scholarly journals Direct Bioprinting of Vessel-Like Tubular Microfluidic Channels

Author(s):  
Yahui Zhang ◽  
Yin Yu ◽  
Ibrahim T. Ozbolat

Despite the progress in tissue engineering, several challenges must be addressed for organ printing to become a reality. The most critical challenge is the integration of a vascular network, which is also a problem that the majority of tissue engineering technologies are facing. An embedded microfluidic channel network is probably the most promising solution to this problem. However, the available microfluidic channel fabrication technologies either have difficulty achieving a three-dimensional complex structure or are difficult to integrate within cell printing process in tandem. In this paper, a novel printable vessel-like microfluidic channel fabrication method is introduced that enables direct bioprinting of cellular microfluidic channels in form of hollow tubes. Alginate and chitosan hydrogels were used to fabricate microfluidic channels showing the versatility of the process. Geometric characterization was performed to understand effect of biomaterial and its flow rheology on geometric properties. Microfluidic channels were printed and embedded within bulk hydrogel to test their functionality through perfusion of cell type oxygenized media. Cell viability experiments were conducted and showed great promise of the microfluidic channels for development of vascular networks.

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1510 ◽  
Author(s):  
Mohammad Ehsan Taghavizadeh Yazdi ◽  
Simin Nazarnezhad ◽  
Seyed Hadi Mousavi ◽  
Mohammad Sadegh Amiri ◽  
Majid Darroudi ◽  
...  

The use of naturally occurring materials in biomedicine has been increasingly attracting the researchers’ interest and, in this regard, gum tragacanth (GT) is recently showing great promise as a therapeutic substance in tissue engineering and regenerative medicine. As a polysaccharide, GT can be easily extracted from the stems and branches of various species of Astragalus. This anionic polymer is known to be a biodegradable, non-allergenic, non-toxic, and non-carcinogenic material. The stability against microbial, heat and acid degradation has made GT an attractive material not only in industrial settings (e.g., food packaging) but also in biomedical approaches (e.g., drug delivery). Over time, GT has been shown to be a useful reagent in the formation and stabilization of metal nanoparticles in the context of green chemistry. With the advent of tissue engineering, GT has also been utilized for the fabrication of three-dimensional (3D) scaffolds applied for both hard and soft tissue healing strategies. However, more research is needed for defining GT applicability in the future of biomedical engineering. On this object, the present review aims to provide a state-of-the-art overview of GT in biomedicine and tries to open new horizons in the field based on its inherent characteristics.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3149
Author(s):  
Angelika Zaszczyńska ◽  
Maryla Moczulska-Heljak ◽  
Arkadiusz Gradys ◽  
Paweł Sajkiewicz

Tissue engineering (TE) scaffolds have enormous significance for the possibility of regeneration of complex tissue structures or even whole organs. Three-dimensional (3D) printing techniques allow fabricating TE scaffolds, having an extremely complex structure, in a repeatable and precise manner. Moreover, they enable the easy application of computer-assisted methods to TE scaffold design. The latest additive manufacturing techniques open up opportunities not otherwise available. This study aimed to summarize the state-of-art field of 3D printing techniques in applications for tissue engineering with a focus on the latest advancements. The following topics are discussed: systematics of the available 3D printing techniques applied for TE scaffold fabrication; overview of 3D printable biomaterials and advancements in 3D-printing-assisted tissue engineering.


2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Sungil Kim ◽  
Jeongtae Kim ◽  
Yeun-Ho Joung ◽  
Sanghoon Ahn ◽  
Jiyeon Choi ◽  
...  

Abstract We present the selective laser-induced etching (SLE) process and design guidelines for the fabrication of three-dimensional (3D) microfluidic channels in a glass. The SLE process consisting of laser direct patterning and wet chemical etching uses different etch rates between the laser modified area and the unmodified area. The etch selectivity is an important factor for the processing speed and the fabrication resolution of the 3D structures. In order to obtain the maximum etching selectivity, we investigated the process window of the SLE process: the laser pulse energy, pulse repetition rate, and scan speed. When using potassium hydroxide (KOH) as a wet etchant, the maximum etch rate of the laser-modified glass was obtained to be 166 μm/h, exhibiting the highest selectivity about 333 respect to the pristine glass. Based on the optimized process window, a 3D microfluidic channel branching to three multilayered channels was successfully fabricated in a 4 mm-thick glass. In addition, appropriate design guidelines for preventing cracks in a glass and calibrating the position of the dimension of the hollow channels were studied.


