Induction of Hydroxyapatite Particles Formation on PEGDA-Based Hydrogels by Nanobacteria

2010 ◽  
Vol 105-106 ◽  
pp. 569-571
Author(s):  
Guo Xin Tan ◽  
Cheng Yun Ning ◽  
Shu Jiang Zhang
Keyword(s):  
Culture Media ◽  
Chemical Constituents ◽  
Polyethylene Glycol Diacrylate ◽  
Glycol Diacrylate ◽  
Synthetic Hydrogel ◽  
Marrow Mesenchymal Stem Cells ◽  
Inorganic Chemical ◽  
Hydrogel Surface ◽  
Cell Culture Contamination ◽  
Hydroxyl Apatite

Nanobacteria is a tiny structure with size varying 80 to 500nm, commonly occurring in clusters and producing a biofilm which contains carbonate or hydroxyl apatite. In this study, the bioactive synthetic hydrogel materials were prepared with polyethylene glycol diacrylate (PEGDA) and 2-hydroxyethyl mathacrylate (HEMA) by UV photo-polymerization. Bone marrow mesenchymal stem cells (BMSCs) were seeded onto hydrogel surface for five days. The BMSCs cell adhesion on hydrogels was confirmed by SEM to evaluate the biocompatibility of the materials. It was found groups of nanoparticles on the hydrogel surface and the particles were analyzed by SEM. The particles were analyzed for its inorganic chemical constituents using energy dispersive X-ray microanalysis (EDS). The predominant components were found to be calcium (24.40%) and phosphorus (13.98%). The most likely source of cell culture contamination by such organisms is bovine serum albumin (BSA) used as supplement in culture media. Nanobacteria in BSA may be the important factor which accelerated hydroxyapatite crystal growth on hydrogels. It is important to study the biomineralization in biological system and has potential application in biomaterials science and biotechnology.

scholarly journals Bioprinting the Tumor Microenvironment with an Upgraded Consumer Stereolithographic 3D Printer

2021 ◽  
Author(s):  
Louise Breideband ◽  
Kaja Nicole Wächtershäuser ◽  
Levin Hafa ◽  
Konstantin Wieland ◽  
Achilleas Frangakis ◽  
...  
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Tumor Model ◽  
Standard Technique ◽  
Widespread Application ◽  
Polyethylene Glycol Diacrylate ◽  
Glycol Diacrylate ◽  
Synthetic Hydrogel ◽  
Specific Tumor ◽  
Tissue Models

A widespread application of three-dimensional (3D) bioprinting in basic and translational research requires the accessibility to affordable printers able to produce physiologically relevant tissue models. To facilitate the use of bioprinting as a standard technique in biology, an open-source device based on a consumer-grade 3D stereolithographic (SL) printer was developed. This SL bioprinter can produce complex constructs that preserve cell viability and recapitulate the physiology of tissues. The detailed documentation of the modifications apported to the printer as well as a throughout performance analysis allow for a straightforward adoption of the device in other labs and its customization for specific applications. Given the low cost, several modified bioprinters could be simultaneously operated for a highly parallelized tissue production. To showcase the capability of the bioprinter, we produced constructs consisting of patient-derived cholangiocarcinoma organoids encapsulated in a gelatin methacrylate (GelMA)/polyethylene glycol diacrylate (PEGDA) hydrogel. A thorough characterization of different GelMA/PEGDA ratios revealed that the mechanical properties of the bioprinted tumor model can be accurately fine-tuned to mimic a specific tumor micro-environment. Immunofluorescence and gene expression analyses of tumor markers confirmed that the bioprinted synthetic hydrogel provides a flexible and adequate replacement of animal-derived reconstituted extracellular matrix.

