Distribution of technetium-99m PEG-liposomes during oligofructose-induced laminitis development in horses.

The research paper focuses on the use of liposomes, a type of phospholipid nanoparticle, as potential targeted drug delivery mechanisms in the treatment of laminitis in horses. The study followed how these liposomes accumulated in lamellar tissue during the development of laminitis.

Methodology

• The researchers prepared Polyethylene-glycol (PEG) coated liposomes with the film hydration method. They labelled these liposomes with Technetium-99m, a radioactive tracer, that helped in tracking their progress within the body.
• The study consisted of two groups of horses: six that received a dose of 10g/kg oligofructose to induce laminitis, and a control group of four horses that received water.
• All the horses were intravenously infused with the prepared Technetium-99m liposomes. They were carefully monitored through scintigraphic imaging at intervals of 0, 6, and 12 hours post-infusion.
• Using the imaging, Technetium-99m liposome uptake was measured in specific areas such as the hoof, fetlock, and metacarpus. The aim was to see if the liposomes were accumulating in lamellar tissues.
• At the end of the study, horses were euthanised and tissue samples were collected for further analysis.

Findings

• All horses that received oligofructose developed clinical and histological signs of laminitis.
• For the horses with laminitis, the uptake of Technetium-99m liposomes in the hoof region increased over time, whereas it decreased in the control horses.
• Levels of Technetium-99m liposomes in lamellar tissue from laminitis horses were found to be 3.2-fold higher than in the control group.
• Liposomes were also found in higher levels in the skin, muscle, jejunum, colon, and kidneys of horses with laminitis compared to control horses, suggesting potential systemic inflammation.

Implications

• The results demonstrate that liposomes can effectively accumulate in lamellar tissue during the development of laminitis. This suggests the potential of using liposomes for targeted drug delivery in the treatment of acute laminitis.
• The study also shows that the inflammation associated with laminitis is not limited to the hooves, but can be systemic, a finding that may impact future approaches to laminitis treatment.