Cellular Cross-linking of Peptide Modified Hydrogels

Peptide modification of hydrogel-forming materials is being widely explored as a means to regulate the phenotype of cells immobilized within the gels. Alternatively, we hypothesized that the adhesive interactions between cells and peptides coupled to the gel-forming materials would also enhance the overall mechanical properties of the gels. To test this hypothesis, alginate polymers were modified with RGDSP-containing peptides and the resultant polymer was used to encapsulate C2C12 myoblasts. The mechanical properties of these gels were then assessed as a function of both peptide and cell density using compression and tensile tests. Overall, it was found that above a critical peptide and cell density, encapsulated myoblasts were able to provide additional mechanical integrity to hydrogels composed of peptide-modified alginate. This occurred presumably by means of cell-peptide cross-linking of the alginate polymers, in addition to the usual Ca++ cross-linking. These results are potentially applicable to other polymer systems and important for a range of tissue engineering applications.

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Scaffolds and Tissue Engineering Applications by 3D Bio-Printing Process

Research Anthology on Emerging Technologies and Ethical Implications in Human Enhancement ◽

10.4018/978-1-7998-8050-9.ch037 ◽

2021 ◽

pp. 718-733

Author(s):

Ranjit Barua ◽

Sudipto Datta ◽

Pallab Datta ◽

Amit Roy Chowdhury

Keyword(s):

Mechanical Properties ◽

Tissue Engineering ◽

Manufacturing Process ◽

Cross Linking ◽

Engineering Applications ◽

Printing Process ◽

Important Thing ◽

Bone Scaffolds ◽

Complex Design ◽

Different Types

3D bio-printing is a revolutionary manufacturing process that is widely used in medical fields especially in preparing bone scaffolds and tissue engineering. With the help of new biocompatible material like polymers, bio-gels, ceramics, this technology has created a new site in advanced tissue engineering and scaffolds manufacturing area. Another important thing is that, with the use of CAD file software, any complex design can be prepared (i.e., this technology does not have any limited sites). But here it is very much essential to study and analyze machine printability characteristics, cross-linking time and biocompatibility of printing objects as well as bio-ink. However, mechanical properties like shear thinning, mechanical elasticity are also required. In this chapter, different types of scaffold-preparing methods and the bio-printing process are discussed, which are used in scaffold and tissue engineering.

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Scaffolds and Tissue Engineering Applications by 3D Bio-Printing Process

Design, Development, and Optimization of Bio-Mechatronic Engineering Products - Advances in Mechatronics and Mechanical Engineering ◽

10.4018/978-1-5225-8235-9.ch004 ◽

2019 ◽

pp. 78-99 ◽

Cited By ~ 2

Author(s):

Ranjit Barua ◽

Sudipto Datta ◽

Pallab Datta ◽

Amit Roy Chowdhury

Keyword(s):

Mechanical Properties ◽

Tissue Engineering ◽

Manufacturing Process ◽

Cross Linking ◽

Engineering Applications ◽

Printing Process ◽

Important Thing ◽

Bone Scaffolds ◽

Complex Design ◽

Different Types

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Synthesis and characterization of poly(glycerol sebacate)-based elastomeric copolyesters for tissue engineering applications

Polymer Chemistry ◽

10.1039/c5py01993a ◽

2016 ◽

Vol 7 (14) ◽

pp. 2553-2564 ◽

Cited By ~ 23

Author(s):

Yating Jia ◽

Weizhong Wang ◽

Xiaojun Zhou ◽

Wei Nie ◽

Liang Chen ◽

...

Keyword(s):

Mechanical Properties ◽

Tissue Engineering ◽

Water Uptake ◽

Synthesis And Characterization ◽

Uptake Capacity ◽

Engineering Applications ◽

Water Uptake Capacity

A poly(glycerol sebacate)-based elastomeric copolyesters with improved mechanical properties and higher water uptake capacity.

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Mechanical properties, degradation kinetics and cytocompatibility of photopolymerized thermosensitive hydrogels for tissue engineering applications

Journal of Controlled Release ◽

10.1016/j.jconrel.2008.09.034 ◽

2008 ◽

Vol 132 (3) ◽

pp. e50-e51 ◽

Cited By ~ 1

Author(s):

T. Vermonden ◽

N.E. Fedorovich ◽

D. van Geemen ◽

J. Alblas ◽

C.F. van Nostrum ◽

...

Keyword(s):

Mechanical Properties ◽

Tissue Engineering ◽

Degradation Kinetics ◽

Engineering Applications ◽

Thermosensitive Hydrogels

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Effects of Encapsulated Cells on the Physical–Mechanical Properties and Microstructure of Gelatin Methacrylate Hydrogels

International Journal of Molecular Sciences ◽

10.3390/ijms20205061 ◽

2019 ◽

Vol 20 (20) ◽

pp. 5061 ◽

Cited By ~ 8

Author(s):

Srikumar Krishnamoorthy ◽

Behnam Noorani ◽

Changxue Xu

Keyword(s):

