A viscoelastic evaluation of an injectable disulfide cross-linked thiol-collagen hydrogel: for tissue bulking post-myocardial infarction to prevent heart failure

Sammanfattning: Cardiovascular diseases are currently the leading cause of death globally. Progression of the disease affects the composition and function of the heart and in many cases subsequently results in heart failure over time where a heart transplant is vital. Therefore, there is a need for medical treatments to stop the progression of the disease. Hydrogels as a biomaterial have been investigated for this purpose, but most known research to date has focused on their bioactive properties. Since a part of the disease progression is affected by the mechanical differences between myocardial tissue and the collagen the body replaces the loss of viable myocardium with after myocardial infarction, this thesis conducted a novel approach of comparing a thiol functionalized collagen hydrogel with a healthy left ventricle in terms of viscoelastic properties for tissue-bulking application. Swelling tests showed that the gel did not swell significantly over time during incubation in phosphate buffer and even if self-healing of the gel after subjection to ultrasound radiation could not be proven and previously used methods to obtain mechanical stiffness of a tissue (compression tests) could not be utilized for soft materials such as hydrogels, the material is of great interest as a candidate for tissue bulking purposes. The gel showed viscoelastic properties similar to the healthy left ventricle and was injectable, to be administrated in a minimally invasive manner, indicating that the material could act as a tissue-bulking agent. This project has developed a new approach to evaluating hydrogels as a biomaterial by comparing it to the viscoelastic characterization of the intended application tissue.