3D-Bioprinting: A stepping stone towards enhanced medical approaches

In the past few decades, tissue engineering has been seen unprecedented escalation driving the field of artificial tissue and organ construct and brought metamorphosis in regenerative medicine. Prime advancement has been attained through the expansion of novel biomanufacturing approaches to devise and convene cells in three dimensions to fabricate tissue contrive. Accompaniment manufacturing differently known as 3D bioprinting is leading prime innovation in a number of applications in life sciences such as tissue and organ construct, personalized drug dosing, cancer model and heart tissue engineering. Overall, this review summarizes most prevalent bioprinting technologies; including laser-based bioprinting, extrusion bioprinting, injection bioprinting, stereolithography as well as biomaterial such as bioink. It also explores 3D industries, approaches such as Biomimicry, autonomous self-assembly, mini tissues and biomedical applications. Existing challenges that impede clinical mileage of bioprinting are also discussed along with future prospective.Keywords: Bioprinting, tissue engineering, tissue and organ construct, medicinal approac

Application of 3-D Printing for Tissue Regeneration in Oral and Maxillofacial Surgery: What is Upcoming?

The ultimate goal of any surgical procedure is to improve perioperative form and function and to minimize operative and postoperative morbidity. In recent years, many exciting and novel technological advances have been introduced in the field of oral and maxillofacial surgery. One example of such technology that is continuing to increase in prevalence is the use of 3-dimensional (3-D) printing techniques with special properties, which seems hopeful for practitioners in the field of regenerative medicine. Tissue engineering is a critical and important area in biomedical engineering for creating biological alternatives for grafts, implants, and prostheses. One of the main triad bases for tissue engineering is scaffolds, which play a great role for determining growth directions of stem cells in a 3-dimensional aspect. Mechanical strength of these scaffolds is critical as well as interconnected channels and controlled porosity or pores distribution. However, existing 3-D scaffolds proved less than ideal for actual clinical applications. In this chapter, we review the application and advancement of rapid prototyping (RP) techniques in the design and creation of synthetic scaffolds for use in tissue engineering. Also, we survey through new and novel merging era of “bioprinting.

Three-Dimensional (3D) Printed Microneedles for Microencapsulated Cell Extrusion

Cell-hydrogel based therapies offer great promise for wound healing. The specific aim of this study was to assess the viability of human hepatocellular carcinoma (HepG2) cells immobilized in atomized alginate capsules (3.5% (w/v) alginate, d = 225 µm ± 24.5 µm) post-extrusion through a three-dimensional (3D) printed methacrylate-based custom hollow microneedle assembly (circular array of 13 conical frusta) fabricated using stereolithography. With a jetting reliability of 80%, the solvent-sterilized device with a root mean square roughness of 158 nm at the extrusion nozzle tip (d = 325 μm) was operated at a flowrate of 12 mL/min. There was no significant difference between the viability of the sheared and control samples for extrusion times of 2 h (p = 0.14, α = 0.05) and 24 h (p = 0.5, α = 0.05) post-atomization. Factoring the increase in extrusion yield from 21.2% to 56.4% attributed to hydrogel bioerosion quantifiable by a loss in resilience from 5470 (J/m3) to 3250 (J/m3), there was no significant difference in percentage relative payload (p = 0.2628, α = 0.05) when extrusion occurred 24 h (12.2 ± 4.9%) when compared to 2 h (9.9 ± 2.8%) post-atomization. Results from this paper highlight the feasibility of encapsulated cell extrusion, specifically protection from shear, through a hollow microneedle assembly reported for the first time in literature

Addressing present pitfalls in 3D printing for tissue engineering to enhance future potential

Additive manufacturing in tissue engineering has significantly advanced in acceptance and use to address complex problems. However, there are still limitations to the technologies used and potential challenges that need to be addressed by the community. In this manuscript, we describe how the field can be advanced not only through the development of new materials and techniques but also through the standardization of characterization, which in turn may impact the translation potential of the field as it matures. Furthermore, we discuss how education and outreach could be modified to ensure end-users have a better grasp on the benefits and limitations of 3D printing to aid in their career development

Bioprinting

Bioprinting is an emerging field in the areas of tissue engineering and regenerative medicine. It is defined as the printing of structures consisting of living cells, biomaterials and active biomolecules. The ultimate aim is to produce implantable organs and tissues to replace the use of autografts, which cause donor site morbidity and require two invasive surgeries. Not only is bioprinting aimed at the restoration of tissue, it has significant potential for drug delivery and cancer studies. Bioprinting provides control over cell placement and therefore creates a homogenous distribution of cells correlating to a uniform tissue ingrowth. Another attribute of bioprinting is the production of patient-specific spatial geometry, controllable microstructures and a high degree of reproducibility and scalability between designs. This book chapter will discuss the many parameters of bioprinting; manufacturing techniques, precursor materials, types of printed cells and the current research

