3D bioprinting for biomedical devices and tissue engineering: A review of recent trends and advances

Abstract

3D printing, an additive manufacturing based technology for precise 3D construction, is currently widely employed to enhance applicability and function of cell laden scaffolds. Research on novel compatible biomaterials for bioprinting exhibiting fast crosslinking properties is an essential prerequisite toward advancing 3D printing applications in tissue engineering. Printability to improve fabrication process and cell encapsulation are two of the main factors to be considered in development of 3D bioprinting. Other important factors include but are not limited to printing fidelity, stability, crosslinking time, biocompatibility, cell encapsulation and proliferation, shear-thinning properties, and mechanical properties such as mechanical strength and elasticity. In this review, we recite recent promising advances in bioink development as well as bioprinting methods. Also, an effort has been made to include studies with diverse types of crosslinking methods such as photo, chemical and ultraviolet (UV). We also propose the challenges and future outlook of 3D bioprinting application in medical sciences and discuss the high performance bioinks.

Keywords: 3D printing; Bioprinting; Extrusion; Hydrogel; Inkjet; Laser-assisted; Review; Stereolithography.

Graphical abstract

Fig. 1

Schematic diagram of common extrusion-based bioprinting methods: (A) pneumatic, (B) Piston-driven, and (C) screw-driven dispensing method. In pneumatic dispensing air pressure provides the driving force while in piston and screw-driven dispensing, mechanical displacement and rotation are utilized to drive a continuous flow of biomaterial through the nozzle.

Fig. 2

Schematic diagram of drop-on-demand inkjet printing method using A) Thermal, and B) Piezoelectric actuators. A thermal printing head employs a heating element that raises the temperature locally and creates a bubble that drives droplets through the nozzle. A piezoelectric head is utilized with a material that changes shape upon voltage application and pushes droplets out.

Fig. 3

Schematic diagram of stereolithography using beam projector. Focused light beams allow for precise photopolymerization of layers of light-sensitive polymer to apply any desired pattern to the bioink.

Fig. 4

Schematic diagram of laser-assisted bioprinting. A nozzle-free technique using pulsed laser source to deposit microdroplets of bioink with/without cells on a substrate.

Fig. 5

3D printed constructs of conductive and nonconductive bioinks. A) A typical chitosan-based extrusion bioprinted mesh structure, B-D) a conductive 3D printed sensor based on chitosan and acrylic acid, sealed in PDMS. The resistance response at various bending angles from testing the hydrogel as a sensor in strip form (left) and in 3D printed mesh form (right) is displayed. ^© 2017 Reprinted with permission of John Wiley and Sons .