Characterization and hemocompatibility of poly (N-acryloyl-L-tryptophan) nanoparticles as targeting delivery carriers for vinblastine

Favorable biocompatibility is essential to biomaterials, and natural amino acids are recognized as the promising building block of polymers due to their non-toxicity and tunable side chains. We prepared polymeric nanoparticles (NPs) using N-acryloyl-L-tryptophan monomer by precipitation polymerization, and modified with polyethylene glycol and folate (PEG-FA) to improve the solubility and target folate-receptors (FR) overexpressed tumor tissues. Serving as drug carriers for vinblastine (VBL), NPs-PEG-FA with about 212.4 nm had the drug loading of VBL of 6.65 ± 0.41% after co-incubating for 1 h and showed sustained-release in pH 7.4 PBS, in which 99.87 ± 1.00% of VBL was released from NPs-PEG-FA during 72 h. Furthermore, NPs-PEG-FA was more efficiently taken up by FR positive Hela cells compared with NPs-PEG, which signified folate could enhance the internalization of NPs-PEG-FA into FR over-expressed cells. And NPs-PEG-FA began to enter Hela cells in large quantities from 3 h onwards, meanwhile the released drug increased more quickly in the first 3 h, which indicated most of the drugs would be released after entering tumor cells. More importantly, NPs-PEG-FA had good biocompatibility to L929 mouse fibroblast cells and exhibited hemocompatibility via the assays of hemolysis, antithrombogenicity, coagulation activation and platelet activation. NPs-PEG-FA could serve as drug carriers for delivering drugs into FR positive tumor cells.