The potential of the incorporated collagen microspheres in alginate hydrogel as an engineered three-dimensional microenvironment to attenuate apoptosis in human pancreatic islets

Abstract Background: Tissue engineering is considered as a promising tool for remodeling the native cells microenvironment. In the present study, the effect of alginate hydrogel and collagen microspheres integrated with extracellular matrix components were evaluated in the decrement of apoptosis in human pancreatic islets. Methods: For three dimensional culture, the islets were encapsulated in collagen microspheres, containing laminin and collagen IV and embedded in alginate scaffold for one week. After that the islets were examined in terms of viability, apoptosis, genes and proteins expression including BAX, BCL2, active caspase-3, and insulin. Moreover, the islets function was evaluated through glucose-induced insulin and C-peptide secretion assay. In order to evaluate the structure of the scaffolds and the morphology of the pancreatic islets in three-dimensional microenvironments, we performed scanning electron microscopy. Results: Our findings showed that the designed hydrogel scaffolds significantly improved the islets viability using the reduction of activated caspase-3 and TUNEL positive cells. Conclusion: The reconstruction of the destructed matrix with alginate hydrogels and collagen microspheres might be an effective step to promote the culture of the islets.

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Potential of the incorporated collagen microspheres in alginate hydrogel as an engineered three-dimensional microenvironment to attenuate apoptosis in human pancreatic islets

10.21203/rs.2.24328/v1 ◽

2020 ◽

Author(s):

Maryam Kaviani ◽

Somayeh Keshtkar ◽

Fatemeh Sabet Sarvestani ◽

Negar Azarpira ◽

Ramin Yaghobi ◽

...

Keyword(s):

Extracellular Matrix ◽

Pancreatic Islets ◽

Caspase 3 ◽

Three Dimensional ◽

Alginate Hydrogel ◽

Human Pancreatic Islets ◽

Hydrogel Scaffolds ◽

Promising Tool ◽

Extracellular Matrix Components ◽

And Function

Abstract Background Tissue engineering is considered as a promising tool for remodeling the native cells microenvironment. In the present study, the effect of alginate hydrogel and collagen microspheres integrated with extracellular matrix components were evaluated in the decrement of apoptosis in human pancreatic islets. Methods For three dimensional culture, the islets were encapsulated in collagen microspheres, containing laminin and collagen IV and embedded in alginate scaffold for one week. After that the islets were examined in terms of viability, apoptosis, genes and proteins expression including BAX; BCL2; active caspase-3; and insulin. Moreover, the islets function was evaluated through the glucose-induced insulin and C-peptide secretion assay. In order to evaluate the scaffolds structure and the pancreatic islets morphology in three-dimensional microenvironments, scanning electron microscopy was done. Results Our findings showed that the designed hydrogel scaffolds significantly improved the islets viability the activated caspase-3 and TUNEL positive cells were clearly reduced. Conclusion The reduced pancreatic islet survival and function occurs, following the degradation of extracellular matrix and the stresses introduced into the cells during isolation and culture. The reconstruction of the destructed matrix with alginate hydrogels and collagen microspheres might be an effective step to promote the culture and transplantation of the islets.

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The potential of the incorporated collagen microspheres in alginate hydrogel as an engineered three-dimensional microenvironment to attenuate apoptosis in human pancreatic islets

Acta Histochemica ◽

10.1016/j.acthis.2021.151775 ◽

2021 ◽

Vol 123 (7) ◽

pp. 151775

Author(s):

Maryam Kaviani ◽

Somayeh Keshtkar ◽

Fatemeh Sabet Sarvestani ◽

Negar Azarpira ◽

Ramin Yaghobi ◽

...

Keyword(s):

Pancreatic Islets ◽

Three Dimensional ◽

Alginate Hydrogel ◽

Human Pancreatic Islets

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Printability of 3D Printed Hydrogel Scaffolds: Influence of Hydrogel Composition and Printing Parameters

Applied Sciences ◽

10.3390/app10010292 ◽

2019 ◽

Vol 10 (1) ◽

pp. 292 ◽

Cited By ~ 8

Author(s):

Saman Naghieh ◽

MD Sarker ◽

N. K. Sharma ◽

Zohra Barhoumi ◽

Xiongbiao Chen

Keyword(s):

