🧬 LL-37 Peptide – Antimicrobial and Immunomodulatory Research Peptide;

1. Introduction

LL-37 peptide is a naturally occurring antimicrobial peptide derived from the human cathelicidin protein (hCAP18). It plays a vital role in the body’s innate immune defense system, acting as a first-line barrier against bacteria, viruses, and fungi.

In research environments, LL-37 is recognized for its antimicrobial, anti-inflammatory, and tissue-regenerative properties. It’s commonly studied in fields like microbiology, immunology, wound healing, and inflammation biology.

As a research compound, LL-37 peptide is for laboratory use only and is not approved for medical or therapeutic use.

2. What Is LL-37 Peptide?

LL-37 is the only human cathelicidin peptide identified to date. It is generated when the precursor protein, hCAP18, is cleaved during immune response activation.

In its natural form, LL-37 circulates in various tissues, including skin, respiratory tract, and immune cells, where it contributes to defense against microbial invaders.

In laboratory settings, synthetic LL-37 peptide is used to study:

• Antimicrobial signaling mechanisms

• Tissue regeneration and wound healing

• Immune cell modulation

• Inflammation and cytokine balance

These properties make LL-37 one of the most versatile research peptides in the study of human immunity and infection control.

3. Chemical Profile and Physical Properties

4. Mechanism of Action

LL-37 exhibits both direct antimicrobial and immune-modulating activity.

a) Antimicrobial Action

LL-37 disrupts bacterial cell membranes, leading to cell lysis. It acts against gram-positive and gram-negative bacteria, fungi, and even some viruses.

b) Immunomodulation

LL-37 influences immune cell behavior by:

• Regulating cytokine release

• Enhancing macrophage and neutrophil activation

• Supporting tissue regeneration and angiogenesis

c) Wound Healing and Repair

In research, LL-37 has shown potential to:

• Stimulate keratinocyte migration

• Enhance collagen synthesis

• Promote vascular repair and epithelial closure

Its dual action—antimicrobial defense and healing support—makes LL-37 a valuable peptide for inflammation and tissue recovery studies.

5. Research Applications

While LL-37 is not approved for clinical use, it is extensively explored across multiple scientific disciplines.

🧫 1. Antimicrobial Research

LL-37 is a cornerstone peptide in host defense studies, used to examine mechanisms of bacterial resistance and innate immunity.

💪 2. Immune System Modulation

LL-37 is studied for its role in immune regulation, influencing cytokines such as IL-6 and TNF-α.

🩹 3. Wound Healing and Regeneration

Its capacity to promote cell migration, collagen production, and angiogenesis makes it key in tissue repair research.

🧠 4. Inflammatory Conditions

LL-37 may help regulate inflammatory signaling in autoimmune and infection models, helping scientists understand chronic inflammation.

🦠 5. Biofilm and Microbial Defense Studies

Because of its biofilm-disrupting effects, LL-37 is a frequent subject in antimicrobial resistance research.

⚠️ Note: LL-37 peptide is for research use only. It is not for human or veterinary use.

6. Advantages in Research

7. Handling and Storage

To preserve LL-37 peptide’s stability and performance:

• Storage: Keep lyophilized powder at −20 °C, sealed, and moisture-free.

• Reconstitution: Use sterile water or phosphate-buffered saline (PBS).

• Handling: Avoid repeated freeze–thaw cycles.

• Labeling: Clearly marked “For Research Use Only – Not for Human Use.”

• Shelf Life: 24 months (unopened, lyophilized).

8. Selecting High-Quality LL-37 Peptide

When sourcing LL-37 peptide for laboratory research, ensure:

1. ≥ 98% purity verified by HPLC or LC-MS.

2. Certificate of Analysis (COA) available for each lot.

3. Proper labeling and compliance with research-use standards.

4. Temperature-controlled packaging during shipping.

5. Transparent synthesis details from a reputable supplier.

High-quality synthesis ensures consistent biological performance in experiments.

9. FAQs – LL-37 Peptide Research

Q1. What is LL-37 peptide?
LL-37 is a human cathelicidin-derived antimicrobial peptide that helps defend against pathogens and supports tissue repair in research models.

Q2. What is LL-37 used for in research?
It is studied for its roles in antimicrobial defense, immune modulation, and wound healing.

Q3. Is LL-37 naturally found in humans?
Yes. It’s the only known human cathelicidin peptide, produced by immune and epithelial cells.

Q4. Can LL-37 be used therapeutically?
No. It is strictly for research use and not approved for medical or clinical applications.

Q5. How is LL-37 stored?
Store at −20 °C, dry and dark, to maintain long-term stability.

10. Summary

LL-37 peptide is one of the most dynamic research peptides known for its antimicrobial and immune-modulating potential. As the only human cathelicidin-derived peptide, it plays a vital role in defense, healing, and immune balance.

In research laboratories, LL-37 continues to provide valuable insights into infection control, skin regeneration, and immune response regulation, making it an indispensable molecule for modern biomedical studies.

Disclaimer: LL-37 peptide is for research and laboratory use only. It is not approved for human or veterinary use.