Current limitations in the application of radiomodifiers refer to significant acute toxicity, intravenous administration for most of them and loss of most antiradiation properties when radiation types other than low Linear Energy Transfer (LET) radiation are concerned. This paper describes research on 'molecular combinations' – structural modification of clinically approved preparations with biologically active compounds; incorporation in biodegradable polymers to prolong effects; and investigations with herbal preparations. Inspiring results were achieved for adenine nucleotides linked to aminothiols. Some products manifested marked therapeutic properties on the survival rate and reduction of postradiation adinamy incidence in rats after oral administration. The effect of the bond character in molecular combinations was evaluated, as well as the influence of the polymer-carrier molecular weight and degree of immobilisation. Radiosensitising preparations based on nucleotides and 2′-deoxynucleotides co-precipitation with ethanidazole were more effective in tumour-bearing mice after whole-body fractionated irradiation. In case of low-dose prolonged irradiation, the herbal preparation Elixir-3 (E-3) diminished the radiation damage and facilitated repair processes.
Keywords: radiomodifiers, molecular combinations, polymer complexes, herbal preparations, low-dose radiation, low radiation, radiation response modification, structural modification, biologically active compounds, biodegradable polymers, adenine nucleotides, aminothiols, survival rate, postradiation adinamy incidence, rats, radiation damage, repair processes