Date of Award

5-12-2024

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Biomedical and Chemical Engineering

Advisor(s)

Mary Beth Monroe

Second Advisor

Alison Patteson

Keywords

Biomaterials;Hemorrhaging;In vitro model;Liver injury;Shape memory polymers;Traumatic wounds

Abstract

Uncontrolled hemorrhage is a leading cause of trauma-related deaths, particularly in combat situations. The most administered treatment is gauze and tourniquets, which are shown to be ineffective for up to 80% of wounds, including non-compressible hemorrhage sites, such as those in the torso region. Shape memory polymer (SMP) foams have been shown to be an effective hemostatic dressing for traumatic wounds due to the tunability of their rapid clotting, mechanical properties, biocompatibility, biodegradability, and drug-loading abilities. The SMP foam design can be characterized with animal models, and a porcine liver injury is the current ‘gold standard’ animal model. To address the ethical concerns regarding the number of animals studies that may be required, an in vitro model was developed to mimic a non-compressible, grade 4 liver injury to optimize the formulation of the SMP foams. In multiple in vitro trials at 75 ml blood flow per minute, SMP foams outperformed the clinical control, QuikClot Combat Gauze, by retaining more blood with gentle compression on simulated wounds, resulting in reduced bleeding. Within the SMP foam formulations, shredded foams retained the most blood at this flow rate compared with cylindrical samples (dry or pre-wetted). With higher bleeding rates (100 ml/min), cylinders out-performed shredded foams. This model will enable characterization of the effects of delivery systems and foam architectures on hemorrhage control efficacy to ensure more efficient animal testing with the most promising candidates in future work.

Access

Open Access

Download

Available for download on Saturday, June 21, 2025

Share

COinS