scholarly journals Dispensing-Based Bioprinting of Hybrid Scaffolds with Vessel-like Channels for Tissue Engineering Applications – A Brief Review

2017 ◽  
Author(s):  
Saman Naghieh ◽  
Md Sarker ◽  
Mohammad Izadifar ◽  
Xiongbiao Chen
Keyword(s):  
Tissue Engineering ◽  
Imaging Techniques ◽  
Critical Role ◽  
Three Dimensional ◽  
Biological Properties ◽  
Biological Molecules ◽  
Future Research ◽  
Key Issues ◽  
Future Research Directions ◽  
Hybrid Scaffolds

Over the past two decades, significant progress has been achieved in the field of tissue engineering (TE) to restore/repair damaged tissues or organs and, in this regard, scaffolds made from biomaterials have played a critical role. Notably, recent advances in biomaterials and three-dimensional (3D) printing have enabled the manipulation of two or more biomaterials of distinct, yet complementary, mechanical and/or biological properties to form so-called hybrid scaffolds mimicking native tissues. Among various biomaterials, hydrogels synthesized to incorporate living cells and/or biological molecules have dominated due to their hydrated tissue-like environment. Moreover, dispensing-based bioprinting has evolved to the point that it can now be used to create hybrid scaffolds with complex structures. However, the complexities associated with multi-material bioprinting and synthesis of hydrogels used for hybrid scaffolds pose many challenges for their fabrication. This paper presents a brief review of dispensing-based bioprinting of hybrid scaffolds for TE applications. The focus is on the design and fabrication of hybrid scaffolds, including imaging techniques, potential biomaterials, physical architecture, mechanical properties, cell viability, and the importance of vessel-like channels. The key issues and challenges for dispensing-based bioprinting of hybrid scaffolds are also identified and discussed along with recommendations for future research directions. Addressing these issues will significantly enhance the design and fabrication of hybrid scaffolds to and pave the way for translating them into clinical applications.

scholarly journals Bioprinting Scaffolds for Vascular Tissues and Tissue Vascularization

2021 ◽  
Vol 8 (11) ◽  
pp. 178
Author(s):  
Peter Viktor Hauser ◽  
Hsiao-Min Chang ◽  
Masaki Nishikawa ◽  
Hiroshi Kimura ◽  
Norimoto Yanagawa ◽  
...  
Keyword(s):  
3D Printing ◽  
Large Scale ◽  
Three Dimensional ◽  
Biological Properties ◽  
Biological Molecules ◽  
Future Directions ◽  
Artificial Tissue ◽  
Hydrogel Synthesis ◽  
Cell Sources ◽  
Hybrid Scaffolds

In recent years, tissue engineering has achieved significant advancements towards the repair of damaged tissues. Until this day, the vascularization of engineered tissues remains a challenge to the development of large-scale artificial tissue. Recent breakthroughs in biomaterials and three-dimensional (3D) printing have made it possible to manipulate two or more biomaterials with complementary mechanical and/or biological properties to create hybrid scaffolds that imitate natural tissues. Hydrogels have become essential biomaterials due to their tissue-like physical properties and their ability to include living cells and/or biological molecules. Furthermore, 3D printing, such as dispensing-based bioprinting, has progressed to the point where it can now be utilized to construct hybrid scaffolds with intricate structures. Current bioprinting approaches are still challenged by the need for the necessary biomimetic nano-resolution in combination with bioactive spatiotemporal signals. Moreover, the intricacies of multi-material bioprinting and hydrogel synthesis also pose a challenge to the construction of hybrid scaffolds. This manuscript presents a brief review of scaffold bioprinting to create vascularized tissues, covering the key features of vascular systems, scaffold-based bioprinting methods, and the materials and cell sources used. We will also present examples and discuss current limitations and potential future directions of the technology.

scholarly journals Bone tissue engineering therapeutics: controlled drug delivery in three-dimensional scaffolds

2009 ◽  
Vol 7 (43) ◽  
pp. 209-227 ◽  
Author(s):  
Viviana Mouriño ◽  
Aldo R. Boccaccini
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Three Dimensional ◽  
Future Research ◽  
Therapeutic Drugs ◽  
Polymeric Biomaterials ◽  
Future Research Directions ◽  
Inflammatory Drugs

