Pseudomonas aeruginosa and Staphylococcus aureus causes severe infections, especially in nosocomial environments. The cells are often deeply imbedded in biofilms, which makes treatment of the infections extremely difficult. Cells exposed to antibiotic levels below MIC (minimal inhibitory concentration) may develop resistance. The aim of this study was to develop a drug carrier that would keep antibiotic levels, in this case Ciprofloxacin, well above MIC for the duration of treatment. By electrospinning Ciprofloxacin into a nanofiber scaffold consisting of poly(D,L-lactide) (PDLLA) and poly(ethylene oxide) (PEO), the antibiotic was released within 2 h, killing 99% of P. aeruginosa and 91% of a methicillin-resistant strain of S. aureus in a biofilm. Ciprofloxacin, which remained intact, were released from the nanofibers for 7 days at levels above MIC. The nanofibers were not toxic when tested against MCF-12A breast epithelial cells. Antibiotic-filled nanofibers may be the answer to the eradication of P. aeruginosa and S. aureus biofilms.
Antibiotic resistance in bacterial pathogens is a major cause of concern for modern medicine, as this renders these “miracle drugs” ineffective. The accidental discovery of penicillin in 1928 by Alexander Fleming and the countless lives saved by this antibiotic in the 1940’s pioneered modern medicine. However, injudicious use of penicillin and various other antibiotics has caused a major problem in the treatment of “once easily treatable” bacterial infections. A marked increase in antibiotic-resistant pathogens has been reported over the last few decades, including the well-known methicillin-resistant Staphylococcus aureus (MRSA). The emergence of multi-drug resistant bacteria has amplified this problem. Antibiotic resistance is causing a regression back to a “pre-antibiotic era” where a minor scrape or cut can lead to a battle between life and death. Skin is our first line of defence against the onslaught of various pathogens causing infection; it plays a role in thermoregulation and maintaining of homeostasis in addition to having immunological, neurosensory and metabolic functions. Severe skin damage, however, exposes underlying tissue to microbial invasion which can easily progress into severe life threatening infections if not treated successfully.