Synthesis and characterization of paclitaxel loaded PLGA nanoparticles

A block copolymer of poly(lactide) and poly(ethylene glycol) was synthesized via ring opening polymerization reaction as described before (13). The block copolymer was characterized using ¹H-NMR (Varian 400 MHz) (13).

PLGA nanoparticles loaded with paclitaxel were synthesized by a single emulsion technique. Nanoparticles were surface functionalized with the block copolymer using the interfacial activity assisted surface functionalization technique developed in our lab. Nanoparticles were separated from free drug by repeated (three times) ultracentrifugation and resuspension in deionized water, and then lyophilized (13). PLGA nanoparticles loaded with a fluorescent dye (coumarin 6) were synthesized similarly (14).

To determine particle size and zeta potential, nanoparticles were dispersed in deionized water and then subjected to dynamic light scattering analysis (Delsa Nano C, Beckmann Coulter, California, USA).

To determine drug loading, nanoparticles were dispersed in methanol (~1 mg/mL) and the drug was extracted overnight. Nanoparticles were separated from extracted drug by centrifugation (14000 RPM, 15 minutes). Drug concentration in the extract was analyzed using HPLC (Beckmann Coulter, California, USA) (15).