LL-37

LL-37 is the sole cathelicidin-derived antimicrobial peptide found in humans, cleaved from the hCAP18 precursor protein. Its research profile is dual-natured: the literature includes direct antimicrobial activity against bacteria and fungi, and separately examines roles in immune signalling, wound healing and inflammatory pathology. That complexity makes it scientifically interesting and keeps its characterisation incomplete. FAB Research supplies LL-37 in a 5mg pre-filled metered research pen for laboratory investigation.

LL-37 is a 37-residue cationic amphipathic alpha-helical peptide. Research describes direct antimicrobial activity through electrostatic interaction with microbial membranes followed by membrane disruption. Beyond direct killing, studies document chemotactic recruitment of immune cells via formyl peptide receptor-like 1, neutralisation of bacterial lipopolysaccharide, and effects on angiogenesis and re-epithelialisation in wound models. Research also implicates the peptide in nucleic acid complex formation relevant to autoimmune inflammatory processes including psoriasis and rosacea models.

A large and mechanistically detailed literature spanning microbiology, immunology and dermatology, with significant work on inflammatory pathology. Antimicrobial research demonstrated in vitro activity against bacterial, fungal and viral targets including biofilms. Immune signalling studies examined chemotaxis, cytokine modulation and LPS neutralisation. Wound healing research investigated re-epithelialisation and angiogenesis. Inflammatory pathology work implicated the peptide in psoriasis and rosacea disease models.

• 5 mg total (single metered dose per pen)
• 1 dose per pen (5 mg total)
• The only human cathelicidin — 37-residue cationic amphipathic alpha-helical peptide
• Pre-filled sterile solution — no reconstitution step required

Storage: Store refrigerated at 2–8 °C in the original sealed box. Do not freeze. Protect from light.

• For in-vitro laboratory and preclinical research only — not for human or animal administration
• Dual biological role: direct antimicrobial membrane disruption AND immune cell recruitment / modulation — study design must specify which endpoint is intended
• Implicated in inflammatory pathology (psoriasis, rosacea models) alongside wound-healing research — this reflects genuine dual character, not compound inconsistency
• Nucleic acid complex formation: LL-37 complexes with self-DNA/RNA — relevant for TLR7/TLR9 signalling studies and autoimmune disease models

• Research data: administration site irritation expected — cationic amphipathic mechanism causes membrane interaction
• Immune activation: cytokine changes are expected outputs of the mechanism; represent intended activity in most research contexts rather than adverse effects
• Limited human intervention trial data — most published data is in vitro or from topical / local applications
• No established clinical adverse effect profile from large-scale human trials

Effects listed are observations from published research literature and are not predictions for any specific use. All FAB Research products are for in-vitro laboratory research — not for human or animal administration.