Overview LL-37 is a 37-residue cationic antimicrobial peptide (AMP) and the only member of the cathelicidin family identified in humans. Its amino acid sequence is LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES.[1] Parent molecule: LL-37 is derived from a larger, inactive precursor protein called hCAP18 (human Cationic Antimicrobial Protein, 18 kDa). The CAMP gene on chromosome 3p21.3 encodes hCAP18. The active LL-37 peptide is released extracellularly through proteolytic cleavage — primarily by proteina

How does Ll 37 work? What is its mechanism of action?

Mechanism of Action Primary Antimicrobial: "Carpet-Like" Membrane Disruption LL-37 disrupts bacterial membranes via electrostatic attraction to anionic bacterial surfaces → hydrophobic insertion → toroidal pore formation or micellization ("carpet-like" mechanism). It acts preferentially on Gram-negative bacteria but is effective against both Gram-positive and drug-resistant strains. Eukaryotic membranes are protected by high cholesterol content.[3][7] Receptor Targets ReceptorTypeFunctional Effe

What are the research applications of Ll 37?

Research Applications LL-37 research spans antimicrobial resistance, wound healing, oncology, and immunology across 8+ indication categories: Chronic Wound Healing — Promotes granulation tissue, re-epithelialization, and angiogenesis in venous leg ulcers (VLUs) and diabetic foot ulcers (DFUs).[5][13] Antimicrobial Resistance — Broad-spectrum activity against MDR bacteria; anti-biofilm; synergy with conventional antibiotics (azithromycin, colistin, ciprofloxacin, vancomycin).[7] Oncology (Dual Ro

What does the research summary say about Ll 37?

Preclinical Research Summary Key Preclinical Studies StudyModelKey FindingsRef Zhang et al. (2022)C57/BL6 mice, Pan02 PDAC — 20 mg/kg/day IP × 14d42% reduction in tumor growth (p[11] Overhage et al. (2008)P. aeruginosa biofilm — 0.5 µg/mLInhibits biofilm formation via quorum-sensing downregulation (Las/Rhl); promotes twitching motility at sub-MIC[7] Wu et al. (2010)Colon cancer cellsLL-37 inhibits proteasome → activates BMP signaling → p21Waf1 → cell cycle arrest[10] Koczulla et al. (2003)Dexame

How should Ll 37 be stored?

Lyophilized powder/concentrate stored at -20°C. Cream formulation stable >99 months at 4°C, >75 months at 28°C (melts at 40°C). Reconstituted solutions should be used immediately or frozen.

Ll 37 Research Applications — Scientific Studies & Evidence

Research Applications

LL-37 research spans antimicrobial resistance, wound healing, oncology, and immunology across 8+ indication categories:

Chronic Wound Healing — Promotes granulation tissue, re-epithelialization, and angiogenesis in venous leg ulcers (VLUs) and diabetic foot ulcers (DFUs).[5][13]
Antimicrobial Resistance — Broad-spectrum activity against MDR bacteria; anti-biofilm; synergy with conventional antibiotics (azithromycin, colistin, ciprofloxacin, vancomycin).[7]
Oncology (Dual Role) — Anti-tumorigenic: colon, gastric, and pancreatic cancer (apoptosis, autophagy suppression, immune reprogramming). Pro-tumorigenic: breast, lung, ovarian, and melanoma (context-dependent).[11][10]
Antiviral Research — RSV, Influenza A, HSV-1, HIV-1 — disrupts viral envelopes and blocks entry.[3]
Antifungal Research — Active against Candida albicans and Cryptococcus neoformans via membrane permeabilization.[3]
Sepsis/Endotoxemia — LPS neutralization prevents endotoxin-induced macrophage activation and cytokine storms.[12]
Bone Regeneration — Stimulates proliferation and osteogenic differentiation of BMSCs; recruits MSCs to injury sites.[14]
Drug Delivery Systems — Lipid nanoparticles, chitosan nanoparticles, hydrogels for improved stability and reduced cytotoxicity.[15]
Bell-Shaped Dose-Response Profiling — Investigated for the biphasic concentration-response in which sub-micromolar exposures yield anti-apoptotic and pro-healing endpoints while supra-micromolar exposures shift toward cytotoxicity, informing concentration-window design in chronic-wound research.[5]
Quorum-Sensing and Anti-Biofilm Studies — Examined for capacity to disrupt Pseudomonas aeruginosa Las/Rhl quorum-sensing networks at sub-MIC concentrations (~0.5 microg/mL), supporting research models that decouple biofilm-disruption activity from frank bactericidal kill curves.[7]
Receptor Pleiotropy Mapping — Used as a tool ligand to investigate signaling at FPR2/FPRL1, P2X7, EGFR, IGF-1R, CXCR2, MrgX2, and TLR9, informing research into how a single host-defense peptide engages multiple parallel innate-immune and tissue-repair pathways.[8][9]
Vitamin-D Axis Crosstalk — Studied as a downstream effector of vitamin-D-receptor activation in keratinocytes and macrophages, supporting research into how circulating 1,25-dihydroxyvitamin-D status modulates innate antimicrobial capacity.[6]

