Controlling the process of cell adhesion by using biomaterials in biological environments is a challenge to biotechnological processes. In this context, the immobilization of cells on surfaces can be affected by the properties of a substrate such as charge, surface chemistry and topography. Recent studies have explored the interaction between hyaluronic acid (HA) and CD44 receptors to understand the adhesion of tumor cells on the surface of nanometric coatings produced via Layer-by-Layer (LbL). CD44 receptors are glycoproteins present at high concentrations on the extracellular surface of tumor cells. In turn, the LbL technique is a simple and robust surface modification approach that has called attention because it enables a significative control over the physical and chemical properties of the films produced.  Here we assessed the influence of the pH (3.0 and 5.0), ionic strength (0 and 100mM) and the number of bilayers (3.0 and 3.5) conditions on the cell capture potential (PC3 line) of chitosan/hyaluronan films via LbL. Films were assembled onto glass substrates by alternating immersion into polyelectrolyte solutions of opposite charges. The characterization of these coatings was carried out using the Atomic Force Microscopy. Topography and capacitance gradient (dC/dz) images were obtained aiming to evaluate the effect<b> </b>of the roughness and the charge mobility on the cell adhesion. Topography results indicated that the increase of pH and ionic strength result in the decreased roughness of the films, while the presence of the hyaluronic acid on the surface increased the roughness of the coatings. Capacitance gradient results showed that the films with higher charge mobility presented a higher number of cells adhered. Furthermore, we propose that there is a combined effect of roughness and capacitance gradient on the selective potential of each coating. Cell adhesion results suggest that increasing the capacitance gradient induces cell-film aggregation, whereas more irregular and rough surfaces inhibit this process. In summary, it is possible to point out charge mobility and surface regularity as critical factors to the biomaterials development for a wide range of applications involving the cell adhesion process. These findings make it possible to use these films as platforms for the selective capture of tumor cell lines.

Chitosan/hyaluronan coatings tailored for tumor cell adhesion: Influence of the topography and capacitance gradient

255th National Meeting (2018)

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