scholarly journals Bioenergetic-active materials enhance tissue regeneration by modulating cellular metabolic state

2020 ◽  
Vol 6 (13) ◽  
pp. eaay7608 ◽  
Author(s):  
Haoming Liu ◽  
Yingying Du ◽  
Jean-Philippe St-Pierre ◽  
Mads S. Bergholt ◽  
Hélène Autefage ◽  
...  
Keyword(s):  
Tissue Regeneration ◽  
Weight Bearing ◽  
Critical Role ◽  
Active Material ◽  
Rabbit Model ◽  
Poly Lactic Acid ◽  
Metabolic State ◽  
Calcium Phosphate Ceramic ◽  
Active Materials ◽  
Cellular Bioenergetics

Cellular bioenergetics (CBE) plays a critical role in tissue regeneration. Physiologically, an enhanced metabolic state facilitates anabolic biosynthesis and mitosis to accelerate regeneration. However, the development of approaches to reprogram CBE, toward the treatment of substantial tissue injuries, has been limited thus far. Here, we show that induced repair in a rabbit model of weight-bearing bone defects is greatly enhanced using a bioenergetic-active material (BAM) scaffold compared to commercialized poly(lactic acid) and calcium phosphate ceramic scaffolds. This material was composed of energy-active units that can be released in a sustained degradation-mediated fashion once implanted. By establishing an intramitochondrial metabolic bypass, the internalized energy-active units significantly elevate mitochondrial membrane potential (ΔΨm) to supply increased bioenergetic levels and accelerate bone formation. The ready-to-use material developed here represents a highly efficient and easy-to-implement therapeutic approach toward tissue regeneration, with promise for bench-to-bedside translation.

scholarly journals Bacterial Spore-Based Hygromorphs: A Novel Active Material with Potential for Architectural Applications

2021 ◽  
Vol 13 (7) ◽  
pp. 4030
Author(s):  
Emily Birch ◽  
Ben Bridgens ◽  
Meng Zhang ◽  
Martyn Dade-Robertson
Keyword(s):  
Bacillus Subtilis ◽  
Architectural Design ◽  
Energy Input ◽  
Shape Change ◽  
Active Material ◽  
Meaningful Work ◽  
Sensors And Actuators ◽  
Active Materials ◽  
Environmental Humidity ◽  
New Material

This paper introduces a new active material which responds to changes in environmental humidity. There has been growing interest in active materials which are able to respond to their environment, creating dynamic architectural systems without the need for energy input or complex systems of sensors and actuators. A subset of these materials are hygromorphs, which respond to changes in relative humidity (RH) and wetting through shape change. Here, we introduce a novel hygromorphic material in the context of architectural design, composed of multiple monolayers of microbial spores of Bacillus subtilis and latex sheets. Methods of fabrication and testing for this new material are described, showing that small actuators made from this material demonstrate rapid, reversible and repeatable deflection in response to changes in RH. It is demonstrated that the hygromorphic actuators are able to lift at least 150% of their own mass. Investigations are also extended to understanding this new biomaterial in terms of meaningful work.

A Dynamic Model of Magneto-Active Elastomer Actuation of the Waterbomb Base

2014 ◽  
Author(s):  
Landen Bowen ◽  
Mary Frecker ◽  
Timothy W. Simpson ◽  
Paris von Lockette
Keyword(s):  
Dynamic Model ◽  
Special Interest ◽  
Software Package ◽  
Applied Field ◽  
Active Material ◽  
Active Materials ◽  
Stiffness And Damping ◽  
Torsion Springs ◽  
Elastomer Actuation ◽  
Origami Engineering

Of special interest in the growing field of origami engineering is self-folding, wherein a material is able to fold itself in response to an applied field. In order to simulate the effect of active materials on an origami-inspired design, a dynamic model is needed. Ideally, the model would be an aid in determining how much active material is needed and where it should be placed to actuate the model to the desired position. A dynamic model of the origami waterbomb base, a well-known and foundational origami structure, is developed using Adams, a commercial dynamics software package. Creases are approximated as torsion springs with stiffness and damping. The stiffness of an origami crease is calculated, and the dynamic model is verified using the bistability of the waterbomb. An approximation of the torque produced by magneto-active elastomers (MAE) is calculated and is used to simulate MAE-actuated self-folding of the waterbomb.

