Cationic Amphiphiles as Antimicrobial Agents

Numerous antimicrobial peptides (AMP) obtained from natural sources are currently tested in clinical or preclinical settings for treating infections triggered by antimicrobial-resistant bacteria. Several experiments with cyclic, linear and diastereomeric AMPs have proved that the geometry, along with the chemical properties of an AMP, is important for the microbiological activities of these compounds. It is understood that the combination of the hydrophobic and hydrophilic nature of AMPs is crucial for the adsorption and destruction of the bacterial membrane. However, the application of AMPs in therapeutics is still limited due to their poor pharmacokinetics, low bacteriological efficacy and overall high manufacturing costs. To overcome these problems, a variety of newly synthesized cationic amphiphiles have recently appeared, which imitate not only the amphiphilic nature but also the potent antibacterial activities of the AMPs with better pharmacokinetic properties and lesser in vitro toxicity. Thus, amphiphiles of this new genre have enough potential to deliver several antibacterial molecules in years to come.