Non-Invasive Detection of Lung Inflammation by Near-Infrared Fluorescence Imaging Using Bimodal Liposomes

Area of Science:

• Biomedical Imaging
• Nanotechnology
• Pulmonary Medicine

Background:

• Acute lung injury (ALI) and acute respiratory distress syndrome cause severe lung inflammation and respiratory compromise.
• Key features of ALI include alveolar edema, leukocyte infiltration, pro-inflammatory cytokine release, and integrin receptor activation.

Purpose of the Study:

• To develop a non-invasive method for detecting lung inflammation using fluorescence liposomes targeted to integrin receptors.
• To visualize and quantify lung inflammation in an ALI rodent model.

Main Methods:

• Induced ALI in rodents via intra-tracheal interleukin-1beta (IL-1beta) instillation.
• Administered cyclic arginine glycine-(D)-aspartic acid-peptide (cRGD-peptide) grafted fluorescence liposomes to target lung integrin receptors.
• Utilized near-infrared fluorescence imaging (NIRFI) for inflammation detection and correlated signals with inflammatory markers.

Main Results:

• NIRFI signals showed a positive correlation with lung inflammatory markers.
• ALI-induced rats exhibited intense NIRF signals between 6-24 hours post-IL-1beta instillation.
• RT-PCR confirmed elevated alphavbeta5 integrin receptor expression in the lungs of ALI rats.

Conclusions:

• Integrin receptor-targeted fluorescence liposomes combined with NIRFI offer a non-invasive approach for detecting lung inflammation.
• Targeted liposomes bind specifically to integrin receptors, such as alphavbeta5, expressed on alveolar cells.
• This method shows promise for early diagnosis and monitoring of lung inflammation in conditions like ALI.