2020 ◽  
Vol 12 (3) ◽  
pp. 243-246
Author(s):  
Jiarong Zhang ◽  
Han Wang ◽  
Zhifeng Wang ◽  
Honghui Yao ◽  
Guojie Xu ◽  
...  

Background: Microfluidic channels have been widely applied in biomedicine and microelectronics. However, the manufacturing methods of microfluidic channel devices, such as photolithography, three-dimensional printing and Melt-electrospinning direct writing (MEDW), have the problem of high cost and complex process, which still can't reach a sub-micron scale stably. Method: To improve the resolution of microfluidic channels, we developed a simple and flexible method to fabricate polydimethylsiloxane (PDMS) submicrofluidic channels. It depends on the following steps: (1) Direct Writing Polyethylene oxide (PEO) nanofiber by Near-field Electrospinning (NFES). (2) Packaging the nanofiber with PDMS. (3) Obtaining the PDMS submicrofluidic channel by inverted mode of PEO nanofiber. Results: According to the result of the experiment, nanofiber can be stably prepared under the following conditions, the electrode-to-collector distance of 3.0 mm, the voltage of 1.7 KV, the collector moving speed of 80mm/s and the mixed solutions of ethanol and deionized water (1:1). Finally, the PDMS submicrofluidic channel was manufactured by NFES and PDMS molding technique, and the diameter of the channel was 0.84±0.08 μm. Conclusion: The result verified the rationality of that method. In addition, the method can be easily integrated with high resolution channels for various usages, such as microelectronics, micro electro mechanical systems, and biomedical.


2017 ◽  
Vol 9 (6) ◽  
pp. 506-518 ◽  
Author(s):  
Yuji Nashimoto ◽  
Tomoya Hayashi ◽  
Itsuki Kunita ◽  
Akiko Nakamasu ◽  
Yu-suke Torisawa ◽  
...  

Creating vascular networks in tissues is crucial for tissue engineering.


2021 ◽  
Vol 11 (11) ◽  
pp. 5096
Author(s):  
Aipeng Deng ◽  
Yang Yang ◽  
Shimei Du

Electrospinning, the only method that can continuously produce nanofibers, has been widely used to prepare nanofibers for tissue engineering applications. However, electrospinning is not suitable for preparing clinically relevant three-dimensional (3D) nanofibrous scaffolds with hierarchical pore structures. In this study, recombinant human collagen (RHC)/chitosan nanofibers prepared by electrospinning were combined with porous scaffolds produced by freeze drying to fabricate 3D nanofibrous scaffolds. These scaffolds exhibited high porosity (over 80%) and an interconnected porous structure (ranging from sub-micrometers to 200 μm) covered with nanofibers. As confirmed by the characterization results, these scaffolds showed good swelling ability, stability, and adequate mechanical strength, making it possible to use the 3D nanofibrous scaffolds in various tissue engineering applications. In addition, after seven days of cell culturing, NIH 3T3 was infiltrated into the scaffolds while maintaining its morphology and with superior proliferation and viability. These results indicated that the 3D nanofibrous scaffolds hold great promise for tissue engineering applications.


2020 ◽  
Author(s):  
Adeel Ahmed ◽  
Indranil M. Joshi ◽  
Mehran Mansouri ◽  
Stephen Larson ◽  
Shayan Gholizadeh ◽  
...  

ABSTRACTFibrillar collagens are structural proteins in the extracellular matrix (ECM), and cellular processes, including differentiation, proliferation, and migration, have been linked to the orientation (directionality) and alignment (anisotropy) of collagen fibers. Given the importance of cell-substrate interactions in driving biological functions, several microfluidic approaches have demonstrated three-dimensional (3D) collagen gels with defined fiber properties that enable quantitative correlations between structural cues and observed cell responses. Although existing methods provide excellent definition over collagen fiber anisotropy, independent control over both anisotropy and directionality (that we collectively refer to as the collagen landscape) has not been demonstrated. Therefore, to advance collagen microengineering capabilities, we present a user-friendly approach that uses controlled fluid flows within a non-uniform microfluidic channel network to create well-defined collagen landscapes. We demonstrate capabilities including i) control over fiber anisotropy, ii) spatial gradients in fiber anisotropy, iii) defined fiber directionality, and iv) multi-material interfaces. We then show that cells respond to the microengineered topographic cues by aligning along the anisotropy domains and following fiber directionality. Finally, this platform’s modular capability is demonstrated by integrating an ultrathin porous parylene (UPP) membrane on the microengineered collagen as a mask to control cell-substrate interactions.


