International Journal of Bioprinting
ISSN / EISSN : 24247723 / 24248002
Current Publisher: Whioce Publishing Pte Ltd (10.18063)
Total articles ≅ 123
Latest articles in this journal
International Journal of Bioprinting, Volume 6; doi:10.18063/ijb.v6i3.275
The aim of the study was the development of three-dimensional (3D) printed gene-activated implants based on octacalcium phosphate (OCP) and plasmid DNA encoding VEGFA. The first objective of the present work involved design and fabrication of gene-activated bone substitutes based on the OCP and plasmid DNA with VEGFА gene using 3D printing approach of ceramic constructs, providing the control of its architectonics compliance to the initial digital models. X-ray diffraction, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and compressive strength analyses were applied to investigate the chemical composition, microstructure, and mechanical properties of the experimental samples. The biodegradation rate and the efficacy of plasmid DNA delivery in vivo were assessed during standard tests with subcutaneous implantation to rodents in the next stage. The final part of the study involved substitution of segmental tibia and mandibular defects in adult pigs with 3D printed gene-activated implants. Biodegradation, osteointegration, and effectiveness of a reparative osteogenesis were evaluated with computerized tomography, SEM, and a histological examination. The combination of gene therapy and 3D printed implants manifested the significant clinical potential for effective bone regeneration in large/critical size defect cases.
International Journal of Bioprinting, Volume 6; doi:10.18063/ijb.v6i2.273
Electrically conducting hydrogels are gaining increasing attention due to their potential application in smart patches, biosensors, functional tissue engineering scaffolds, wound management, and implants. The current review focuses on these novel materials, their synthesis routes, and their composites. Special attention is paid to fabrication routes to produce functional composites with organic and inorganic components. The design of conductive hydrogels leads to inheritance of the advantages of each component and offers new features from the synergistic effects between the components, thus opening new application areas. The review also discusses the emerging role of 3D printing as an advanced approach toward new design, functionality, and material combination possibilities. The issue of lack of the spatial control with current techniques is highlighted, and possible new routes to solve it are discussed. The review will provide readers with knowledge tool to select appropriate methodology for designing desired hydrogel material composites.
International Journal of Bioprinting, Volume 6; doi:10.18063/ijb.v6i2.265
Bone has a hierarchy of porosity that is often overlooked when creating tissue engineering scaffolds where pore sizes are typically confined to a single order of magnitude. High internal phase emulsion (HIPE) templating produces polymerized HIPEs (polyHIPEs): highly interconnected porous polymers which have two length scales of porosity covering the 1–100 µm range. However, additional larger scales of porosity cannot be introduced in the standard emulsion formulation. Researchers have previously overcome this by additively manufacturing emulsions; fabricating highly microporous struts into complex macroporous geometries. This is time consuming and expensive; therefore, here we assessed the feasibility of combining porogen leaching with emulsion templating to introduce additional macroporosity. Alginate beads between 275 and 780 µm were incorporated into the emulsion at 0, 50, and 100 wt%. Once polymerized, alginate was dissolved leaving highly porous polyHIPE scaffolds with added macroporosity. The compressive modulus of the scaffolds decreased as alginate porogen content increased. Cellular performance was assessed using MLO-A5 post-osteoblasts. Seeding efficiency was significantly higher and mineralized matrix deposition was more uniformly deposited throughout porogen leached scaffolds compared to plain polyHIPEs. Deep cell infiltration only occurred in porogen leached scaffolds as detected by histology and lightsheet microscopy. This study reveals a quick, low cost and simple method of producing multiscale porosity scaffolds for tissue engineering.
International Journal of Bioprinting, Volume 6; doi:10.18063/ijb.v6i2.276
This study explored the potential of three-dimensional printing (3DP) technology in producing a three-dimensional (3D) medication label for blind and visually impaired (BVI) patients to ease their drug administration. Different variations of label wordings, dosing instructions, and medication identifiers were designed with reference to guidelines by the American Foundation for the Blind. Shapes and symbols were used as dosing instructions and medication identifiers to the patient’s medical conditions. Prototype designs were created with common graphics computer-assisted drafting software and 3D-printed using acrylonitrile butadiene styrene as the polymer filament. Feedback was then obtained from five people with normal vision and four BVI persons. The initial prototype comprised four components, namely, medication name and strength, patient’s name, dosing instruction, and medication identifier. A revised label comprising the latter two components was developed after feedback by BVI persons. Words were in all uppercase and regular font type, with a 5-mm center-to-center letter spacing. Elevation heights of the letters alternated between 1 mm and 1.5 mm. A half sphere represented the medication dose unit, while vertical lines and a horizontal center line with alternating elevation of arrowheads represented the frequency of administration and the medication’s consumption in relation to food, respectively. Symbols based on target organs were used as medication identifiers. With rapid advancements in 3DP technologies, there is tremendous potential for producing 3D labels in patients’ medication management.
