Abstract: Objective: To prepare polyamino acid micelles with functional groups and appropriate particle size by a simple and
efficient method. Methods: Using Lys（Z）-NCA and Gly-NCA as raw materials, a series of glycine-lysine copolymers Poly［KmGn］with
side-chain containing amino were prepared by ring-opening polymerization of NCA. The structure of the product was analyzed by
nuclear magnetic resonance（1H-NMR）. The morphology, particle size and distribution of the synthesized poly（amino acid）copolymer
were studied by using scanning electron microscopy（SEM）and dynamic light scattering（DLS）. Results: The synthesized polyamino
acid copolymers were in accordance with the molecular design. Different polyamino acid copolymers could be self-assembled into
spherical micelles with particle size of less than 200 nm and a uniform particle size distribution, and the particle size of the micelles
changed with the composition and content of polyamino acid monomers. Conclusion: A series of polyamino acid nano-micelles have
been prepared successfully, and the particle size of the micelles can be adjusted by changing the molecular composition of polyamino acid.

Key words: polyamino acid, NCA-ring-opening polymerization, nano-micelle, particle size and distribution