Subventions et des contributions :

Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2022-2023)

The proposed research program aims at the development of novel tissue engineering methods and stethoscopes that may lead to improved diagnosis and treatment of voice, respiratory, and cardiovascular disorders, which are pervasive and affect a large fraction of the population, at high socioeconomic costs. These physiological problems are mainly caused by the malfunction of relatively soft tissues and organs, namely vocal folds, lungs and heart. These soft tissues are highly anisotropic, as they contain fibrillary proteins such as collagen. The dynamics of voice, respiration and blood flow result in surface bending or Rayleigh waves, shear waves, or compressional acoustic waves that are highly damped and scattered through air-tissue or blood-tissue interfaces as well as through the skeletal components of the body.

The first aim of the proposed program is to gain a better understanding of the mechanics of fibrillary composite hydrogels. Collagen I and collagen III fibrils will be synthesized using tropocollagen molecules in solution and their elastic properties will be measured using atomic force microscopy. These collagen fibrils will be incorporated in the composition of a chitosan hydrogel matrix to improve cell recruitment and migration, which was previously found to be insufficient in homogeneous bulk gels. The proposed program will further develop, test and optimize the fibrillary composite hydrogels through a series of mechanical tests. The bonding strength and toughness of a novel tissue adhesive for vocal fold wound closure will be tested.

The second aim of the proposed program lies on the use of minimally invasive accelerometer arrays to capture the acoustic characteristics of the body’s physiological sounds at multiple body locations. The signals captured are lower in frequency than ultrasonic waves, which are used primarily for imaging purposes. Signal processing methods will be used to reduce background noise in order to protrude valid components of interest in raw data. Machine learning and data mining techniques will be used to characterize, identify and diagnose normal and diseased voice, as well as respiratory and cardiac malfunctions.

The proposed research program will help to build diagnostic tools and health monitoring devices, for example a phono-dosimeter that could quantify voice use to prevent phono-trauma, or a stethoscope that could help characterize pathological heart conditions. Our composite chitosan-glycol/glyoxal/collagen scaffolds offer the prospect of a permanent treatment for repair and reconstruction of soft tissues, in particular the vocal fold lamina propria, for the restoration of voice function following atrophy or the ablation of nodules, polyps or other lesions. The proposed research will help create novel health care technologies that will benefit Canadians with voice and other disabilities involving the malfunction of soft organs.