Karamalakova Y, Chuttani K, Sharma R, Zheleva A, Gadjeva V, Mishra A. Biological evaluation of new potential anticancer agent for tumour imaging and radiotherapy by two methods:
99mTc-radiolabelling and EPR spectroscopy.
BIOTECHNOL BIOTEC EQ 2014;
28:1172-1180. [PMID:
26019604 PMCID:
PMC4434051 DOI:
10.1080/13102818.2014.978666]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 05/20/2014] [Indexed: 11/21/2022] Open
Abstract
Recently, a new class of in vitro and ex vivo radiotracers/radioprotectors, the nitroxyl-labelled agent 1-ethyl-1-nitroso-3-[4-(2,2,6,6-tetramethylpiperidine-1-oxyl)]-urea (SLENU), has been discovered. Our previous investigations demonstrated that SLENU is a low-molecular-weight stable free radical which is freely membrane permeable, easily crosses the blood brain barrier and exhibited in/ex vivo the lowest general toxicity and higher anticancer activity against some experimental tumour models. Further investigation was aimed to develop a 99mTc-labelled SLENU (97%) as a chelator and evaluate its labelling efficiency and potential use as a tumour seeking agent and for early diagnosis. Tissue biodistribution of 99mTc-SLENU was determined in normal mice at 1, 2 and 24 h (n = 4/time interval, route of administration i.v.). The distribution data were compared using male albino non-inbred mice and electron paramagnetic resonance investigation. The imaging characteristics of 99mTc-SLENU conjugate examined in BALB/c mice grafted with Ehrlich Ascitis tumour in the thigh of hind leg demonstrated major accumulation of the radiotracer in the organs and tumour. Planar images and auto-radiograms confirmed that the tumours could be visualized clearly with 99mTc-SLENU. Blood kinetic study of radio-conjugate showed a bi-exponential pattern, as well as quick reduced duration in the blood circulation. This study establishes nitroxyls as a general class of new spin-labelled diagnostic markers that reduce the negative lateral effects of radiotherapy and drug damages, and are appropriate for tumour-localization.
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