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Updated: Dec 24, 2025
Affordable Oxygen Microscopy-Assisted Biofabrication of Multicellular Spheroids
Published on: April 6, 2022
Rapid fluorescence detection of hypoxic microenvironments by nitro-benzyl conjugated chitosan nanoparticles
Long Ren1, Young Joon Kim, Song Yi Park
1SKKU Advanced Institute of Nanotechnology (SAINT), School of Chemical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea. yongtaik@skku.edu.
Abstract:
In this study, hypoxia-responsive chitosan nanoparticles (HRCNs) were synthesized by the conjugation of nitro-benzyl derivatives into chitosan polymers and the subsequent self-assembly of them with hydrophobic fluorophores. The nitro-benzyl substrate of HRCNs could be selectively reduced by NTR/NADH that was overexpressed under hypoxic conditions, while it was not responsive to reductive agents (GSH or DTT) commonly existing in biological systems. The HRCN encapsulated with Rhodamine 6G (HRCN-R6G) was successfully applied for the rapid determination of the hypoxic status of lung carcinoma cells (A549) within 30 min, while several hours were required in a conventional assay. In the hypoxic microenvironment, the fluorescence intensity of HRCN-R6G was 2.6-fold higher than that in normoxic conditions. Taken together, the HRCN-R6G is expected to be used for the rapid diagnosis and treatment of hypoxia-related acute diseases, after the incorporation of therapeutic drugs into them.
