LL-37, human (1-20 μg/mL; 24 hours) influences HCEC migration [2]. LL-37, human (0.0001-5 μg/mL; 6-24 hours) modulates cytokine secretion in HCEC [2]. LL-37, human (1-100 μg/mL; 24 hours) displays dose-dependent cytotoxicity against HCEC at concentrations above 10 μg/mL [2].

LL-37, human (1-20 μg/mL; 24 hours) influences HCEC migration [2]. LL-37, human (0.0001-5 μg/mL; 6-24 hours) modulates cytokine secretion in HCEC [2]. LL-37, human (1-100 μg/mL; 24 hours) displays dose-dependent cytotoxicity against HCEC at concentrations above 10 μg/mL [2].

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LL-37 exhibits broad-spectrum antimicrobial activity against Gram-positive bacteria (e.g., Staphylococcus epidermidis MIC ~7.6 µg/ml; Listeria monocytogenes MIC ~1.5 µg/ml), Gram-negative bacteria (e.g., Escherichia coli MIC 2–13 µM; Pseudomonas aeruginosa MIC >32 µM), the yeast Candida albicans (MIC >20 µg/ml), and some viruses (e.g., reduces vaccinia virus replication).
Its antimicrobial activity is reduced under high salt conditions and in the presence of serum or lung surfactant.
LL-37 shows cytotoxic activity, lysing human leukocytes, T-cells, and red blood cells at concentrations of 13–25 µM.
It binds and neutralizes bacterial lipopolysaccharide (LPS), inhibiting LPS-induced cytokine secretion (e.g., TNF-α) from macrophages.
LL-37 exhibits chemotactic activity, attracting T-cells, monocytes, neutrophils, and mast cells.
It promotes wound healing by inducing migration of keratinocytes and airway epithelial cells, and stimulating re-epithelialization.
LL-37 induces angiogenesis in tissue and rabbit models.
It activates intracellular signaling pathways (e.g., ERK, p38 MAPK) in monocytes and keratinocytes, and can induce apoptosis in lung epithelial cells.
Synergistic antimicrobial effects are observed when LL-37 is combined with β-defensins and lysozyme. [1]

Mice with MRSA-induced pneumonia benefit from a single intratracheal injection of human LL-37 (0.4–2.0 mg/kg) [3].

Cell migration assay[2]
Cell Types: Human corneal epithelial cells (HCEC)
Tested Concentrations: 1, 2.5, 5, 10 and 20 μg/mL
Incubation Duration: 24 hrs (hours)
Experimental Results: Dose-dependent stimulation of HCEC migration but no effect on cell proliferation .

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Cell viability assay[2]
Cell Types: Human corneal epithelial cells (HCEC)
Tested Concentrations: 0.0001, 0.001, 0.01, 0.1, 0.5, 1 and 5 μg/mL
Incubation Duration: 6 hrs (hours) and 24 hrs (hours)
Experimental Results: IL- in a dose-dependent manner Added Figure 8, IL-6, IL-1β, and TNF-α secretion in HCEC at 6 and 24 hrs (hours).

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Antimicrobial activity is typically tested by determining the minimum inhibitory concentration (MIC) against various bacterial and fungal strains in culture media. Assays are performed in the presence or absence of salts, serum, or other modulators to assess activity under physiological conditions.
Cytotoxicity assays measure lysis of human leukocytes, T-cells, or red blood cells after incubation with LL-37.
LPS neutralization assays involve pre-incubating LPS with LL-37 before adding to macrophage cultures, followed by measurement of TNF-α or nitric oxide release.
Chemotaxis assays are performed using Boyden chambers or similar setups to measure migration of neutrophils, monocytes, T-cells, or mast cells towards a gradient of LL-37.
For wound healing studies, keratinocyte or epithelial cell migration is assessed in scratch assays or using transwell membranes after treatment with LL-37.
Angiogenesis assays may involve tube formation of endothelial cells in Matrigel or neovascularization in tissue models.
Receptor activation and signaling pathway studies employ Western blotting to detect phosphorylation of ERK, p38, or use calcium mobilization assays in cells expressing receptors like FPRL-1. [1]

Animal/Disease Models: 6-8 weeks old MRSA-induced pneumonia C57BL/6 mice [3]
Doses: 0.4, 0.8, 1.2, 1.6 and 2.0 mg/kg
Route of Administration: intratracheal injection; 0.4-2.0 mg/kg Primary
Experimental Results: diminished release of IL-6 and TNF-α can alleviate MRSA-induced pneumonia in test mice.

[1]. LL-37, the only human member of the cathelicidin family of antimicrobial peptides. Biochim Biophys Acta. 2006 Sep;1758(9):1408-25.

[2]. Multifunctional roles of human cathelicidin (LL-37) at the ocular surface. Invest Ophthalmol Vis Sci. 2006 Jun;47(6):2369-80.

