LL-37 is the only cathelicidin-type host defense peptide naturally produced in human body, cleaved from the C-terminal segment of hCAP18 precursor protein. Distinct from narrow-spectrum synthetic antibiotics, this positively charged peptide targets negatively charged microbial membrane lipids instead of specific enzyme receptors, enabling broad activity across gram-positive, gram-negative bacteria, fungi and enveloped virus models. Its membrane disruption mechanism also grants unique capability to interfere with mature bacterial biofilm architecture, a hot research direction for overcoming drug-resistant strains.

Beyond direct microbe suppression, LL-37 serves as a versatile immune signalling regulator. It mediates chemotaxis of immune cells, balances pro-inflammatory and anti-inflammatory cytokine release, and participates in epithelial tissue regeneration and vascular remodelling. Researchers utilize it to explore skin barrier restoration, mucosal immunity, and inflammatory dermatosis mechanisms, as well as novel peptide antibiotic development.

Manufactured by solid-phase peptide synthesis followed by multi-step reversed-phase purification and lyophilization. The lyophilized state greatly slows peptide backbone hydrolysis. As a long cationic peptide, LL-37 is sensitive to proteases once dissolved. Prepare stock solution under aseptic conditions and divide into small single-use aliquots. Avoid repeated freeze-thaw cycles, which will degrade peptide chains and reduce biological activity.