Phosphorylated Polyesters Inspired by Phospholipids: Synthesis, Characterization, and Potential Applications

We report the synthesis of phosphorylated polyesters by the phosphorylation of hydroxylated polyesters synthesized by the lipase-catalyzed polycondensation of glycerol and aliphatic dicarboxylic acids and their characterization. The use of phosphoryl chloride as a phosphorylating agent and triethylamine as a catalyst in mild reaction conditions resulted in polyesters with repetitive units structurally similar to phospholipids, molar mass of around 14-38 kDa, and a degree of phosphorylation of 36 ± 11 mol %. These polyesters are composed mainly of 10 different repetitive units as determined by 1D and 2D NMR. Their properties change from more hydrophilic and amorphous for phosphorylated poly(glycerol adipate) to more hydrophobic and semicrystalline for phosphorylated poly(glycerol dodecanedioate). Preliminary investigations have shown the potential of these polyesters to self-assemble in aqueous media forming nanoparticles, which can be loaded with hydrophobic molecules and released into an organic phase, acting as a phase transfer agent, and used as a pH-responsive emulsifier.