Hydrolyzed gelatin-based polymersomes as delivery devices of anticancer drugs

Monodispersed polymersomes based on a hydrophobically-modified protein with dimensional range between 154 and 254 nm were prepared employing a water addition/solvent evaporation method. Gelatin hydrolyzate and PEG40-stearate, acting as hydrophilic and hydrophobic blocks, respectively, underwent radical coupling and three materials with different hydrophilic/lipophilic ratio were obtained by varying the amount of PEG40-stearate in the reaction feed. Critical aggregation concentrations of each amphiphilic polymer were found ranged from 3.9 to 10.2 μg mL−1, with lower values recorded for conjugate with lower hydrophilic/lipophilic ratio. Anticancer drug methotrexate was loaded into the vesicular systems with efficiency strictly dependent on the gelatin hydrolyzate content and the in vitro releasing profile assessed and analyzed by suitable mathematical models. To prove the applicability of the proposed delivery vehicle, the biocompatibility properties were assessed in normal human lung fibroblasts cells MRC-5, while the anticancer efficiency was tested on H1299 lung cancer cells, proving that the drug encapsulation into the polymersomes dramatically reduced the cytotoxicity on healthy cells while preserving its efficiency in killing cancer cells.