2016 ◽  
Vol 13 (125) ◽  
pp. 20160768 ◽  
Author(s):  
Alexander W. Justin ◽  
Roger A. Brooks ◽  
Athina E. Markaki

Vascularization is essential for living tissue and remains a major challenge in the field of tissue engineering. A lack of a perfusable channel network within a large and densely populated tissue engineered construct leads to necrotic core formation, preventing fabrication of functional tissues and organs. We report a new method for producing a hierarchical, three-dimensional (3D) and perfusable vasculature in a large, cellularized fibrin hydrogel. Bifurcating channels, varying in size from 1 mm to 200–250 µm, are formed using a novel process in which we convert a 3D printed thermoplastic material into a gelatin network template, by way of an intermediate alginate hydrogel. This enables a CAD-based model design, which is highly customizable, reproducible, and which can yield highly complex architectures, to be made into a removable material, which can be used in cellular environments. Our approach yields constructs with a uniform and high density of cells in the bulk, made from bioactive collagen and fibrin hydrogels. Using standard cell staining and immuno-histochemistry techniques, we showed good cell seeding and the presence of tight junctions between channel endothelial cells, and high cell viability and cell spreading in the bulk hydrogel.


2018 ◽  
Vol 2018 ◽  
pp. 1-24 ◽  
Author(s):  
Kevin Dzobo ◽  
Nicholas Ekow Thomford ◽  
Dimakatso Alice Senthebane ◽  
Hendrina Shipanga ◽  
Arielle Rowe ◽  
...  

Humans and animals lose tissues and organs due to congenital defects, trauma, and diseases. The human body has a low regenerative potential as opposed to the urodele amphibians commonly referred to as salamanders. Globally, millions of people would benefit immensely if tissues and organs can be replaced on demand. Traditionally, transplantation of intact tissues and organs has been the bedrock to replace damaged and diseased parts of the body. The sole reliance on transplantation has created a waiting list of people requiring donated tissues and organs, and generally, supply cannot meet the demand. The total cost to society in terms of caring for patients with failing organs and debilitating diseases is enormous. Scientists and clinicians, motivated by the need to develop safe and reliable sources of tissues and organs, have been improving therapies and technologies that can regenerate tissues and in some cases create new tissues altogether. Tissue engineering and/or regenerative medicine are fields of life science employing both engineering and biological principles to create new tissues and organs and to promote the regeneration of damaged or diseased tissues and organs. Major advances and innovations are being made in the fields of tissue engineering and regenerative medicine and have a huge impact on three-dimensional bioprinting (3D bioprinting) of tissues and organs. 3D bioprinting holds great promise for artificial tissue and organ bioprinting, thereby revolutionizing the field of regenerative medicine. This review discusses how recent advances in the field of regenerative medicine and tissue engineering can improve 3D bioprinting and vice versa. Several challenges must be overcome in the application of 3D bioprinting before this disruptive technology is widely used to create organotypic constructs for regenerative medicine.


2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Tanveer Ahmad Mir ◽  
Shintaroh Iwanaga ◽  
Taketoshi Kurooka ◽  
Hideki Toda ◽  
Shinji Sakai ◽  
...  

Biofabrication is an emerging multidisciplinary field that makes a revolutionary impact on the researches on life science, biomedical engineering, and both basic and clinical medicine, has progressed tremendously over the past few years. Recently, there has been a big boom in three-dimensional (3D) printing or additive manufacturing (AM) research worldwide, and there is a significant increase not only in the number of researchers turning their attention to AM but also publications demonstrating the potential applications of 3D printing techniques in multiple fields. Biofabrication and bioprinting hold great promise for the innovation of engineering-based organ replacing medicine. In this mini review, various challenges in the field of tissue engineering are focused from the point of view of the biofabrication - strategies to bridge the gap between organ shortage and mission of medical innovation research seek to achieve organ-specific treatments or regenerative therapies. Four major challenges are discussed including (i) challenge of producing organs by AM, (ii) digitalization of tissue engineering and regenerative medicine, (iii) rapid production of organs beyond the biological natural course, and (iv) extracorporeal organ engineering.


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