Although mechanical support to the printing materials and

Although 3D printing has the
ability to fabricate on-demand, highly personalized complex designs at low
costs, this technology’s medical applications are limited due to lack of
diversity in biomaterials. Even with the availability of variety of
biomaterials including metals, ceramics, polymers and composites, medical 3D
printing is still confined by factors such as biomaterial printability, control
of their biodegradation and biocompatible properties.

            Usually, in
extrusion based bioprinting, higher concentrations of polymers are used in
fabricating bioinks to obtain structural integrity of the end product. This
dense hydrogel environment limits cellular network and functional integration
of the scaffold. For any moderate sized biological scaffold to be functional,
vascularization is utmost important and is not possible with the current 3D
printing technology. Small scale scaffolds currently printed in the
laboratories of researchers can easily survive through diffusion, but a
live-size functional organ must have a profuse vascularization. To address this
problem, sacrificial materials during the scaffold fabrication have been used
by many researchers. These materials fill up the void spaces providing mechanical
support to the printing materials and once constructs are fabricated they are
removed by post-processing methods. Many sacrificial/fugitive materials
including carbohydrate glass 44, pluronic glass 45, gelatin microparticles 46 have been used for this
purpose 47.