS as a drug delivery carrier exhibited high loading capability for the anticancer drug doxorubicin. The release of doxorubicin from the nanohybrids was triggered by a decrease in pH, and increases in glutathione concentration and near-infrared irradiation. The faster release behavior of the nanohybrids under near-infrared irradiation was confirmed by a cellular uptake study. In addition, local hyperthermia was verified using an imaging test and an infrared thermal camera. Tumor growth was remarkably inhibited in mice after two weeks of treatment with Pd@OH-BNNS/doxorubicin injection, demonstrating the high efficacy of combining chemotherapy and photothermal therapy. The Pd@OH-BNNS as a drug delivery system exhibited good stability, low cytotoxicity and multi-stimuli responsiveness.
关键词： photothermal therapy,Pd nanoparticles,drug delivery system,hydroxy boron nitride,nanohybrids
更新于2025-09-23 15:23:52
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Topical treatment with oleocanthal extract in reducing inflammatory reactions after photodynamic therapy: a prospective quasi-experimental pilot study
摘要： Objective: Photodynamic therapy (PDT) is an effective treatment against skin field cancerization. Its main side effect is local inflammation in the treated area. The phenolic compound oleocanthal (decarboxy methyl ligstroside aglycone), which is present in extra virgin olive oil (EVOO), has anti-inflammatory properties. The purpose of this study was to evaluate the topical efficacy of an oily fluid enriched with oleocanthal (OC) extract, in comparison with a conventional oily fluid, in reducing the degree of inflammatory reaction after conventional PDT. Methods: Quasi-experimental pilot study, before-after with a control group, performed with a cohort of consecutive patients diagnosed with actinic keratosis/field cancerization (AK/FC) in the forehead and/or scalp, treated by PDT. The study was carried out from April 2016 to November 2017 at a speciality hospital in southern Spain. A group of 24 consecutive patients received the topical application, three times daily for one week, of an emollient oily fluid in the area treated with PDT. Subsequently, another group, of 23 consecutive patients, received the same treatment pattern with an oily fluid enriched with OC extract. The post-PDT inflammatory reaction was measured by an independent member of the hospital's dermatology department, using the following visual scale of erythema (from 0 to 4). The assessment was conducted at 30 min and at 48 h post-PDT. Results: In the assessment at 48 h after treatment, the inflammation had improved more among the patients treated with OC (median: 25%, 95%CI: -5.3 to 28.5) than in the non-OC group (median: 0%; 95%CI: -45.2 to -6.2). The difference was statistically significant (p < 0.01), and the Cohen's d value was 0.89 (large effect). At three months after PDT, a complete response had been obtained by 60.9% of the patients treated with OC compared to 29.2% of the non-OC group, and the difference was close to statistical significance (p=0.059). Conclusions: The topical application of an oily fluid enriched with OC extract achieved a greater reduction in post-PDT cutaneous inflammation and a better treatment response, in comparison with the application of a conventional oily fluid.
关键词： Skin barrier,Oleocanthal,Emulsions,Virgin olive oil,Skin physiology,Photodynamic therapy
更新于2025-09-23 15:23:52
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Effect of the Photodynamic Therapy Applications with Potent Microalgae Constituents on Several Types of Tumor
摘要： Background: In recent years, microalgae (MA) have attracted much interest considering their possible therapeutic application. They contain active natural compounds or derivatives (extracts, pure or chemically modified compounds) that have increasing applications in the pharmaceutical industry. Methods: The present study aims to examine microalgae for new photosensitizers, with a potential to be used in the light-associated treatment of tumors. Semi-purified extracts of several microalgae strains were evaluated as photosensitizers for photodynamic therapy (PDT) applications. Four tumor cell lines (A549, LNCap, MCF-7, and MDA-MB 435) were used to assess 34 samples extracted by three methods: cellulase enzyme, lysozyme enzyme and ultra-sonication. The fluorescence measurements and the recorded images alongside the spectral intensities between 650–800 nm wavelengths provided characteristic features to some of the contents of the examined extracts. Results: Several microalgae constituents activated by blue light (BL), red light (RL) or both (in sequence) exhibited significant effects on the viability of the tumor cell lines, decreasing it as much as 95% for certain MA constituents. Majority of the MA constituents showed a higher phototoxicity after exposure to both blue and red lights than the photo-induced toxicity when exposed to a single light source. The viability of the tumor cells exhibited the dose dependent response with the MA constituents. Conclusion: The results clearly showed that MA constituents are potential photosensitizers that have a significant photo-damage effects on the tested cancer cells.
关键词： Anticancer agent,Microalgae,Enzymatic extraction,Photodynamic therapy,Photosensitizers
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE Biomedical Circuits and Systems Conference (BioCAS) - Cleveland, OH, USA (2018.10.17-2018.10.19)] 2018 IEEE Biomedical Circuits and Systems Conference (BioCAS) - Development of a Portable Intraoral Camera and a Smartphone Application for Oral Cancer PDT Treatment Guidance and Monitoring
摘要： Oral cancer presents a public health crisis, particularly in regions where widespread use of tobacco, betel quid and acacia extract lead to disproportionately high incidences of oral malignancies. Photodynamic therapy (PDT) has shown to work efficiently in early-stage oral cancer lesions; however, physicians require a method capable of assisting them during therapy delivery, so treatments can be more effective. Several studies explore how to take advantage of photosensitized fluorescent lesions to perform imaging with the purpose of guiding and monitoring patients undergoing PDT; however, these streamlined systems for intraoral PDT treatment guidance and monitoring are needed in order for this approach to achieve optimal outcomes. This paper proposes the development of a smartphone application capable of processing images taken with an endoscopy camera directly connected to the device. PDT guidance and monitoring can be simplified, and treatment could be delivered more efficiently, increasing the chance of achieving a complete tumor response.
关键词： intraoral camera,smartphone application,image processing,android development,photodynamic therapy,Oral cancer,fluorescence
更新于2025-09-23 15:23:52