Figure 1

Synthesis and characterization of PLGA-PEG^PS341 nanoparticles. The PS-341 or fluorescent marker dye, nile red, loaded PLGA nanoparticles were synthesized using non-polar core of oil-in-water microemulsion technique with PEGylated phospholipid DSPE-mPEG²⁰⁰⁰ as the emulsifier. Dynamic laser scattering (DLS) was employed to measure the size, distribution and colloidal stability of the PLGA-PEG^PS341 nanoparticles while transmission electron microscopy (TEM) was used to characterize the size and shape of the nanoparticles. (A) Schematic shows that PS-341 and/or nile red dye is encapsulated in PLGA nanoparticles. The hydrophobic phospholipid part of the emulsifier remains embedded in the PLGA matrix by hydrophobic interactions, whereas the hydrophilic PEG part point outwards on the nanoparticle surface, forming a polymeric brush. (B) The DLS results show that radius of PLGA-PEG^PS341 nanoparticles is 121.5 ± 15 nm (PDI = 0.106). The radius of nanoparticles varied by less than 15%, suggesting that their colloidal stability is not affected under physiological pH. (C) TEM shows that PLGA-PEG^PS341 nanoparticles are mono-dispersed, spherical and are ~200 nm in size. DLS and TEM based size and surface characterization of nanoparticles confirms size distribution and colloidal stability of mono-dispersed particles.