Comparative Research Context

Within the antimicrobial-peptide research literature, LL-37 is most directly compared with KPV for parallel anti-inflammatory and innate-immune profiles, with Thymosin alpha-1 for companion immunoregulatory mechanisms, and with BPC-157 for shared wound-healing and angiogenic crosstalk. These cross-comparisons inform research designs investigating whether host-defense peptides converge on a single integrative signaling node or operate through independent receptor-coupled pathways.[3]

Research Applications

LL-37 research spans antimicrobial resistance, wound healing, oncology, and immunology across 8+ indication categories:

Chronic Wound Healing — Promotes granulation tissue, re-epithelialization, and angiogenesis in venous leg ulcers (VLUs) and diabetic foot ulcers (DFUs).[5][13]
Antimicrobial Resistance — Broad-spectrum activity against MDR bacteria; anti-biofilm; synergy with conventional antibiotics (azithromycin, colistin, ciprofloxacin, vancomycin).[7]
Oncology (Dual Role) — Anti-tumorigenic: colon, gastric, and pancreatic cancer (apoptosis, autophagy suppression, immune reprogramming). Pro-tumorigenic: breast, lung, ovarian, and melanoma (context-dependent).[11][10]
Antiviral Research — RSV, Influenza A, HSV-1, HIV-1 — disrupts viral envelopes and blocks entry.[3]
Antifungal Research — Active against Candida albicans and Cryptococcus neoformans via membrane permeabilization.[3]
Sepsis/Endotoxemia — LPS neutralization prevents endotoxin-induced macrophage activation and cytokine storms.[12]
Bone Regeneration — Stimulates proliferation and osteogenic differentiation of BMSCs; recruits MSCs to injury sites.[14]
Drug Delivery Systems — Lipid nanoparticles, chitosan nanoparticles, hydrogels for improved stability and reduced cytotoxicity.[15]
Bell-Shaped Dose-Response Profiling — Investigated for the biphasic concentration-response in which sub-micromolar exposures yield anti-apoptotic and pro-healing endpoints while supra-micromolar exposures shift toward cytotoxicity, informing concentration-window design in chronic-wound research.[5]
Quorum-Sensing and Anti-Biofilm Studies — Examined for capacity to disrupt Pseudomonas aeruginosa Las/Rhl quorum-sensing networks at sub-MIC concentrations (~0.5 microg/mL), supporting research models that decouple biofilm-disruption activity from frank bactericidal kill curves.[7]
Receptor Pleiotropy Mapping — Used as a tool ligand to investigate signaling at FPR2/FPRL1, P2X7, EGFR, IGF-1R, CXCR2, MrgX2, and TLR9, informing research into how a single host-defense peptide engages multiple parallel innate-immune and tissue-repair pathways.[8][9]
Vitamin-D Axis Crosstalk — Studied as a downstream effector of vitamin-D-receptor activation in keratinocytes and macrophages, supporting research into how circulating 1,25-dihydroxyvitamin-D status modulates innate antimicrobial capacity.[6]

Ll 37: Research Applications

Research Applications

Comparative Research Context

References

Related Research Questions

Ll 37: Research Applications

Research Applications

Comparative Research Context

References

Related Research Questions