The increasing need for point-of-care diagnosis has sparked the development of label-free sensing platforms, some of which are based on impedance measurements with biological cells. Here, interdigitated electrodes were functionalized with layer-by-layer (LbL) films of hyaluronan (HA) and chitosan (CHI) to detect prostatic tumor cells (PC3 line). The deposition of LbL films was confirmed with atomic force microscopy and polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS), which featured the vibrational modes of the HA top layer capable of interacting specifically with glycoprotein CD44 receptors overexpressed in tumor cells. Though the CHI/HA LbL films cannot be considered as a traditional biosensor due to their limited selectivity, it was possible to distinguish prostate tumor cells in the range from 50 to 600 cells/µL in in vitro experiments with impedance spectroscopy. This was achieved by treating the impedance data with information visualization methods, which confirmed the distinguishing ability of the films by observing the absence of false positives in a series of control experiments. The CD44-HA interactions may, therefore, be exploited in clinical analyses and point-of-care diagnostics for cancer, particularly if computational methods are used to process the data.

The cluster of differentiation 44 (CD44) and the hyaluronan-mediated motility receptor (RHAMM), also known as CD168, are perhaps the most studied receptors for hyaluronic acid (HA); among their various functions, both are known to play a role in the motility of a number of cell types. In peripheral nerve regeneration, the stimulation of glial cell motility has potential to lead to better therapeutic outcomes, thus this study aimed to ascertain the presence of these receptors in Schwann cells (rat adult aSCs and neonatal nSCs) and to confirm their influence on motility. We included also a Schwann-like phenotype (dAD-MSCs) derived from adipose-derived mesenchymal stem cells (uAD-MSCs), as a possible basis for an autologous cell therapy. CD44 was expressed similarly in all cell types. Interestingly, uAD-MSCs were RHAMM(low), whereas both Schwann cells and dASCs turned out to be similarly RHAMM(high), and indeed antibody blockage of RHAMM effectively immobilized (in vitro scratch wound assay) all the RHAMM(high) Schwann(-like) types, but not the RHAMM(low) uAD-MSCs. Blocking CD44, on the other hand, affected considerably more uAD-MSCs than the Schwann(-like) cells, while the combined blockage of the two receptors immobilized all cells. The results therefore indicate that Schwann-like cells have a specifically RHAMM-sensitive motility, where the motility of precursor cells such as uAD-MSCs is CD44- but not RHAMM-sensitive; our data also suggest that CD44 and RHAMM may be using complementary motility-controlling circuits.