Antimicrobial Peptides and the Challenge of Therapeutic Selectivity

Natural defense inspired the field

Organisms across biology produce cationic peptides that disrupt membranes or coordinate host defense. Their rapid, multi-target activity is attractive in a period of antimicrobial resistance.

Membranes are similar enough to create risk

Microbial membranes differ from mammalian membranes, but selectivity is not absolute. Charge, lipid composition, salt, serum, and peptide concentration influence both antimicrobial activity and hemolysis.

Resistance can still emerge

Although membrane-active mechanisms may reduce some forms of resistance, microbes can change surface charge, protease production, efflux, or biofilm behavior. Claims that resistance is impossible are not supported.

Delivery and stability are difficult

Proteolysis, protein binding, rapid clearance, tissue toxicity, and manufacturing cost can limit translation. Chemical modification may improve one property while changing immunogenicity or activity.

LL-37 shows the duality

LL-37 can be antimicrobial, chemotactic, pro-repair, inflammatory, or cytotoxic depending on context. That complexity is representative of the field.

This article is provided for scientific and educational purposes. It does not describe or recommend human or veterinary use. Research findings may be limited by study design, model selection, material identity, sample size, or lack of independent replication.