Three Dimensional (3D) Printable Gel-Inks for Skin Tissue Regeneration

Recent and rapid progression in three-dimensional (3D) printing techniques has revolutionized conventional therapies in medicine; 3D printed constructs are gradually being recognized as common substitutes for the replacement of skin wounds. As gel-inks, large numbers of natural and synthetic (e.g., collagen and polyurethane, respectively) substances were used to be printed into different shapes and sizes for managing both acute and chronic skin wounds. The resultant 3D printed scaffolds not only provide physical support but also act as supporting niches for improving immunomodulation and vascularization and subsequent accelerated wound healing. Recently, the use of thermosensitive and pH-responsive gels has made it possible to prepare 3D printed constructs with the ability to facilitate in situ crosslinking within the biopolymer and with native wound edge tissue as well as to fill the exact shape of wound damage. In this chapter, we aim to introduce the current state of 3D printable gel-inks utilized for skin wound treatment and illustrate future prospects in this amazing area of science

Rapid prototyping for biomedical engineering: current capabilities and Challenges

A new set of manufacturing technologies has emerged in the past decades to address market requirements in a customized way and to provide support for research tasks that require prototypes. These new techniques and technologies are usually referred to as rapid prototyping and manufacturing technologies, and they allow prototypes to be produced in a wide range of materials with remarkable precision in a couple of hours. Although they have been rapidly incorporated into product development methodologies, they are still under development, and their applications in bioengineering are continuously evolving. Rapid prototyping and manufacturing technologies can be of assistance in every stage of the development process of novel biodevices, to address various problems that can arise in the devices' interactions with biological systems and the fact that the design decisions must be tested carefully. This review focuses on the main fields of application for rapid prototyping in biomedical engineering and health sciences, as well as on the most remarkable challenges and research trends

Construction of 3D in vitro models by bioprinting human pluripotent stem cells: Challenges and opportunities

Three-dimensional (3D) printing of biological material, or 3D bioprinting, is a rapidly expanding field with interesting applications in tissue engineering and regenerative medicine. Bioprinters use cells and biocompatible materials as an ink (bioink) to build 3D structures representative of organs and tissues, in a controlled manner and with micrometric resolution. Human embryonic (hESCs) and induced (hiPSCs) pluripotent stem cells are ideally able to provide all cell types found in the human body. A limited, but growing, number of recent reports suggest that cells derived by differentiation of hESCs and hiPSCs can be used as building blocks in bioprinted human 3D models, reproducing the cellular variety and cytoarchitecture of real tissues. In this review we will illustrate these examples, which include hepatic, cardiac, vascular, corneal and cartilage tissues, and discuss challenges and opportunities of bioprinting more demanding cell types, such as neurons, obtained from human pluripotent stem cells

Cell bioprinting: The 3D-bioplotter™ case

The classic cell culture involves the use of support in two dimensions, such as a well plate or a Petri dish, that allows the culture of different types of cells. However, this technique does not mimic the natural microenvironment where the cells are exposed to. To solve that, three-dimensional bioprinting techniques were implemented, which involves the use of biopolymers and/or synthetic materials and cells. Because of a lack of information between data sources, the objective of this review paper is, to sum up, all the available information on the topic of bioprinting and to help researchers with the problematics with 3D bioprinters, such as the 3D-Bioplotter™. The 3D-Bioplotter™ has been used in the pre-clinical field since 2000 and could allow the printing of more than one material at the same time, and therefore to increase the complexity of the 3D structure manufactured. It is also very precise with maximum flexibility and a user-friendly and stable software that allows the optimization of the bioprinting process on the technological point of view. Different applications have resulted from the research on this field, mainly focused on regenerative medicine, but the lack of information and/or the possible misunderstandings between papers makes the reproducibility of the tests dicult. Nowadays, the 3D Bioprinting is evolving into another technology called 4D Bioprinting, which promises to be the next step in the bioprinting field and might promote great applications in the future

Biofabricated Constructs of Carbon-based Nanoparticles with Mesenchymal Stem Cells for Orthopedic Repair

Breakthroughs in tissue engineering are moving at a rapid rate especially in the regenerative bone biofabrication. Technology growth in the field of additive manufacturing (AM) such 3D bioprinting which provides the ability to create biocompatible 3D construct on which a cell source could be seeded is an encouraging substitute to autologous grafts. This present research aims to biofabricate a construct for bone tissue engineering using AM technology. The biocompatible material was chosen corresponding to bones extracellular matrix (ECM) composition, which demonstrates an inorganic and organic development phase: Poly (lactic-glycolic acid) was chosen as the polymeric matrix of the compound, due to its bioactivity, biocompatibility, and ability to regulate biodegradability to support cell and bone function; graphene-nanoparticle was chosen for mechanical and organic reinforcement to support the mineral phase of the ECM. A commercial 3D bioprinter called the Aether 1 was used. The printer is a pneumatic based printer, which allows printing from hydrogels to thermo polymers. The bioprinter is located in the Regenerative Medicine Lab in the Large Animal Clinical Sciences. The first part of our study was to show the relationship of mesenchymal stem cells and graphene-nanoparticles. This was to evaluate the ECM layout on the graphene for biocompatibility and establish markers for supporting osteogenesis. Second part of the research dealt with finding a safe solvent to melt the different molar ratios of PLGA and the blending in of graphene-nanoparticles for low thermodynamic and low-pressure printing. This work dealt with the characterization, constating in the evaluation of different extrusion speeds, pressure values and nozzle diameters to construct a 3D print for testing the biocompatibility and cellular behavior. The final study was to utilize the 3D constructs in a long bone segmental defect model to characterize its in vivo capabilities. This work proved that the biofabrication of the PLGA+graphene blend could be achieved and repeatable with 3D bioprinting, supports cellular behavior for regeneration and provided results in the long bone defect study