Synthesis and Properties of Polyethylene Glycol Diacrylate /2-Hydroxyethyl Mathacrylate Hydrogels

2008 ◽  
Vol 368-372 ◽  
pp. 1175-1177 ◽  
Author(s):  
Guo Xin Tan ◽  
Ying Jun Wang ◽  
Yan Xia Guang
Keyword(s):  
Polyethylene Glycol ◽  
Feed Ratio ◽  
Structure And Properties ◽  
Scaffold Material ◽  
Equilibrium Water Content ◽  
Swelling Properties ◽  
Polyethylene Glycol Diacrylate ◽  
Glycol Diacrylate ◽  
Photo Polymerization ◽  
Synthetic Hydrogel

The bioactive synthetic hydrogel materials were prepared with polyethylene glycol diacrylate (PEGDA) and 2-hydroxyethyl mathacrylate (HEMA) by UV photo-polymerization. The aim of this study was to prepare a scaffold material by combining HEMA into a composite polymeric PEGDA-based hydrogel, which were used as bioactive artificial cartilage. The structure and properties of the synthetic hydrogels were investigated in details using FTIR techniques. The swelling data indicated that the equilibrium water content depended on the precursor feed ratio. It was found that adding the HEMA into the PEGDA-based hydrogels was very helpful to improve the swelling properties.

scholarly journals Elucidating the Molecular Mechanisms for the Interaction of Water with Polyethylene Glycol-Based Hydrogels: Influence of Ionic Strength and Gel Network Structure

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 845
Author(s):  
Xin Yang ◽  
Bronwin Dargaville ◽  
Dietmar Hutmacher
Keyword(s):  
Polyethylene Glycol ◽  
Ionic Strength ◽  
Molecular Mechanisms ◽  
Repeat Unit ◽  
Bound Water ◽  
Weight Fraction ◽  
Swelling Ratio ◽  
Polyethylene Glycol Diacrylate ◽  
Glycol Diacrylate ◽  
Hydrogel System

The interaction of water within synthetic and natural hydrogel systems is of fundamental importance in biomaterial science. A systematic study is presented on the swelling behavior and states of water for a polyethylene glycol-diacrylate (PEGDA)-based model neutral hydrogel system that goes beyond previous studies reported in the literature. Hydrogels with different network structures are crosslinked and swollen in different combinations of water and phosphate-buffered saline (PBS). Network variables, polyethylene glycol (PEG) molecular weight (MW), and weight fraction are positively correlated with swelling ratio, while “non-freezable bound water” content decreases with PEG MW. The presence of ions has the greatest influence on equilibrium water and “freezable” and “non-freezable” water, with all hydrogel formulations showing a decreased swelling ratio and increased bound water as ionic strength increases. Similarly, the number of “non-freezable bound water” molecules, calculated from DSC data, is greatest—up to six molecules per PEG repeat unit—for gels swollen in PBS. Fundamentally, the balance of osmotic pressure and non-covalent bonding is a major factor within the molecular structure of the hydrogel system. The proposed model explains the dynamic interaction of water within hydrogels in an osmotic environment. This study will point toward a better understanding of the molecular nature of the water interface in hydrogels.

scholarly journals Generation of Photopolymerized Microparticles Based on PEGDA Using Microfluidic Devices. Part 1. Initial Gelation Time and Mechanical Properties of the Material

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 293
Author(s):  
José M. Acosta-Cuevas ◽  
José González-García ◽  
Mario García-Ramírez ◽  
Víctor H. Pérez-Luna ◽  
Erick Omar Cisneros-López ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Gelation Time ◽  
Mesh Size ◽  
Microfluidic Devices ◽  
Future Generation ◽  
Mechanical Tests ◽  
Continuous Systems ◽  
Polyethylene Glycol Diacrylate ◽  
Glycol Diacrylate ◽  
Close Relationship

Photopolymerized microparticles are made of biocompatible hydrogels like Polyethylene Glycol Diacrylate (PEGDA) by using microfluidic devices are a good option for encapsulation, transport and retention of biological or toxic agents. Due to the different applications of these microparticles, it is important to investigate the formulation and the mechanical properties of the material of which they are made of. Therefore, in the present study, mechanical tests were carried out to determine the swelling, drying, soluble fraction, compression, cross-linking density (Mc) and mesh size (ξ) properties of different hydrogel formulations. Tests provided sufficient data to select the best formulation for the future generation of microparticles using microfluidic devices. The initial gelation times of the hydrogels formulations were estimated for their use in the photopolymerization process inside a microfluidic device. Obtained results showed a close relationship between the amount of PEGDA used in the hydrogel and its mechanical properties as well as its initial gelation time. Consequently, it is of considerable importance to know the mechanical properties of the hydrogels made in this research for their proper manipulation and application. On the other hand, the initial gelation time is crucial in photopolymerizable hydrogels and their use in continuous systems such as microfluidic devices.

