scholarly journals Conductive GelMA–Collagen–AgNW Blended Hydrogel for Smart Actuator

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1217
Author(s):  
Jang Ho Ha ◽  
Jae Hyun Lim ◽  
Ji Woon Kim ◽  
Hyeon-Yeol Cho ◽  
Seok Geun Jo ◽  
...  

Blended hydrogels play an important role in enhancing the properties (e.g., mechanical properties and conductivity) of hydrogels. In this study, we generated a conductive blended hydrogel, which was achieved by mixing gelatin methacrylate (GelMA) with collagen, and silver nanowire (AgNW). The ratio of GelMA, collagen and AgNW was optimized and was subsequently gelated by ultraviolet light (UV) and heat. The scanning electron microscope (SEM) image of the conductive blended hydrogels showed that collagen and AgNW were present in the GelMA hydrogel. Additionally, rheological analysis indicated that the mechanical properties of the conductive GelMA–collagen–AgNW blended hydrogels improved. Biocompatibility analysis confirmed that the human umbilical vein endothelial cells (HUVECs) encapsulated within the three-dimensional (3D), conductive blended hydrogels were highly viable. Furthermore, we confirmed that the molecule in the conductive blended hydrogel was released by electrical stimuli-mediated structural deformation. Therefore, this conductive GelMA–collagen–AgNW blended hydrogel could be potentially used as a smart actuator for drug delivery applications.

Micromachines ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 3
Author(s):  
Kyo-in Koo ◽  
Andreas Lenshof ◽  
Le Thi Huong ◽  
Thomas Laurell

In the field of engineered organ and drug development, three-dimensional network-structured tissue has been a long-sought goal. This paper presents a direct hydrogel extrusion process exposed to an ultrasound standing wave that aligns fibroblast cells to form a network structure. The frequency-shifted (2 MHz to 4 MHz) ultrasound actuation of a 400-micrometer square-shaped glass capillary that was continuously perfused by fibroblast cells suspended in sodium alginate generated a hydrogel string, with the fibroblasts aligned in single or quadruple streams. In the transition from the one-cell stream to the four-cell streams, the aligned fibroblast cells were continuously interconnected in the form of a branch and a junction. The ultrasound-exposed fibroblast cells displayed over 95% viability up to day 10 in culture medium without any significant difference from the unexposed fibroblast cells. This acoustofluidic method will be further applied to create a vascularized network by replacing fibroblast cells with human umbilical vein endothelial cells.


2017 ◽  
Vol 33 (9) ◽  
pp. 592-599 ◽  
Author(s):  
Francesca Felice ◽  
Ester Belardinelli ◽  
Alessandro Frullini ◽  
Tatiana Santoni ◽  
Egidio Imbalzano ◽  
...  

Objectives Aminaphtone, a naphtohydrochinone used in the treatment of capillary disorders, may affect oedema in chronic venous insufficiency. Aim of study is to investigate the effect of aminaphtone on vascular endothelial permeability in vitro and its effects on three-dimensional capillary-like structures formed by human umbilical vein endothelial cells. Method Human umbilical vein endothelial cells were treated with 50 ng/ml VEGF for 2 h and aminaphtone for 6 h. Permeability assay, VE-cadherin expression and Matrigel assay were performed. Results VEGF-induced permeability was significantly decreased by aminaphtone in a range concentration of 1–20 µg/ml. Aminaphtone restored VE-cadherin expression. Finally, 6 h pre-treatment with aminaphtone significantly preserved capillary-like structures formed by human umbilical vein endothelial cells on Matrigel up to 48 h compared to untreated cells. Conclusions Aminaphtone significantly protects endothelium permeability and stabilises endothelial cells organised in capillary-like structures, modulating VE-cadherin expression. These data might explain the clinical benefit of aminaphtone on chronic venous insufficiency.


