(In progress)

Table of Contents

Perspective Articles

by Rong Feng Zhang, Peng Yun Wang, Ming Yang, Xuebo Dong, Xue Liu, Yiguang Sang, An Tong
58 Views, 28 PDF Downloads

Additive manufacturing has been used in complex spinal surgical planning since the 1990s and is now increasingly utilized to produce surgical guides, templates, and more recently customized implants. Surgeons report beneficial impacts using additively manufactured biomodels as pre-operative planning aids as it generally provides a better representation of the patient’s anatomy than on-screen viewing of computed tomography (CT) or magnetic resonance imaging (MRI). Furthermore, it has proven to be very beneficial in surgical training and in explaining complex deformity and surgical plans to patients/ parents. This paper reviews the historical perspective, current use, and future directions in using additive manufacturing in complex spinal surgery cases. This review reflects the authors’ opinion of where the field is moving in light of the current literature. Despite the reported benefits of additive manufacturing for surgical planning in recent years, it remains a high niche market. This review raises the question as to why the use of this technology has not progressed more rapidly despite the reported advantages – decreased operating time, decreased radiation exposure to patients intraoperatively, improved overall surgical outcomes, pre-operative implant selection, as well as being an excellent communication aid for all medical and surgical team members. Increasingly, the greatest benefits of additive manufacturing technology in spinal surgery are customdesigned drill guides, templates for pedicle screw placement, and customized patient-specific implants. In view of these applications, additive manufacturing technology could potentially revolutionize health care in the near future.

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Perspective Articles

by Yi Zhang
12 Views, 7 PDF Downloads

As microfluidic devices are designed to tackle more intricate tasks, the architecture of microfluidic devices
becomes more complex, and more sophisticated fabrication techniques are in demand. Therefore, it is sensible to fabricate
microfluidic devices by three-dimensional (3D)-printing, which is well-recognized for its unique ability to monolithically
fabricate complex structures using a near-net-shape additive manufacturing process. Many 3D-printed microfluidic platforms
have been demonstrated but can 3D-printed microfluidics meet the demanding requirements in today’s context, and has
microfluidics truly benefited from 3D-printing? In contrast to 3D-printed microfluidics, some go the other way around and
exploit microfluidics for 3D-printing. Many innovative printing strategies have been made possible with microfluidicsenabled
3D-printing, although the limitations are also largely evident. In this perspective article, we take a look at the current
development in 3D-printed microfluidics and microfluidics-enabled 3D printing with a strong focus on the limitations of the
two technologies. More importantly, we attempt to identify the innovations required to overcome these limitations and to
develop new high-value applications that would make a scientific and social impact in the future.

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Original Articles

by Mishbak H. H, Glen Cooper, Paulo Jorge Da Silva Bartolo
68 Views, 38 PDF Downloads

Alginate is a biocompatible material suitable for biomedical applications, which can be processed under mild conditions upon irradiation.  This paper investigates the preparation and the rheological behaviour of different pre-polymerised and polymerised alginate-methacrylate systems for 3D photopolymerisation bioprinting. The effect of the functionalization time on the mechanical, morphological, swelling and degradation characteristics of crosslinked alginate hydrogel is also discussed.  Alginate was chemically-modified with methacrylate groups and different reaction times considered. Photocurable alginate systems were prepared  by dissolving functionalized alginate with 0.5-1.5% photoinitiator solution and crosslinked by ultraviolet (UV) light (8 mW/cm2).

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Original Articles

by Daisuke Takagi, Waka Lin, Takahiko Matsumoto, Hidekazu Yaginuma, Natsuko Hemmi, Shigeo Hatada, Manabu Seo
61 Views, 38 PDF Downloads
In recent years, bioprinting has emerged as a promising technology for the construction of three-dimensional (3D) tissues to be used in regenerative medicine or in vitro screening applications. In the present study, we present the development of an inkjet-based bioprinting system to arrange multiple cells and materials precisely into structurally organized constructs. A novel inkjet printhead has been specially designed for live cell ejection. Droplet formation is powered by piezoelectric membrane vibrations coupled with mixing movements to prevent cell sedimentation at the nozzle. Stable drop-on-demand dispensing and cell viability were validated over an adequately long time to allow the fabrication of 3D tissues. Reliable control of cell number and spatial positioning was demonstrated using two separate suspensions with different cell types printed sequentially. Finally, a process for constructing stratified Mille-Feuille-like 3D structures is proposed by alternately superimposing cell suspensions and hydrogel layers with a controlled vertical resolution. The results show that inkjet technology is effective for both two-dimensional patterning and 3D multilayering and has the potential to facilitate the achievement of live cell bioprinting with an unprecedented level of precision.
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Original Articles