This paper provides an extensive overview of published studies on the development and applications of three-dimensional bone tissue engineering (TE) scaffolds with potential capability for the controlled delivery of therapeutic drugs. Typical drugs considered include gentamicin and other antibiotics generally used to combat osteomyelitis, as well as anti-inflammatory drugs and bisphosphonates, but delivery of growth factors is not covered in this review. In each case reviewed, special attention has been given to the technology used for controlling the release of the loaded drugs. The possibility of designing multifunctional three-dimensional bone TE scaffolds for the emerging field of bone TE therapeutics is discussed. A detailed summary of drugs included in three-dimensional scaffolds and the several approaches developed to combine bioceramics with various polymeric biomaterials in composites for drug-delivery systems is included. The main results presented in the literature are discussed and the remaining challenges in the field are summarized with suggestions for future research directions.

scholarly journals Three-Dimensional Thematic Map Imaging of the Yacht Port on the Example of the Polish National Sailing Centre Marina in Gdańsk

2021 ◽  
Vol 11 (15) ◽  
pp. 7016
Author(s):  
Pawel S. Dabrowski ◽  
Cezary Specht ◽  
Mariusz Specht ◽  
Artur Makar
Keyword(s):  
Spatial Data ◽  
Convex Surface ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Future Research ◽  
Two Dimensional ◽  
Thematic Maps ◽  
Research Directions ◽  
Future Research Directions ◽  
The Many

The theory of cartographic projections is a tool which can present the convex surface of the Earth on the plane. Of the many types of maps, thematic maps perform an important function due to the wide possibilities of adapting their content to current needs. The limitation of classic maps is their two-dimensional nature. In the era of rapidly growing methods of mass acquisition of spatial data, the use of flat images is often not enough to reveal the level of complexity of certain objects. In this case, it is necessary to use visualization in three-dimensional space. The motivation to conduct the study was the use of cartographic projections methods, spatial transformations, and the possibilities offered by thematic maps to create thematic three-dimensional map imaging (T3DMI). The authors presented a practical verification of the adopted methodology to create a T3DMI visualization of the marina of the National Sailing Centre of the Gdańsk University of Physical Education and Sport (Poland). The profiled characteristics of the object were used to emphasize the key elements of its function. The results confirmed the increase in the interpretative capabilities of the T3DMI method, relative to classic two-dimensional maps. Additionally, the study suggested future research directions of the presented solution.

scholarly journals Polymeric Biomaterials for the Treatment of Cardiac Post-Infarction Injuries

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1038
Author(s):  
Sonia Trombino ◽  
Federica Curcio ◽  
Roberta Cassano ◽  
Manuela Curcio ◽  
Giuseppe Cirillo ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cardiac Tissue ◽  
Polymeric Nanoparticles ◽  
Three Dimensional ◽  
Cardiac Regeneration ◽  
Biological Properties ◽  
Positive Influence ◽  
Regenerative Process ◽  
Current Status ◽  
Polymeric Biomaterials

Cardiac regeneration aims to reconstruct the heart contractile mass, preventing the organ from a progressive functional deterioration, by delivering pro-regenerative cells, drugs, or growth factors to the site of injury. In recent years, scientific research focused the attention on tissue engineering for the regeneration of cardiac infarct tissue, and biomaterials able to anatomically and physiologically adapt to the heart muscle have been proposed as valuable tools for this purpose, providing the cells with the stimuli necessary to initiate a complete regenerative process. An ideal biomaterial for cardiac tissue regeneration should have a positive influence on the biomechanical, biochemical, and biological properties of tissues and cells; perfectly reflect the morphology and functionality of the native myocardium; and be mechanically stable, with a suitable thickness. Among others, engineered hydrogels, three-dimensional polymeric systems made from synthetic and natural biomaterials, have attracted much interest for cardiac post-infarction therapy. In addition, biocompatible nanosystems, and polymeric nanoparticles in particular, have been explored in preclinical studies as drug delivery and tissue engineering platforms for the treatment of cardiovascular diseases. This review focused on the most employed natural and synthetic biomaterials in cardiac regeneration, paying particular attention to the contribution of Italian research groups in this field, the fabrication techniques, and the current status of the clinical trials.

scholarly journals Children’s outdoor active mobility behaviour and neighbourhood safety: a systematic review in measurement methods and future research directions

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Roula Zougheibe ◽  
Jianhong (Cecilia) Xia ◽  
Ashraf Dewan ◽  
Ori Gudes ◽  
Richard Norman
Keyword(s):  
Three Dimensional ◽  
Measurement Methods ◽  
Future Research ◽  
Inclusion Criteria ◽  
Eligibility Criteria ◽  
Research Directions ◽  
Spatial Locality ◽  
Mobility Behaviour ◽  
Health Studies ◽  
Future Research Directions

