Distribution of technetium-99m PEG-liposomes during oligofructose-induced laminitis development in horses.
Authors: Underwood Claire, Pollitt Christopher C, Metselaar Josbert M, Laverman Peter, van Bloois Louis, van den Hoven Jolanda M, Storm Gert, van Eps Andrew W
Journal: Veterinary journal (London, England : 1997)
Summary
# Editorial Summary: Liposome Accumulation in Laminitic Tissue Researchers investigated whether intravenously administered nanoparticle liposomes preferentially accumulate in lamellar tissue during acute laminitis, with the aim of developing targeted drug-delivery systems for this condition. Six horses were induced into oligofructose laminitis whilst four controls received saline, with both groups receiving radiolabelled polyethylene-glycol (PEG)-coated liposomes tracked via scintigraphic imaging at 0, 6 and 12 hours post-infusion, followed by tissue sampling at endpoint. Lamellar tissue from laminitis horses accumulated 3.2-fold more liposomes than controls (P=0.02), with uptake increasing significantly over time in affected hooves whilst decreasing in controls, demonstrating genuine selective accumulation rather than passive distribution. Notably, elevated liposome levels also appeared in skin, muscle, and gastrointestinal and renal tissues of laminitis horses, indicating that the inflammatory cascade extends systemically beyond the hoof. These findings suggest that PEG-liposomes could serve as effective carriers for targeted therapeutic delivery to inflamed lamellar tissue during acute laminitis, opening possibilities for improved drug efficacy and reduced systemic side-effects—though the widespread tissue uptake observed warrants consideration of broader pharmacological effects when designing liposome-based treatments.
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Practical Takeaways
- •Liposome-based drug delivery systems show promise for treating acute laminitis by targeting anti-inflammatory or therapeutic agents directly to affected lamellar tissue
- •The documented accumulation of liposomes in lamellar tissue during laminitis development provides a rationale for developing novel targeted treatments that may be more effective than systemic administration
- •Recognition that laminitis involves systemic as well as local inflammation may influence future treatment strategies beyond purely local lamellar interventions
Key Findings
- •Technetium-99m liposome uptake in hoof tissue increased over 12 hours in laminitis horses but decreased in controls
- •Lamellar tissue liposome levels were 3.2-fold higher in laminitis horses compared to controls (P=0.02)
- •PEG-coated liposomes accumulate selectively in inflamed lamellar tissue, demonstrating potential for targeted drug delivery during acute laminitis
- •Systemic inflammation was confirmed by elevated liposome levels in skin, muscle, jejunum, colon, and kidney tissues in laminitis horses