Synthesis of the hemoglobin-conjugated polymer micelles by click chemistry as the oxygen carriers^†

Amphiphilic triblock copolymers were synthesized using MPEG, cyclic carbonic ester monomer including propargyl group (MPC) and L-lactide (LA). These copolymers could self-assemble into core–shell spherical micelles with propargyl groups on the surface. Azided hemoglobin (Hb) was conjugated with the micelles through click reaction to form Hb-bearing nano-micelles. The click reaction conditions, such as the molar ratio of sodium azide to Hb, the binding ratio of Hb to copolymers, the components of catalytic solution, the reaction temperature and time, were thoroughly investigated and optimized. The resulted nano-micelles had 100 nm diameter with 50–60 wt% of Hb content. The Hb-based nano-micelles showed appropriate stability and oxygen carrying capacity, and would have the potential to be used as the new type of artificial oxygen carrier. Copyright © 2011 John Wiley & Sons, Ltd.