Cellular Response to Linear and Branched Poly(acrylic acid)

Poly(acrylic acid‐co‐sodium acrylate) (PNaA) is a pH‐responsive polymer with potential in anticancer drug delivery. The cytotoxicity and intracellular effects of 3‐arm star, hyperbranched and linear PNaA were investigated with L1210 progenitor leukemia cells and L6 myoblast cells. Free solution capillary electrophoresis demonstrated interactions of PNaA with serum proteins. In a 72 h MTT assay most PNaAs exhibited a IC50 between 7 and 14 mmol L−1, showing that precipitation may be a sufficient purification for PNaA dilute solutions. Dialyzed 3‐arm star and hyperbranched PNaA caused an increase in L6 cell viability, challenging the suitability of MTT as cytotoxicity assay for PNaA. Fluorescent confocal microscopy revealed merging of cellular lipids after exposure to PNaA, likely caused by serum starvation. The cytotoxicity and intracellular effects of poly(acrylic acid)/poly(sodium acrylate) (PNaA) are investigated. This pH‐responsive polymer has potential in anticancer drug delivery. Capillary electrophoresis demonstrates interactions of PNaA with serum proteins. The MTT assay is used to assess the cytotoxicity of PNaA with different branching architectures for L1210 progenitor leukemia cells and L6 myoblast cells.