I have been doing some study on the mechanics of ultrasonic cleaners in relation to liposomes and I am curious of some of the ramifications:
1) Ultrasonic cleaners work by producing alternating low and high sound waves. The unit I am using does 50/60 Hz. The low phase produces the bubble and the high phase implodes the bubbles which produces the cleaning action so desired in such cleaners. Question: I can see the low phase producing liposomes, but how are the liposomes immune to the high phase that normally ruptures bubbles? 2) Using the cheap harbor freight ultrasonic cleaner, it is recommended to stir the solution and that the more shallow the solution, the higher the quality of liposome. Is stirring really necessary as it is so time consuming? It seems to me that the solution has natural movement all by itself from the production of the ultrasonic waves. 3) It is suggested that the best cavitation of the solution in the ultrasonic cleaner occurs when the solution is warm, plus the cavittion produces heat too. How much danger is this produced heat from ultrasonic wave production to ascorbic acid or the ascorbates' integrity over a long period of time? Is it minimal? One would logically conclude that the more heat produced, the more energetic the cavitation---would one not? If this is true, would it not be more efficient to produce liposomes with specialized instruments like sonifiers (pulsing and placing the lipo-C in ice water to keep temps low)? 4) It sounds to me that the longer one can run your lipo-C solution in a ultrasonic cleaner the better the quality of liposomes according to some of Brooks' later posts, however there is what is known as "degassing" in ultrasonic cleaning. Many instruction manuals for cleaners will advise you to "de-gas" your solution from 5-10 minutes before actually starting the cleaning process. Degassing is the initial removal of gases present in the solution. Useful cavitation occurs after the gasses have been removed from the solution leaving a vacuum in the later formed bubbles as it is written in these manuals. So it seems to me on first glance after reading this, that one would not want to extend our Lipo-C solution cavitation much longer than the recommended 6 minutes as that would degas the solution, producing an "empty bubble". Is this true or am I missing some thing? 5) Finally, there seems to me, better ways to produce a liposome via sound waves. Would not lab devices known as sonifiers/sonicators/cell disruptors be a better choice since these devices produce an intense steady frequency unlike the ultrasonic cleaner? Agreed, this device would not be in the reach of the average home-made tech, but would it produce a smaller, better liposome than ultrasonic cleaners? I realize that heat generation would be a problem from such intense ultrasound involvement from a cell disruptor, but having the solution in ice and pulsing should over come this problem, eh? doug
