In vitro toxicity of Stearoyl-poly(glycerol adipate) nanoparticles

Poly(glycerol adipate) (PGA)-based nanoparticles are promising carriers for drug delivery with a wide range of available structures. The biodegradable polymer with pendant free hydroxyl groups can be diversely functionalized. In this study, the toxicity of different Stearoyl-PGA nanoparticles with respect to erythrocytes and HepG2 cells was assessed. These cells are crucial test systems for intravenously injected biomedical particles.

For this work, a series of PGA polyesters with 0, 20, 50 and 65 mol% of converted hydroxyl groups was synthesized with stearic acid (PGABB, S20, S50, S65). Nanoparticles were prepared with these polymers by an optimized nanoprecipitation method. Physicochemical characterization was performed by photon correlation spectroscopy and zeta potential measurement. Cell compatibility was studied by a hemolysis assay with separated red blood cells as well as a QBlue viability test and a modified LDH cytotoxicity assay with HepG2 cells.

Different self-stabilizing nanoparticles with narrow size distributions in the range of 100-140 nm were prepared. All tested nanoparticle samples were nontoxic for HepG2 cells. In fact, increased metabolic activity and proliferation was observed after 24 h incubation with the Stearoyl-PGA particles. Apart from PGAS20, all samples did not show any hemolytic effect. Hemolysis of PGAS20 particles could be considerably decreased by adding Poloxamer 188 during the preparation process.