# Labeled Bovine Serum Albumin as a Fluorescent Biosensor to Monitor the Stability of Lipid-Based Formulations

## TL;DR

Researchers developed a fluorescent biosensor using labeled bovine serum albumin to monitor the stability of lipid-based drug delivery systems.

## Contribution

The novel use of acrylodan-labeled bovine serum albumin as a biosensor to detect lipid degradation products in real-time.

## Key findings

- The biosensor can detect phospholipids and their degradation products like fatty acids and lysophospholipids.
- It can monitor lipid distribution in aqueous phases and track nanoparticle stability over time.

## Abstract

In the pharmaceutical field, lipid-based nanoparticles are extensively used for drug or vaccine delivery, particularly for treating respiratory disorders. However, their physico-chemical instability, particularly associated with lipid degradation through hydrolysis or oxidation, can affect their encapsulation properties. To monitor the stability of lipid-based formulations over time, we prepared acrylodan-labeled bovine serum albumin (here called albuminodan), and showed it is a fluorescent biosensor capable of concomitantly detect phospholipids as well as their degradation products, i.e., fatty acids and lysophospholipids. We demonstrated that this tool can be used to follow the distribution of lipids in an aqueous phase and hence could be suitable to characterize the hydrolysis of phospholipids in a lipid-based formulation to monitor the stability of nanoparticles.