[3]. Antimicrobial peptide LL-37 and IDR-1 ameliorate MRSA pneumonia in vivo. Cell Physiol Biochem. 2013;32(3):614-23.

LL-37 is a human antimicrobial peptide that inhibits viral replication and plays a role in the host's defense mechanisms against infection. Lobocanide is a synthetic human antimicrobial peptide (37 amino acids) belonging to the antimicrobial peptide family, possessing antibacterial, anti-inflammatory, immunostimulatory, and potential antitumor activities. Intratumoral injection of lobocantide increases p53 expression and induces phosphatidylserine eversion, DNA fragmentation, cell cycle arrest, and caspase-independent apoptosis-inducing factor (AIF)/endonuclease G (EndoG)-mediated apoptosis in susceptible cancer cells. This inhibits tumor cell proliferation. LL-37 is a protein secreted by bone marrow cells, circulating leukocytes, and various epithelial tissues, playing a crucial role in innate host immune defense by regulating leukocyte chemotaxis and cytokine production; it also promotes wound healing. The antimicrobial cationic peptide possesses a highly conserved N-terminal cathelin-like domain and a highly variable C-terminal domain. They are initially synthesized as protoproteins and then cleaved. They are expressed in various tissues of the human body and localized to epithelial cells. They kill non-viral pathogens by forming channels in the cell membrane. LL-37 is currently the only antimicrobial peptide derived from cathelicidin found in the human body, derived from the cleavage of the precursor protein hCAP18. It is constitutively expressed in various tissues, including the skin, respiratory tract, gastrointestinal tract, and genitourinary tract, as well as in various leukocytes. LL-37 plays a dual role in innate immunity: direct antimicrobial killing and immune-regulating signal transduction. Its expression is upregulated in inflammatory diseases (e.g., psoriasis, infections) and downregulated in some diseases (e.g., atopic dermatitis, chronic ulcers). Structurally, LL-37 is a cationic amphiphilic peptide composed of 37 amino acid residues that forms an α-helix conformation upon interaction with the cell membrane. Structure induces the environment.
In the lipid bilayer, it is located on the membrane surface and disrupts lipid buildup through a carpet-like or ring-like pore mechanism, rather than through transmembrane barrel pores.
This peptide can oligomerize in solution and zwitterionic membranes.
Fragments of LL-37 (e.g., KS-30, RK-31) can exhibit altered or enhanced antibacterial and immunomodulatory activities. [1]

C205H340N60O53

4493.26334571838

4492.582

154947-66-7

LL-37, human TFA;LL-37, human acetate

16198951

White to off-white solid powder

-20.7

68

65

166

318

10700

39

O=C([C@H](C(C)C)NC([C@H](CC(C)C)NC([C@H](CC(N)=O)NC([C@H](CCCNC(=N)N)NC([C@H](CC(C)C)NC([C@H](CC1C=CC=CC=1)NC([C@H](CC(=O)O)NC([C@H](CCCCN)NC([C@H]([C@@H](C)CC)NC([C@H](CCCNC(=N)N)NC([C@H](CCC(N)=O)NC([C@H](C(C)C)NC([C@H]([C@@H](C)CC)NC([C@H](CCCNC(=N)N)NC([C@H](CCCCN)NC([C@H](CC1C=CC=CC=1)NC([C@H](CCC(=O)O)NC([C@H](CCCCN)NC(CNC([C@H]([C@@H](C)CC)NC([C@H](CCCCN)NC([C@H](CCC(=O)O)NC([C@H](CCCCN)NC([C@H](CO)NC([C@H](CCCCN)NC([C@H](CCCNC(=N)N)NC([C@H](CC1C=CC=CC=1)NC([C@H](CC1C=CC=CC=1)NC([C@H](CC(=O)O)NC(CNC([C@H](CC(C)C)NC([C@H](CC(C)C)N)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)N1CCC[C@H]1C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(=O)O)CO)=O)CCC(=O)O)=O)[C@@H](C)O)=O)CCCNC(=N)N)=O

