Search Results for extrusion bioprinting

This article begins with a description of extrusion-based bioprinting for tissue scaffold fabrication. It also examines various extrusion-based bioprinting processes and related tissue scaffolding strategies, presents the selection criteria of various bioinks with various polymers and their printed scaffolds for applications in tissue engineering and regenerative medicines, and provides future research recommendations to address the shortcomings and issues found in current extrusion-based bioprinting processes.

The field of bioprinting is a subset of additive manufacturing (AM) that is rapidly expanding to meet the needs of regenerative medicine and tissue engineering. Bioprinting encompasses a broad spectrum of issues, from cell expansion and novel bioink development to cell/stem cell printing, from organoid-based tissue organization to bioprinting of human-scale tissue structures, and from building cell/tissue/organ-on-a-chip to biomanufacturing of multicellular engineered living systems. This article focuses on two challenges regarding bioprinting: bioinks and crosslinking. It describes the methods for characterizing the performance of bioink formulations and the effectiveness of crosslinking strategies. The topics covered include modalities of bioprinting, characteristics of bioink, rheological properties of bioink sols, rheological measurements, mathematical models of bioink rheology, postfabrication polymer network mechanics, mechanical properties of crosslinked bioinks, and printability of bioinks. Finally, specific strategies used for crosslinking bioinks, as well as some emerging strategies to further improve bioinks and their crosslinking, are summarized.

This article focuses on the pneumatic extrusion-based system for biomaterials. It provides an overview of additive manufacturing (AM) processes, followed by sections covering steps and major approaches for the 3D bioprinting process. Then, the article discusses the types, processes, advantages, limitations, and applications of AM technology and extrusion-based approaches. Next, it provides information on the research on extrusion-based printing. Finally, the article provides a comparison of the extrusion-based approach with other approaches.

Three-dimensional plotting of biomaterials (also known as bioprinting) has been a major milestone for scientists and engineers working in nanobiotechnology, nanoscience, and nanomedicine. It is typically classified into two major categories, depending on the plotting principle, as contact and noncontact techniques. This article focuses on the working principles of contact and noncontact printing methods along with their advantages, disadvantages, applications, and challenges. Contact printing methods include micro-plotter, pen printing, screen printing, nanoimprint printing, flexography printing, and gravure printing. Noncontact printing methods include extrusion printing, droplet printing, laser-based polymerization, and laser-based cell transfer. The wide variety of printable biomaterials, such as DNA, peptides, proteins, lipids, and cells, also are discussed.

Of the seven additive manufacturing (AM) processes, this article focuses on the vat photopolymerization, or simply vat polymerization, process, while briefly discussing the other six AM processes. Vat polymerization and its characteristics, AM applications in medical fields, and the regulatory challenges of vat polymerization-based bioprinting are presented.

The use of 3D bioprinting techniques has contributed to the development of novel cellular patterns and constructs in vitro, ex vivo, and even in vivo. There are three main bioprinting techniques: inkjet printing, extrusion printing (also known as bioextrusion), laser-induced forward transfer (LIFT) printing, which is also known as modified LIFT printing, matrix-assisted pulsed-laser evaporation direct write, and laser-based printing (laser-assisted bioprinting, or biological laser printing). This article provides an overview of the LIFT process, including the LIFT process introduction, different implementations, jetting dynamics, printability phase diagrams, and printing process simulations. Additionally, materials involved during LIFT are introduced in terms of bioink materials and energy-absorbing layer materials. Also, the printing of single cells and 2D and 3D constructs is introduced, showcasing the current state of the art with the ultimate goal for tissue- and organ-printing applications.

Bioprinting has been advancing in the field of tissue engineering as the process for fabricating scaffolds, making use of additive manufacturing technologies. In situ bioprinting (also termed intraoperative bioprinting) is a promising solution to address the limitations of conventional bioprinting approaches. This article discusses the main approaches and technologies for in situ bioprinting. It provides a brief overview of the bioprinting pipeline, highlighting possible solutions to improve currently used approaches. Additionally, case studies of in situ bioprinting are provided and in situ bioprinting future perspectives are discussed.

