2026-10-14T07:23:47Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34027684 2026-09-29T21:06:21Z category_4 category_146 category_915 category_7 category_12 category_64 portal_63 item_type_6 month_year_09_2026

Modular Orthogonal Dual-Channel Gold Nanosensor Platform for Ratiometric Imaging of Tumor-Associated Macrophage M1/M2 Polarization Ben Liu (143682) Xiaoxi Luo (6087395) Kui He (6293333) Luoqi Mo (14069264) Jinbin Liu (1311705) Biochemistry Space Science Physical Sciences not elsewhere classified Medicine Cell Biology Cancer resolving spatial heterogeneity reliable optical tool flow cytometry (< 2d cell cultures free ratiometric detection analyte ratiometric nanosensors 3 following immunotherapy murine tumor models channel ratiometric nanosensor 3d tumor spheroids modular orthogonal dual simultaneously detect m1 confirming efficient m2 associated macrophage m1 2 </ sup modular dual ratiometric imaging ∼ 3 r </ nanosensor maintains associated macrophages >< sup m2 tumor ” baseline “ always work delivers situ visualization simultaneous imaging progressive reduction phenotypic balance nitric oxide mφ polarization invasively visualizes induced quenching immunotherapeutic outcomes generalized strategy enabling cross design multi cytological approaches conventional histological 96 ). The phenotypic balance between M1 and M2 tumor-associated macrophages (MΦs) governs tumor immune homeostasis and immunotherapeutic outcomes. However, in situ visualization of this polarization equilibrium remains challenging. Conventional histological and cytological approaches only afford static ex vivo phenotyping, while single-biomarker-responsive fluorescent probes lack the capacity to simultaneously detect M1 and M2. Herein, we fabricate a modular dual-channel ratiometric nanosensor for simultaneous imaging and assessment of M1/M2 MΦ polarization states. Two spectrally orthogonal fluorophores responsive to nitric oxide (M1) and arginase-1 (M2) are conjugated onto ultrasmall gold nanoparticles (<3 nm) via orthogonal surface functionalization. This nanosensor maintains an “always-off” baseline through proximity-induced quenching and selectively recovers fluorescence upon biomarker activation, enabling cross-interference-free ratiometric detection. Capable of resolving spatial heterogeneity in MΦ polarization, the nanosensor reveals phenotypic switching in 2D cell cultures and 3D tumor spheroids, and imaging outputs show excellent consistency with flow cytometry (<i>R</i>² = 0.96). Moving further to murine tumor models, it captures the progressive reduction in intratumoral M1/M2 ratiometric signals across tumor progression and non-invasively visualizes an elevation from ∼1.2 to ∼3.3 following immunotherapy, confirming efficient M2-to-M1 reprogramming. This work delivers a reliable optical tool for unraveling tumor immune microenvironment remodeling and provides a generalized strategy to design multi-analyte ratiometric nanosensors. 2026-09-29T00:00:00Z Text Journal contribution 10.1021/jacs.6c16349.s001 https://figshare.com/articles/journal_contribution/Modular_Orthogonal_Dual-Channel_Gold_Nanosensor_Platform_for_Ratiometric_Imaging_of_Tumor-Associated_Macrophage_M1_M2_Polarization/34027684 CC BY-NC 4.0