Bio-inks for 3D bioprinting: recent advances and future prospects

Abstract

In the last decade, interest in the field of three-dimensional (3D) bioprinting has increased enormously. This review describes all the currently used bio-printing inks, including polymeric hydrogels, polymer bead microcarriers, cell aggregates and extracellular matrix proteins.

3D bioprinting for cardiovascular regeneration and pharmacology

“…Soft biomaterials (mostly hydrogels) are classified as being either naturally occurring or synthetic polymers. Natural materials and their derivatives are often isolated from bacterial, plant, animal, or human cells and tissues, while synthetic materials (water-soluble and solidifiable polymers) are manufactured [16,124,125]. The advantages of natural polymers are in their similarity to human ECM, and their inherent bioactivity and biocompatibility [16].…”

“…The advantages of natural polymers are in their similarity to human ECM, and their inherent bioactivity and biocompatibility [16]. However, their disadvantages are in their immunogenicity, weak mechanical strength, and lack of control in composition/molecular weight [16,124,125]. Comparatively, synthetic polymers can achieve specific physiochemical properties for targeted tissues requirements, including adjustable molecular weights, chemical structures, and functional groups, as well as bioactive anchorage sites [16,124].…”

“…However, their disadvantages are in their immunogenicity, weak mechanical strength, and lack of control in composition/molecular weight [16,124,125]. Comparatively, synthetic polymers can achieve specific physiochemical properties for targeted tissues requirements, including adjustable molecular weights, chemical structures, and functional groups, as well as bioactive anchorage sites [16,124]. For cardiovascular bioprinting, soft biomaterials can recapitulate the native elastic modulus and components through optimizing the bioink chemistry, bioink concentration, and crosslinking chemistry.…”

“…Therefore, standardized assays for the requirements of bioink consistency, reproducibility, and high-throughput capability need to be established [2]. To overcome the limitations of natural bioink material printability and other physiochemical properties, chemical modifications to bioink composition have succeeded in adjusting ink viscosity, optimizing degradation and swelling behaviors, and increasing mechanical strength, among other improvements [16,124]. Matrix mechanical properties can influence vascular network formation and sprouting density, as well as cardiomyocyte alignment and maturation.…”

Multifaceted polymeric materials in three‐dimensional processing (3DP) technologies: Current progress and prospects

“…Because the use of an ink in a particular 3DP technique may not be able to meet the required properties of the fabricated materials, the incorporation of other additive materials to formulate composite inks to enhance the ink properties includes bioactivity, stiffness, processability, and printability. For bioink composites, the materials to be used should be biocompatible, bioprintable, biodegradable with no toxic effect including their waste compounds and intermediates, and enable rapid cell growth and proliferation . Composite ink systems employed in tissue engineering application are broadly divided into 3 major classes, namely: polymer‐based, hydrogel‐based, and ceramic‐based.…”