Mechanical Properties ◽

Tissue Engineering ◽

Cell Viability ◽

Physical Properties ◽

Pore Size ◽

Cell Density ◽

Tensile Modulus ◽

Encapsulated Cells ◽

3T3 Fibroblasts ◽

Cell Densities

Gelatin methacrylate (GelMA) has been gaining popularity in recent years as a photo-crosslinkable biomaterial widely used in a variety of bioprinting and tissue engineering applications. Several studies have established the effects of process-based and material-based parameters on the physical–mechanical properties and microstructure of GelMA hydrogels. However, the effect of encapsulated cells on the physical–mechanical properties and microstructure of GelMA hydrogels has not been fully understood. In this study, 3T3 fibroblasts were encapsulated at different cell densities within the GelMA hydrogels and incubated over 96 h. The effects of encapsulated cells were investigated in terms of mechanical properties (tensile modulus and strength), physical properties (swelling and degradation), and microstructure (pore size). Cell viability was also evaluated to confirm that most cells were alive during the incubation. It was found that with an increase in cell density, the mechanical properties decreased, while the degradation and the pore size increased.

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PEG Cross-Linked Alginate Hydrogels with Controlled Mechanical Properties

MRS Proceedings ◽

10.1557/proc-530-37 ◽

1998 ◽

Vol 530 ◽

Cited By ~ 2

Author(s):

Petra Eiselt ◽

Jon A. Rowley ◽

David J. Mooney

Keyword(s):

Mechanical Properties ◽

Tissue Engineering ◽

Molecular Weight ◽

Elastic Modulus ◽

Cell Transplantation ◽

Cross Linking ◽

Cross Link ◽

Link Density ◽

A Cell ◽

Cross Link Density

AbstractReconstruction of tissues and organs utilizing cell transplantation offers an attractive approach for the treatment of patients suffering from organ failure or loss. Highly porous synthetic materials are often used to mimic the function of the extracellular matrix (ECM) in tissue engineering, and serve as a cell delivery vehicle for the formation of tissues in vivo. Alginate, a linear copolysaccharide composed of D-mannuronic acid (M) and L-guluronic acid (G) units is widely used as a cell transplantation matrix. Alginate is considered to be biocompatible, and hydrogels are formed in the presence of divalent cations such as Ca2+, Ba2+ and Sr2+. However, ionically cross-linked alginate gels continuously lose their mechanical properties over time with uncontrollable degradation behavior. We have modified alginate via covalent coupling of cross-linking molecules to expand and stabilize the mechanical property ranges of these gels. Several diamino PEG molecules of varying molecular weight (200, 400, 1000, 3400) were synthesized utilizing carbodiimide chemistry. Sodium alginate was covalently cross-linked with these cross-linking molecules, and mechanical properties of the resulting hydrogels were determined. The elastic modulus of the cross-linked alginates depended on the molecular weight of the cross-linking molecules, and ranged from 10-110 kPa. The theoretical cross-link density in the hydrogels was also varied from 3 to 47% (relative to the carboxylic groups in the alginate) and the mechanical properties were measured. The elastic modulus increased gradually and reached a maximum at a cross-link density of 15%. In summary, covalently coupled hydrogels can be synthesized which exhibit a wide range of mechanical properties, and these materials may be useful in a number of tissue engineering applications.

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Alginate/Gelatin Hydrogels Reinforced with TiO2 and β-TCP Fabricated by Microextrusion-based Printing for Tissue Regeneration

Polymers ◽

10.3390/polym11030457 ◽

2019 ◽

Vol 11 (3) ◽

pp. 457 ◽

Cited By ~ 9

Author(s):

Rodrigo Urruela-Barrios ◽

Erick Ramírez-Cedillo ◽

A. Díaz de León ◽

Alejandro Alvarez ◽

Wendy Ortega-Lara

Keyword(s):

Mechanical Properties ◽

Tissue Engineering ◽

Tissue Regeneration ◽

Average Pore Size ◽

Three Dimensional ◽

Engineering Applications ◽

Average Pore ◽

Viscous Deformation ◽

Freeze Dried ◽

3D Printed

Three-dimensional (3D) printing technologies have become an attractive manufacturing process to fabricate scaffolds in tissue engineering. Recent research has focused on the fabrication of alginate complex shaped structures that closely mimic biological organs or tissues. Alginates can be effectively manufactured into porous three-dimensional networks for tissue engineering applications. However, the structure, mechanical properties, and shape fidelity of 3D-printed alginate hydrogels used for preparing tissue-engineered scaffolds is difficult to control. In this work, the use of alginate/gelatin hydrogels reinforced with TiO2 and β-tricalcium phosphate was studied to tailor the mechanical properties of 3D-printed hydrogels. The hydrogels reinforced with TiO2 and β-TCP showed enhanced mechanical properties up to 20 MPa of elastic modulus. Furthermore, the pores of the crosslinked printed structures were measured with an average pore size of 200 μm. Additionally, it was found that as more layers of the design were printed, there was an increase of the line width of the bottom layers due to its viscous deformation. Shrinkage of the design when the hydrogel is crosslinked and freeze dried was also measured and found to be up to 27% from the printed design. Overall, the proposed approach enabled fabrication of 3D-printed alginate scaffolds with adequate physical properties for tissue engineering applications.

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