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The minimally invasive elimination of tumours using heating as a therapeutic agent is an emerging technology in medical applications. Particularly, the intratumoural application of magnetic nanoparticles as potential heating sources when exposed to an alternating magnetic field has been demonstrated. The present work deals with the estimation of the basic relationships when the magnetic material has access and binds to structures on cell membranes of target cells at the tumour region, particularly as a consequence of administration through tumour supplying vessels. Therefore, using mouse endothelial cells in culture, the binding of dextran coated magnetic nanoparticles (mean hydrodynamic particle diameter 65 nm) was modelled using the periodate method. The efficacy of cell labelling was demonstrated by magnetorelaxometry (MRX)—a selective method for the detection of only those magnetic nanoparticles that were immobilized—as well as by electron microscopy and iron staining. The amount of iron immobilized on cells was found to be 153 ± 56 µg Fe per 1 × 107 cells as determined by atomic absorption spectrometry. Moreover, after exposure of those 1 × 107 labelled cells to an alternating magnetic field (frequency 410 kHz, amplitude 11 kA m−1) for 5 min, temperature increases of 2 °C were achieved. The consequences of particle immobilization are reflected by the results of the measurements related to the specific heating power (SHP) of the magnetic material. Basically, the heating potential is explained by the superposition of Brown and Neél relaxation while for immobilized nanoparticles the Brown contribution is absent. In the long term the data could open the door to targeted magnetic heating after further optimization of the heating potential of magnetic material as well as after functionalization with biomolecules which recognize specific structures on the surface of cells at the target region.

Flow cytometric analysis of eosin-5′-maleimide-labeled red blood cells has been proposed as a new method of identifying hereditary spherocytosis (HS). The aim of the present study was to analyze sensitivity and specificity of this method. Red blood cells from patients with HS (n = 58) revealed significantly lower mean channel fluorescence values than red blood cells from normal subjects (n = 110), unaffected HS family members (n = 8), and patients with other anemias (n = 44). Taking a mean channel fluorescence of 400.0 units as the threshold value identified by logistic regression, sensitivity and specificity of the test for HS were 96.6 and 99.1%, respectively. Flow cytometric analysis is a valuable screening test for the diagnosis of HS.

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