Unusual Diffuse Ground-Glass Opacities in the Lungs on 18F-FDG PET/CT: A Case of Melanoma With Pulmonary Metastasis.

ABSTRACT: A 61-year-old man was diagnosed with a malignant melanoma and underwent a resection; he presented with progressive dyspnea after treatment with interferon for 2 months. 18F-FDG PET/CT scan revealed diffuse ground-glass opacities (GGOs) in both lungs with mildly elevated 18F-FDG uptake, similar to that observed with interstitial inflammation. However, a lung biopsy confirmed that the diffuse GGOs were pulmonary metastases of melanoma and were positive for the BRAF mutation. The diffuse GGOs and the progressive dyspnea disappeared after BRAF-targeted therapy. This represents an unusual case of lung metastases from melanoma, mistakenly interpreted as lung inflammation induced by immunotherapy.

The improvement of lysosome targetability with oligoethyleneoxy chains linked benzo[a]phenoxazine.

In order to improve lysosome targetability of probes, fluorescent probes based on benzo[a]phenoxazine attaching different length oligoethyleneoxy chains were designed and prepared. Probes 2a-c containing N-pyridineium-3-yl exhibited almost ON-OFF near-infrared emission responses at 697-701 nm from pH 2.8 to 7.2, and the calculated pKa values of 2a-c were 4.90, 4.92 and 5.03 respectively. More importantly, fluorescent imaging experiments indicated that probes 2a-c were all lysosome biomarkers for Ges-1 and HeLa cells, which was because the introduction of oligoethyleneoxy groups improved the biocompatibility of probes, so that the probes 2a-c were better transported to lysosomes via the endocytosis pathway of the cells. Moreover, the probe 2a was selected as a representative, which not only showed good reversibility and selectivity, but used to successfully image lysosomal pH increases induced by chloroquine.

Construction of dual-functional polymer nanomaterials with near-infrared fluorescence imaging and polymer prodrug by RAFT-mediated aqueous dispersion polymerization.

The performance of functional polymer nanomaterials is a vigorously discussed topic in polymer science. We devoted ourselves to investigating polymer nanomaterials based on near-infrared (NIR) fluorescence imaging and polymer prodrug in this study. Aza-boron dipyrromethene (BODIPY) is an important organic dye, having characteristics such as environmental resistance, light resistance, high molar extinction coefficient, and fluorescence quantum yield. We incorporated it into our target monomer, which can be polymerized without changing its parent structure in a polar solvent and copolymerized with water-soluble monomer to improve the solubility of the dye in an aqueous solution. At the same time, the hydrophobic drug camptothecin (CPT) was designed as a prodrug monomer, and the polymeric nanoparticles (NPs) with NIR fluorescence imaging and prodrug were synthesized in situ in reversible addition-fragmentation chain transfer (RAFT)-mediated aqueous dispersion polymerization. The dynamic light scattering (DLS) and transmission electron microscopy (TEM) revealed the final uniform size of the dual-functional polymeric NPs morphology. The dual-functional polymeric NPs had a strong absorption and emission signal in the NIR region (>650 nm) based on the fluorescence tests. In consideration of the long-term biological toxicity, confocal laser scanning microscopy (CLSM) results indicated that the dual-functional NPs with controlled drug content exhibited effective capability of killing HeLa cells. In addition, in vivo imaging of the dual-functional NPs was observed in real time, and the fluorescent signals clearly demonstrated the dynamic process of prodrug transfer.

Rosamine with pyronine-pyridinium skeleton: unique mitochondrial targetable structure for fluorescent probes.

Two rosamine-based probes (1a-b) with pyronine-pyridinium skeleton were designed and prepared. Probe 1a bearing boron ester unit was oxidized and eliminated upon addition of hydrogen peroxide (H2O2), and the emission spectrum exhibited OFF-ON response accompanied by 33-fold fluorescent enhancement. In contrast, the fluorescence intensity of probe 1b enhanced 58 times after the dinitrophenyl ether part within the probe was removed by nucleophilic substitution with hydrosulfide (H2S). The design concept was based on the d-PET process in pyronine-pyridinium structures, and free 4-pyridinyl-substituted pyronine dye showing strong fluorescence was released followed by elimination. Furthermore, as biocompatible molecules, probes 1a-b have been successfully applied for imaging in live HeLa and Ges-1 cells, and all of them can serve as mitochondrial targetable probes in red channel for detecting independent species.

The pH-influenced PET processes between pyronine and different heterocycles.

The OFF-ON and ON-OFF type pH probes based on rosamine were designed by using the relative electron densities between pyronine and various linked heterocycles. Probe 1a with an indole-pyronine skeleton gave an OFF-ON pH response (pKa = 1.41) with decreasing pH, and the relative fluorescence intensity increased 15-fold, while probe 1b with an imidazole-pyronine skeleton did not give an ON-OFF response to different pH values. When pyronine was connected with a quinolinyl group, i.e., probes 1c-d, the red emission (around 575-800 nm) gave a monotonous ON-OFF pH response (pKa = 3.26 and 2.62, respectively) with decreasing pH. The relative fluorescence intensities decreased 263- and 46-fold, respectively. Changes in the electron donating abilities of the nitrogen containing heterocycles were used to explain variations in PET processes within the probes, and their pH-dependent PET mechanisms were verified using time-dependent density functional theory calculations. Confocal fluorescence imaging was also used to evaluate the potential biomedical application of probes 1a-d. Ultimately, probe 1d with an appropriate pKa value and good biocompatibility showed lysosome targeting ability.