Fluorescent Hydrogel Sensor Particles for Detection of Protease Activity

摘要

We demonstrate the design of novel sensor particles that display fluorescence in the presence of elastase, an enzyme that is present at elevated levels in chronic (non-healing) wounds. Poly(ethyleneglycol acrylamide) hydrogel particles, approximately 200μm in diameter are used as a polymeric matrix, to which a peptide based sensing element is attached. This sensing element consists of a Forster resonance energy transfer (FRET) pair separated by an enzyme cleavable linker. In addition, negatively charged Glutamic acid (Glu) residues are incorporated into the hydrogel structure to facilitate diffusion of the positively charged enzyme into the hydrogel matrix. Enzymatic hydrolysis of the enzyme cleavable linker results in fluorescence of the donor molecule being switched on. We have shown that these particles can detect elastase to a concentration of 100ng/ml, a concentration found in chronic wound fluids. These particles simultaneously detect and address balances in elastase levels and may therefore find applications as smart wound dressings.