scholarly journals A dual crosslinking strategy to tailor rheological properties of gelatin methacryloyl

Author(s):  
Miaomiao Zhou ◽  
Bae Hoon Lee ◽  
Lay Poh Tan

3D bioprinting is an emerging technology that enables fabrication of three-dimensional organised cellular constructs. One of the major challenges in 3D bioprinting is to develop a material to meet the harsh requirements (cell-compatibility, printability, structural stability post-printing and bio-functionality to regulate cell behaviours) suitable for printing. Gelatin methacryloyl (GelMA) has recently emerged as an attractive biomaterial in tissue engineering, because it satisfies the requirements of bio-functionality and mechanical tunability. However, the poor rheological property such as low viscosity at body temperature inhibits its application in 3D bioprinting. In this work, an enzymatic crosslinking method triggered by Ca2+-independent microbial transglutaminase (MTGase) was introduced to catalyse isopeptide bonds formation between chains of GelMA, which could improve its rheological behaviours, specifically viscosity. By combining enzymatic crosslinking and photo crosslinking, it is possible to tune the solution viscosity and quickly stabilize the gelatin macromolecules at the same time. The results showed that the enzymatic crosslinking can increase the solution viscosity. Subsequent photo crosslinking could aid in fast stabilization of the structure and make handling easy.

2021 ◽  
Vol 7 (1) ◽  
pp. 3
Author(s):  
Ahmed Fatimi

There are a variety of hydrogel-based bioinks commonly used in three-dimensional bioprinting. In this study, in the form of patent analysis, the state of the art has been reviewed by introducing what has been patented in relation to hydrogel-based bioinks. Furthermore, a detailed analysis of the patentability of the used hydrogels, their preparation methods and their formulations, as well as the 3D bioprinting process using hydrogels, have been provided by determining publication years, jurisdictions, inventors, applicants, owners, and classifications. The classification of patents reveals that most inventions intended for hydrogels used as materials for prostheses or for coating prostheses are characterized by their function or properties Knowledge clusters and expert driving factors show that biomaterials, tissue engineering, and biofabrication research is concentrated in the most patents.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3522
Author(s):  
Su Jeong Lee ◽  
Jun Hee Lee ◽  
Jisun Park ◽  
Wan Doo Kim ◽  
Su A Park

Recently, many research groups have investigated three-dimensional (3D) bioprinting techniques for tissue engineering and regenerative medicine. The bio-ink used in 3D bioprinting is typically a combination of synthetic and natural materials. In this study, we prepared bio-ink containing porcine skin powder (PSP) to determine rheological properties, biocompatibility, and extracellular matrix (ECM) formation in cells in PSP-ink after 3D printing. PSP was extracted without cells by mechanical, enzymatic, and chemical treatments of porcine dermis tissue. Our developed PSP-containing bio-ink showed enhanced printability and biocompatibility. To identify whether the bio-ink was printable, the viscosity of bio-ink and alginate hydrogel was analyzed with different concentration of PSP. As the PSP concentration increased, viscosity also increased. To assess the biocompatibility of the PSP-containing bio-ink, cells mixed with bio-ink printed structures were measured using a live/dead assay and WST-1 assay. Nearly no dead cells were observed in the structure containing 10 mg/mL PSP-ink, indicating that the amounts of PSP-ink used were nontoxic. In conclusion, the proposed skin dermis decellularized bio-ink is a candidate for 3D bioprinting.


