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Table of Contents

Special Section: Research and Applications of 3D Printing and Bioprinting for Covid-19








Regular Section

Original Articles

by Linzhi Jing, Jie Sun, Hang Liu, Xiang Wang, Dejian Huang
311 Views, 131 PDF Downloads

Electrohydrodynamic printing (EHDP) is capable of fabricating micro- to nano-scale fibrous scaffolds for three-dimensional (3D) cell cultures and tissue engineering applications. One of the major bottlenecks that limits the widespread EHDP is the lack of biomaterial ink solutions with tunable mechanical, chemical, and biological properties. In this work, we blend plant protein nanoparticles with synthetic polymer poly(ε-caprolactone) (PCL) to develop composite biomaterial inks, such as PCL/gliadin and PCL/zein for EHDP scaffold fabrication. The tensile test results showed that the composite materials with a relatively small amount of plant protein nanoparticles, such as PCL/gliadin-10, PCL/zein-10 can significantly increase both Young’s modulus and yield stress of the fabricated scaffolds. These scaffolds are further evaluated by culturing mouse embryonic fibroblasts (NIH/3T3) cells, and proven to enhance cell adhesion and proliferation, apart from temporary inhibition effects for PCL/gliadin-20 scaffold at the initial growth stage. After these plant protein nanoparticles are gradually released into culture medium, the generated nanoporous structures on the scaffolds are also favorable to cellular attachment, migration, and proliferation. As competent candidates to upregulate cell biological behaviors in 3D microenvironment, such composite scaffolds manifest a great potential in drug screening and 3D in vitro model development.     

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Original Articles

by Bin Xie, Ming-Chun Zhao, Rong Xu, Ying-Chao Zhao, Deng-Feng Yin, Chengde Gao, Andrej Atrens
290 Views, 46 PDF Downloads

An antibacterial biomedical Mg alloy was designed to have a low biodegradation rate. ZK30-0.2Cu-xMn (x = 0, 0.4, 0.8, 1.2, and 1.6 wt.%) was produced by selective laser melting (SLM). Alloying with Mn had a significant influence on the grain size, hardness, and biodegradation rate. Increasing Mg content to 0.8 wt% decreased the biodegradation rate, attributed to the decreased grain size and the relatively protective manganese surface oxide layer. Higher Mn contents increased the biodegradation rate attributed to the presence of the Mn-rich particles. ZK30-0.2Cu-0.8Mn exhibited the lowest biodegradation rate, strong antibacterial performance and good cytocompatibility.

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Original Articles

by Marlon Wesley Machado Cunico
211 Views, 26 PDF Downloads

Dental prosthesis and restoration technologies have been developed in the past years. Despite the advantages of additive manufacturing, computer-aided design, and computer-aided manufacturing technologies are still the dominant type of method for fabricating prostheses. Therefore, the main goal of this study is to assess the feasibility of using indirect fused deposition modeling to fabricate dental prosthesis made of ZrSiO4-glass composites. To achieve this goal, filaments were filled by 90% of ZrSiO4 and 50 μm glass spheres to fabricate prosthesis. Multivariable approach was applied to evaluate the feasibility of the proposed method. Holding temperature, holding time, heating rate, and cooling rate were considered the control factors, while shrinkage, flexural strength, and process feasibility were the study responses. In addition, the flexural strength of materials was found between 25 and 85 MPa, while shrinkage fluctuated between 10 and 25%.

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Original Articles

by Chuanchuan Zheng, Shokouh Attarilar, Kai Li, Chong Wang, Jia Liu, Liqiang Wang, Junlin Yang, Yujin Tang
27 Views, 5 PDF Downloads