Flow Behavior ◽

Three Dimensional ◽

Methyl Cellulose ◽

Alginate Hydrogel ◽

Hydrogel Scaffolds ◽

Number Of Factors ◽

3D Printed ◽

The Difference ◽

Printing Processes ◽

Printing Parameters

Extrusion-based bioprinting of hydrogel scaffolds is challenging due to printing-related issues, such as the lack of capability to precisely print or deposit hydrogels onto three-dimensional (3D) scaffolds as designed. Printability is an index to measure the difference between the designed and fabricated scaffold in the printing process, which, however, is still under-explored. While studies have been reported on printing hydrogel scaffolds from one or more hydrogels, there is limited knowledge on the printability of hydrogels and their printing processes. This paper presented our study on the printability of 3D printed hydrogel scaffolds, with a focus on identifying the influence of hydrogel composition and printing parameters/conditions on printability. Using the hydrogels synthesized from pure alginate or alginate with gelatin and methyl-cellulose, we examined their flow behavior and mechanical properties, as well as their influence on printability. To characterize the printability, we examined the pore size, strand diameter, and other dimensions of the printed scaffolds. We then evaluated the printability in terms of pore/strand/angular/printability and irregularity. Our results revealed that the printability could be affected by a number of factors and among them, the most important were those related to the hydrogel composition and printing parameters. This study also presented a framework to evaluate alginate hydrogel printability in a systematic manner, which can be adopted and used in the studies of other hydrogels for bioprinting.

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A Tunable, Three-Dimensional In Vitro Culture Model of Growth Plate Cartilage Using Alginate Hydrogel Scaffolds

Tissue Engineering Part A ◽

10.1089/ten.tea.2017.0091 ◽

2018 ◽

Vol 24 (1-2) ◽

pp. 94-105 ◽

Cited By ~ 3

Author(s):

Alek G. Erickson ◽

Taylor D. Laughlin ◽

Sarah M. Romereim ◽

Catherine N. Sargus-Patino ◽

Angela K. Pannier ◽

...

Keyword(s):

In Vitro Culture ◽

Growth Plate ◽

Three Dimensional ◽

Alginate Hydrogel ◽

Hydrogel Scaffolds ◽

Growth Plate Cartilage ◽

Culture Model

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Designing TIMP (tissue inhibitor of metalloproteinases) variants that are selective metalloproteinase inhibitors

Biochemical Society Symposium ◽

10.1042/bss0700201 ◽

2003 ◽

Vol 70 ◽

pp. 201-212 ◽

Cited By ~ 51

Author(s):

Hideaki Nagase ◽

Keith Brew

Keyword(s):

Three Dimensional ◽

Therapeutic Interventions ◽

Tissue Inhibitors Of Metalloproteinases ◽

Structural Basis ◽

Structural Elements ◽

Ridge Structure ◽

Extracellular Matrix Components ◽

Metalloproteinase Inhibitors ◽

The Matrix ◽

A Disintegrin And Metalloproteinase

The tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors of the matrix metalloproteinases (MMPs), enzymes that play central roles in the degradation of extracellular matrix components. The balance between MMPs and TIMPs is important in the maintenance of tissues, and its disruption affects tissue homoeostasis. Four related TIMPs (TIMP-1 to TIMP-4) can each form a complex with MMPs in a 1:1 stoichiometry with high affinity, but their inhibitory activities towards different MMPs are not particularly selective. The three-dimensional structures of TIMP-MMP complexes reveal that TIMPs have an extended ridge structure that slots into the active site of MMPs. Mutation of three separate residues in the ridge, at positions 2, 4 and 68 in the amino acid sequence of the N-terminal inhibitory domain of TIMP-1 (N-TIMP-1), separately and in combination has produced N-TIMP-1 variants with higher binding affinity and specificity for individual MMPs. TIMP-3 is unique in that it inhibits not only MMPs, but also several ADAM (a disintegrin and metalloproteinase) and ADAMTS (ADAM with thrombospondin motifs) metalloproteinases. Inhibition of the latter groups of metalloproteinases, as exemplified with ADAMTS-4 (aggrecanase 1), requires additional structural elements in TIMP-3 that have not yet been identified. Knowledge of the structural basis of the inhibitory action of TIMPs will facilitate the design of selective TIMP variants for investigating the biological roles of specific MMPs and for developing therapeutic interventions for MMP-associated diseases.

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