Heat enhances gas delivery and acoustic attenuation in CO(2) filled microbubbles.
Thermo-responsive chitosan microbubbles were developed as new therapeutic device for vehiculating gases to tissues concomitantly to hyperthermic treatments. Aiming at applications to non-invasive temperature monitoring, microbubbles were characterized for acoustic attenuation properties in the 1-15 MHz range both by direct methods and by B-mode Ultrasound imaging up to 43 degrees C, which is the temperature used in clinical hyperthermia. The chitosan microbubbles showed a mean diameter of 1 microm at room temperature, which slightly decreases after heating, enhancing gas delivery. Acoustic attenuation monotonically increases with temperature, being the extent of such variation larger than that observed in tissues. Both the physico-chemical and the acoustic profiles showed reversible variations of microbubbles approaching 43 degrees C, which might be of interest for applications in hyperthermic therapies.
Giustetto
Pierangela
P
Department of Neuroscience, University of Torino, Italy. pgiustetto@gmail.com
Bisazza
Agnese
A
Biagioni
Angelo
A
Alippi
Adriano
A
Bettucci
Andrea
A
Cavalli
Roberta
R
Guiot
Caterina
C
D001672:Biocompatible Materials; D002245:Carbon Dioxide / Q000737:chemistry*; D048271:Chitosan; D003287:Contrast Media / Q000737:chemistry*; D006358:Hot Temperature; D045423:Microbubbles; D014464:Ultrasonic Therapy / Q000379:methods; D014465:Ultrasonics
D001672:Biocompatible Materials; D003287:Contrast Media; D002245:Carbon Dioxide; D048271:Chitosan