In this study, a β-tricalcium phosphate (β-TCP)/poly (lactic-co-glycolic acid) (PLGA) bone tissue scaffold was loaded with osteogenesis-promoting drug HA15 and constructed by three-dimensional (3D) printing technology. This drug delivery system with favorable biomechanical properties, bone conduction function, and local release of osteogenic drugs could provide the basis for the treatment of bone defects. The biomechanical properties of the scaffold were investigated by compressive testing, showing comparable biomechanical properties with cancellous bone tissue. Furthermore, the microstructure, pore morphology, and condition were studied. Moreover, the drug release concentration, the effect of anti-tuberculosis drugs in vitro and in rabbit radial defects, and the ability of the scaffold to repair the defects were studied. The results show that the scaffold loaded with HA15 can promote cell differentiation into osteoblasts in vitro, targeting HSPA5. The micro-computed tomography scans showed that after 12 weeks of scaffold implantation, the defect of the rabbit radius was repaired and the peripheral blood vessels were regenerated. Thus, HA15 can target HSPA5 to inhibit endoplasmic reticulum stress which finally leads to promotion of osteogenesis, bone regeneration, and angiogenesis in the rabbit bone defect model. Overall, the 3D-printed β-TCP/PLGA-loaded HA15 bone tissue scaffold can be used as a substitute material for the treatment of bone defects because of its unique biomechanical properties and bone conductivity.

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Review Articles

by Yi Zhang, Bin Wang, Junchao Hu, Tianyuan Yin, Tao Yue, Na Liu, Yuanyuan Liu
188 Views, 42 PDF Downloads

Three-dimensional (3D) bioprinting is an important technology for fabricating artificial tissue. To effectively reconstruct the multiscale structure and multi-material gradient of natural tissues and organs, 3D bioprinting has been increasingly developed into multi-process composite mode. The current 3D composite bioprinting is a combination of two or more printing processes, and oftentimes, physical field regulation that can regulate filaments or cells during or after printing may be involved. Correspondingly, both path planning strategy and process control all become more complex. Hence, the
computer-aided design and computer-aided manufacturing (CAD/CAM) system that is traditionally used in 3D printing system
is now facing challenges. Thus, the scale information that cannot be modeled in the CAD process should be considered in
the design of CAM by adding a process management module in the traditional CAD/CAM system and add more information
reflecting component gradient in the path planning strategy.

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Review Articles

by Shokouh Attarilar, Mahmoud Ebrahimi, Faramarz Djavanroodi, Yuanfei Fu, Liqiang Wang, Junlin Yang
218 Views, 36 PDF Downloads

Additive manufacturing (AM) is among the most attractive methods to produce implants, the processes are very swift and it can be precisely controlled to meet patient’s requirement since they can be produced in exact shape, dimension, and even texture of different living tissues. Until now, lots of methods have emerged and used in this field with diverse characteristics. This review aims to comprehensively discuss 3D printing (3DP) technologies to manufacture metallic implants, especially on techniques and procedures. Various technologies based on their main properties are categorized, the effecting parameters are introduced, and
the history of AM technology is briefly analyzed. Subsequently, the utilization of these AM-manufactured components in medicine along with their effectual variables is discussed, and special attention is paid on to the production of porous scaffolds, taking pore size, density, etc., into consideration. Finally, 3DP of the popular metallic systems in medical applications such as titanium, Ti6Al4V, cobalt-chromium alloys, and shape memory alloys are studied. In general, AM manufactured implants need to comply with important requirements such as biocompatibility, suitable mechanical properties (strength and elastic modulus), surface conditions, custom-built designs, fast production, etc. This review aims to introduce the AM technologies in implant applications and find new ways to design more sophisticated methods and compatible implants that mimic the desired tissue functions.

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Review Articles

by Colin Sherborne, Frederik Claeyssens
86 Views, 13 PDF Downloads

This review paper explores the potential of combining emulsion-based inks with additive manufacturing (AM) to produce filters for respiratory protective equipment (RPE) in the fight against viral and bacterial infections of the respiratory tract. The value of these filters has been highlighted by the current severe acute respiratory syndrome coronavirus-2 crisis where the importance of protective equipment for health care workers cannot be overstated. Three-dimensional (3D) printing of emulsions is an emerging technology built on a well-established field of emulsion templating to produce porous materials such as polymerized high internal phase emulsions (polyHIPEs). PolyHIPE-based porous polymers have tailorable porosity from the submicron to 100 s of μm. Advances in 3D printing technology enables the control of the bulk shape while a micron porosity is controlled independently by the emulsion-based ink. Herein, we present an overview of the current polyHIPE-based filter applications. Then, we discuss the current use of emulsion templating combined with stereolithography and extrusion-based AM technologies. The benefits and limitation of various AM techniques are discussed, as well as considerations for a scalable manufacture of a polyHIPE-based RPE.

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