Functional L-lysine dendritic macromolecules as liver-imaging probes

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Medical Imaging

Background:

• Developing targeted contrast agents for liver imaging is crucial for early disease detection.
• Gadolinium (Gd) chelates are widely used in MRI contrast agents.
• Dendrimers offer a versatile platform for creating multifunctional nanoprobes.

Purpose of the Study:

• To synthesize and characterize novel Gd-chelate-conjugated peptide dendrimers for liver imaging.
• To evaluate the in vitro and in vivo performance of these targeted dendritic probes.

Main Methods:

• Conjugation of Gd chelates and galactosyl moieties to peptide dendrimers.
• Measurement of T(1) relaxivity and in vitro cytotoxicity assays.
• Assessment of hepatocyte uptake in vitro and liver signal enhancement in vivo in mice.

Main Results:

• Dendritic probes exhibited a two-fold increase in T(1) relaxivity (9.1 x 10(3) (Gd M)(-1) s(-1)) compared to Gd-DTPA.
• No significant in vitro cytotoxicity was observed.
• Dendrimers with galactosyl moieties showed significantly higher hepatocyte uptake and achieved 35% liver signal enhancement in vivo, compared to 11% for non-targeting dendrimers.

Conclusions:

• Peptide dendrimers conjugated with Gd chelates and galactosyl moieties serve as effective liver-imaging probes.
• These targeted probes demonstrate enhanced relaxivity, cellular uptake, and in vivo liver contrast.
• The developed dendritic agents show potential for improved liver imaging diagnostics.