Biomedical applications of the Mössbauer effect

Control of the Iron State in Pharmaceuticals Used for Treatment and Prevention of Iron Deficiency Using Mössbauer Spectroscopy

Various iron-containing medicaments, vitamins and dietary supplements are used or developed for treatment and prevention of the iron deficiency anemia which is very dangerous for human and may cause various disorders. From the other hand, blood losses, iron poor diet, microelements (co-factors) deficiency, metabolic failures, absorption problems, etc. can change the iron status and affect the health. These pharmaceuticals contain iron compounds in the ferrous and ferric states. It is known that ferrous salts are more suitable for the intestinal intake than ferric ones. On the other hand, pharmaceutically important ferritin analogues contain ferric hydrous oxides and appear to be effective for both injections and peroral administration. 57Fe Mössbauer spectroscopy is a unique physical technique which allows one to study various iron-containing materials including pharmaceuticals. Therefore, this technique was applied to study iron-containing pharmaceuticals for the analysis of the iron state, identification of ferric and ferrous compounds, revealing some structural peculiarities and for detection of aging processes in relation to the iron compounds. This review considers the main results of a long experience in the study of iron-containing pharmaceuticals by Mössbauer spectroscopy with critical analysis that may be useful for pharmacists, biochemists, biophysicists, and physicians.

Applications of Mössbauer Spectroscopy in Biomedical Research

A brief review on the applications of Mössbauer spectroscopy in biomedical research discusses the results of more than fifty years of experience in this field. Basing on the numerous results the main directions of biomedical applications of Mössbauer spectroscopy are considered as follows: 1) studies of the quantitative changes of iron-containing biomolecules related to pathological processes; 2) studies of the qualitative changes in iron-containing biomolecules related to pathological processes; 3) studies of the effect of various environmental factors (physical, chemical, and biological) on iron-containing biomolecules; 4) studies of metabolic processes by means of analysis of the Mössbauer nuclides pathways in organisms; 5) studies of dynamic processes; 6) studies of pharmaceutical compounds and blood substitutes containing Mössbauer nuclides; 7) miscellaneous studies. Some examples of biomedical research using ⁵⁷Fe, ⁵⁷Co, ¹¹⁹Sn, ¹⁵³Sm, and ¹⁹⁷Au Mössbauer nuclides are presented.

Mössbauer spectroscopy with a high velocity resolution in the study of iron-containing proteins and model compounds

Mössbauer spectroscopy with a high velocity resolution was used for comparative studies of human adult, rabbit and pig oxyhemoglobins, human liver ferritin and its pharmaceutically important models Imferon and Maltofer(®) as well as liver and spleen tissues from normal and lymphoid leukemia chicken. These studies revealed small variations of Mössbauer hyperfine parameters which were related to small variations of iron electronic structure and stereochemistry in these samples.

Determination of the iron state in ferrous iron containing vitamins and dietary supplements: Application of Mössbauer spectroscopy

Determination of the iron state in commercially manufactured iron containing vitamins and dietary supplements is important for evaluation of pharmaceuticals quality. Mössbauer (nuclear gamma-resonance) spectroscopy was used for analyzing the iron state in commercial pharmaceutical products containing ferrous fumarate (FeC(4)H(2)O(4)), ferrous sulfate (FeSO(4)), ferrous bisglycinate chelate (Ferrochel) and ferrous iron (hydrolyzed protein chelate). Mössbauer parameters and the iron states were determined for iron compounds in the studied pharmaceuticals. Various ferric and ferrous impurities were found in all of the commercial products. The quantities of ferric impurities exceeded the FDA limitation of 2% in products containing ferrous fumarate. The quantities of ferric impurities exceeded 58% and 30% in products containing ferrous bisglycinate chelate and ferrous iron (hydrolyzed protein chelate), respectively. The presence of ferrous and ferric impurities was not related to the ageing of the vitamins and dietary supplements. Two pharmaceutical products contained major iron compounds, the Mössbauer parameters of which did not correspond to the ferrous fumarate or ferrous bisglycinate chelate claimed by the manufacturer.

Study of the relationship of small variations of the molecular structure and the iron state in iron containing proteins by Mössbauer spectroscopy: biomedical approach

This review considers the results of experimental Mössbauer studies and theoretical calculations of the effect of small variations of protein molecular structure on the iron electronic structure and stereochemistry in order to understand the proteins structural heterogeneity and functional variety. Structural changes in iron containing proteins during various diseases are also considered. These results show the relationship of the small structural variations and Mössbauer parameters of iron containing proteins and demonstrate the possibilities of Mössbauer spectroscopy to obtain new information at the molecular level in biomedical research.

Mössbauer spectroscopy in biomedical research

This work discusses the main directions and results of the application of Mössbauer spectroscopy of iron containing species in biomedical research. These studies demonstrate the wide possibilities of Mössbauer spectroscopy to obtain physical parameters and information about the iron electronic structure in normal and pathological biomolecules, model compounds and pharmaceutical samples as well as about qualitative and quantitative changes of iron containing biomolecules during pathological processes or the effect of environmental factors. The results obtained may be useful for further understanding of the molecular nature of diseases and pathological processes.