Human neutrophil elastase detection with fluorescent peptide sensors conjugated to cellulosic and nanocellulosic materials: part II, structure/function analysis

Authors: Fontenot, Krystal; Edwards, Judson - Vince; HALDANE, DAVID - Innovatech-Engineering; Graves, Elena; Santiago Cintron, Michael; Prevost, Nicolette; French, Alfred - Al; Condon, Brian

Submitted to: Cellulose
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2015
Publication Date: 3/26/2016
Citation: Fontenot, K.R., Edwards, J.V., Haldane, D., Graves, E.E., Santiago Cintron, M., Prevost, N.T., French, A.D., Condon, B.D. 2016. Human neutrophil elastase detection with fluorescent peptide sensors conjugated to cellulosic and nanocellulosic materials: part II, structure/function analysis. Cellulose. 23(2):1297-1309.

Interpretive Summary: A natural source of cotton and wood is employed to generate cellulose and nanocellulose sensors for the detection of human neutrophil elastase. As previously reported, the cellulose (filter paper and print cloth fabric) and nanocellulose (wood cellulose nanocrystals and wood nanocellulose composites) were immobilized with a fluorogenic peptide substrate and here we evaluate its ability to detect human neutrophil elastase. Due to the higher surface area and peptide loading the nanocellulose transducers, wood cellulose nanocrystals were more sensitive towards detecting human neutrophil elastase. The wood cellulose nanocrystals (in comparison to previously reported data for cotton cellulose nanocrystals) had a two-fold increase in detecting human neutrophil elastase at levels found in chronic wounds. The nanocrystals are a promising biosensor for detecting human neutrophil elastase and other inflammatory diseases.

Technical Abstract: Human neutrophil elastase (HNE) is one of a number of proteases that is receiving increased attention as a marker for inflammatory diseases and sensor-based point of care diagnostics. Integral to sensor-based detection is the transducer surface which is the platform of the sensor's signal transmittance. Here we describe the bioactivity and related transducer surface properties of cellulose and nanocellulose matrices as peptide-cellulose fluorescent sensors. Detection sensitivity of the sensor signals for HNE levels typically found in chronic wounds is characterized. The fluorescent elastase peptide substrate, Succinamidyl-Ala-Ala-Pro-Valamidylcoumadin (Pep) was employed in both cellulose and nanocellulose transducer surfaces evaluated for biosensor sensitivity to HNE. The cellulose transducers selected are filter paper (FP) and print cloth (PC) fabric and are comprised of processed cotton fibers. The nanocellulose transducers are the wood cellulose nanocrystals (wCNC) and the wood nanocellulose composites (wNCC). The wNCCs consist of blended quantities of nanocrystalline and microfibrillated cellulose at 66/33 and 50/50, and are characterized as thin films. The biosensor activity was in the order of wCNC-Pep>FP-Pep =NCCPep(50/50)>NCC-Pep(66/33)>PC-Pep. Sensor sensitivity correlated with specific surface area (SSA). A depiction of peptide substitution on nanocellosic and cellulosic surfaces is rendered through peptide-cellulose crystallite models derived from x-ray diffraction analysis of the material, and the models discussed in light of biosensor structure activity relationships. In addition, the overall morphology, pore size and porosity of the materials are discussed for their suitability as protease sensors.