This may seem like a foolish question and I admit I am a beginner, but it still baffles me how scientists can inject such tiny volumes! For example, there is a study that does the following in a nutshell:
Extract adipose tissue(liposuction)
Isolate Preadipocytes(which are in the SVF)
Inject preadipocytes intradermally into scalp of patient.
My question is simple. How do they even begin to inject such tiny amounts? After isolating the preadipocytes(SVF, which is a tiny pellet!), do they first mix it with PBS before injection? The particular study deals with regrowing hair on bald patients, so what I would like to know, is if you isolate the SVF containing preadipocytes and mix it with PBS, will that be sufficient in terms of cell number to help the bald patient? What volume of PBS would YOU mix the SVF with in this case?
They say for every 20ml's of adipose tissue, there is between 300,000 to 2 million preadipocytes(after full isolation). Would that be enough for a patients entire scalp? Or just one region such as the crown? And how much pbs would YOU mix with the preadipocytes/SVF?
The real problem is that injecting cells in high volumes there's the risk of spreading the cells to a broader area or, at least, of swelling the skin in an unwanted way. 300.000 preadipocytes could be sufficient depending on the application and on the area the operator intends to cover. Since a subcutaneous injection (up to few milliliters maximum) would concentrate the cells in a limited area, several injection could be required. Given enough time to spread and divide, some millions preadipocytes could serve.
So with the SVF from 20 milliliters of adipose tissue, you would mix that with say 4 milliliters of PBS? And that injection would be sufficient for the whole head? or just one area such as the right temple or crown? The will be injected intradermally.
@Ellie Major, I am not any expert in this subject. But the surface area of human scalp is 600 cm2 and if you spread the entire scalp into a sheet of thickness 0.5 cm, the volume would be around 300 cm3 or 300 ml. I think the empty volume (void) in the scalp where the injection liquid can be accommodated would be very less. So wouldn't 4-5 ml be sufficient, which if increased may result in swellings?
@B. Chandrashekhar Wow, that's a brilliant response! Thanks so much for that, very insightful! Maybe 4-5ml's would be sufficient, but I am weary that the number of cells in that 4-5ml's won't be enough. Do you think the 300,000 preadipocytes in the SVF mixed with 4-5ml's of PBS would be enough to induce adipogenesis?