by Fan Feng, Jiankang He, Jiaxin Li, Mao Mao, Dichen Li
17 Views,
Multimaterial bioprinting provides a promising strategy to recapitulate complex heterogeneous architectures of native tissues in artificial tissue analogs in a controlled manner. However, most of the existing multimaterial bioprinting techniques relying on multiple printing nozzles and complicate control program make it difficult to flexibly change the material composition during the printing process. Here, we developed a multicomponent bioprinting strategy to produce heterogeneous constructs using a microfluidic printhead with multiple inlets and one outlet. The composition of the printed filaments can be flexibly changed by adjusting volumetric flow rate ratio. Heterogeneous hydrogel constructs were successfully printed to have predefined spatial gradients of inks or microparticles. A rotary microfluidic printhead was used to maintain the heterogeneous morphology of the printed filaments as the printing path direction changed. Multicellular concentric ring constructs with two kinds of cell types distribution in the printed filaments were fabricated by utilizing coaxial microfluidic printhead and rotary collecting substrate, which significantly improves the printing efficiency for multicomponent concentric structures. The presented approach is simple and promising to potentially print multicomponent heterogeneous constructs for the fabrication of artificial multicellular tissues.

Original Articles

by Cijun Shuai, Wenjing Yang, Youwen Yang, Chengde Gao, Chongxian He, Hao Pan
13 Views, 14 PDF Downloads

Mg alloys degrade rather rapidly in a physiological environment, although they have good biocompatibility and
favorable mechanical properties. In this study, Ti was introduced into AZ61 alloy fabricated by selective laser melting,
aiming to improve the corrosion resistance. Results indicated that Ti promoted the formation of Al-enriched eutectic α phase
and reduced the formation of β-Mg17Al12 phase. With Ti content reaching to 0.5 wt.%, the Al-enriched eutectic α phase
constructed a continuous net-like structure along the grain boundaries, which could act as a barrier to prevent the Mg matrix
from corrosion progression. On the other hand, the Al-enriched eutectic α phase was less cathodic than β-Mg17Al12 phase in
AZ61, thus alleviating the corrosion progress due to the decreased potential difference. As a consequence, the degradation
rate dramatically decreased from 0.74 to 0.24 mg·cm-2·d-1. Meanwhile, the compressive strength and microhardness were
increased by 59.4% and 15.6%, respectively. Moreover, the Ti-contained AZ61 alloy exhibited improved cytocompatibility.
It was suggested that Ti-contained AZ61 alloy was a promising material for bone implants application.

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Original Articles

by Yu Fang Shen
0 Views, 0 PDF Downloads
With the development of 3D printing, many commercial 3D printing materials have been applied in the fields of biomedicine and medical. MED610 is a clear, biocompatible PolyJet material that is medically certified for bodily contact. In this study, the poly dopamine (PDA)/ hydroxyapatite (HA) coating was added to the printed MED610 objects to evaluate its physical properties, cell proliferation, cell morphology, and alkaline phosphatase (ALP) expression level. The results show that the PDA/HA coating helps printed objects to enhance the hardness, biocompatibility and osteogenic differentiation potential. We expect that PDA/HA coatings contribute to the applicability of MED610 in biomedical and medical applications.
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Retraction Note

Retraction: Application of 3D printing technology in orthopedic medical implant - Spinal surgery as an example
by Chee Kai Chua
0 Views, 0 PDF Downloads
Retraction: Application of 3D printing technology in orthopedic medical implant - Spinal surgery as an example
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