Synthesis and in vitro evaluation of a hyaluronic acid–quantum dots–melphalan conjugate

• A hyaluronic acid–quantum dots–melphalan conjugate was synthesized.
• The conjugate had proper physical and chemical properties.
• The conjugate had a pH-enzyme sensitive drug release property.
• The conjugate had a weaker cytotoxicity to normal cell than melphalan.
• The conjugate can be effectively internalized into the tumor cell.

Polymer-drug conjugates have played an important role in improving tumor cell targeting and the selectivity of anticancer drugs. In this study, quantum dots and melphalan were attached to the backbone of hyaluronic acid to synthesize a polymer–drug conjugate. The physicochemical properties of the conjugate were characterized by FT-IR, XRD, 1H NMR, UV-Vis spectra and DLS. The in vitro drug release profiles and cell evaluation were investigated. The results showed that the conjugate was synthesized and self-assembled into nanoparticles with a diameter of 115 ± 2.3 nm. The conjugate had a pH-sensitive drug controlled release property. It was an ideal receptor-mediated delivery system and can be internalized into the human breast cancer cell. It had a better inhibition effect on human breast cancer cell and a poorer inhibition effect on normal breast cell than melphalan. These results supported that the conjugate would be a promising candidate for cancer therapy.