The molecular weight of BSA is 66 kDa.

If you prepared the particles by thermal gelation, then just cooling them should be enough to reliquify the poloxamer 40, releasing the BSA into solution. Additionally, diluting the resulting solution below 20% should prevent gelation when the mixture is warmed up again.

Hi Mr Shapiro

yes i used thermal gelation but i need to measure BSA in a different time

whan i cooling every micelle will be open and all of BSA loaded will be release

You mean that you want to measure the time-dependent release of BSA from the particles? In that case, you need a method to separate the particles from the released BSA so that you can measure the amount of external BSA.

If a suspension of the particles can be sedimented by centrifugation, leaving the BSA in the supernatant, you could then measure the BSA concentration in the supernatant using a protein assay. There are several commercial protein assay kits available that are easy to use and require a spectrophotometer for the measurement. If a more sensitive method is needed, there are fluorescent protein assays.

Thank you so much Mr Adam B Shapiro for your help

Hi Adam B Shapiro

As you said i used centrifugation but i have not any sediment

Is there any other way?

Did you use an ultracentrifuge? Depending on the size and density of the particles, it may require very high g-force, such as 100,000. If the particles are less dense than the medium, they will float instead of pellet.

Another separation method that you could use is gel filtration chromatography (also called size exclusion chromatography), which separates substances on the basis of size. For separating BSA from nanoparticles, you could use Bio-gel A0.5m or related resin.

Thank you Adam B Shapiro but we need stimulant for opening micelle and release drug and release It should not be explosive and the entire drug should not be released first But it should be done slowly