Design of an Injectable p-Hairpin Peptide Hydrogel That Kills Methicillin-Resistant Staphylococcus aureus

摘要

Hydrogels are heavily hydrated materials that are finding use in a number of technological applications, including use as inject-ables to treat wounds and as surface coatings for implantable materials. In general, infection at a wound site prolongs healing, and with respect to medical implants, infection at the implant-tissue interface can play a causative role in implant failure. Methicillin-resistant Staphylococcus aureus (MRSA) is a now common drug-resistant bacterium that accounts for about 55% of all nosocomial infections acquired in intensive care units in the United States. It is also found in isolates of medical implant-related infections. MRSA gained resistance to conventional β-lactam antibiotics by evolving a cell surface, penicillin-binding protein (PBP2a) that participates in peptidoglycan synthesis but is minimally affected by β-lactam antibiotics. Thus, MRSA infections are normally treated with a combination of drugs, such as quinuprisitn and dalfopristin, that inhibit the early and late stages of protein synthesis, respectively. However, there is concern that MRSA may eventually evolve resistance to these therapies in the near future. Here, we describe the design of a peptide-based, injectable hydrogel that is inherently antibacterial and can kill MSRA on contact.