From Shape to Function: The Next Step in Bioprinting

Abstract

In 2013, the “biofabrication window” was introduced to reflect the processing challenge for the fields of biofabrication and bioprinting. At that time, the lack of printable materials that could serve as cell‐laden bioinks, as well as the limitations of printing and assembly methods, presented a major constraint. However, recent developments have now resulted in the availability of a plethora of bioinks, new printing approaches, and the technological advancement of established techniques. Nevertheless, it remains largely unknown which materials and technical parameters are essential for the fabrication of intrinsically hierarchical cell–material constructs that truly mimic biologically functional tissue. In order to achieve this, it is urged that the field now shift its focus from materials and technologies toward the biological development of the resulting constructs. Therefore, herein, the recent material and technological advances since the introduction of the biofabrication window are briefly summarized, i.e., approaches how to generate shape, to then focus the discussion on how to acquire the biological function within this context. In particular, a vision of how biological function can evolve from the possibility to determine shape is outlined.

Expanding and optimizing 3D bioprinting capabilities using complementary network bioinks

“…3D bioprinting is based on the free-form fabrication of biomaterials into customized geometries informed by digital design. The most common modality for tissue fabrication is extrusion bioprinting, in which living constructs are additively manufactured via layer-by-layer deposition of cellularized bioinks ( 1 , 3 ). The design of bioinks is a central topic in this field-formulations rarely have both the physicochemical properties required for the 3D printing process and the physicochemical cues to meet the biological needs of the encapsulated cells.…”

Strategies to Functionalize the Anionic Biopolymer Na-Alginate without Restricting Its Polyelectrolyte Properties

“…Examples of advanced manufacturing techniques include microfluidics and 3D or 4D bioprinting. Alg-based materials are prospective bioinks for bioprinting, where one of the biggest challenges is finding a good compromise between printability (polymer concentration) and cytocompatibility [116]. Chemical modification of alg materials into dynamic hydrogels [117], stimuli-responsive materials [118], or functionalization with drugs, growth factors, or biological clues could lead to the development of more sophisticated biologically functional 3D constructs.…”

Laser-based additively manufactured polymers: a review on processes and mechanical models

“…A simple reaction scheme is reported in Eq. (18) and is described in depth in [138][139][140][141][142], while a sketch of this photopolymerisation process is depicted in Fig. 11.…”

“…Nowadays, the potential of additive manufacturing is exploited in several fields [3], including the aerospace [4], automotive [5], construction [6] and healthcare sectors [7,8]. New frontiers are being explored in the field of advanced materials science [9,10], with applications to the design of structured materials [11][12][13][14], stimuli-responsive materials [15][16][17] and bioprinting [18,19]. The fast diffusion of additive manufacturing points to its advantages, including high precision, flexibility and a vast range of printable materials, comprising metals, ceramics, polymers, hydrogels and composites [20][21][22][23][24][25][26].…”