Fractal Analysis and Biophysical Investigation of Muscular Tissue Damaged due to Low Temperature: A Pilot Study

Severe damage is produced in tissues by freezing and thawing. Until now, a great majority of the studies are performed qualitatively, lacking any quantitative approach. An important step is to choose the best option among different freezing methods. To approach the complex problem of damage produced in tissues by freezing, in this paper we present the classical mechanics approach and a quantitative study making use of a fractal methodology (evaluation of fractal dimension by box-counting method). A comparative fractal analysis between two different steps of freezing the human thoracic diaphragm muscle has been performed to quantify the voids and cracks produced by freezing (samples were placed in a cryostat chamber). Moreover, a standard Euclidean morphometry was performed to determine area and shape of the muscle nuclei after the two steps of freezing. Fractal dimension of the ice-tissue interface structures increased with decreasing temperature (p<0.0001), percentage of cell muscle decreased (p<0.01), while standard morphometry of the nuclei didnt show any modifications. Our results show the ability of the fractal approach to accurately quantify the damage produced by freezing and reveals that the lowest temperature produces the most damage.