Current state of a dual behaviour of antimicrobial peptides—Therapeutic agents and promising delivery vectors

Abstract

Micro-organism resistance is an important challenge in modern medicine due to the global uncontrolled use of antibiotics. Natural and synthetic antimicrobial peptides (AMPs) symbolize a new family of antibiotics, which have stimulated research and clinical interest as new therapeutic options for infections. They represent one of the most promising antimicrobial substances, due to their broad spectrum of biological activity, against bacteria, fungi, protozoa, viruses, yeast and even tumour cells. Besides, being antimicrobial, AMPs have been shown to bind and neutralize bacterial endotoxins, as well as possess immunomodulatory, anti-inflammatory, wound-healing, angiogenic and antitumour properties. In contrast to conventional antibiotics, which have very defined and specific molecular targets, host cationic peptides show varying, complex and very rapid mechanisms of actions that make it difficult to form an effective antimicrobial defence. Importantly, AMPs display their antimicrobial activity at micromolar concentrations or less. To do this, many peptide-based drugs are commercially available for the treatment of numerous diseases, such as hepatitis C, myeloma, skin infections and diabetes. Herein, we present an overview of the general mechanism of AMPs action, along with recent developments regarding carriers of AMPs and their potential applications in medical fields.

Esculentin‐1a derived peptides kill Pseudomonas aeruginosa biofilm on soft contact lenses and retain antibacterial activity upon immobilization to the lens surface

“…It should be emphasized that besides displaying antimicrobial activities, AMPs are also endowed with immunomodulatory properties, for example wound‐healing activity, which may speed up the recovery process from an infectious agent by restoring the integrity of the damaged tissue . This makes AMPs even more attractive molecules over classical antibiotics …”

Insights on the structure‐activity relationship of peptides derived from Sticholysin II

“…These features turns, in particular StII 1–30 , into an interesting model to design new therapeutic immunocomplexes when bound to a monoclonal antibody raised against cancer cells . Indeed, the use, as a cargo‐molecule, of StII 1–30 instead of the whole sticholysin toxins would result in immunocomplexes more suited for clinical applications because of the less toxic cargo‐moiety as suggested for other peptides …”

Drug delivery systems designed to overcome antimicrobial resistance

“…With regard to the Trojan horse strategy, we will focus on the conjugation of ATBs with AMPs, the latter serving as delivery vehicules for the former. Other potential applications of AMPs in anti‐infectious treatment have already been studied in previous reviews …”

“…Over the last few decades, AMPs have garnered increasing interest, not only as potential ATB agents, 106 but also as ATB carriers. 107,108 AMPs, also called host defense peptides (HDPs), are small polycationic amphipathic peptides (often, with fewer than 50 amino acid-sequences) that have been found in all multicellular organisms. 106,[109][110][111] In structural analysis, AMPs possess different secondary structures, often stabilized by disulfide bridges.…”

“…Other potential applications of AMPs in anti-infectious treatment have already been studied in previous reviews. [106][107][108]110,[143][144][145]…”