Indocyanine green-incorporated exosomes for improved in vivo imaging of sentinel lymph node

Gyeonghui Yu,Heesun Jung,Hyejung Mok

doi:10.1007/s13765-015-0141-8

Gyeonghui Yu, Heesun Jung + Show 1 more

Open Access

https://doi.org/10.1007/s13765-015-0141-8

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Abstract

For improved physical stability and fast accumulation in sentinel lymph nodes in vivo, indocyanine green (ICG) was incorporated into exosomes (EXOs) to form a novel ICG-based near-infrared fluorescence probe. Compared with free ICG, prepared ICG-TBAI-encapsulated EXOs (ICG/EXOs) smaller than 50 nm had greater physicochemical stability in aqueous solution when exposed to light at 37 °C. In addition, sentinel lymph nodes were visualized within minutes with ICG/EXOs at a low ICG dose (0.05 mg/kg) owing to its well-controlled size distribution. Taken together, the results show that ICG/EXOs are effective biocompatible and sensitive near-infrared probes for real-time sentinel lymph node imaging in vivo.

Highlights

For improved physical stability and fast accumulation in sentinel lymph nodes in vivo, indocyanine green (ICG) was incorporated into exosomes (EXOs) to form a novel ICG-based near-infrared fluorescence probe
After the isolation of EXOs from Fetal bovine serum (FBS), the amount of isolated exosomal protein was quantified with a BCA assay (Twu et al 2013)
The total amount of protein in the EXOs in phosphate-buffered saline (PBS) solution with detergent (1 % Tx-100) was similar to that in EXOs in solution without detergent, which suggests that the total exosomal proteins in the exterior and interior regions of the EXOs were measured with the BCA assay

Summary

Introduction

For improved physical stability and fast accumulation in sentinel lymph nodes in vivo, indocyanine green (ICG) was incorporated into exosomes (EXOs) to form a novel ICG-based near-infrared fluorescence probe. ICG was incorporated into EXOs, and the combination was evaluated for real-time imaging of sentinel lymph nodes. EXOs (protein amount, 40 lg) were mixed with ICG-TBAI at an ICG/exosomal protein weight ratio of 0.1 at 37 °C for 2 h.

Results

Conclusion