Design and Printing Strategies in 3D Bioprinting of Cell‐Hydrogels: A Review

Abstract

Bioprinting is an emerging technology that allows the assembling of both living and non‐living biological materials into an ideal complex layout for further tissue maturation. Bioprinting aims to produce engineered tissue or organ in a mechanized, organized, and optimized manner. Various biomaterials and techniques have been utilized to bioprint biological constructs in different shapes, sizes and resolutions. There is a need to systematically discuss and analyze the reported strategies employed to fabricate these constructs. We identified and discussed important design factors in bioprinting, namely shape and resolution, material heterogeneity, and cellular‐material remodeling dynamism. Each design factors are represented by the corresponding process capabilities and printing parameters. The process‐design map will inspire future biomaterials research in these aspects. Design considerations such as data processing, bio‐ink formulation and process selection are discussed. Various printing and crosslinking strategies, with relevant applications, are also systematically reviewed. We categorized them into 5 general bioprinting strategies, including direct bioprinting, in‐process crosslinking, post‐process crosslinking, indirect bioprinting and hybrid bioprinting. The opportunities and outlook in 3D bioprinting are highlighted. This review article will serve as a framework to advance computer‐aided design in bioprinting technologies.

Principles of the Kenzan Method for Robotic Cell Spheroid-Based Three-Dimensional Bioprinting

“…Additionally, the constructs based on hydrogels are by necessity soft, unless the scaffolds are made more solid upfront, which is possible only for a limited number of tissues, such as bone and cartilage. To deal with this constraint, some research groups incorporate polymeric microfibers within the bio-printed structures, a process called 'hybrid bioprinting' 5,24,25 . This provides the needed sturdiness but complicates the other features of a biologically-inspired construct.…”

3D printing for drug manufacturing: A perspective on the future of pharmaceuticals

“…Hydrogels may be formed with either naturally-derived or synthetic materials, each having nuanced properties and applications. Natural hydrogel materials include alginate, gelatin, agarose, fibrin and chitosan [57,62] . Synthetic materials include poly (ethylene glycol) (PEG), oligo(poly(ethylene glycol) fumarate) (OPF) and poly (acrylic acid) derivatives (PAA).…”

Roles of support materials in 3D bioprinting – Present and future

“…Therefore, at the current stage, bioprinting of complex hollow structures that can completely mimic human's vascular systems or hollow organs such as heart or kidney is very challenging. Single material printing will not be sufficient to provide all the required properties (including biocompatibility, mechanical integrity and printability) [1][2][3][4][5][6][7][8][9] B for bioprinted 3D complex hollow structures.…”

“…ioprinting is an emerging technology that shows potential for regenerative medicine and other biomedical applications [1][2][3] . Unlike other 3D printing techniques which print non-living materials, bioprinting incorporates living materials during the printing process.…”