2002 ◽  
Vol 11 (4) ◽  
pp. 369-377 ◽  
Author(s):  
Makarand V. Risbud ◽  
Erdal Karamuk ◽  
René Moser ◽  
Joerg Mayer

Three-dimensional (3-D) scaffolds offer an exciting possibility to develop cocultures of various cell types. Here we report chitosan–collagen hydrogel-coated fabric scaffolds with defined mesh size and fiber diameter for 3-D culture of human umbilical vein endothelial cells (HUVECs). These scaffolds did not require pre-coating with fibronectin and they supported proper HUVEC attachment and growth. Scaffolds preserved endothelial cell-specific cobblestone morphology and cells were growing in compartments defined by the textile mesh. HUVECs on the scaffold maintained the property of contact inhibition and did not exhibit overgrowth until the end of in vitro culture (day 6). MTT assay showed that cells had preserved mitochondrial functionality. It was also noted that cell number on the chitosan-coated scaffold was lower than that of collagen-coated scaffolds. Calcein AM and ethidium homodimer (EtD-1) dual staining demonstrated presence of viable and metabolically active cells, indicating growth supportive properties of the scaffolds. Actin labeling revealed absence of actin stress fibers and uniform distribution of F-actin in the cells, indicating their proper attachment to the scaffold matrix. Confocal microscopic studies showed that HUVECs growing on the scaffold had preserved functionality as seen by expression of von Willebrand (vW) factor. Observations also revealed that functional HUVECs were growing at various depths in the hydrogel matrix, thus demonstrating the potential of these scaffolds to support 3-D growth of cells. We foresee the application of this scaffold system in the design of liver bioreactors wherein hepatocytes could be cocultured in parallel with endothelial cells to enhance and preserve liver-specific functions.


2016 ◽  
Vol 113 (12) ◽  
pp. 3179-3184 ◽  
Author(s):  
David B. Kolesky ◽  
Kimberly A. Homan ◽  
Mark A. Skylar-Scott ◽  
Jennifer A. Lewis

The advancement of tissue and, ultimately, organ engineering requires the ability to pattern human tissues composed of cells, extracellular matrix, and vasculature with controlled microenvironments that can be sustained over prolonged time periods. To date, bioprinting methods have yielded thin tissues that only survive for short durations. To improve their physiological relevance, we report a method for bioprinting 3D cell-laden, vascularized tissues that exceed 1 cm in thickness and can be perfused on chip for long time periods (>6 wk). Specifically, we integrate parenchyma, stroma, and endothelium into a single thick tissue by coprinting multiple inks composed of human mesenchymal stem cells (hMSCs) and human neonatal dermal fibroblasts (hNDFs) within a customized extracellular matrix alongside embedded vasculature, which is subsequently lined with human umbilical vein endothelial cells (HUVECs). These thick vascularized tissues are actively perfused with growth factors to differentiate hMSCs toward an osteogenic lineage in situ. This longitudinal study of emergent biological phenomena in complex microenvironments represents a foundational step in human tissue generation.


2020 ◽  
Vol 982 ◽  
pp. 51-58
Author(s):  
Fu Liang Jiang ◽  
Hong Bo Zhang ◽  
Wen Jun Zhang

Microfluidics has great control over the size and uniformity of microspheres, which has been widely used in fabrication of different types of microspheres such as core-shell microbubbles. Gelatin Methacrylate (GelMa) as a biodegradable material that is closely resemble to native extracellular matrix (ECM). Photocrosslinked GelMa microspheres have gained numerous concerns in biomedical applications especially in three-dimensional cell culture and tissue engineering. In this article, we presented a suitable core-shell cell carrier based on biocompatible GelMa microbubbles. Highly monodispersed microbubbles were fabricated using a non-planar flow focusing microfluidic device. Both intact and collapsed microbubbles morphology were characterized through scanning electron microscopy (SEM), where clear hollow structures were found resulting from the gas core collapsing during the manipulation process. Furthermore, human umbilical vein endothelial cells (HUVEC) were seeded in the existence of microbubbles. Cells adhesion, migration and proliferation were observed in one week. It was notable that cells maintained high level of cell viability throughout the experiment. GelMa microbubble surface was also covered with cells, which became a facile carrier for cell culturing and targeted cell delivery.