2018 ◽  
Vol 782 ◽  
pp. 103-115
Author(s):  
Yang Zi Zhao ◽  
You Fa Wang

Being one of the three elements of tissue engineering, three-dimensional porous structure scaffold plays an important role in tissue engineering. As it not only prvovide cells for the life, but also serves as a template to guide tissue regeneration and control of organizational structure and other functions. In this study, hyaluronic acid and gelatin are successfully cross-linked by 1-ethyl- (3-dimethylaminopropyl) -carbodiimide hydrochloride (EDC) , and compound β-TCP microspheres to prepare porous hydrogel scaffolds. The microspheres were analyzed by X-ray diffraction (XRD). The scaffolds were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). At the same time, the compressive strength, swelling ratio, degradation of the scaffold were tested. To assess the in vitro cell compatibility of the scaffolds, mouse L929 fibroblasts were seeded onto scaffolds for cell morphology and cell viability studies. The results showed that the pore size of the porous scaffold can be adjusted by changing the ratio of gelatin to hyaluronic acid (HA), increasing the proportion of hyaluronic acid in a certain range, pore size will be significantly increased. With the increase of the proportion of hyaluronic acid in the scaffold, the swelling ratio and the degradation rate also increased. The compressive strength of the scaffold increased with the increase of the proportion of gelatin. The appropriate ratio of β-TCP can promote cell growth and proliferation.


Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2377
Author(s):  
Wonseop Lim ◽  
Gyeong Jin Kim ◽  
Hyun Woo Kim ◽  
Jiyeon Lee ◽  
Xiaowei Zhang ◽  
...  

Bioink based 3D bioprinting is a promising new technology that enables fabrication of complex tissue structures with living cells. The printability of the bioink depends on the physical properties such as viscosity. However, the high viscosity bioink puts shear stress on the cells and low viscosity bioink cannot maintain complex tissue structure firmly after the printing. In this work, we applied dual crosslinkable bioink using Kappa-carrageenan (κ-CA) to overcome existing shortcomings. κ-CA has properties such as biocompatibility, biodegradability, shear-thinning and ionic gelation but the difficulty of controlling gelation properties makes it unsuitable for application in 3D bioprinting. This problem was solved by synthesizing methacrylated Kappa-carrageenan (MA-κ-CA), which can be dual crosslinked through ionic and UV (Ultraviolet) crosslinking to form hydrogel using NIH-3T3 cells. Through MA substitutions, the rheological properties of the gel could be controlled to reduce the shear stress. Moreover, bioprinting using the cell-laden MA-κ-CA showed cell compatibility with enhanced shape retention capability. The potential to control the physical properties through dual crosslinking of MA-κ-CA hydrogel is expected to be widely applied in 3D bioprinting applications.


2018 ◽  
Vol 934 ◽  
pp. 129-133 ◽  
Author(s):  
Chao Fan Lv ◽  
Li Ya Zhu ◽  
Jian Ping Shi ◽  
Zong An Li ◽  
Wen Lai Tang ◽  
...  

Three-dimensional (3D) printing has been playing an important role in diverse areas in medicine. In order to promote the development of tissue engineering, this study attempts to fabricate tissue engineering scaffolds using the inkjet printing technology. Sodium alginate, exhibiting similar properties to the native human extracellular matrix (ECM), was used as bioink. The jetted fluid of sodium alginate would be gelatinized when printed into the calcium chloride solution. The characteristics of the 3D-printed sodium alginate scaffold were systematically measured and analyzed. The results show that, the pore size, porosity and degradation property of these scaffolds could be well controlled. This study indicates the capability of 3D bioprinting technology for preparing tissue engineering scaffolds.


2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Nicanor Moldovan ◽  
Leni Maldovan ◽  
Michael Raghunath

The overarching principle of three-dimensional (3D) bioprinting is the placing of cells or cell clusters in the 3D space to generate a cohesive tissue microarchitecture that comes close to in vivo characteristics. To achieve this goal, several technical solutions are available, generating considerable combinatorial bandwidth: (i) Support structures are generated first, and cells are seeded subsequently; (ii) alternatively, cells are delivered in a printing medium, so-called “bioink,” that contains them during the printing process and ensures shape fidelity of the generated structure; and (iii) a “scaffold-free” version of bioprinting, where only cells are used and the extracellular matrix is produced by the cells themselves, also recently entered a phase of accelerated development and successful applications. However, the scaffold-free approaches may still benefit from secondary incorporation of scaffolding materials, thus expanding their versatility. Reversibly, the bioink-based bioprinting could also be improved by adopting some of the principles and practices of scaffold-free biofabrication. Collectively, we anticipate that combinations of these complementary methods in a “hybrid” approach, rather than their development in separate technological niches, will largely increase their efficiency and applicability in tissue engineering.


