scholarly journals Chitosans for Tissue Repair and Organ Three-Dimensional (3D) Bioprinting

Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 765 ◽  
Author(s):  
Shenglong Li ◽  
Xiaohong Tian ◽  
Jun Fan ◽  
Hao Tong ◽  
Qiang Ao ◽  
...  
Keyword(s):  
Tissue Repair ◽  
Biomedical Applications ◽  
Large Scale ◽  
Scale Up ◽  
Three Dimensional ◽  
The Body ◽  
3D Bioprinting ◽  
Chemically Modified ◽  
Excellent Candidate ◽  
Complex Organ

Chitosan is a unique natural resourced polysaccharide derived from chitin with special biocompatibility, biodegradability, and antimicrobial activity. During the past three decades, chitosan has gradually become an excellent candidate for various biomedical applications with prominent characteristics. Chitosan molecules can be chemically modified, adapting to all kinds of cells in the body, and endowed with specific biochemical and physiological functions. In this review, the intrinsic/extrinsic properties of chitosan molecules in skin, bone, cartilage, liver tissue repair, and organ three-dimensional (3D) bioprinting have been outlined. Several successful models for large scale-up vascularized and innervated organ 3D bioprinting have been demonstrated. Challenges and perspectives in future complex organ 3D bioprinting areas have been analyzed.

Unsteady measurements in a separated and reattaching flow

1984 ◽  
Vol 144 ◽  
pp. 13-46 ◽  
Author(s):  
N. J. Cherry ◽  
R. Hillier ◽  
M. E. M. P. Latour
Keyword(s):  
Shear Layer ◽  
Large Scale ◽  
Separation Bubble ◽  
Scale Up ◽  
Three Dimensional ◽  
Low Frequency ◽  
Vortical Structures ◽  
Large Scale Structures ◽  
Bubble Length ◽  
Low Frequency Motion

Measurements of fluctuating pressure and velocity, together with instantaneous smoke-flow visualizations, are presented in order to reveal the unsteady structure of a separated and reattaching flow. It is shown that throughout the separation bubble a low-frequency motion can be detected which appears to be similar to that found in other studies of separation. This effect is most significant close to separation, where it leads to a weak flapping of the shear layer. Lateral correlation scales of this low-frequency motion are less than the reattachment length, however; it appears that its timescale is about equal to the characteristic timescale for the shear layer and bubble to change between various shedding phases. These phases were defined by the following observations: shedding of pseudoperiodic trains of vortical structures from the reattachment zone, with a characteristic spacing between structures of typically 60% to 80% of the bubble length; a large-scale but irregular shedding of vorticity; and a relatively quiescent phase with the absence of any large-scale shedding structures and a significant ‘necking’ of the shear layer downstream of reattachment.Spanwise correlations of velocity in the shear layer show on average an almost linear growth of spanwise scale up to reattachment. It appears that the shear layer reaches a fully three-dimensional state soon after separation. The reattachment process does not itself appear to impose an immediate extra three-dimensionalizing effect upon the large-scale structures.

scholarly journals The Effect of Agarose on 3D Bioprinting

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4028
Author(s):  
Chi Gong ◽  
Zhiyuan Kong ◽  
Xiaohong Wang
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Internal Structure ◽  
Three Dimensional ◽  
3D Bioprinting ◽  
Two Temperatures ◽  
Formed Structure ◽  
Accuracy And Stability ◽  
Physical Crosslinking ◽  
Complex Organ

In three-dimensional (3D) bioprinting, the accuracy, stability, and mechanical properties of the formed structure are very important to the overall composition and internal structure of the complex organ. In traditional 3D bioprinting, low-temperature gelatinization of gelatin is often used to construct complex tissues and organs. However, the hydrosol relies too much on the concentration of gelatin and has limited formation accuracy and stability. In this study, we take advantage of the physical crosslinking of agarose at 35–40 °C to replace the single pregelatinization effect of gelatin in 3D bioprinting, and printing composite gelatin/alginate/agarose hydrogels at two temperatures, i.e., 10 °C and 24 °C, respectively. After in-depth research, we find that the structures manufactured by the pregelatinization method of agarose are significantly more accurate, more stable, and harder than those pregelatined by gelatin. We believe that this research holds the potential to be widely used in the future organ manufacturing fields with high structural accuracy and stability.

