The anomalous Mössbauer fraction of ferritin and polysaccharide iron complex (PIC)

Evaluation of the Debye temperature for iron cores in human liver ferritin and its pharmaceutical analogue, Ferrum Lek, using Mössbauer spectroscopy

“…Lek, an iron-polymaltose complex, obtained in the present study appeared to be significantly larger than Ө D =27020 K found from the CS(T) measured in the temperature interval of 295-4 K for the 6 polysaccharide iron complexes (Niferex) in [22]. In spite of the same form of the iron core (-FeOOH) in both Ferrum Lek and Niferex (for the latter see [21]), these pharmaceutical products were produced by different manufactures in different conditions which, unfortunately, are unknown.…”

A comparison of the magnetic properties of polysaccharide iron complex (PIC) and ferritin

“…For PIC, no such detailed estima tion of the number of Fe 3 + ions in its core has been made. However, ~iven that the average core diameter of PIC is 70 A [10,17], and knowing the density of ferrihydrite [13,24] as well as its unit cell dimensions, this implies a theoretical number of 5100 iron atoms in the PIC core. Diamagnetic susceptibilities were evaluated for all samples and sample holders and were corrected for.…”

“…It is reported to be ef fective in the treatment of iron deficiency anemia [16]. PIC is reported to be spheroidal in shape with a 48% iron content, and having a distribu tion of core volumes with an average diameter of 70 A [10,17]. PIC is synthesized on an industrial scale by Central Pharmaceuticals essentially by a patented procedure [18] which is described in detail elsewhere [1].…”

“…Both the PIC and ferritin samples are com prised of a distribution of particle sizes [10,19]. Experimentally, it is very difficult, but not impos sible, to prepare an assemblage of particles with a narrow size distribution, hence, each sample has a distribution of blocking temperatures.…”

“…In this paper we present results of an investi gation of the magnetic behavior of PIC and fer ritin using different methods to determine their regions of superparamagnetism, maximum block ing temperatures, magnetic moments as well as number of uncompensated spins per core (par ticle), anisotropy constants given the particles' volumes, and their Neel temperatures. Basically, we want to know if PIC and ferritin give a consis tent picture of small antiferromagnetic particles, because our primary goal is to find whether the synthetic PIC molecule is a useful 'biomimic' model in investigating and comparing the recently observed [10] Lamb-Mossbauer I-factor anomaly in ferritin. This anomaly reveals itself in the sud den drop in the I-factor with increasing tempera ture around (mammalian) ferritin's blocking tem perature TB = 37 K, which is also the tempera ture above which the hyperfine structure, in fer ritin's Mossbauer spectrum, disappears and is replaced by a quadrupole doublet.…”