Fig. 1From: Improvement of stem cell-derived exosome release efficiency by surface-modified nanoparticlesProperties of positively charged PCS NPs. a Schematic representation of PLGA-PEI PCS NPs. b ζ-potential. c Size. d TEM image. e SEM image. f Stability test of PLGA-PEI PCS NPs in the medium and PBSBack to article page