The effect of Gd-DOTA locations within PLGA-b-PEG micelle encapsulated IR-1061 on bimodal over-1000 nm near-infrared fluorescence and magnetic resonance imaging. (15th September 2022)

• Record Type: Journal Article
• Authors: Doan, Thi Kim Dung; Umezawa, Masakazu; Okubo, Kyohei; Kamimura, Masao; Yamaguchi, Masayuki; Fujii, Hirofumi; Soga, Kohei
• Is Part Of: Biomaterials science. Volume 10:Number 21(2022)
• Page Start: 6244
• Page End: 6257
• Publication Date: 2022-09-15
• Subjects: Biomedical materials -- Periodicals; 610.28
• DOI: 10.1039/d2bm01213h
• Languages: English
• ISSNs: 2047-4830

Abstract

Abstract : The influence of Gd-DOTA locations on the fate of imaging probe in vivo . Abstract : Multimodal imaging is attractive in biomedical research because it can provide multidimensional information about objects that individual techniques cannot accomplish. In particular, combining over one-thousand-nanometer near-infrared (OTN-NIR) fluorescence and magnetic resonance (MR) imaging is promising for detecting lesions with high sensitivity and structural information. Herein, we describe the development of a bimodal OTN-NIR/MRI probe from gadolinium-tetraazacyclododecanetetraacetic acid (Gd-DOTA) conjugated poly(lactic- co -glycolic acid)- block -poly(ethylene glycol) copolymer (PLGA- b -PEG) micelle encapsulated IR-1061 at two different locations. One configuration contains Gd-DOTA at the end of the PEG of the hydrophilic shell and the other contains Gd-DOTA at the border of PLGA/PEG. The two structures show remarkable differences in fluorescence and R 1 relaxation rates in biological environments; the structure with Gd-DOTA at the border of PLGA/PEG exhibits stable fluorescence and T 1 signal distribution in live mice. The introduction ratio of Gd-DOTA to PEG is significant for controlling the properties of both structures; a higher Gd-DOTA ratio is preferable for the contrast enhancement effect. We found that Gd-DOTA ratios higher than 10% degraded the fluorescence intensity when Gd-DOTA was bound to the end of PEG. In contrast, the introduction of 70% Gd-DOTA at the border of PLGA/PEG did not exhibit a degraded signal, and the structural stability was enhanced with higher ratios of Gd-DOTA. In conclusion, we confirmed that the location of Gd-DOTA is a crucial factor in designing high-performance probes. The overall properties improve when Gd-DOTA is set on the border of PLGA/PEG. These improvements in the properties by controlling the probe structures are promising for future biomedical applications.