Self-assembling peptides as biofunctional component in medical fabrics

The importance of medical fabrics is reflected by increased clinical need and consumption over the past decade in the health and medical sectors. Medical fabric products, including wound dressings, are currently defined as ‘medical devices’ by European legislation. To ensure effectiveness as a wound dressing, these fabrics should assist the repair process by providing sufficient protection against bacterial spread in the wound bed. Chronic wounds are an increasingly urgent health problem, owing to the rising population of elderly, obese and diabetic patients. When treating such wounds with drug releasing dressings, the immediate release of the drug is a common limitation. Thus, the development of smart drug delivery dressings that release antibacterial agents into the wound bed when required would be a useful aid in medicine. The overall aim of this study was to develop a wound dressing that was able to release the antibacterial agents only in the presence of bacteria. Medical dressings were treated with pH-responsive, self-assembling peptides as antibacterial carriers that were able to release the loaded drug when stimulated by the bacterial pH. A methodology developed for potential future medical application is presented. The preliminary design consisted of three stages. First, the self-assembled peptide candidates were studied and selected as drug carriers. Second, fabrics were treated with the selected self-assembled peptides using two different methods: (1) coating with the peptides from the outer surface by impregnating in peptide solution and (2) incorporating the self-assembled peptides within the structure by electrospinning. The treatment success of the dressing was investigated using a series of complementary techniques such as FTIR, TEM, SEM and CLSM. Third, potential effectiveness of the dressings was assessed in vitro using two antibiotics model, vancomycin and levofloxacin separately, against a Staphylococcus epidermidis bacterial strain, a species commonly found in infected wounds. The study findings clearly demonstrated the in vitro potential of self-assembling peptide technology in improving the function of medical fabrics.