A peptide derivatized cellulosic aerogel from cotton as a point of care diagnostic protease sensor

Authors: Fontenot, Krystal; Edwards, Judson - Vince; PIRCHER, NICOLE - University Of Natural Resources & Applied Life Sciences - Austria; LIEBNER, FALK - University Of Natural Resources & Applied Life Sciences - Austria; Prevost, Nicolette

Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 1/15/2016
Publication Date: 3/16/2016
Citation: Fontenot, K.R., Edwards, J.V., Pircher, N., Liebner, F., Prevost, N.T. 2016. A peptide derivatized cellulosic aerogel from cotton as a point of care diagnostic protease sensor. American Chemical Society National Meeting. CELL 322.

Interpretive Summary:

Technical Abstract: Lightweight aerogels are highly porous with usually very small pore size making them suitable for a variety of potential applications as sensors including deformation strain, humidity, organic vapors, thermal, and optical sensing properties. However, little has been reported on their use as biosensors in detecting large biomolecules or proteins. Here we contrast the molecular assembly, and biochemical utility of cellulosic aerogels (CA) prepared from raw cotton. The cotton-based aerogels were prepared by use of a special solubilizing solvent, followed by casting and drying. Characterization of the aerogel included porosity (99 %), average pore size (11 nm), and specific surface area (163 m2g-1) assessment. The nanocellulosic material was derivatized with a fluorescent peptide substrate of elastase (Suc-Ala-Ala-Pro-Val-Amino-methyl-coumarin), and evaluated as a potential diagnostic point of care protease sensor for efficacy at protease concentrations found in wound fluid. The aerogel was assessed with and without the fluorescent peptide substrates using analytical techniques including spectroscopy, molecular modeling, and elemental analysis. Additionally, the aerogels retained some constituents native to the cuticle and primary cell wall of raw cotton, as supported by attenuated total reflectance infrared (ATR-IR). The biosensing activity of the peptide substrate was monitored using a microtiter enzyme assay to determine the response, sensitivity, and kinetic behavior of the biosensor with HNE. The results show that the aerogel is an effective biosensor for detecting elastase (0.125 U/mL), which is a biomarker for chronic wounds and a variety of inflammatory diseases. Furthermore, the utility of using this type of nanocellulosic material in tandem with chronic wound dressings of varying composition is demonstrated by its rapid wicking and highly absorbent character, coupled with a rapid and sensitive fluorescent signal that can be detected by placing a thumbnail size disc on the wound dressing surface.