In vivo imaging of reactive oxygen species (ROS)-producing pro-inflammatory macrophages in murine carotid atheromas using a CD44-targetable and ROS-responsive nanosensor
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
Authors: Park, Eun Jin; Song, Joon Woo; Kim, Hyun Jung; Kim, Chang-Soo; Song, Yeong Jun; Yang, Dae Hyeok; Yoo, Hongki; Kim, Jin Won; Park, Kyeongsoon
Abstract
In this study, we report the in vivo imaging of reactive oxygen species (ROS)-overproducing pro-inflammatory macrophages in atherosclerotic plaques using a fluorescent ROS nanosensor. We designed the nanosensor by chemically conjugating hyaluronic acid (HA, a targeting ligand for CD44 receptor), chlorin e6 [Ce6; a near-infrared fluorescent (NIRF) dye], and a thioketal (TK) linker (ROS-degradable linker). The self-assembled nanosensor emitted weak NIRF signals in normal physiological conditions, whereas it emitted strong NIRF signals under ROS-abundant conditions. The cytocompatible nanosensor showed higher intracellular internalization via receptor-mediated endocytosis, which enabled the visualization of intracellular ROS in pro-inflammatory macrophages. Moreover, we demonstrated that the nanosensor enabled the successful targeting and imaging of CD44- and ROS-overproducing pro-inflammatory macrophages in atherosclerotic plaques, as validated by confocal microscopy and immunohistological analyses. These data suggest that our ROS nanosensor is suitable for ROS imaging in pro-inflammatory macrophages in vitro and in vivo and will be a promising approach for imaging atherosclerotic tissues and evaluating the effects of antioxidants. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
Effect of photodynamic therapy on the morphological changes of periapical inflammation: An experimental study in rats
PHOTODIAGNOSIS AND PHOTODYNAMIC THERAPY
Authors: Khan, Sultan Zeb; Karim, Samina; Mirza, Sana
Abstract
Aim: We aimed to explore the morphological changes with photodynamic therapy (PDT) in experimentally produced periapical lesions in rats, and to investigate if PDT used as an adjunct to conventional root canal debridement helps to enhance healing the inflammatory response around root apex of rats. Materials and Methods: Sixty adult Sprague-Dawley male rats (70-90 days/140-160 g) were experimented. Pulp was removed from the mesial root of the first maxillary molar and left open to oral environment to allow the formation of periapical lesion. The rats were numbered and randomly divided into two groups: (i) PDT group (n = 30) received a single session of PDT with conventional debridement and, (ii) Control group (n = 30) received conventional debridement but with no PDT. PDT application involved the use of methylene blue photosensitizer for 5 min inside the root canals and irradiated with diode laser of 805 nm and 20 W power output for 90 s and sealed. After 4 weeks, the experimental rats were sacrificed by cervical dislocation. The maxillary first molar was then collected along with the surrounding tissue for further processing. Hematoxylin and eosin and immunohistochemical staining were used to observe the morphological effects. Proliferating Cell Nuclear Antigen (PCNA), STRO-1 and CD-44 were used as the primary antibodies for the immunohistochemical study. Results: A reduction in inflammatory cells, which were mainly composed of lymphocytes, was observed in the periapical lesions after PDT. The number of PCNA-positive cells increased to approximately twice in the PDT as compared to the control group. These PCNA-positive cells included STRO-1 and CD-44 positive cells, indicating enhancement of wound healing and reduction in inflammatory cells. Conclusion: The findings of the present experimental study indicate that PDT application induced proliferation of PCNA-positive cells, which included STRO-1 and CD44-positive cells. This suggests that PDT may help to enhance healing periapical lesion, indicating the potential of PDT in the treatment of periapical periodontitis.