Abstract Background Numerous studies have examined the association between safety and primary school-aged children’s forms of active mobility. However, variations in studies’ measurement methods and the elements addressed have contributed to inconsistencies in research outcomes, which may be forming a barrier to advancing researchers’ knowledge about this field. To assess where current research stands, we have synthesised the methodological measures in studies that examined the effects of neighbourhood safety exposure (perceived and measured) on children’s outdoor active mobility behaviour and used this analysis to propose future research directions. Method A systematic search of the literature in six electronic databases was conducted using pre-defined eligibility criteria and was concluded in July 2020. Two reviewers screened the literature abstracts to determine the studies’ inclusion, and two reviewers independently conducted a methodological quality assessment to rate the included studies. Results Twenty-five peer-reviewed studies met the inclusion criteria. Active mobility behaviour and health characteristics were measured objectively in 12 out of the 25 studies and were reported in another 13 studies. Twenty-one studies overlooked spatiotemporal dimensions in their analyses and outputs. Delineations of children’s neighbourhoods varied within 10 studies’ objective measures, and the 15 studies that opted for subjective measures. Safety perceptions obtained in 22 studies were mostly static and primarily collected via parents, and dissimilarities in actual safety measurement methods were present in 6 studies. The identified schematic constraints in studies’ measurement methods assisted in outlining a three-dimensional relationship between ‘what’ (determinants), ‘where’ (spatial) and ‘when’ (time) within a methodological conceptual framework. Conclusions The absence of standardised measurement methods among relevant studies may have led to the current diversity in findings regarding active mobility, spatial (locality) and temporal (time) characteristics, the neighbourhood, and the representation of safety. Ignorance of the existing gaps and heterogeneity in measures may impact the reliability of evidence and poses a limitation when synthesising findings, which could result in serious biases for policymakers. Given the increasing interest in children’s health studies, we suggested alternatives in the design and method of measures that may guide future evidence-based research for policymakers who aim to improve children’s active mobility and safety.

scholarly journals Computer modelling and simulation of a novel printing head for complex tissue engineering constructs

2020 ◽  
Vol 318 ◽  
pp. 01045
Author(s):  
Gokhan Ates
Keyword(s):  
Tissue Engineering ◽  
Computer Modelling ◽  
Three Dimensional ◽  
Biological Tissues ◽  
Biological Properties ◽  
Functionally Graded ◽  
Mixing Efficiency ◽  
Tissue Constructs ◽  
Multiple Materials ◽  
Graded Structures

In tissue engineering, three-dimensional functional scaffolds with tailored biological properties are needed to be able to mimic the hierarchical structure of biological tissues. Recent developments in additive biomanufacturing allow to extrude multiple materials enabling the fabrication of more sophisticated tissue constructs. These multi-material biomanufacturing systems comprise multiple printing heads through which individual materials are sequentially printed. Nevertheless, as more printing heads are added the fabrication process significantly decreases, since it requires mechanical switching among the physically separated printheads to enable printing multiple materials. In addition, this approach is not able to create biomimetic tissue constructs with property gradients. To address these limitations, this paper presents a novel static mixing extrusion printing head to enable the fabrication of multi-material, functionally graded structures using a single nozzle. Computational fluid dynamics (CFD) was used to numerically analyze the influence of Reynolds number on the flow pattern of biomaterials and mixing efficiency considering different miscible materials.

The Challenge of International Market Segmentation in Emerging Markets

2016 ◽  
pp. 2274-2293
Author(s):  
Ramazan Nacar ◽  
Nimet Uray
Keyword(s):  
Emerging Markets ◽  
Market Segmentation ◽  
International Market ◽  
International Markets ◽  
Future Research ◽  
Methodological Issues ◽  
Research Directions ◽  
Paradoxical Effects ◽  
Key Issues ◽  
Future Research Directions

Increasing paradoxical effects of globalization resulted in the increased homogenization and heterogenization of international markets. Globalization with its varying effects also increased the significance of international market segmentation over the last few decades. Despite the increased presence and usage of international market segmentation, in recent times, the rise of emerging markets have challenged the concepts and methods of international market segmentation. In order to address key issues of international market segmentation in emerging markets, this study briefly examined and assessed foremost conceptual and methodological issues of international market segmentation in emerging markets. Suggestions and future research directions are also provided.

