EncapsulationofastaxanthinintoPCPLCnanospheresbysolventdisplacementresultedina98% encapsulation efficiencyandyielded 312±5.83nm nanospheres with a 40% (w/w) astaxanthin loading. Two other amphiphilic polymers, EC and PB4, were less suitable and, with reference to their chemical structure (Fig. 1), suggest that a suitable compatibility between astaxanthin and polymeric nanospheres is required for successful encapsulation. The freeze- dried astaxanthin-loaded PCPLC nanospheres dispersed well in water forming a stable aqueous colloidal suspension. The thermal stability of astaxanthin was greatly improved upon PCPLC nanoen- capsulation, i.e., the loss of olefinic functionality observed when unencapsulated astaxanthin was heated at 70◦C for two hours could be prevented by PCPLC encapsulation.