Bacterial protease-responsive shape memory polymers for infection surveillance and biofilm inhibition in chronic wounds

Maryam Ramezani, Mary Beth Browning Monroe

Research output: Contribution to journalArticlepeer-review


Chronic wound healing is often negatively impacted by infection. Efficient infection assessment is crucial for effective treatment, and biofilm inhibition could improve treatment efficacy. To that end, we developed a bacterial protease-responsive shape memory polymer based on a segmented polyurethane with incorporated poly(glutamic acid) peptide (PU-Pep). Poly(glutamic acid) degrades in response to bacterial proteases to trigger shape recovery of PU-Pep films that are programmed into a secondary shape. These materials have transition temperatures well above body temperature (~60°C), which enables stable storage in temporary shapes after implantation. Synthesized polymers have high shape fixity (~74%–88%), shape recovery (~93%–95%), and cytocompatibility (~100%). Strained PU-Pep samples underwent shape recovery within ≤24 h in response to the V8 enzyme from Staphylococcus aureus (S. aureus, ~50% recovery) and multiple bacteria strains (S. aureus [~40%], Staphylococcus epidermidis [~30%], and Escherichia coli [~25%]), and they had minimal shape change in response to media controls and mammalian cells. Shape recovery of strained PU-Pep samples prevented biofilm formation on the sample surfaces, and resulting attached planktonic bacteria were vulnerable to applied treatments. PU-Pep with physically incorporated antimicrobials simultaneously prevented biofilm formation and killed isolated bacteria. PU-Pep dressings displayed visible shape change and resistance to biofilm formation in in vitro and ex vivo models. In the in vitro model, PU-Pep shape change also disrupted pre-formed biofilm structures. This novel bacterial protease-responsive biomaterial could serve as a wound dressing that changes shape specifically during bacterial colonization to alert clinicians to infection and make biofilm-associated infections easier to treat.

Original languageEnglish (US)
JournalJournal of Biomedical Materials Research - Part A
StateAccepted/In press - 2023


  • bacteria-responsive
  • biofilm inhibition
  • chronic wounds
  • infection assessment
  • polyurethane
  • shape memory polymer

ASJC Scopus subject areas

  • Ceramics and Composites
  • Biomaterials
  • Biomedical Engineering
  • Metals and Alloys


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