Due to the unique physical structure and chemical properties

amphiphilic polymers have an important role in biomedicine

especially in the field of drug release. In this study

a new block copolymer poly (aspartate-tyrosine-alanine) was synthesized by ring-opening polymerization

and its structure was characterized by FT-IR and 1H-NMR. The model drug doxorubicin was loaded by self-assembly based on the block polymer

and the drug nanocarriers with pH response were constructed. The morphology

particle size and distribution of drug-loaded nanoparticles were characterized by scanning electron microscopy (SEM) and dynamic light scattering (DLS)

respectively. The results showed that the particle size of drug-loaded nanoparticles in solution is less than 220nm and had obvious pH response. The release effect of drug-loaded nanoparticles in acidic conditions is obviously higher than that in neutral and alkaline conditions. In addition

in vitro cytotoxicity experiments showed that the polyamino acid material was not toxic to L-929 cells.