Xanthan Gum and Tamarind Seed Polysaccharide Blend Bioinks: Toward Solving Printability‐Integrity Conundrum in Extrusion Bioprinting Without a Crosslinking Agent

Bioprinting technologies face challenges in designing bioinks that possess optimal pre- and post-bioprinting properties. In most cases, enhancing flowability to improve pre-bioprinting properties results in inferior mechanical properties of the post-printed constructs. To achieve adequate mechanical strength, physical or chemical cross-linking is used, which compromises the biocompatibility and degradability of the constructs. A xanthan gum (XG) and tamarind seed polysaccharide (TSP) blend bioink was developed to overcome these limitations. Amongst several ratios, 4XG:1TSP (4X1T) demonstrated the highest printability with accuracy >95%. Rheological investigations revealed shear thinning viscosity while the LVER and creep recovery for 4X1T (698 MPa, 97%) and 4X (624 MPa, 85%) showed suitable properties for bioprinting applications. FTIR indicated hydrogen-bonding interactions between XG and TSP, conferring structural stability to the post-printed constructs without any crosslinking agent. The constructs showed loss of microstructure after 21 days of incubation in phosphate buffer (pH 7.5) at 37°C. In vitro cytocompatibility studies with human-derived SH-SY5Y cells disclosed no significant difference between the viability of cells seeded on XG and 4X1T, or cells bioprinted with 4X1T bioinks. It is concluded that the XG-TSP blend provides a bioink with promising printability, mechanical integrity, degradability, and cytocompatibility for the fabrication of tissue engineering constructs.