Formulation of peptide-functionalized PLGA-PEG nanoparticles

The functionalized PLGA-PEG NPs were formulated following a nanoprecipitation method. PLGA-PEG-AXT050 and PLGA-mPEG were each dissolved in DMF in any desired mass ratio (i.e. 10% NP: 1 to 9 mass ratio of PLGA-PEG-AXT050 to PLGA-mPEG) at 10 mg/mL total polymer concentration. For encapsulation, this was then mixed with AXT050 in DMSO at 5% (w/w) and/or with a dye such as 5-carboxytetramethyl-rhodamine (TAMRA). The polymer/peptide mix was then added dropwise to a volume of deionized water ten times larger than the DMF solution under magnetic stirring. After 4-6 hours stirring in a chemical hood, the NPs were filtered and concentrated using ultra centrifugation columns (EMD Millipore, UFC810096) and GPC spin columns (Thermo Scientific) using S-400 HR media (Sephacryl) to ensure all free peptide was filtered. NPs were then either used immediately or stored overnight at 4°C before use.