I currently use an ultracentrifuge (40,000g/20mins) to wash PLGA nanoparticles following encapsulation and coating with chitosan, however the wash step in deionised water results in a considerable loss of nanoparticle yield from the desired particle population size of ~200nm. Does anyone know of an optimised spin speed and time for PLGA nanoparticles that can minimise the loss from the supernatant discard? I have spun for longer times but find that the particle pellet becomes difficult to re-suspend. Please help :)
I would say either compensate between the losing of the particles and the compaction or simply use dialysis bag or tube for the washing. You will find it quite nifty!
Hi, I wash my nanoparticles (80-100 nm) which are made of copolymer blends (include PLGA) at 25,000 rpm (74067 rcf) for an hour at 10 oC with BSA solution three times. I lose about 17% of nanoparticles during purification. I recommend you to look through the paper that I've attached. In the paper, PLGA nanoparticles were recovered by centrifugation for 10 min at 48,000 × g by resuspending the pellet in BSA solution.
http://www.ncbi.nlm.nih.gov/pubmed/17716122
Thanks for the answers everybody. Dialysis is not an option for me so centrifugation is the best and make-do really. I have to pursue and optimise this further but thanks for providing some options.