2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000549-000556 ◽  
Author(s):  
William L. Mercke ◽  
Thomas Dziubla ◽  
Richard E. Eitel ◽  
Kimberly Anderson

Expansion of Low-Temperature Co-fired Ceramic materials into microfluidic systems technology has many beneficial applications due to their ability to combine complex three dimensional structures with optical, fluidic, electrical functions. Evaluations of the biocompatibility of these Low-Temperature Co-fired Ceramic materials are vital for expanding into biomedical research. The few biocompatibility studies on Low-Temperature Co-fired Ceramics generally show negative cellular response to thick film pastes used in generating the electronic circuitry patterns. In this study, biocompatibility of Human Umbilical Vein Endothelial Cells was examined on Heraeus's Low-Temperature Co-fired Ceramic tape and two of their conductive pastes. The biocompatibility was assessed by monitoring cellular attachment and viability up to three days. This study examines the idea of leachates being detrimental to cells due to a study that suggests the possibility of harmful leachates. Results indicate difficulty in initial attachment of Human Umbilical Vein Endothelial Cells to sintered Low-Temperature Co-fired Ceramic tapes, but no hindrance of cellular attachment and growth onto the two conductive pastes. Outcomes also demonstrate that possible harmful leachates from Low-Temperature Co-fired Ceramic materials don't thwart cellular attachment and growth for up to three days of cell culturing. These results provide a basis for biological devices using Low-Temperature Co-fired Ceramic materials.


2014 ◽  
Vol 11 (101) ◽  
pp. 20141027 ◽  
Author(s):  
Weizhi Liu ◽  
Xiaocong Wang ◽  
Ke Bai ◽  
Miao Lin ◽  
Gleb Sukhorukov ◽  
...  

Microcapsules made of polyelectrolyte multilayers exhibit no or low toxicity, appropriate mechanical stability, variable controllable degradation and can incorporate remote release mechanisms triggered by various stimuli, making them well suited for targeted drug delivery to live cells. This study investigates interactions between microcapsules made of synthetic (i.e. polystyrenesulfonate sodium salt/polyallylamine hydrochloride) or natural (i.e. dextran sulfate/poly- l -arginine) polyelectrolyte and human umbilical vein endothelial cells with particular focus on the effect of the glycocalyx layer on the intake of microcapsules by endothelial cells. Neuraminidase cleaves N -acetyl neuraminic acid residues of glycoproteins and targets the sialic acid component of the glycocalyx on the cell membrane. Three-dimensional confocal images reveal that microcapsules, functionalized with neuraminidase, can be internalized by endothelial cells. Capsules without neuraminidase are blocked by the glycocalyx layer. Uptake of the microcapsules is most significant in the first 2 h. Following their internalization by endothelial cells, biodegradable DS/PArg capsules rupture by day 5; however, there is no obvious change in the shape and integrity of PSS/PAH capsules within the period of observation. Results from the study support our hypothesis that the glycocalyx functions as an endothelial barrier to cross-membrane movement of microcapsules. Neuraminidase-loaded microcapsules can enter endothelial cells by localized cleavage of glycocalyx components with minimum disruption of the glycocalyx layer and therefore have high potential to act as drug delivery vehicles to reach tissues beyond the endothelial barrier of blood vessels.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Liling Ren ◽  
Dongyang Ma ◽  
Bin Liu ◽  
Jinda Li ◽  
Jia Chen ◽  
...  

