Human Tissue Simulants for Study of Traumatic Brain Injury (TBI)

Abstract

Blast exposure or head impacts in accidents or contact sports may cause Traumatic Brain Injury (TBI), which is one of most crucial and poorly understood areas of research in the 21st century. To date, human tissues especially the skin and brain tissues (white and grey matter especially) are difficult to obtain and work in a lab setting due to ethical and biosafety issues. This has not allowed for much experimental research into the study of the mechanics of brain tissues under impact or dynamic loading, which is the key to TBI investigation. In the current work, tissue surrogates were developed to precisely mimic the linear and non-linear mechanical behavior of the skin, white and grey matter tissues using a low cost, castable (to any shape or size), multi-part silicone based material system. The fabrication methodology involves the iterative mixing of the two or four parts of silicone at certain mix ratios (by weight) to generate a biomechanical behavior similar to the specific tissues at different strain rates. The non-linear stress versus stretch responses of the tissue surrogates were characterized using the Yeoh’s hyperelastic constitutive model. Besides TBI studies, these novel tissue surrogates have no biosafety or handling issues, and could be indispensable for replacing cadavers and human tissues for clinical surgical trainings.