Battling Bacteria with Free and Surface-Immobilized Polymeric Nanostructures

With the discovery of antibiotics, bacterial infections and previously fatal diseases suddenly became curable. During the golden era of antibiotics, new classes of antibiotics were discovered. However, antibiotic-resistant bacteria rapidly evolved while fewer new antimicrobial drugs were discovered and marketed. Today, a growing number of infections are becoming harder to treat as the bacterial resistance is spreading and antibiotics become less effective. Evidently, there is an urgent demand for new strategies that efficiently battle pathogenic bacteria. Among emerging technologies, those involving polymeric nanostructures, especially polymersomes, offer many features that make them attractive candidates for battling infections. Polymersomes can be designed to be biocompatible and respond to various environmental signals. They are more robust than liposomes and can host hydrophobic and hydrophilic antimicrobial compounds, which can be released and act locally. Last but not least, they are biodegradable. Moreover, platforms comprising polymeric nanostructures can be designed as sensors for diagnosing infections. Many of these approaches require the immobilization of the antimicrobial nanostructures on a surface whereby the activity is localized to a specific region. Several recent examples of polymeric nanostructures with antimicrobial activity, both free in solution or immobilized on surfaces, are highlighted and discussed in this chapter