Engineering three-dimensional (3D) vascularized constructs remains a challenge due to the inability to form rich microvessel networks. In this study we engineered a prevascularized 3D cell sheet construct for tissue regeneration using human bone marrow-derived mesenchymal stem cells (hMSCs) and human umbilical vein endothelial cells as cell sources. hMSCs were cultured to form a thick cell sheet, and human umbilical vein endothelial cells (HUVECs) were then seeded on the hMSCs sheet to form networks. The single prevascularized HUVEC/hMSC cell sheet was folded to form a 3D construct by a modified cell sheet engineering technique.In vitroresults indicated that the hMSCs cell sheet promoted the HUVECs cell migration to form networks in horizontal and vertical directions.In vivoresults showed that many blood vessels grew into the 3D HUVEC/hMSC cell sheet constructs after implanted in the subcutaneous pocket of immunodeficient mice. The density of blood vessels in the prevascularized constructs was higher than that in the nonprevascularized constructs. Immunohistochemistry staining further showed thatin vitropreformed human capillaries in the prevascularized constructs anastomosed with the host vasculature to form functional blood vessels. These results suggest the promising potential of this 3D prevascularized construct using hMSCs cell sheet as a platform for wide applications in engineering vascularized tissues.


Author(s):  
Qianheng Jin ◽  
Guangzhe Jin ◽  
Jihui Ju ◽  
Lei Xu ◽  
Linfeng Tang ◽  
...  

Three-dimensional (3D) bioprinting shows great potential for autologous vascular grafts due to its simplicity, accuracy, and flexibility. 6mm diameter vascular grafts are used in clinic. However, producing small-diameter vascular grafts are still an enormous challenge. Normally, sacrificial hydrogels are used as temporary lumen support to mold tubular structure which will affect the structure’s stability. In this study, we develop a new bioprinting approach to fabricating small-diameter vessel using two-step crosslinking process. ¼ lumen wall of bioprinted gelatin mechacrylate (GelMA) flat structure is exposed to ultraviolet (UV) light briefly for having certain strength, while ¾ lumen wall shows as concave structure remained uncrosslinked. Pre-crosslinked flat structure is merged towards the uncrosslinked concave structure. Two individual structures will be combined tightly into an intact tubular structure by receiving more UV exposure time. Complicated tubular structures are constructed by these method. Notably, the GelMA-based bioink loaded with smooth muscle cells (SMCs) are bioprinted as the outer layer and human umbilical vein endothelial cells (HUVECs) are seeded onto the inner surface. A bionic vascular vessel with dual layers is fabricated successfully and keeps good viability, and functionality. This study may provide a novel idea for fabricating biomimetic vascular network or other more complicated organs.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Manabu Itoh ◽  
Koichi Nakayama ◽  
Ryo Noguchi ◽  
Keiji Kamohara ◽  
Kojirou Furukawa ◽  
...  

Introduction: Small caliber synthetic vascular grafts are not clinically available. We developed a novel method to create scaffold-free tubular tissue from multicellular spheroids (MCS) using a “Bio-3D printer”-based system, which enables the creation of various three-dimensional structures pre-designed using a computer system. With this system, we created a tubular structure (Fig. 1), and studied its biological features. Methods: We made 1.5 mm in diameter scaffold-free tubular tissues from MCS (1.25 x 10[[Unable to Display Character: ⁷]] cells) composed of human umbilical vein endothelial cells (40%), human aortic smooth muscle cells (10%) and normal human dermal fibroblasts (50%) using a Bio-3D printer. The vessels were cultured in a perfusion system. We implanted grafts into the abdominal aortas of F344 nude rats, and assessed the flow by ultrasonography and performed histological examinations on the second (N=5) and fifth (N=5) days after implantation. Results: All grafts were patent. Remodeling of the vessel (enlargement of the lumen area and thinning of the wall) was observed (Fig. 2). A layer of endothelial cells was developed after implantation of the graft (Fig. 3). Conclusions: The scaffold-free vascular grafts made of MCS using a Bio-3D printer showed biological features comparable to native vessels. Further studies are warranted toward the clinical application of this novel technology.


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