A H2O2-Responsive Boron Dipyrromethene-Based Photosensitizer for Imaging-Guided Photodynamic Therapy

Abstract

In this study, we demonstrate a novel H2O2 activatable photosensitizer (compound 7) which contains a diiodo distyryl boron dipyrromethene (BODIPY) core and an arylboronate group that quenches the excited state of the BODIPY dye by photoinduced electron transfer (PET). The BODIPY-based photosensitizer is highly soluble and remains nonaggregated in dimethyl sulfoxide (DMSO) as shown by the intense and sharp Q-band absorption (707 nm). As expected, compound 7 exhibits negligible fluorescence emission and singlet oxygen generation efficiency. However, upon interaction with H2O2, both the fluorescence emission and singlet oxygen production of the photosensitizer can be restored in phosphate buffered saline (PBS) solution and PBS buffer solution containing 20% DMSO as a result of the cleavage of the arylboronate group. Due to the higher concentration of H2O2 in cancer cells, compound 7 even with low concentration is particularly sensitive to human cervical carcinoma (HeLa) cells (IC50 = 0.95 μM) but hardly damage human embryonic lung fibroblast (HELF) cells. The results above suggest that this novel BODIPY derivative is a promising candidate for fluorescence imaging-guided photodynamic cancer therapy.

pH-Responsive Pluronic F127–Lenvatinib-Encapsulated Halogenated Boron-Dipyrromethene Nanoparticles for Combined Photodynamic Therapy and Chemotherapy of Liver Cancer

“…Vigorous metabolism in tumor tissues promotes the glucose consumption and lactic acid accumulation, and therefore, the pH conditions in tumor tissues are frequently 0.5–1.0 units lower compared with healthy tissues . As the pH values vary between different tissues and cellular compartments, pH responsiveness has become one of the most extensively exploited triggers . The environment of cancer tissues is more acidic (pH 6.5–6.8) than that of blood and normal tissues (pH 7.0–7.4), while the pH value in cellular endo/lysosomes is even lower (pH 4.5–5.0) …”

“…32 As the pH values vary between different tissues and cellular compartments, pH responsiveness has become one of the most extensively exploited triggers. 33 The environment of cancer tissues is more acidic (pH 6.5−6.8) than that of blood and normal tissues (pH 7.0−7.4), while the pH value in cellular endo/lysosomes is even lower (pH 4.5−5.0). 34 With decreasing pH, the accumulative release of lenvatinib increased, demonstrating the excellent pH-responsive property of LBPNPs.…”

Protective effects of cannabidiol on the membrane proteins of skin keratinocytes exposed to hydrogen peroxide via participation in the proteostasis network

“…H 2 O 2 , used in medicine because of its antiseptic properties (against bacteria, yeasts, fungi and viruses) [ 3 ] and promoting wound healing [ 2 ], has numerous therapeutic advantages in the treatment of certain skin diseases, such as acne [ 45 ], skin infections [ 46 ], actinic keratosis [ 47 ], seborrheic keratosis [ 48 ], squamous cell carcinoma [ 4 ]. Moreover, as a second messenger H 2 O 2 , used alone or with other compounds or nanoparticles, can also increase the sensitization of abnormal cells (such as keratinocytes in seborrheic keratosis) and ultimately the effectiveness of photodynamic therapy [ [49] , [50] , [51] ]. On the other hand, as it is pointed out, H 2 O 2 can also generate serious side effects.…”

Effect of antibacterial photodynamic therapy on Streptococcus mutans plaque biofilm in vitro

“…Due to the change of absorption peak, the absorption rate of the same wavelength laser at di®erent concentrations is di®erent, thus a®ecting the e±ciency of producing singlet oxygen by photosensitizer. 27,28 Due to the enrichment of photosensitizer by bacteria and their surrounding proteins, what form of photosensitizer exists in the microscopic environment and whether this aggregation form will a®ect the selection of excitation light still needs further experimental clari¯cation.…”