Procedures for hemin-tyrosine (H-Tyros) conjugation. To dried hemin-N-oxysuccinimide ester (50 mg, 0.06 mmol., 1.0 eq.), DMSO (2 mL) was added under a nitrogen atmosphere with stirring for 30 min at room temperature with the exclusion of light. Tyrosine (100 mg) was dissolved in a solvent mixture of DMSO (900 μL), double distilled water (16.7 μL) and HCl (83.3 μL). Tyrosine solution (855.2 μL, 0.472 mmol., 8.0 eq.) was added to the activated hemin solution, followed by triethylamine.HCl (130 μl, 0.945 mmol, 16 eq.). The mixture was stirred for a further 24 hours under the same conditions as those described previously. The final product was precipitated as explained in the case of H-Tyra conjugate, with the same purification procedures. The final dark brown powder was characterized by HPLC, UV-Vis, cells/well in a 48-multiwell plate for 24 hours in phenol red-free FBS-containing RPMI for attachment.