Study On Enhancement Of Loading Trehalose Into Human Platelets With Ultrasound

Freeze-drying is one of perfect methods for presvervation of human platelets. It is a simple, effective, safe and long-term technique. However, platelets may be damaged during freezing and drying. It is shown by many researchers that platelets can be protected during freeze-drying by trehalose, a sugar found at high concentrations in organisms that naturally survive drying. There are strong evidences that trehalose must be loaded into platelets so that their protection can take effect.Many methods have been used to load trehalose into platelet cells, such as thermal poration, swithable membrane pores, genetic modification, electroporation and microinjection. All of them suffer from one or more practical limitations. Since ultrasound has been reported to help drug transiently permeate cell membranes and to offer a non-chemical, non-viral, and non-invasive method for cellular drug delivery, it was proposed to load trehalose into human platelets in this paper.The investigation of loading trehalose into platelets with ultrasound was carried out on a self-made device. The platelets were incubated in trehalose solution of 50mM at 37°C for 4h, with or without ultrasound. Two kinds of ultrasound frequency were used, 800 kHz and 25 kHz. A propagation model of ultrasound was developed and employed to theoretically estimate its intensity in the platelet suspension.The experimental results at high frequency showed that, for the three intensitiesinvestigated, 0.4W/cm~2 , 0.8W/cm~2 and 1.2W/cm~2 , only 0.8W/cm~2 ultrasound had significant impact on loading trehalose into platelets. When the exposure time was 30min, the...