Synthesis and characterization of a magnetic bacterial cellulose-chitosan nanocomposite and evaluation of its applicability for osteogenesis

(ProQuest: ... denotes formulae omitted.) Introduction Polymer composites, nanocomposites, hydrogels, and bioceramics are used as scaffolds in tissue engineering.1,2 The structure of scaffolds in tissue engineering, imitating the extracellular matrix, acts as a template to guide the growth of cells and ultimately tissue regeneration.3 Repair in tissue engineering is accomplished through the appropriate use of cells, scaffolds, and cell growth-stimulating factors. [...]natural polymers have relatively weak mechanical properties, which can be improved by combining them with synthetic polymers.5-7 To enhance the mechanical properties of various scaffolds in bone tissue engineering, synthetic polymers are often used and coated with natural-based polymers or extracellular matrix proteins.8 Biopolymers are a suitable choice for various applications, including tissue engineering, implantation, wound healing, and drug delivery, due to their appropriate biochemical and biophysical properties in both in vivo and in vitro environments.9 Biopolymers, when processed in the desired structure as a scaffold with special functions, can cause the differentiation of mesenchymal stem cells into target cells.10 In fact, the type of biopolymer and scaffold design is very important for the successful differentiation of mesenchymal stem cells (MSCs) into target cells10. BC possesses high porosity, excellent permeability, low density, a large surface area (10-50 nm in diameter and 100,000 nm in length),11 suitable biocompatibility, high water retention capacity (up to 99%), enough heat stability, high crystallinity (70 to 80 percent), mechanical stability, and high purity.12,13 Due to its fibrous structure and consequent pore size and shape,14,15 optical transparency, non-toxicity, and the ability to mold into three-dimensional shapes and structures, researchers utilized BC fibers frequently in various scaffolds.16,17 Characteristics including low biodegradability, high hydrophilicity, low compatibility with other hydrophobic polymers, and lack of antibacterial characteristics limit BC application as a single material.18,19 Chitosan (CS) is a cationic polymer, (due to the NH2- amino group) which is obtained through the deacetylation of chitin.20 Interaction between the positive charges of CS and negatively charged molecules, such as proteoglycans, causes the formation of the extracellular matrix.21-23 In addition, CS has several hydroxyl groups, which increase interaction with pos