Bacterial Cellulose (Komagataeibacter rhaeticus) Biocomposites and Their Cytocompatibility

A series of novel polysaccharide-based biocomposites was obtained by impregnation of bacterial cellulose produced by Komagataeibacter rhaeticus (BC) with the solutions of negatively charged polysaccharides—hyaluronan (HA), sodium alginate (ALG), or κ-carrageenan (CAR)—and subsequently with positively charged chitosan (CS). The penetration of the polysaccharide solutions into the BC network and their interaction to form a polyelectrolyte complex changed the architecture of the BC network. The structure, morphology, and properties of the biocomposites depended on the type of impregnated anionic polysaccharides, and those polysaccharides in turn determined the nature of the interaction with CS. The porosity and swelling of the composites increased in the order: BC–ALG–CS > BC–HA–CS > BC–CAR–CS. The composites show higher biocompatibility with mesenchymal stem cells than the original BC sample, with the BC–ALG–CS composite showing the best characteristics

Novel biocompatible Cu2+-containing composite hydrogels based on bacterial cellulose and poly-1-vinyl-1,2,4-triazole

Novel composite hydrogels representing interpenetrating polymeric networks (IPN) have been synthesized and consisted of Gluconacetobacter xylinus cellulose (GxC) and poly-1-vinyl-1,2,4-triazole (PVT) with Cu2⁺. The composite hydrogels’ mesostructure has been studied from 1.6 ​nm to 2.5 ​μm by small-angle and ultra-small-angle neutron scattering methods. It has been found that IPN complexes have three types of inhomogeneities: GxC, PVT, and PVT complex with Cu2⁺. The amount of the absorbed ions can be tuned as confirmed by electron paramagnetic spectroscopy. Besides, three hierarchy levels of GxC remained in the supramolecular structure of composite hydrogels. Reveling structure formation in these composite hydrogels is essential in fabricating hybrid polymeric materials for regenerative medicine, involving antibacterial or antifungal applications

Bacterial Cellulose-Based Nanocomposites Containing Ceria and Their Use in the Process of Stem Cell Proliferation

A technique for the 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 makes it possible to obtain composites with a uniform distribution of nanoparticles. The catalytic effect of ceria, regarding the thermal oxidative destruction of cellulose, has been confirmed by TGA and DTA methods. An increase in CeO2 content led to an increase in the elastic modulus (a 1.27-fold increase caused by the introduction of 5 wt.% of the nanofiller into the 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 were characterized by a limited ability to swell in water. Swelling caused a 20- to 30-fold reduction 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. An analysis of gene expression confirmed improved cultivation conditions on CeO2-containing scaffolds

Composite Hydrogels Based on Bacterial Cellulose and Poly-1-vinyl-1,2,4-triazole/Phosphoric Acid: Supramolecular Structure as Studied by Small Angle Scattering

New composite hydrogels (CH) based on bacterial cellulose (BC) and poly-1-vinyl-1,2,4-triazole (PVT) doped with orthophosphoric acid (oPA), presenting interpenetrating polymeric networks (IPN), have been synthesized. The mesoscopic study of the supramolecular structure (SMS) of both native cellulose, produced by the strain Komagataeibacter rhaeticus, and the CH based on BC and containing PVT/oPA complex were carried out in a wide range of momentum transfer using ultra- and classical small-angle neutron scattering techniques. The two SMS hierarchical levels were revealed from 1.6 nm to 2.5 μm for the objects under investigation. In addition, it was shown that the native BC had a correlation peak on the small-angle scattering curves at 0.00124 Å−1, with the correlation length ξ being equal to ca. 510 nm. This motive was also retained in the IPN. The data obtained allowed the estimation of the fractal dimensions and ranges of self-similarity and gave new information about the BC mesostructure and its CH. Furthermore, we revealed them to be in coincidence with Brown’s BC model, which was earlier supported by Fink’s results