Protein Encapsulation: A Nanocarrier Approach to the Fluorescence Imaging of an Enzyme-Based Biomarker
Zhiyuan Jia, Hai‐Hao Han, Adam C. Sedgwick, George T. Williams, Lauren Gwynne, James T. Brewster, Steven D. Bull, A. Toby A. Jenkins, Xiao‐Peng He, Holger Schönherr, Jonathan L. Sessler, Tony D. James
Abstract
We report a new pentafluoropropanamido rhodamine fluorescent probe (ACS-HNE) that facilitates the selective detection of neutrophil elastase (NE). ACS-HNE displayed high sensitivity, with a low limit of detection (< 5.3 nM), and excellent selectivity towards elastase over other relevant biological analytes and enzymes. The comparatively poor solubility and cell permeability of ACS-HNE was improved by creating a ACS-HNE-albumin complex; this approach allowed for improvements in the in situ visualisation of elastase activity in RAW264.7 cells relative to ACS-HNE alone. As such the present study serves to demonstrate a simple strategy that may be used to overcome cell impermeability and solubility limitations, and to prepare probes suitable for the cellular imaging of enzymatic activity in vitro.