scholarly journals Shear Stress-Triggered Deformation of Microparticles in a Tapered Microchannel

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 55
Author(s):  
Cheolheon Park ◽  
Junghyun Bae ◽  
Yeongjae Choi ◽  
Wook Park
Keyword(s):  
Shear Stress ◽  
Void Fraction ◽  
Applied Pressure ◽  
Microfluidic Channel ◽  
Volume Index ◽  
Effective Volume ◽  
Particle Deformation ◽  
Polyethylene Glycol Diacrylate ◽  
Glycol Diacrylate ◽  
Deformation Ratio

We demonstrate that it is possible to produce microparticles with high deformability while maintaining a high effective volume. For significant particle deformation, a particle must have a void region. The void fraction of the particle allows its deformation under shear stress. Owing to the importance of the void fraction in particle deformation, we defined an effective volume index (V*) that indicates the ratio of the particle’s total volume to the volumes of the void and material structures. We chose polyethylene glycol diacrylate (Mn ~ 700) for the fabrication of the microparticles and focused on the design of the particles rather than the intrinsic softness of the material (E). We fabricated microparticles with four distinct shapes: discotic, ring, horseshoe, and spiral, with various effective volume indexes. The microparticles were subjected to shear stress as they were pushed through a tapered microfluidic channel to measure their deformability. The deformation ratio R was introduced as R = 1−Wdeformed/Doriginal to compare the deformability of the microparticles. We measured the deformation ratio by increasing the applied pressure. The spiral-shaped microparticles showed a higher deformation ratio (0.901) than those of the other microparticles at the same effective volume index.

Drug-eluting microneedles for self-administered treatment of keloids

TECHNOLOGY ◽  
2014 ◽  
Vol 02 (02) ◽  
pp. 144-152 ◽  
Author(s):  
Peng Xue ◽  
David Chen Loong Yeo ◽  
Yon Jin Chuah ◽  
Hong Liang Tey ◽  
Yuejun Kang ◽  
...  
Keyword(s):  
Clinical Supervision ◽  
Fibrous Tissue ◽  
Polyethylene Glycol Diacrylate ◽  
Glycol Diacrylate ◽  
Keloid Fibroblast ◽  
Culture Models ◽  
Drug Eluting ◽  
Good Potential ◽  
Microneedle Patch

Keloid is a long-term dermatological scarring disease characterized by disfiguring lesions resulting from overgrowth of dense fibrous tissue. Current therapeutics are ineffective, require clinical supervision and can be costly. This study investigated the use of microneedle technology in the self-management of keloid lesions. Specifically, a microneedle patch comprising of polyethylene glycol diacrylate (PEGDA) and encapsulating 5-fluorouracil (5-FU) has been developed for transdermal delivery. The microneedle patches showed requisite mechanical strength (hardness 45 ± 11 MPa, elastic modulus 0.66 ± 0.16 GPa) and were able to puncture porcine epidermis. The choice of PEGDA substrate enabled conformability to non-planar anatomical regions (e.g. elbow), with about 50% of the loaded 5-FU released during the first 12 hours. Thereafter, the microneedle efficacy was evaluated on in vitro keloid fibroblast culture models, where 5-FU loaded microneedles effectively abolished keloid fibroblast proliferation activity. In summary, we have developed a microneedle device with a good potential as an effective, economical and self-applied therapy for keloid scars.

scholarly journals More natural more better: triple natural anti-oxidant puerarin/ferulic acid/polydopamine incorporated hydrogel for wound healing

