LJ-2P
LJ-2P is an NIR-II small-molecule fluorescent probe with fibrin/fibrinogen affinity. LJ-2P can bind coagulation-related proteins and restrict dye molecular motion, thereby enhancing local fluorescence for high-contrast imaging of bleeding and blood clots in vivo. LJ-2P can also co-precipitate with Ca2+ to form LJ-2P nanoparticles, significantly enhancing NIR-II luminescence through the precipitation-enhanced emission (PEE) mechanism. LJ-2P can be used for research on bleeding disorders and breast cancer. LJ-2P exhibits dual-modal emission properties (Ex/Em ≈740/945 nm or 740/1066 nm).
For research use only. We do not sell to patients.
- CAS No.: 2863678-02-6
- Formula: C60H52N4O20P2S4
- Molecular Weight:1339.28
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Storage:
Please store the product under the recommended conditions in the Certificate of Analysis.
Biological Activity
Description
In Vitro
Guidelines (The following is our recommended protocol. This protocol is for reference only and should be modified according to your specific needs).
1. Stock Solution Preparation
1.1 Solvent: H2O[1].
1.2 Concentration: A high-concentration stock solution of 1-10 mM is generally recommended.
2. Working Solution Preparation
2.1 Note: Adjust the working solution concentration according to needs; prepare fresh before use.
2.2 Diluent: Serum-free medium or PBS is typically used.
2.3 Working concentration: 0.15 nM.
3. Staining Procedure
3.1 For in vitro protein samples[1]:
3.1.1 Sample types: fibrinogen, thrombin, and fibrin clots.
3.1.2 Incubate with 0.15 nM LJ-2P for 5 min.
3.1.3 To verify binding, the mixture can be placed in a 10 kDa ultrafiltration tube and centrifuged (4500 rpm, 2 min) to separate and remove the fluorescence background of unbound free dye.
4. Controls
4.1 Blank control:
LJ-2P solution is mixed with PBS buffer to adjust instrument voltage and remove background baseline.
4.1 Positive control:
Mix fibrinogen with thrombin to initiate coagulation (thrombus formation), then co-incubate with LJ-2P.
4.3 Negative control:
Use Indocyanine green (ICG) (HY-D0711) at a similar concentration and excitation wavelength for parallel incubation experiments.
5. Detection and Analysis
5.1 Instruments:
Near-infrared spectrometer, in vivo fluorescence imaging system.
5.2 Wavelength and acquisition settings:
5.2.1 Excitation: 808 nm laser.
5.2.2 Laser power: 90 mW/cm2.
5.2.3 Emission filter: 900 nm long-pass or 1000 nm long-pass.
5.3 Result analysis:
After dye staining, the fluorescence intensity of LJ-2P significantly increases 8.46-fold upon binding to fibrinogen; upon further binding to thrombus (fibrin), the fluorescence intensity surges 16.83-fold, precisely targeting the coagulation site.
LJ-2P (1-30 µM; 24 h) maintains a high cell viability and exhibits good biocompatibility in 293T cells[1].
LJ-2P can also co-precipitate with Ca2+ to form LJ-2P NPs particles, significantly enhancing NIR-II luminescence through the PEE mechanism[2].
MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.
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Cell Line:293T cell line
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Concentration:1, 5, 10, 15, 20, 25, 30 µM
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Incubation Time:24 h
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Result:Maintained high cell viability without showing obvious cytotoxicity, demonstrating good biocompatibility.
In Vivo
LJ-2P (0.25 mg/mL, 200 µL; i.v.; single administration; continuous imaging up to 24 h) enables precise localization of pulmonary hemorrhage sites and long-term stable imaging with resistance to photobleaching in the LPS (HY-D1056)-induced acute lung injury/pulmonary hemorrhage model in C57BL/6 mice[1].
LJ-2P (0.25 mg/mL, 200 µL; i.v.; single administration; continuous imaging) accurately indicates the hemorrhagic region and quantifies hemorrhage severity via fluorescence intensity in a collagenase-induced intracerebral hemorrhage model in C57BL/6 mice[1].
MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.
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Animal Model:C57BL/6 (male/female not specified; gastric hemorrhage induced by 48 h fasting followed by oral administration of 10 mL/kg anhydrous ethanol)[1]
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Dosage:0.25 mg/mL, 200 μL (imaging); 0.25 mg/kg (half-life measurement)
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Administration:i.v.; single dose; 24 h
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Result:Gradually accumulated in gastric bleeding sites, reaching peak brightness at 4 h post-injection, with fluorescence signals precisely corresponding to hemorrhagic points.
Reached a signal-to-background ratio of 10.42.
Had an imaging window of 2-8 h and a plasma half-life of approximately 2 h.
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Animal Model:C57BL/6 (male/female not specified; pulmonary hemorrhage induced by intratracheal instillation of 3 mg/kg lipopolysaccharide)[1]
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Dosage:0.25 mg/mL, 200 μL
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Administration:i.v.; single dose; 24 h
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Result:Accumulated in the lung over time, reaching peak brightness at 2 h post-injection, with fluorescence corresponding well to hemorrhage sites.
Showed minimal fluorescence intensity change after 30 min of ex vivo laser irradiation at 90 mW/cm2.
Chemical Information
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CAS No. 2863678-02-6
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Molecular Weight 1339.28
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Formula C60H52N4O20P2S4
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SMILES
OP(OC1=CC2=C(C(C=CC(C3=C(OCCO4)C4=C(C5=C6C(N=S=N6)=C(C7=C8C(OCCO8)=C(C9=CC(C(CCCC(O)=O)(CCCC(O)=O)C%10=C%11C=CC(OP(O)(O)=O)=C%10)=C%11C=C9)S7)C%12=NSN=C5%12)S3)=C%13)=C%13C2(CCCC(O)=O)CCCC(O)=O)C=C1)(O)=O
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Shipping
Room temperature in continental US; may vary elsewhere.
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Storage
Please store the product under the recommended conditions in the Certificate of Analysis.
Purity & Documentation
References
Calculators
Concentration (start) × Volume (start) = Concentration (final) × Volume (final)