Hemorrhage is the
primary cause of trauma-related death. Of patients
that survive, polymicrobial infection occurs in 39% of traumatic wounds
within a week of injury. Moreover, traumatic wounds are susceptible
to hospital-acquired and drug-resistant bacterial infections. Thus,
hemostatic dressings with antimicrobial properties could reduce morbidity
and mortality to enhance traumatic wound healing. To that end,p-coumaric acid (PCA) was incorporated into hemostatic shape
memory polymer foams by two mechanisms (chemical and physical) to
produce dual PCA (DPCA) foams. DPCA foams demonstrated excellent antimicrobial
and antibiofilm properties against nativeEscherichia
coli,Staphylococcus aureus, andStaphylococcus epidermidis;
co-cultures ofE. coliandS. aureus; and drug-resistantS. aureusandS. epidermidisat short (1 h)
and long (7 days) time points. Resistance against biofilm formation
on the sample surfaces was also observed. Inex vivoexperiments in a porcine skin wound model, DPCA foams exhibited
similarly high antimicrobial properties as those observedin vitro, indicating that PCA was released from the DPCA
foam to successfully inhibit bacterial growth. DPCA foams consistently
showed improved antimicrobial properties relative to those of clinical
control foams containing silver nanoparticles (AgNPs) against single
and mixed species bacteria, single and mixed species biofilms, and
bacteria in theex vivowound model. This system
could allow for physically incorporated PCA to first be released into
traumatic wounds directly after application for instant wound disinfection.
Then, more tightly tethered PCA can be continuously released into
the wound for up to 7 days to kill additional bacteria and protect
against biofilms.