•Biopolymer layer-by-layer nanocoatings change the surface properties of nitinol plates.•Using κ-carrageenan as the top layer reduces hydrophobicity and surface roughness.•The use of chitosan as the lower layer of the film allows increasing the stability polymer coatings on the nitinol.•Chitosan/carrageenan films that were applied to nitinol plates reduce cytotoxicity in relation to the MG-63 cells line. Thin films based on the natural polysaccharides κ-carrageenan (Carr) and chitosan (Chit) were formed by layer-by-layer deposition technique. Surface topography and mechanical characteristics (Young's modulus, adhesion strength) of the polymer films with different number of layers were determined using various modes of atomic force microscopy (AFM). Polymer films were used to deposit on the surface of nitinol (NiTi) plates. The creation of polysaccharide coatings on nitinol led to a change in surface properties, such as hydrophilicity and root mean square roughness. in vitro cytotoxicity assay for nitinol plates with and without polymer coating by the MG-63 osteoblast-like cell line was conducted and was shown that all the studied samples are not toxic. A decrease in cytotoxicity for samples with a polymer film consisting of 4 layers of chitosan and carrageenan was shown as compared to an uncoated nitinol plates.