I tried incubation with lyophilized PLGA NPs, Incubation with PLGA NPs in solution and I tried to synthesize the PLGA NPs with the Chitosan dissolved in the aqueous phase.
The answer depends on if you accomplished what you wanted. I guess you want to have a positively charged nanoparticles surface. Th best method will be the one that results in the highest negatively charge. If precipitation did not occur in anyone, then both are fine. Are you using the nanoparticles to realese a drug?
First of all, thank you for your answer. Yes, I want to have a positively charged surface, and precipitation doesnt occur when I use Acetic Acid pH =5 as buffer. Yes, I am using the NPs to release a drug, the thing is that with the DLS is hard to know if this change in charge is due to the pH or due to the right deposition of chitosan over my nanoparticles. I would like to know if there is a better way to get the chitosan shell.