Magnetic Resonance Microscopy of Collagen Mineralization

Published

August 1, 2008

Author(s)

Ingrid E. Chesnick, Jeffrey T. Mason, Anthony A. Giuseppetti, Naomi Eidelman, Kimberlee Potter

Abstract

A model mineralizing system was subjected to magnetic resonance microscopy (MRM), to investigate how water proton transverse (T2) relaxation times and magnetization transfer ratios (MTRs) can be applied to monitor collagen mineralization. In our model system, a collagen sponge was mineralized with polymer-stabilized amorphous calcium carbonate. The lower hydration and water proton T2 values of collagen sponges during the initial mineralization phase were attributed to the replacement of the water within the collagen fibrils by amorphous calcium carbonate. The significant reduction in T2 values by day 6 (p < 0.001) was attributed to the appearance of sufficient mineral crystallites, that were also detected by X-ray diffraction and scanning electron microscopy. In the second phase, between days 6 and 13, MRM properties appear to plateau as amorphous calcium carbonate droplets begin to coalesce within the intrafibrillar space of collagen. In the third phase, after day 15, the amorphous mineral phase crystallized, resulting in the reduction in the absolute intensity of the collagen diffraction pattern. We speculate that MTR values for collagen sponges, with similar collagen contents, increased from 0.25 ± 0.02 for controls strips to a maximum value of 0.31 ± 0.04 at day 15 (p = 0.03) because mineral crystals greatly reduce the mobility of the collagen fibrils.

Citation

Biophysical Journal

Volume

95

Issue

4

Pub Type

Journals

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Keywords

magnetic resonance microscopy, magnetization transfer ratio, X-ray diffraction, collagen mineralization, biomineralization, amorphous mineral precursor, calcite, scanning electron microscopy

Citation

Chesnick, I. , Mason, J. , Giuseppetti, A. , Eidelman, N. and Potter, K. (2008), Magnetic Resonance Microscopy of Collagen Mineralization, Biophysical Journal, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=854116 (Accessed October 22, 2025)