Abstract
We developed a new type of sensor based on enzymatic activity related to inflammation or infection in wounds. This wireless device, integrated into the dressing, will be able to transmit an electrical signal to monitor wound evolution. In this thesis, we focused on designing the sensor part of the device. As biomarkers, we identified proteases that are over-expressed in chronic wounds: MMP-13, a matrix metalloproteinase which indicates inflammation, and human neutrophil elastase (HNE) which indicates infection. The approach used has been to modify the sensor surface with a hybrid material incorporating recognized peptide sequences specific to these proteases. These innovative materials are prepared by sol-gel process using hybrid peptides with one or several alkoxysilane groups able to form a three-dimensional network by polymerization on the sensor surface. We hypothesized that the degradation of this material would lead to a significant change in the electrical properties of the sensor to be detected, indicating active enzymes. To improve sensitivity, we added a metallocene moiety to the peptides that would be degraded, allowing a significant change in the electrical signal. Physicochemical properties of this material were studied and allowed to validate covalent grafting of hybrid material on the sensor and specific degradation of this material by enzymatic activity. These studies were performed by impedance measurement and enabled to design a sensor model grafted by a hybrid material. This work offers opportunities for integrating this sensor, for example, into RFID devices which might enable smart wound dressings to be developed.