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Qianmin Ou ◽  
Shaohan Zhang ◽  
Chuanqiang Fu ◽  
Le Yu ◽  
Peikun Xin ◽  
...  
Keyword(s):  
Wound Healing ◽  
Ferulic Acid ◽  
Natural Antioxidants ◽  
Wound Dressings ◽  
Polyethylene Glycol Diacrylate ◽  
Glycol Diacrylate ◽  
Antioxidant Function ◽  
Healing Tissue ◽  
Anti Oxidant ◽  
Gel Network

Abstract Background During wound healing, the overproduction of reactive oxygen species (ROS) can break the cellular oxidant/antioxidant balance, which prolongs healing. The wound dressings targeting the mitigation of ROS will be of great advantages for the wound healing. puerarin (PUE) and ferulic acid (FA) are natural compounds derived from herbs that exhibit multiple pharmacological activities, such as antioxidant and anti-inflammatory effects. Polydopamine (PDA) is made from natural dopamine and shows excellent antioxidant function. Therefore, the combination of natural antioxidants into hydrogel dressing is a promising therapy for wound healing. Results Hydrogel wound dressings have been developed by incorporating PUE or FA via PDA nanoparticles (NPs) into polyethylene glycol diacrylate (PEG-DA) hydrogel. This hydrogel can load natural antioxidant drugs and retain the drug in the gel network for a long period due to the presence of PDA NPs. Under oxidative stress, this hydrogel can improve the activity of superoxide dismutase and glutathione peroxidase and reduce the levels of ROS and malondialdehyde, thus preventing oxidative damage to cells, and then promoting wound healing, tissue regeneration, and collagen accumulation. Conclusion Overall, this triple antioxidant hydrogel accelerates wound healing by alleviating oxidative injury. Our study thus provides a new way about co-delivery of multiple antioxidant natural molecules from herbs via antioxidant nanoparticles for wound healing and skin regeneration. Graphic Abstract

Abstract 219: Induced Pluripotent Stem Cells as a Potential Cell Source for Tissue Engineered Heart Valves

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Aline L Yonezawa ◽  
Monalisa Singh ◽  
David Safranski ◽  
Kenneth M Dupont ◽  
Chunhui Xu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Pluripotent Stem Cells ◽  
Heart Valves ◽  
3D Culture ◽  
Polyethylene Glycol Diacrylate ◽  
Glycol Diacrylate ◽  
Cell Source ◽  
Induced Pluripotent ◽  
Tissue Engineered Heart Valves

Despite recent advances in tissue engineered heart valves (TEHV), one of the major challenges is finding a suitable cell source for seeding TEHV scaffolds. Native heart valves are durable because valve interstitial cells (VICs) maintain tissue homeostasis by synthesizing and remodeling the extracellular matrix. In this study, we demonstrate that induced pluripotent stem cells (iPSCs) can be derived into induced mesenchymal stem cells (iMSCs) using our feeder-free protocol and then further differentiated into VICs using a 3D cell culture environment. The differentiation efficiency was quantified using flow cytometry, immunohistochemistry staining, RT-PCR, and trilineage differentiation. In addition, iMSCs were encapsulated in polyethylene (glycol) diacrylate (PEGDA) hydrogels of varying stiffness, grafted with adhesion peptide (RGDS), to promote cell proliferation, remodeling, and further differentiation into VIC-like cells. VICs phenotype was characterized by the expression of αSMA, vimentin, F-actin, and the ECM production after 7, 14, and 21 days. The results demonstrated that using our feeder-free differentiation protocol, iMSCs were differentiated from iPSCs. Our iMSCs had a 99.9% and 99.4% positive expression for MSC markers CD90 and CD44, respectively. As expected, there was 0.019% expression of CD45, which is a hematopoietic marker. In addition, iMSCs differentiated into adipogenic, chondrogenic, and osteogenic. When MSC derived cells were encapsulated in PEGDA hydrogels that mimic the leaflet modulus, we observed expression of αSMA and F-actin after 7 days. Thus, the results from this study suggest that iPSCs can be a suitable cell source for TEHV by using a feeder-free differentiation approach and 3D culture.

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