Natural Biomaterials and Their Use as Bioinks for Printing Tissues

Abstract

The most prevalent form of bioprinting—extrusion bioprinting—can generate structures from a diverse range of materials and viscosities. It can create personalized tissues that aid in drug testing and cancer research when used in combination with natural bioinks. This paper reviews natural bioinks and their properties and functions in hard and soft tissue engineering applications. It discusses agarose, alginate, cellulose, chitosan, collagen, decellularized extracellular matrix, dextran, fibrin, gelatin, gellan gum, hyaluronic acid, Matrigel, and silk. Multi-component bioinks are considered as a way to address the shortfalls of individual biomaterials. The mechanical, rheological, and cross-linking properties along with the cytocompatibility, cell viability, and printability of the bioinks are detailed as well. Future avenues for research into natural bioinks are then presented.

Chitosan‐based nanocomposites for medical applications

“…67,68 At present, there are numerous techniques available to fabricate a chitosan-based membrane or scaffold for tissue engineering such as particle salt leaching, 69,70 electrospinning, 71,72 stereolithography, 73,74 gas foaming, 75,76 freeze-drying, 57,67,75 and 3D bioprinting. [77][78][79][80] Electrospinning is a simple, straightforward, and costeffective technique for producing nanofibers. In a typical electrospinning set-up, high voltage is applied from a polymeric solution to draw fibers toward a grounded collector.…”

Physical and Mechanical Characterization of Fibrin-Based Bioprinted Constructs Containing Drug-Releasing Microspheres for Neural Tissue Engineering Applications

“…A biocompatible bioink should result in high cell viability, proliferation, adhesion, migration, and differentiation into mature tissues [6]. The mechanical properties of the bioink play an important role in maintaining the desired tissue shape after bioprinting and influence the behavior of cells seeded inside the bioprinted construct [3,[7][8][9]. Moreover, achieving the desired print resolution for the bioprinted construct depends on the rheological properties of bioinks [10][11][12][13].…”

“…Therefore, bioinks should possess appropriate rheological, mechanical, biocompatible, and biofunctional properties for the target tissue [6,14]. Other important properties that need to be considered when 2 of 21 choosing bioinks include the material source (natural or synthetic) and required printing conditions [8,15].…”

“…To overcome this issue, the naturally derived materials alginate and chitosan were added to the bioink to increase its viscosity and gelation speed and, thus, the printability of the ink. Alginate and chitosan are also broadly used as bioink components [8,62,64]. The ionic potential differences cause an interaction between alginate and chitosan, in which a polyelectrolyte complex is formed through their interactions.…”

“…Additionally, pore size was also affected by genipin, with larger pores in gels made with genipin (1-5 mM) compared to those with no genipin added. Moreover, the porous structure of chitosan allowed cells and nutrients to diffuse and migrate through the structure and can be formed by crosslinking chitosan with a variety of agents [8,18,62]. However, to successfully engineer mature bioprinted tissues for drug testing, a bioink should be printed as a desired structure to maintain its integrity over the culture period to support cell growth and differentiation [13,40,42].…”