Comparison of some physico-chemical parameters and biological behaviour of fullerenol labelled with technetium -99m

Abstract

The biological behavior of fullerene derivatives shows their considerable potential for medical application. Polyhidroxilated, water soluble fullerenol C60(OH)22, used in these studies, was synthesized by procedure complete substitution of bromine atoms from polybromine derivatives C60Br24 in alkaline media. In order to investigate the pharmacological behaviour and metabolism of the fullerenol, quickly and conveniently, we present the way and possibilities for its labelling with 99mTc (T1/2=6.02h, En=141keV), which bind to the outside, leaving the cage intact. Two different labelling approaches with technetium-99m were performed: direct labelling by tin (II) chloride method and labelling with 99mTc(I) using [99mTc(CO) 3(H2O)3]+ precursor. The radiochemical studies results have shown that content of free 99mTcO4- in the samples was depend on fullerenol-stannous chloride ratio and increased if ratio was higher. HPLC quality control results of 99mTc(CO)3-[C 60(OH)22] have shown that the labelling yield, in alkaly media, was 95.35%. Protein binding to HA was species-dependent process. The biological behaviour of labelled fullerenol were different in dependence of labelling method and the time of sacrificed of animals. From recent investigations it can be concluded that oxidation state in technetium coordination complexes has a great impact on in vitro and in vivo behaviour of the these complexes.