This document summarizes research developing new photodynamic therapy agents that specifically target cancer cells. The researchers synthesized two complexes, folate-hemoglobin-chlorin and folate-albumin-chlorin, to test if hemoglobin could increase singlet oxygen production by bringing in more oxygen. They found the folate-hemoglobin-chlorin conjugate had higher oxygen affinity than unmodified hemoglobin. Cell culture studies also showed the conjugates had promising phototoxicity against HeLa cervical cancer cells. Overall, the research aims to increase the specificity of photodynamic therapy for cancer cells using folate targeting and hemoglobin to enhance oxygen delivery.