PVA:ALG Hybrid Bioink for Biofabrication of 3D Neural Models

Three-dimensional (3D) bioprinting technology has enabled the tunable and reproducible biofabrication of tissue models for in vitro neural tissue engineering. Combining natural and synthetic polymers offers a synergistic approach that harnesses the strengths of both materials to create bioinks with optimal printability and biocompatibility. In this study, a PVA/alginate hybrid bioink was developed for neural tissue engineering, and its suitability for bioprinting was evaluated through rheological analysis and pore factor characterization. Optimal bioprinting and cross-linking parameters were determined as 15% ALG, 16% PVA, 0.03 M GTA, and 5% CaCl₂. Then, PVA/alginate scaffolds were characterized in terms of swelling and protein adsorption capacities, where ≥23-fold swelling and 1812.5 μg/mL protein adsorption capacities were reported. These findings show its potential to be utilized as a scaffold in neural tissue engineering. Neural cell proliferation, viability, and morphology were analyzed by culturing SH-SY5Y human neuroblastoma cells in 3D on hybrid scaffolds. Long-term cell viability was observed in 3D models through 15 days with a gradual increase, whereas in 2D cell culture, cell viability started to decrease after day 7 due to limitations of 2D cell culture. Moreover, increased extracellular matrix (ECM) secretion and neural marker expression of neural cells cultured on hybrid scaffolds were reported. 3D bioprinted PVA/Alginate scaffolds favored neural cell proliferation and have promise to be used in further neural tissue engineering applications, including modeling of neurodegenerative diseases in 3D and development of potential drugs.