POIUWJQBRNEFGX-XAMSXPGMSA-N

InChI=1S/C205H340N60O53/c1-20-114(16)162(261-179(296)128(66-40-46-86-211)235-176(293)135(74-78-155(273)274)243-170(287)125(63-37-43-83-208)241-192(309)148(106-266)257-174(291)126(64-38-44-84-209)234-171(288)129(67-47-87-225-201(215)216)240-185(302)142(98-119-55-29-24-30-56-119)252-187(304)144(100-121-59-33-26-34-60-121)253-189(306)146(102-158(279)280)233-154(272)104-230-167(284)138(94-109(6)7)248-166(283)122(212)93-108(4)5)194(311)231-105-153(271)232-123(61-35-41-81-206)168(285)242-136(75-79-156(275)276)177(294)251-141(97-118-53-27-23-28-54-118)184(301)238-124(62-36-42-82-207)169(286)236-131(69-49-89-227-203(219)220)181(298)263-164(116(18)22-3)197(314)259-160(112(12)13)195(312)246-134(73-77-151(213)269)175(292)237-132(70-50-90-228-204(221)222)180(297)262-163(115(17)21-2)196(313)245-127(65-39-45-85-210)172(289)256-147(103-159(281)282)190(307)254-143(99-120-57-31-25-32-58-120)186(303)249-139(95-110(8)9)183(300)239-130(68-48-88-226-202(217)218)173(290)255-145(101-152(214)270)188(305)250-140(96-111(10)11)191(308)260-161(113(14)15)199(316)265-92-52-72-150(265)193(310)244-133(71-51-91-229-205(223)224)182(299)264-165(117(19)268)198(315)247-137(76-80-157(277)278)178(295)258-149(107-267)200(317)318/h23-34,53-60,108-117,122-150,160-165,266-268H,20-22,35-52,61-107,206-212H2,1-19H3,(H2,213,269)(H2,214,270)(H,230,284)(H,231,311)(H,232,271)(H,233,272)(H,234,288)(H,235,293)(H,236,286)(H,237,292)(H,238,301)(H,239,300)(H,240,302)(H,241,309)(H,242,285)(H,243,287)(H,244,310)(H,245,313)(H,246,312)(H,247,315)(H,248,283)(H,249,303)(H,250,305)(H,251,294)(H,252,304)(H,253,306)(H,254,307)(H,255,290)(H,256,289)(H,257,291)(H,258,295)(H,259,314)(H,260,308)(H,261,296)(H,262,297)(H,263,298)(H,264,299)(H,273,274)(H,275,276)(H,277,278)(H,279,280)(H,281,282)(H,317,318)(H4,215,216,225)(H4,217,218,226)(H4,219,220,227)(H4,221,222,228)(H4,223,224,229)/t114-,115-,116-,117+,122-,123-,124-,125-,126-,127-,128-,129-,130-,131-,132-,133-,134-,135-,136-,137-,138-,139-,140-,141-,142-,143-,144-,145-,146-,147-,148-,149-,150-,160-,161-,162-,163-,164-,165-/m0/s1

(4S)-5-[[(2S)-6-amino-1-[[(2S,3S)-1-[[2-[[(2S)-6-amino-1-[[(2S)-1-[[(2S)-1-[[(2S)-6-amino-1-[[(2S)-1-[[(2S,3S)-1-[[(2S)-1-[[(2S)-5-amino-1-[[(2S)-1-[[(2S,3S)-1-[[(2S)-6-amino-1-[[(2S)-1-[[(2S)-1-[[(2S)-1-[[(2S)-1-[[(2S)-4-amino-1-[[(2S)-1-[[(2S)-1-[(2S)-2-[[(2S)-5-carbamimidamido-1-[[(2S,3R)-1-[[(2S)-4-carboxy-1-[[(1S)-1-carboxy-2-hydroxyethyl]amino]-1-oxobutan-2-yl]amino]-3-hydroxy-1-oxobutan-2-yl]amino]-1-oxopentan-2-yl]carbamoyl]pyrrolidin-1-yl]-3-methyl-1-oxobutan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]amino]-1,4-dioxobutan-2-yl]amino]-5-carbamimidamido-1-oxopentan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]amino]-1-oxo-3-phenylpropan-2-yl]amino]-3-carboxy-1-oxopropan-2-yl]amino]-1-oxohexan-2-yl]amino]-3-methyl-1-oxopentan-2-yl]amino]-5-carbamimidamido-1-oxopentan-2-yl]amino]-1,5-dioxopentan-2-yl]amino]-3-methyl-1-oxobutan-2-yl]amino]-3-methyl-1-oxopentan-2-yl]amino]-5-carbamimidamido-1-oxopentan-2-yl]amino]-1-oxohexan-2-yl]amino]-1-oxo-3-phenylpropan-2-yl]amino]-4-carboxy-1-oxobutan-2-yl]amino]-1-oxohexan-2-yl]amino]-2-oxoethyl]amino]-3-methyl-1-oxopentan-2-yl]amino]-1-oxohexan-2-yl]amino]-4-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-amino-4-methylpentanoyl]amino]-4-methylpentanoyl]amino]acetyl]amino]-3-carboxypropanoyl]amino]-3-phenylpropanoyl]amino]-3-phenylpropanoyl]amino]-5-carbamimidamidopentanoyl]amino]hexanoyl]amino]-3-hydroxypropanoyl]amino]hexanoyl]amino]-5-oxopentanoic acid

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture and light.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ~50 mg/mL (~11.13 mM)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)