International Journal of Bioprinting, Volume 6; doi:10.18063/ijb.v6i2.274
The pore geometry of scaffold intended for the use in the bone repair or replacement is one of the most important parameters in bone tissue engineering. It affects not only the mechanical properties of the scaffold but also the amount of bone regeneration after implantation. Scaffolds with five different architectures (cubic, spherical, x, gyroid, and diamond) at different porosities were fabricated with bioactive borate glass using the selective laser sintering (SLS) process. The compressive strength of scaffolds with porosities ranging from 60% to 30% varied from 1.7 to 15.5 MPa. The scaffold’s compressive strength decreased significantly (up to 90%) after 1-week immersion in simulated body fluids. Degradation of scaffolds is dependent on porosity, in which the scaffold with the largest surface area has the largest reduction in strength. Scaffolds with traditional cubic architecture and biomimetic diamond architecture were implanted in 4.6 mm diameter full-thickness rat calvarial defects for 6 weeks to evaluate the bone regeneration with or without bone morphogenetic protein 2 (BMP-2). Histological analysis indicated no significant difference in bone formation in the defects treated with the two different architectures. However, the defects treated with the diamond architecture scaffolds had more fibrous tissue formation and thus have the potential for faster bone formation. Overall, the results indicated that borate glass scaffolds fabricated using the SLS process have the potential for bone repair and the addition of BMP-2 significantly improves bone regeneration.
International Journal of Bioprinting, Volume 6; doi:10.18063/ijb.v6i3.272
Bioethical and legal issues of three-dimensional (3D) bioprinting as the emerging field of biotechnology have not yet been widely discussed among bioethicists around the world, including Russia. The scope of 3D bioprinting includes not only the issues of the advanced technologies of human tissues and organs printing but also raises a whole layer of interdisciplinary problems of modern science, technology, bioethics, and philosophy. This article addresses the ethical and legal issues of bioprinting of artificial human organs.
International Journal of Bioprinting, Volume 6; doi:10.18063/ijb.v6i3.269
For the past 10 years, the main efforts of most bioprinting research teams have focused on creating new bioinkformulations, rather than inventing new printing set-up concepts. New tissue-specific bioinks with good printability, shapefidelity, and biocompatibility are based on “old” (well-known) biomaterials, particularly fibrin. While the interest in fibrinbased bioinks is constantly growing, it is essential to provide a framework of material’s properties and trends. This review aimsto describe the fibrin properties and application in three-dimensional bioprinting and provide a view on further developmentof fibrin-based bioinks
International Journal of Bioprinting, Volume 6; doi:10.18063/ijb.v6i2.262
Hypertrophic scars (HS) are considered to be the greatest unmet challenge in wound and burn rehabilitation. The most common treatment for HS is pressure therapy, but pressure garments may not be able to exert adequate pressure onto HS due to the complexity of the human body. However, the development of three-dimensional (3D) scanning and direct digital manufacturing technologies has facilitated the customized placement of additively manufactured silicone gel onto fabric as a component of the pressure therapy garment. This study provides an introduction on a novel and customized fabrication approach to treat HS and discusses the mechanical properties of 3D printed fabric reinforced with a silicone composite. For further demonstration of the suggested HS therapy with customized silicone insert, silicone inserts for the finger webs and HS were additively manufactured onto the fabric. Through the pressure evaluation by Pliance X system, it proved that silicone insert increases the pressure exerted to the HS. Moreover, the mechanical properties of the additively manufactured fabric silicone composites were characterized. The findings suggest that as compared with single viscosity print materials, the adhesive force of the additively manufactured silicone and fabric showed a remarkable improvement of 600% when print materials with different viscosities were applied onto elevated fabric
International Journal of Bioprinting, Volume 6; doi:10.18063/ijb.v6i3.271
Laser-induced forward transfer is a versatile, non-contact, and nozzle-free printing technique which has demonstrated high potential for different printing applications with high resolution. In this article, three most widely used hydrogels in bioprinting (2% hyaluronic acid sodium salt, 1% methylcellulose, and 1% sodium alginate) were used to study laser printing processes. For this purpose, the authors applied a laser system based on a pulsed infrared laser (1064 nm wavelength, 8 ns pulse duration, 1 – 5 J/cm2 laser fluence, and 30 μm laser spot size). A high-speed shooting showed that the increase in fluence caused a sequential change in the transfer regimes: No transfer regime, optimal jetting regime with a single droplet transfer, high speed regime, turbulent regime, and plume regime. It was demonstrated that in the optimal jetting regime, which led to printing with single droplets, the size and volume of droplets transferred to the acceptor slide increased almost linearly with the increase of laser fluence. It was also shown that the maintenance of a stable temperature (±2°C) allowed for neglecting the temperature-induced viscosity change of hydrogels. It was determined that under room conditions (20°C, humidity 50%), the hydrogel layer, due to drying processes, decreased with a speed of about 8 μm/min, which could lead to a temporal variation of the transfer process parameters. The authors developed a practical algorithm that allowed quick configuration of the laser printing process on an applied experimental setup. The configuration is provided by the change of the easily tunable parameters: Laser pulse energy, laser spot size, the distance between the donor ribbon and acceptor plate, as well as the thickness of the hydrogel layer on the donor ribbon slide.
International Journal of Bioprinting, Volume 6; doi:10.18063/ijb.v6i3.270
Biomaterials made using collagen are successfully used as a three-dimensional (3D) substrate for cell culture and considered to be promising scaffolds for creating artificial tissues. An important task that arises for engineering such materials is the simulation of physical and morphological properties of tissues, which must be restored or replaced. Modern additive technologies, including 3D bioprinting, can be applied to successfully solve this task. This review provides the latest evidence on advances of 3D bioprinting with collagen in the field of tissue engineering. It contains modern approaches for printing pure collagen bioinks consisting only of collagen and cells, as well as the obtained results from the use of pure collagen bioinks in different fields of tissue engineering.