scholarly journals PARALLEL INVADED CLUSTER ALGORITHM FOR THE ISING MODEL

1999 ◽  
Vol 10 (01) ◽  
pp. 1-16 ◽  
Author(s):  
Y. S. CHOI ◽  
J. MACHTA ◽  
P. TAMAYO ◽  
L. X. CHAYES
Keyword(s):  
Ising Model ◽  
Large Scale ◽  
Cluster Algorithm ◽  
Scale Up ◽  
Three Dimensional ◽  
Critical Slowing Down ◽  
Slowing Down ◽  
Parallel Version

A parallel version of the invaded cluster algorithm is described. Results from large scale (up to 40962 and 5123) simulations of the Ising model are reported. No evidence of critical slowing down is found for the three-dimensional Ising model. The magnetic exponent is estimated to be 2.482±0.001(β/ν=0.518±0.001) for the three-dimensional Ising model.

scholarly journals Bio-inks for 3D extrusion-based bio-printed scaffolds: Printability assessment

2019 ◽  
Vol 2 (1) ◽  
pp. 43
Author(s):  
Verónica E. Passamai ◽  
Sergio Katz ◽  
Vera Alvarez ◽  
Guillermo R. Castro
Keyword(s):  
Medical Technology ◽  
Large Scale ◽  
New Technology ◽  
Three Dimensional ◽  
3D Bioprinting ◽  
Biophysical Parameters ◽  
Extrusion Method

Three-dimensional bioprinting is a new technology that should be integrated into several areas, including medical technology. However, before designing and applying it on a large scale, several biophysical parameters and particularly printability need to be established. In the present work, general characteristics of the extrusion method, bioinks, and scaffolds are reviewed. Printability analysis of 3D bioprinting is also included.

scholarly journals Determination of Some Body Measurements of Camels With Three Dimensional Modeling Method (3D)

2021 ◽  
Author(s):  
Alkan çağlı ◽  
M. Yılmaz
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Practical Method ◽  
Modeling Method ◽  
The Body ◽  
Body Measurements ◽  
3D Measurement ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
The Difference

Abstract In this study, the use of three-dimensional modeling method was tested in taking some body measurements in camels with a practical method and was compared with other measurement methods. As the animal material of the study, 12 single humped dromedary female camels and 14 double humped Camelus dromedarius X Camelus bactrianus: F1 male camels, totally 26 camels, were used in three camel farms in Incirliova district of Aydın province. The body measurements taken from each animal by using different three methods, namely by Manuel Method (MM), by Photography Method (PM), and by Three Dimensional Modeling Method (3D) were the Cidago Height (CH), the Back Height (BH), the Rump Height (RH), the Body Length (BL), the Brisket Height (BRH), the Abdominal Height (AH), the Shoulder Width (SW) and the Rump Width (RW) and these values were compared with each other. As a result of this study, the mean values of MM and 3D measurement values were very close to each other and the difference between them was found to be statistically insignificant. (P<0.05). The difference between the means of PM and MM/3D measurement values was found to be significant. (P <0.05). In the measurements taken by MM, 3D, PM methods in male camels, the values obtained by MM and 3D methods for CH, BH, RH, BRH, AH, BL, and SW were very close to each other and the differences between them were found insignificant statistically (p < 0.05). On the determined regression graph, a linear was found between MM and 3D measurement values. As a result of this study, it has been determined that the 3D modeling method can be used as a remote and more practical method in determining the morphological features of large-scale animals such as camels more reliably, more easily and more practically.

scholarly journals C-STEM: ENGINEERING NICHE-LIKE MICRO-COMPARTMENTS FOR OPTIMAL AND SCALE-INDEPENDENT EXPANSION OF HUMAN PLURIPOTENT STEM CELLS IN BIOREACTORS

2021 ◽  
Author(s):  
Philippe J.R. Cohen ◽  
Elisa Luquet ◽  
Justine Pletenka ◽  
Andrea Leonard ◽  
Elise Warter ◽  
...  
Keyword(s):  
Stem Cells ◽  
Pluripotent Stem Cells ◽  
Large Scale ◽  
Scale Up ◽  
Three Dimensional ◽  
Culture Conditions ◽  
Human Pluripotent Stem Cells ◽  
Cell Therapies ◽  
Cellular Source

