Event

PhD Dissertation Defense: Paula Montero Atienza

Friday, August 14, 2026
12:00 p.m.
CHM 1112 Chemistry Building
Debbie Chu
301 405 8268
dgchu@umd.edu

Title: Engineering Next-Generation Biomaterials for Hemorrhage Control and Tissue Repair

Committee members:
Dr. Srinivasa R. Raghavan, Chair
Dr. William E. Bentley
Dr. Giuliano Scarcelli
Dr. Matthew B. Dowling
Dr. Shaik O. Rahaman, Dean's Representative

Abstract:
Uncontrolled bleeding from injuries is a leading cause of preventable death in both trauma and surgical settings, and materials engineered to arrest such bleeding are termed hemostats. Many hemostats contain water, including sealants, gels, and foams, but this water adds weight and a risk of microbial contamination, thereby compromising portability and shelf life. This dissertation engineers two classes of water-free hemostats for different classes of bleeding injuries, and thereafter investigates electroadhesive hydrogels as sealants over injuries to tubular organs. The first material is a dry granule based on chitosan functionalized with hydrophobic tails and catechol groups. On contact with a wound, the granules absorb a portion of the blood while the residual liquid forms capillary bridges that bind the granules into a cohesive gel, the same mechanism by which wet sand congeals into a sandcastle, and the catechols anchor this gel to the underlying tissue. The second material addresses non-compressible hemorrhage in the truncal regions, for which most fatal hemorrhages occur and no FDA-approved hemostats exist. It is a self-expanding powder that, upon contact with blood, generates a foam that fills the body cavity while superabsorbent particles gel the fluid between the bubbles, allowing the gelled foam to press against the injured vessels without manual compression. Both materials are evaluated in porcine injury models. Finally, electroadhesion, a recent discovery from our laboratory in which cationic gels are bonded to tissue by a low DC voltage, is explored as a surgical modality for repairing the esophagus and trachea, either in place of sutures for small injuries or as a reinforcement over sutures for larger ones.

The overall goal of this dissertation is to advance biomaterials for hemorrhage control and surgical repair by combining, within a single material, functions that existing hemostats and sealants provide only separately. This is achieved by 1) developing dry granules that both absorb blood and adhere to wet tissue, 2) developing a powder that expands into and holds within a body cavity that cannot be compressed, and 3) demonstrating that an electroadhered gel patch seals repairs that sutures hold closed but do not make leak-tight.