2021 ◽  
Author(s):  
Andrea S. Theus ◽  
Liqun Ning ◽  
Linqi Jin ◽  
Ryan K. Roeder ◽  
Jianyi Zhang ◽  
...  

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.


2007 ◽  
Vol 86 (5) ◽  
pp. 426-430 ◽  
Author(s):  
J. Kirkham ◽  
A. Firth ◽  
D. Vernals ◽  
N. Boden ◽  
C. Robinson ◽  
...  

Rationally designed β-sheet-forming peptides that spontaneously form three-dimensional fibrillar scaffolds in response to specific environmental triggers may potentially be used in skeletal tissue engineering, including the treatment/prevention of dental caries, via bioactive surface groups. We hypothesized that infiltration of caries lesions with monomeric low-viscosity peptide solutions would be followed by in situ polymerization triggered by conditions of pH and ionic strength, providing a biomimetic scaffold capable of hydroxyapatite nucleation, promoting repair. Our aim was to determine the effect of an anionic peptide applied to caries-like lesions in human dental enamel under simulated intra-oral conditions of pH cycling. Peptide treatment significantly increased net mineral gain by the lesions, due to both increased remineralization and inhibition of demineralization over a five-day period. The assembled peptide was also capable of inducing hydroxyapatite nucleation de novo. The results suggest that self-assembling peptides may be useful in the modulation of mineral behavior during in situ dental tissue engineering.


Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 459 ◽  
Author(s):  
Tiffany Cameron ◽  
Emad Naseri ◽  
Ben MacCallum ◽  
Ali Ahmadi

Fabricating multi-cell constructs in complex geometries is essential in the field of tissue engineering, and three-dimensional (3D) bioprinting is widely used for this purpose. To enhance the biological and mechanical integrity of the printed constructs, continuous single-nozzle printing is required. In this paper, a novel single-nozzle printhead for 3D bioprinting of multi-material constructs was developed and characterized. The single-nozzle multi-material bioprinting was achieved via a disposable, inexpensive, multi-fuse IV extension set; the printhead can print up to four different biomaterials. The transition distance of the developed printhead was characterized over a range of pressures and needle inner diameters. Finally, the transition distance was decreased by applying a silicon coating to the inner channels of the printhead.


2021 ◽  
Vol 22 (8) ◽  
pp. 3971
Author(s):  
Jianhua Zhang ◽  
Esther Wehrle ◽  
Marina Rubert ◽  
Ralph Müller

The field of tissue engineering has progressed tremendously over the past few decades in its ability to fabricate functional tissue substitutes for regenerative medicine and pharmaceutical research. Conventional scaffold-based approaches are limited in their capacity to produce constructs with the functionality and complexity of native tissue. Three-dimensional (3D) bioprinting offers exciting prospects for scaffolds fabrication, as it allows precise placement of cells, biochemical factors, and biomaterials in a layer-by-layer process. Compared with traditional scaffold fabrication approaches, 3D bioprinting is better to mimic the complex microstructures of biological tissues and accurately control the distribution of cells. Here, we describe recent technological advances in bio-fabrication focusing on 3D bioprinting processes for tissue engineering from data processing to bioprinting, mainly inkjet, laser, and extrusion-based technique. We then review the associated bioink formulation for 3D bioprinting of human tissues, including biomaterials, cells, and growth factors selection. The key bioink properties for successful bioprinting of human tissue were summarized. After bioprinting, the cells are generally devoid of any exposure to fluid mechanical cues, such as fluid shear stress, tension, and compression, which are crucial for tissue development and function in health and disease. The bioreactor can serve as a simulator to aid in the development of engineering human tissues from in vitro maturation of 3D cell-laden scaffolds. We then describe some of the most common bioreactors found in the engineering of several functional tissues, such as bone, cartilage, and cardiovascular applications. In the end, we conclude with a brief insight into present limitations and future developments on the application of 3D bioprinting and bioreactor systems for engineering human tissue.


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