 Materials which have been used include poly (glycolic acid), poly(lactic-co-glycolic acid), iron-oxide, liposomes, lipid bilayers, sepharose, polystyrene and Polyisocyanopeptides.aAPCs remove the need to harvest patient specific APCs such as dendritic cells (DCs) and the process of activating the DCs in the stimulation of antigen-specific T cells.As specific cancer antigens have been discovered, these antigens can be loaded to aAPCs to successfully stimulate and expand tumor-specific cytotoxic T cells.