Protein Encapsulation: A Nanocarrier Approach to the Fluorescence Imaging of an Enzyme-Based Biomarker

Abstract

Here, we report a new pentafluoropropanamido rhodamine fluorescent probe (ACS-HNE) that allows for the selective detection of neutrophil elastase (NE). ACS-HNE displayed high sensitivity, with a low limit of detection (<5.3 nM), and excellent selectivity toward elastase over other relevant biological analytes and enzymes. The comparatively poor solubility and cell permeability of neat ACS-HNE was improved by creating an ACS-HNE-albumin complex; this approach allowed for improvements in the in situ visualization of elastase activity in RAW 264.7 cells relative to ACS-HNE alone. The present study thus serves to demonstrate a simple universal 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.

Small-molecule fluorescence-based probes for interrogating major organ diseases

“…46 NEP consists of a hemicyanine dye-based NIR fluorophore and a pentafluoropropionamide unit as the recognition unit for NE. 47 The addition of NE (0-10 mg mL À1 ) resulted in a 25-fold fluorescence increase at 700 nm (excitation wavelength 670 nm). The fluorescence emission of NEP displayed good linearity with concentrations of NE (0-1.0 mg mL À1 ) providing a limit of detection (LOD) of 29.42 ng mL À1 .…”

A Deferasirox Derivative That Acts as a Multifaceted Platform for the Detection and Quantification of Fe3+

“…The encapsulation of small molecules in HSA and other proteins has gained increasing attention in recent years since it allows the unique electronic environments inside the protein to be accessed while typically providing increased water solubility [46][47][48]. In our case, it was expected to lead to a fluorescent probe.…”

Most recent advances on enzyme‐activatable optical probes for bioimaging

“…Considering this, it is extremely demanding to develop a reliable assay approach for quantifying the esterase activity as well as analyzing cellular status. In the past 2 years, several activatable probes for esterase have been explored [68][69][70][71][72][73][74] and used for the esterase-related applications, such as discriminating live and dead cells, [69] esterase-triggered PDT, [70] and FL imaging of esterase-based biomarker, [74] etc. The representatives are exhibited in Figure 9.…”