Multimaterial bioprinting approaches and their implementations for vascular and vascularized tissues

Multimaterial bioprinting is a promising technology integrating multimaterial setups into bioprinting platforms for the fabrication of multicellular, heterogeneous and functional tissue constructs. By simultaneously or sequentially dispensing different categories of materials including cell-laden hydrogels or extracellular matrix components, sacrificial materials and scaffolding polymers with hierarchical microarchitecture, multimaterial bioprinting has achieved several milestones for the native tissue biomimicry. Particularly, reconstruction of multiscale, hierarchically branched vascular networks within engineered tissues has been residing as a grand challenge for the fabrication of tissues with long term viability and functionality, which hampers the transition of engineered constructs from research to clinic. To date, various multimaterial bioprinting approaches have been proposed to address the need for fabrication of vascular or vascularized tissues. In this review, a comprehensive overview is given to demonstrate the potential of multimaterial bioprinting technology for the biofabrication of vascular and vascularized tissues. In this regard, different multimaterial bioprinting approaches developed so far are described thoroughly, following the introduction of bioprinting modalities employed in tissue engineering and organization of vascular tissues. Subsequently, multimaterial bioprinting of vascular and vascularized tissues are presented with the main emphasis on the developed fabrication strategies and applied techniques. Comparative evaluation of the multimaterial bioprinting approaches and future perspectives are also delivered to reader.