Laser-induced release of liposome-encapsulated dye to monitor tissue temperature: A preliminary in vivo study

✍ Scribed by Dr. S. Mordon; T. Desmettre; J. M. Devoisselle

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 664 KB
• Volume: 16
• Category: Article
• ISSN: 0196-8092
• DOI: 10.1002/lsm.1900160306

✦ Synopsis

Background and Objective: The objective of this in vivo study was to assess the possible use of temperature-sensitive liposomes as a new approach to monitor the temperature induced by a laser. Study Design: An in vivolex vivo study was performed in rat liver after i.v. injection of liposomes loaded with a fluorescent dye. Materials and Methods: Temperature-sensitive liposomes (DSPC: Di-Stearoyl-Phosphatidyl-Choline) were loaded with carboxyfluorescein. These liposomes (1 ml solution) were injected into adult male Wistar rats. Two hours later, the liver was exposed and irradiated with a 100 W NdYAG laser using pulses lasting from 100 to 260 ms. Simultaneously, the surface temperature was recorded with a thermographic camera. The fluorescence emission was measured with a fluorescent imaging system. Results: The results showed that the dye was released in response to laser energy. The amount of the drug release increased linearly with increasing temperature in the range 4240°C. Moreover, the release occurred in a short period of time upon brief exposure to its phase transition temperature.

Conclusion:

The feasibility of temperature monitoring by using laser-induced release of liposome-encapsulated dye was demonstrated. This procedure could conceivably prove useful for controlling the thermal coagulation of biological tissues such as blood vessels. o