Human pluripotent stem cells (hPSCs) have emerged as the most promising cellular source for cell therapies. To overcome scale up limitations of classical 2D culture systems, suspension cultures have been developed to meet the need of large-scale culture in regenerative medicine. Despite constant improvements, current protocols relying on the generation of micro-carriers or cell aggregates only achieve moderate amplification performance. Here, guided by reports showing that hPSCs can self-organize in vitro into cysts reminiscent of the epiblast stage in embryo development, we developed a physio-mimetic approach for hPSC culture. We engineered stem cell niche microenvironments inside microfluidics-assisted core-shell microcapsules. We demonstrate that lumenized three-dimensional colonies maximize viability and expansion rates while maintaining pluripotency. By optimizing capsule size and culture conditions, we scale-up this method to industrial scale stirred tank bioreactors and achieve an unprecedented hPSC amplification rate of 282-fold in 6.5 days.

scholarly journals Development and Characterisation of a Photocurable Alginate Bioink for 3D Bioprinting

2019 ◽  
Vol 5 (2) ◽  
pp. 12 ◽  
Author(s):  
Mishbak H. H ◽  
Glen Cooper ◽  
Paulo Jorge Da Silva Bartolo
Keyword(s):  
Biomedical Applications ◽  
Uv Light ◽  
Reaction Times ◽  
Rheological Behaviour ◽  
3D Bioprinting ◽  
Alginate Hydrogel ◽  
Chemically Modified ◽  
Mild Conditions ◽  
Biocompatible Material

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).

Nanomaterials for bioprinting: functionalization of tissue-specific bioinks

2021 ◽  
Author(s):  
Andrea S. Theus ◽  
Liqun Ning ◽  
Linqi Jin ◽  
Ryan K. Roeder ◽  
Jianyi Zhang ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Regenerative Medicine ◽  
Biomedical Applications ◽  
Disease Modeling ◽  
Three Dimensional ◽  
3D Bioprinting ◽  
Significant Step ◽  
Printing Processes

Abstract Three-dimensional (3D) bioprinting is rapidly evolving, offering great potential for manufacturing functional tissue analogs for use in diverse biomedical applications, including regenerative medicine, drug delivery, and disease modeling. Biomaterials used as bioinks in printing processes must meet strict physiochemical and biomechanical requirements to ensure adequate printing fidelity, while closely mimicking the characteristics of the native tissue. To achieve this goal, nanomaterials are increasingly being investigated as a robust tool to functionalize bioink materials. In this review, we discuss the growing role of different nano-biomaterials in engineering functional bioinks for a variety of tissue engineering applications. The development and commercialization of these nanomaterial solutions for 3D bioprinting would be a significant step towards clinical translation of biofabrication.

scholarly journals Use of Anionic Polysaccharides in the Development of 3D Bioprinting Technology

2019 ◽  
Vol 9 (13) ◽  
pp. 2596 ◽  
Author(s):  
Chia Tai ◽  
Soukaina Bouissil ◽  
Enkhtuul Gantumur ◽  
Mary Stephanie Carranza ◽  
Ayano Yoshii ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Three Dimensional ◽  
Cell Generation ◽  
Present Review ◽  
3D Bioprinting ◽  
Significant Progress ◽  
Anionic Polysaccharides ◽  
Reactive Groups ◽  
The Way

Three-dimensional (3D) bioprinting technology is now one of the best ways to generate new biomaterial for potential biomedical applications. Significant progress in this field since two decades ago has pointed the way toward use of natural biopolymers such as polysaccharides. Generally, these biopolymers such as alginate possess specific reactive groups such as carboxylate able to be chemically or enzymatically functionalized to generate very interesting hydrogel structures with biomedical applications in cell generation. This present review gives an overview of the main natural anionic polysaccharides and focuses on the description of the 3D bioprinting concept with the recent development of bioprinting processes using alginate as polysaccharide.

scholarly journals Advances in Regenerative Medicine and Tissue Engineering: Innovation and Transformation of Medicine

2018 ◽  
Vol 2018 ◽  
pp. 1-24 ◽  
Author(s):  
Kevin Dzobo ◽  
Nicholas Ekow Thomford ◽  
Dimakatso Alice Senthebane ◽  
Hendrina Shipanga ◽  
Arielle Rowe ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Regenerative Medicine ◽  
Three Dimensional ◽  
The Body ◽  
Congenital Defects ◽  
Great Promise ◽  
Disruptive Technology ◽  
3D Bioprinting ◽  
Huge Impact ◽  
Made In

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.

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