Social Media Corporate Policies for Government Organizations

2012 ◽  
pp. 458-474
Author(s):  
Salem Al Shair Al Suwaidi ◽  
Ibrahim Ahmed Elbadawi
Keyword(s):  
Social Media ◽  
United Arab Emirates ◽  
Social Networking Sites ◽  
Future Research ◽  
Government Officials ◽  
Corporate Policies ◽  
Government Organizations ◽  
Key Issues ◽  
Future Research Directions ◽  
Social Media Tools

As government organizations increasingly recognize the fast growth and expanding influence of social media tools such as social networking sites, blogs, and wikis, they start involving in these tools to increase the value delivered to their citizens. Many government organizations have realized the importance of having corporate policies to guide them while involving in these social media tools. The main purpose of this chapter is to present the key lessons learnt from the process of formulating a government-wide social media policy in the United Arab Emirates. This covers how government officials perceive the adoption of social media by government entities, the main barriers face successful adoption of social media, and the key issues need to be covered by social media policies. The authors analyze the collected answers in light of some of the literature available on the topic. They conclude the chapter with a brief summary and recommendations for future research directions.

Modification of Thai Silk Fibroin Scaffolds by Gelatin Conjugation for Tissue Engineering

2008 ◽  
Vol 55-57 ◽  
pp. 685-688 ◽  
Author(s):  
J. Chamchongkaset ◽  
Sorada Kanokpanont ◽  
David L. Kaplan ◽  
Siriporn Damrongsakkul
Keyword(s):  
Tissue Engineering ◽  
Bombyx Mori ◽  
Silk Fibroin ◽  
Textile Industry ◽  
Three Dimensional ◽  
Biological Properties ◽  
Salt Leaching ◽  
Biological Compatibility ◽  
Salt Crystals

Silk has been used commercially as biomedical sutures for decades. Recently silk fibroin, especially from Bombyx mori silkworm, has been explored for many tissue engineering applications such as bone and cartilage due to its impressive biological compatibility and mechanical properties. In Thailand, Thai native silkworms have been long cultivated. Distinct characteristics of cocoon Thai silk are its yellow color and coarse filament. There is more sericin in Thai silk than in other Bombyx mori silks. These characteristics provide Thai silk a unique texture for textile industry. It is therefore the aim of this study to develop three-dimensional silk fibroin-based scaffolds from Thai yellow cocoon “Nangnoi-Srisaket” of Bombyx mori silkworms using salt-leaching method. To enhance the biological properties, type A gelatin, the denature form of collagen having good biocompactibility, was used to conjugate with silk fibroin scaffolds. The pore size of salt-leached silk fibroin scaffold structure represented the size of salt crystals used (600-710µm). After gelatin conjugation, gelatin was partly formed fibers inside the pores of silk fibroin scaffolds resulting in fiber-like structure with highly interconnection. Gelatin conjugation enhanced the compressive modulus of silk fibroin scaffolds by 93%. The results on in vitro culture using mouse osteoblast-like cells (MC3T3-E1) showed that gelatin conjugation could promote the cell proliferation in silk fibroin scaffolds. Moreover, the observed morphology of cells proliferated inside the scaffold after 14 days of culture showed the larger spreading area of cells on conjugated gelatin/silk fibroin scaffolds, compared to round-shaped cells on silk fibroin scaffolds. The results implied that Thai silk fibroin looked promising to be applied in tissue engineering and gelatin conjugation on Thai silk fibroin scaffolds could enhance the biological properties of scaffolds.

scholarly journals Deep Generative Adversarial Networks for Image-to-Image Translation: A Review

Symmetry ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1705
Author(s):  
Aziz Alotaibi
Keyword(s):  
Three Dimensional ◽  
Super Resolution ◽  
Generative Adversarial Networks ◽  
Future Research ◽  
Comprehensive Overview ◽  
Adversarial Networks ◽  
Current State ◽  
Image Translation ◽  
Translation Techniques ◽  
Future Research Directions

Many image processing, computer graphics, and computer vision problems can be treated as image-to-image translation tasks. Such translation entails learning to map one visual representation of a given input to another representation. Image-to-image translation with generative adversarial networks (GANs) has been intensively studied and applied to various tasks, such as multimodal image-to-image translation, super-resolution translation, object transfiguration-related translation, etc. However, image-to-image translation techniques suffer from some problems, such as mode collapse, instability, and a lack of diversity. This article provides a comprehensive overview of image-to-image translation based on GAN algorithms and its variants. It also discusses and analyzes current state-of-the-art image-to-image translation techniques that are based on multimodal and multidomain representations. Finally, open issues and future research directions utilizing reinforcement learning and three-dimensional (3D) modal translation are summarized and discussed.

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