Organic Solvent-Free Preparation of Chitosan Nanofibers with High Specific Surface Charge and Their Application in Biomaterials

Abstract

The application of chitosan nanofibers in biological tissue-engineering materials has attracted wide attention. A novel and organic solvent-free method was developed for the fabrication of rootlike chitosan nanofibers (CSNFs) with diameters of 40–250 nm. This method includes three-step mechanical processing of swelling–beating-centrifugation or swelling–beating–homogenization. The obtained nanofibers showed high yields (>95%) and positive specific surface charges (up to +375 μeq/g) and could be uniformly dispersed in the aqueous phase. The unique fiber shape and the good length-to-diameter ratio of CSNFs endowed chitosan nanofiber paper (CSNFP) products with excellent mechanical properties, and the wet tensile strength of the CSNFPs was nearly five times higher than common chitosan films. In addition, the calvaria-derived preosteoblastic cells exhibited a higher adherence efficiency and proliferation on CSNFP than on chitosan films. The chitosan nanofiber scaffold products also benefited the attachment of preosteoblastic cells and allowed them to grow in three dimensions. This method has significant industrial potential for the industrialization of chitosan nanofibers, which may have broad applications in various biomaterials.

Preparation of High Mechanical Strength Chitosan Nanofiber/NanoSiO2/PVA Composite Scaffolds for Bone Tissue Engineering Using Sol–Gel Method

“…According to Zhang’s research [ 31 ], the chitosan regenerated fibers were first cut into 2–5 mm lengths using a cutting mill (CM200, GRINDER, Beijing, China) to maintain a uniform morphology. Then the pulp was milled at 30,000 rpm with a PFI refiner set to 3.33 N/mm pressure to further decrease the fiber length.…”

“…Mouse calvaria-derived pre-osteoblastic cells (MC3T3-E1) were used to evaluate the biocompatibility of the composite scaffolds [ 31 ]. The cells were cultured in MEM supplemented with 10% FBS and 1% PS and incubated at 37 °C in a 5% CO 2 atmosphere.…”

“…Technologies such as electrospinning and thermally induced phase separation (TIPS) have been widely used to develop nanoscale chitosan materials [ 27 , 28 ]. However, electrospinning and TIPS have limitations, including using toxic solvents, process complexity, size non-uniformity, and low nanofiber yields [ 28 , 29 , 30 , 31 ]. Our group developed a novel chitosan nanofiber with a high surface charge and a long fiber length using the beating homogenization method, which demonstrates an effective method for the efficient and industrial manufacturing of chitosan nanofibers without the use of organic solvents.…”

Preparation of a “Branch-Fruit” structure chitosan nanofiber physical hydrogels with high mechanical strength and pH-responsive controlled drug release properties

“…Hydrogels were prepared from CSNF, hyaluronic acid (purity > 97%, Macklin), and β-glycerophosphate disodium (purity > 95%, Macklin). Chitosan nanofibers (CSNFs) were prepared in lab according to the research of Zhang 25 of this research group. The water used in the preparation process was obtained by a pure water machine (Purelab, ELGA).…”

“…Chitosan nanofibers (CSNFs) were prepared according to the method recently reported by Zhang. 25 First, the chitosan regenerated fibers (CSFs, ≥95% deacetylated, ≥1000 mPa s viscosity) were cut into a length of 3–5 mm, and the CSFs were cut using a cutting mill (CM200, England) to maintain a uniform appearance during the subsequent processing. Take 30 g of milled CSFs (dry weight) and soak it in deionized (DI) water for swelling, and then concentrate the solid content of the chitosan slurry to 10% (w/v).…”