Green Polymer-Based Nanocomposites Containing Ceria and Their Use in the Process of Stem Cell Proliferation

A technique of fabrication of bacterial cellulose-based films with CeO₂ nanofiller has been developed. The structural and morphological characteristics of the materials have been studied, their thermal and mechanical properties in dry and swollen states having been determined. The preparation methodology gives way to obtaining composites with the uniform distribution of nanoparticles. The catalytic effect of ceria regarding thermal oxidative destruction of cellulose was confirmed by TGA and DTA methods. An increase in CeO₂ content leads to a rise in the elastic modulus (1.27-fold rise caused by the introduction of 5 wt.% of the nanofiller into polymer) and strength of the films. This effect is explained by the formation of additional links between polymer macro-chains via the nanoparticles’ surface. The materials fabricated are characterized by a limited swellability in water. Swelling causes a 20-30-fold drop in the stiffness of the material, the mechanical properties of the films in a swollen state remaining germane to their practical use. The application of the composite films in cell engineering as substrates for the stem cells proliferation has been studied. The increase in CeO₂ content in the films enhanced the proliferative activity of embryonic mouse stem cells. The cells cultured on the scaffold containing 5 wt.% of ceria demonstrated increased cell survival and migration activity. Analysis of gene expression confirmed the improved cultivation conditions on CeO₂-containing scaffolds.