Abstract:Interaction of red blood cells (RBCs) with unmodified and partially (50%) silylated fumed silica A-300 (nanosilica) was studied by microscopic, XRD and thermally stimulated depolarisation current (TSDC) methods. Nanosilica at a low concentration C A−300 < 0.01 wt.% in buffered aqueous suspension is characterised by a weak haemolytic effect on RBCs. However, at C A−300 = 1 wt% all RBCs transform into shadow corpuscles because of 100% haemolysis. Partial (one-half) hydrophobization of nanosilica leads to reduction of the haemolytic effect in comparison with unmodified silica at the same concentrations. A certain portion of the TSDC spectra of the buffered suspensions with RBC/A-300 is independent of the amounts of silica. However, significant portions of the low-and high-temperature TSDC bands have a lower intensity at C A−300 = 1 wt% than that for RBCs alone or RBC/A-300 at C A−300 = 0.01 wt.% because of structural changes in RBCs. Results of microscopic and XRD investigations and calculations using the TSDC-and NMR-cryoporometry suggest that the intracellular structures in RBCs (both organic and aqueous components) depend on nanosilica concentration in the suspension.

The in ter ac tion of ultrafine sil ica (UFS) with mem brane prep a ra tions of do nor eryth ro cytes (ghosts) was in ves ti gated by the method of 1 H NMR spec tros copy. The val ues of their hydratation in con tact with sil ica, interphase en ergy, con cen tra tions of weakly and strongly bound wa ter were mea sured and cal cu lated. Pos si ble mech a nisms of UFS ef fect on cell hemolysis are dis cussed.