Folate-Conjugated PLGA Nanoparticle Synthesis

One mmol of folic acid in 20 ml DMSO with 1 mmol
of ethyl dimethylaminopropyl carbodiimide (EDC) and 2
mmol of N-Hydroxysuccinimide (NHS) was dissolved in
with a magnetic stirrer for 12 hours at room temperature.
Then, to remove excess material, the solution was filtered
and added to the ethylenediamine (EDA) as a linker, and
pyridine (0.2/ml) and acetonitrile added to precipitate the
folate. The precipitate was washed 3 times with diethyl
ether and then dried to give a yellow deposit. 10 mg of
MiR-PLGA was dissolved in 5 ml phosphate-buffered
saline (PBS, Abcam, UK) at pH=7.4 and sonicated
for 1 minute. 1 mg/ml EDC and 1 mg/ml of NHS were
dissolved in DW and each of them washed, and about
500 μl was added to the above solution and agitated with
a magenetic stirrer at room temperature for 2 hours and
then centrifuged for 20 minutes to remove EDC and NHS.
Following, folic acid was added to the product with the
ratio of 1 mg/ml in PBS, incubated overnight at room
temperature, agitated with the magenetic stirrer and then
centrifuged. Using the same procedure as a previous
study (17 (link)) the obtained solution was mixeded at room
temperature once more and then the extra non-conjugated
material was picked up by ultracentrifugation. Finally, the
residual solution was lyophilized and stored. Conjugation
of folate on the PLGA surface was confirmed by fourier
transform infrared spectroscopy (FTIR) analysis.