Chitosan (CH) is a naturally derived biopolymer with significant potential in biomedical applications due to its biocompatibility, biodegradability, and ability to support cell growth. In this study, we investigate the rheological behavior and printability of chitosan-graphene oxide (CH-GO) nanocomposite hydrogels for use in neural tissue engineering. The hydrogels were prepared at 3 wt% and 4 wt% CH concentrations with varying amounts of graphene oxide (GO), ranging from 0.1 to 0.5 wt%. Rheological characterization revealed that even a small addition of 0.5 wt% GO significantly enhanced the storage modulus (G’), viscosity, and yield stress of both 3 wt% and 4 wt% CH hydrogels. This improvement was attributed to strong electrostatic interactions between the positively charged amino groups of chitosan and the negatively charged carboxylate groups on GO nanosheets.
A three-interval thixotropic test (3ITT) demonstrated that the 3 wt% CH hydrogel with 0.5 wt% GO exhibited excellent structural recovery—up to 94% after seven sequential stress cycles—making it the most suitable candidate for direct-write printing. This high recovery indicates good viscoelastic stability under repeated deformation, which is crucial for maintaining filament integrity during extrusion-based printing. Shear-thinning behavior was observed across all samples, with viscosity decreasing under applied shear stress, enabling smooth extrusion through fine nozzles. Yield stress values increased significantly with GO concentration, indicating improved resistance to flow and better structural retention post-deposition.
Filament extrusion tests confirmed that hydrogels containing 0.5 wt% GO produced continuous, uniform filaments without die swell or significant spreading. Printing experiments using a 260 µm nozzle showed that the CH3GO-5 hydrogel (3 wt% CH + 0.5 wt% GO) achieved optimal print fidelity, with strand printability (SP) close to 1 and pore printability (PP) near unity, confirming accurate replication of designed patterns.ACSF2 Antibody supplier Multi-layer printing further validated the structural integrity of the printed constructs, with a structural integrity (SI) value of 0.168273-06-1 MedChemExpress 99 for 25 layers, indicating minimal deformation and excellent layer-by-layer stacking capability.PMID:35188361
Cell culture studies using human neuroblastoma SH-SY5Y cells revealed that GO incorporation promoted cellular differentiation into neuron-like phenotypes. Confocal imaging showed extensive neurite outgrowth, formation of neurospheres, and elongated morphologies consistent with neuronal maturation. These findings confirm that the CH-GO hydrogel not only supports cell adhesion and proliferation but also enhances functional differentiation. Moreover, UV-Vis analysis confirmed that GO remained embedded within the hydrogel matrix, with negligible leaching into the culture medium, ensuring long-term bioactivity and safety.
In conclusion, the integration of 0.5 wt% GO into 3 wt% chitosan hydrogels results in a highly printable, mechanically robust, and biologically active scaffold ideal for neural tissue engineering. The optimized rheological profile enables precise direct-write printing, while the bioactive properties facilitate effective neuronal differentiation. This work provides a rational framework for designing advanced bioinks based on natural polymers and nanomaterials for next-generation regenerative medicine applications.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com