Three-dimensional bioprinting is a rapidly growing field attempting to recreate functional tissues for medical and pharmaceutical purposes. Development of functional tissue requires deposition of multiple biomaterials encapsulating multiple cell types i.e. bio-ink necessitating switching ability between bio-inks. Existing systems use more than one print head to achieve this complex interchangeable deposition, which decreases efficiency, structural integrity, and accuracy. In this research, we developed a nozzle system capable of switching between multiple bio-inks with continuous deposition ensuring the minimum transition distance so that precise deposition transitioning can be achieved. Finally, the effect of rheological properties of different bio-material compositions on the transition distance is investigated by fabricating the sample scaffolds.
3D bioprinting additively assembles bio‐inks to manufacture tissue‐mimicking biological constructs, but with the typical building blocks limited to 1D filaments. Here, it is developed a voxelated bioprinting technique for the digital assembly of spherical particles (DASP), which are effectively 0D voxels—the basic unit of 3D structures. It is shown that DASP enables on‐demand generation, deposition, and assembly of viscoelastic bio‐ink droplets. A two‐parameter diagram is developed to outline the viscoelasticity of bio‐inks required for printing spherical particles of good fidelity. Moreover, a strategy is developed for engineering bio‐inks with independently controllable viscoelasticity and mesh size, two of the most important yet intrinsically coupled physical properties of biomaterials. Using DASP, mechanically robust, multiscale porous scaffolds composed of interconnected yet distinguishable hydrogel particles are created. Finally, it is demonstrated the application of the scaffolds in encapsulating human pancreatic islets for sustained responsive insulin release. Together with the knowledge of bio‐ink design, DASP might be used to engineer highly heterogeneous, yet tightly organized tissue constructs for therapeutic applications.
more » « less- Award ID(s):
- 1944625
- PAR ID:
- 10447954
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 32
- Issue:
- 6
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
null (Ed.)more » « less
Abstract -
more » « less
Abstract Recapitulation of complex tissues signifies a remarkable challenge and, to date, only a few approaches have emerged that can efficiently reconstruct necessary gradients in 3D constructs. This is true even though mimicry of these gradients is of great importance to establish the functionality of engineered tissues and devices. Here, a composable‐gradient Digital Light Processing (DLP)‐based (bio)printing system is developed, utilizing the unprecedented integration of a microfluidic mixer for the generation of either continual or discrete gradients of desired (bio)inks in real time. Notably, the precisely controlled gradients are composable on‐the‐fly by facilely by adjusting the (bio)ink flow ratios. In addition, this setup is designed in such a way that (bio)ink waste is minimized when exchanging the gradient (bio)inks, further enhancing this time‐ and (bio)ink‐saving strategy. Various planar and 3D structures exhibiting continual gradients of materials, of cell densities, of growth factor concentrations, of hydrogel stiffness, and of porosities in horizontal and/or vertical direction, are exemplified. The composable fabrication of multifunctional gradients strongly supports the potential of the unique bioprinting system in numerous biomedical applications.
-
Abstract Three-dimensional bioprinting is a rapidly growing field attempting to recreate functional tissues for medical and pharmaceutical purposes. Development of functional tissue requires deposition of multiple biomaterials encapsulating multiple cell types i.e. bio-ink necessitating switching ability between bio-inks. Existing systems use more than one print head to achieve this complex interchangeable deposition, which decreases efficiency, structural integrity, and accuracy. In this research, we developed a nozzle system capable of switching between multiple bio-inks with continuous deposition ensuring the minimum transition distance so that precise deposition transitioning can be achieved. Finally, the effect of rheological properties of different bio-material compositions on the transition distance is investigated by fabricating the sample scaffolds.more » « less
-
Babski-Reeves, K ; Eksioglu, B ; Hampton, D. (Ed.)Extrusion-based three-dimensional (3D) bio-printing is one of the several 3D bioprinting methods that is frequently used in current times. This method enables the accurate deposition of cell-laden bio-ink while ensuring a predetermined scaffold architecture that may allow living tissue regeneration. Natural hydrogels are a strong choice for bio-ink formulation for the extrusion-based 3D bioprinting method because they have a combination of unique properties, which include biocompatibility, reduced cell toxicity, and high-water content. However, due to its low mechanical integrity, hydrogel frequently struggles to retain structural stability. To overcome this challenge, we evaluated the rheological characteristics of distinct hybrid hydrogels composed of carboxymethyl cellulose (CMC), a widely used alginate, and nanofibers generated from cellulose (TEMPO-mediated nano-fibrillated cellulose, TONFC). Therefore, to examine the rheological properties, a set of compositions was developed incorporating CMC (1%–4%), alginate (1%–4%), and higher and lower contents of TONFC (0.5%) and (0.005%) respectively. From the flow diagram, the shear thinning coefficients of n and K were calculated, which were later linked to the 3D printability. With the guidance of diverse nanofiber ratios, it is possible to regulate the rheological properties and create 3D bioprinted scaffolds with well-defined scaffold architecture.more » « less
-
more » « less
Abstract Bioprinting is an additive manufacturing technique that combines living cells, biomaterials, and biological molecules to develop biologically functional constructs. Three-dimensional (3D) bioprinting is commonly used as an
in vitro modeling system and is a more accurate representation ofin vivo conditions in comparison to two-dimensional cell culture. Although 3D bioprinting has been utilized in various tissue engineering and clinical applications, it only takes into consideration the initial state of the printed scaffold or object. Four-dimensional (4D) bioprinting has emerged in recent years to incorporate the additional dimension of time within the printed 3D scaffolds. During the 4D bioprinting process, an external stimulus is exposed to the printed construct, which ultimately changes its shape or functionality. By studying how the structures and the embedded cells respond to various stimuli, researchers can gain a deeper understanding of the functionality of native tissues. This review paper will focus on the biomaterial breakthroughs in the newly advancing field of 4D bioprinting and their applications in tissue engineering and regeneration. In addition, the use of smart biomaterials and 4D printing mechanisms for tissue engineering applications is discussed to demonstrate potential insights for novel 4D bioprinting applications. To address the current challenges with this technology, we will conclude with future perspectives involving the incorporation of biological scaffolds and self-assembling nanomaterials in bioprinted tissue constructs.
