Moreover, utilising its catalytic oxidation functions, hemin has been employed in fabricating various biomimetic catalysts for different biomedical applications Additionally, the affinity of hemin towards • NO in FBS-containing media and the further influence of hemin-nitrosylation on its cellular uptake has also been reported before . In addition, because it scavenged • NO, hemin protected hyaluronic acid against the • NO-induced modification/degradation . Hence, hemin has a potential as a • NO-scavenging compound, which can have an impact on the • NO-induced migration of breast cancer cells. However, to ensure a continuous and specific affinity towards • NO, the central metal should be maintained in the ferric form. If it is not, the reduced hemin (Fe(II)-PPIX), in spite of its higher binding constant to • NO than that of the Fe(III)-PPIX, it will bind to both O2 and CO produced and transmitted between the living cells as well . Hence, the specificity of hemin towards • NO will be lost. To achieve this, the modification of hemin with an electron donating molecule/group can help restore the Fe(III) following binding to • NO and its oxidation. A similar approach was applied previously by immobilization of hemin onto graphene oxide, whose π electrons interacted with the Fe(III) cation, and resisted the reduction of Fe(III) after binding to • NO (Jiang, S. et al., 2013). In addition, hemin molecules tend to aggregate in aqueous solutions owing to the hydrophobic nature of its tetrapyrrole ring . This limits its application as a • NO-scavenger due to the alterations in electronic structure at the Fe(III)-centres. Furthermore, in addition to its susceptibility to the enzymatic degradation by heme oxygenase , hemin is prone to oxidation and further degradation by the action of H2O2 and hydroperoxyl radical (HO2 • ) ( . Therefore, when the treatment is lengthy, the function of the hemin structure towards • NO-scavenging will be reduced.