Starches from different botanical sources for cell scaffolds and optimization of 3D printing bio-ink composition

With increasing demand for 3D printing in tissue engineering, development of appropriate biomaterials for scaffold fabrication remains a significant challenge. Starch is a promising scaffold material with its biocompatibility and biodegradability. However, limited studies have compared starches from different botanical sources for 3D printing scaffolds. Herein, we compared the pasting and texture properties, microscopic structure of starches from different botanical sources (corn, wheat, rice, potato and cassava) to screen most suitable starch for 3D printing. The corn starch bio-inks for scaffolds were further optimized based on rheological properties and printing performance. Our findings demonstrated that corn starch was more suitable for scaffold printing with its moderate pasting viscosity (final viscosity 1827.33 ± 12.37 cP) and gel hardness (874.46 ± 30.23 g) after retrogradation. Additionally, corn starch had high porosity (81.90 % ± 3.54 %) and uniformly arranged structure, which was favorable for cell adhesion and proliferation. Using a bio-ink formulation comprising 3 % natural corn starch, 4 % high-amylose corn starch, and 5 % methacrylate anhydride-modified corn starch, 3D scaffolds were successfully printed and significantly enhanced the adhesion and proliferation of HEK 293 cells in vitro. Taken together, this study provided theoretical insights and practical guidance for the application of corn starch in 3D-printed scaffolds for tissue engineering.