This article discusses alginate/gelatin-based bioinks in 3D bioprinting applications, providing a summary of the most relevant previous work in the field. It presents advanced compositions to enhance functionality and/or optimize hydrogels for 3D bioprinting. The article discusses advanced printing techniques for alginate/gelatin-based bioinks.

This article discusses the state of the art in the 3D bioprinting field. It examines the printability of protein-based biopolymers and provides key printing parameters, along with a brief description of the main current 3D bioprinting approaches. The article presents some studies investigating 3D bioprinting of naturally derived proteins for the production of structurally and functionally biomimetic scaffolds, which create a microenvironment for cells resembling that of the native tissues. It describes key structural proteins processed in the form of hydrogels, such as collagen, silk, fibrin, and others such as elastin, decellularized matrix, and Matrigel (Corning), which are used as biomaterials.

Due to its layer-by-layer process, 3D printing enables the formation of complex geometries using multiple materials. Three-dimensional printing for bone tissue engineering is called bioprinting and refers to the use of material-transfer processes for patterning and assembling biologically relevant materials, molecules, cells, tissues, and biodegradable biomaterials with a prescribed organization to accomplish one or more biological functions. Currently, 3D bioprinting constructs can be classified into two categories: acellular and cellular. This article introduces and discusses these two approaches based on the suitable materials for these constructs and the fabrication processes used to manufacture them. The materials are grouped into polymers, metals, and hydrogels. The article also summarizes the commonly used 3D printing techniques for these materials, as well as cell types used for various applications. Lastly, current challenges in tissue engineering are discussed.

The article presents an in-depth discussion on the various additive manufacturing techniques such as binder jetting, directed-energy deposition, material extrusion, material jetting, powder-bed fusion, sheet lamination, and vat polymerization processes. This article then discusses the different critical material aspects of additively manufactured medical devices, beginning with the preprinting phase (material consistency and recycling), the printing phase (build orientation), and the postprinting phase (part evaluation, biocompatibility, and sterilization) with supporting materials.

Vat polymerization is a form of three-dimensional (3D) printing. Historically, it is the oldest additive manufacturing technique, with the development of stereolithography apparatus (SLA) by Charles Hull in 1986. This article outlines the various forms of vat polymerization techniques used for biomedical applications. Due to the complex nature of this printing process, many key print parameters and material properties need to be considered to ensure a successful print. These influential parameters are addressed throughout the article to inform the reader of the considerations that should be taken when using the vat polymerization technique. The article provides information on vat polymerization printer setup, the photo-cross-linking mechanism, and considerations using vat polymerization. In addition, it outlines and discusses the advancements of vat polymerization in the biomedical industry.

Inkjet printing is extremely precise in terms of the ejected microdroplets (picoliter volume), contributing an unparalleled lateral resolution. Additionally, the benefits of high-speed deposition, contactless ink delivery, and the use of a range of ink materials endorse this technique as suitable for high-throughput 3D manufacturing. This article provides an overview of inkjet 3D printing (also referred to as 3D inkjetting). It then highlights the major components and accessories used in commercial and laboratory-based 3D inkjet printers. Next, the article describes the process physics of the transient phenomena involved in both binder-jetting- and direct-inkjetting-based 3D printing. It then discusses the scope and advantages of 3D inkjetting in the manufacturing of metallic, ceramic, and polymer-based biomaterials. The article also discusses several approaches and methodologies to examine the in vitro cytocompatibility and in vivo biocompatibility of both binder-jetted and direct-inkjetted scaffolds for biomedical applications. Finally, it discusses the challenges and troubleshooting methodologies in 3D inkjetting of biomaterials.

Material extrusion systems are the most common types of additive manufacturing systems, also known as three-dimensional (3D) printers. This article focuses on the general 3D printing processes as can be demonstrated and manipulated in desktop printers. The discussion includes details of the components involved in material extrusion as well as the melt extrusion solidification (during cooling) process, the underlying mechanism of road bonding, and the factors affecting good part quality. The discussion also covers support material, postprocessing, and road-quality considerations and the addition of infill in melt extrusion to the hollow spaces inside an object to give it structural strength. Information is also provided on different materials and associated material properties that affect the rate the printer is able to advance and retract material, thereby affecting the quality and rate at which a part is printed. The final section provides information on the mechanism of viscous extrusion 3D printing.