Engineering Polysaccharide Biomaterials: Modifications and Crosslinking Strategies for Soft Tissue Bioprinting

Polysaccharides have emerged as promising bioink candidates for three dimensional (3D) bioprinting owing to their outstanding biocompatibility and structural adaptability. Nonetheless, their utilization for soft tissue regeneration has been limited due to their intrinsic drawbacks, such as inadequate mechanical strength, poor printability, and rapid degradation rate. Recently, various modifications and crosslinking strategies have been adopted to improve the suitability of natural polysaccharides for printing robust soft tissue constructs with improved precision and functionality. This review delves into the state-of-the-art modified polysaccharide bioinks utilized for fabricating soft tissue scaffolds. The primary focus of this review is to highlight the key chemical modification approaches, including methacrylation, sulfation, and thiolation, extensively used to alter the properties of polysaccharides for achieving optimal printability and mechanical resilience. By introducing the importance of crosslinking strategies, an important distinction between covalent and non-covalent crosslinking is discussed. Effective modification and crosslinking of the polysaccharides also allow for explicit modulation of their biofunctionality, promoting cell fate processes and facilitating the regeneration of soft tissues such as skin, cartilage, muscles, and neural tissue. We aim to provide a comprehensive understanding of the current advancements in the field and underline future perspectives in fabricating personalized tissue scaffolds for next-generation regenerative solutions.