GPIb-dependent platelet activation is dependent on Src kinases but not MAP kinase or cGMP-dependent kinase

Blood ◽  
2004 ◽  
Vol 103 (7) ◽  
pp. 2601-2609 ◽  
Author(s):  
Stuart J. Marshall ◽  
Yotis A. Senis ◽  
Jocelyn M. Auger ◽  
Robert Feil ◽  
Franz Hofmann ◽  
...  
Keyword(s):  
Map Kinase ◽  
Platelet Activation ◽  
Map Kinases ◽  
Thrombus Formation ◽  
Critical Role ◽  
Rabbit Model ◽  
Guanosine Monophosphate ◽  
Src Kinases ◽  
Aggregate Formation ◽  
No Donor

Abstract Glycoprotein Ib-IX-V (GPIb-IX-V) mediates platelet tethering to von Willebrand factor (VWF), recruiting platelets into the thrombus, and activates integrin αIIbβ3 through a pathway that is dependent on Src kinases. In addition, recent reports indicate that activation of αIIbβ3 by VWF is dependent on protein kinase G (PKG) and mitogen-activated protein (MAP) kinases. The present study compares the importance of these signaling pathways in the activation of αIIbβ3 by GPIb-IX-V. In contrast to a recent report, VWF did not promote an increase in cyclic guanosine monophosphate (cGMP), while agents that elevate cGMP, such as the nitrous oxide (NO) donor glyco–SNAP-1 (N-(β-D-glucopyranosyl)-N2-acetyl-S-nitroso-D,L-penicillaminamide) or the type 5 phosphosdiesterase inhibitor, sildenafil, inhibited rather than promoted activation of αIIbβ3 by GPIb-IX-V and blocked aggregate formation on collagen at an intermediate rate of shear (800 s-1). Additionally, sildenafil increased blood flow in a rabbit model of thrombus formation in vivo. A novel inhibitor of the MAP kinase pathway, which is active in plasma, PD184161, had no effect on aggregate formation on collagen under flow conditions, whereas a novel inhibitor of Src kinases, which is also active in plasma, PD173952, blocked this response. These results demonstrate a critical role for Src kinases but not MAP kinases in VWF-dependent platelet activation and demonstrate an inhibitory role for cGMP-elevating agents in regulating this process.

scholarly journals Critical Role of Human T-Lymphotropic Virus Type 1 Accessory Proteins in Viral Replication and Pathogenesis

2002 ◽  
Vol 66 (3) ◽  
pp. 396-406 ◽  
Author(s):  
Björn Albrecht ◽  
Michael D. Lairmore
Keyword(s):  
T Cell ◽  
Viral Replication ◽  
Virus Type ◽  
Critical Role ◽  
Rabbit Model ◽  
Lymphocyte Activation ◽  
Accessory Proteins ◽  
Viral Infectivity ◽  
Diverse Range

SUMMARY Human T-cell lymphotropic virus type 1 (HTLV-1) infection is associated with a diverse range of lymphoproliferative and neurodegenerative diseases, yet pathogenic mechanisms induced by the virus remain obscure. This complex retrovirus contains typical structural and enzymatic genes but also unique regulatory and accessory genes in four open reading frames (ORFs) of the pX region of the viral genome (pX ORFs I to IV). The regulatory proteins encoded by pX ORFs III and IV, Tax and Rex, respectively, have been extensively characterized. In contrast the contribution of the four accessory proteins p12I, p27I, p13II, and p30II, encoded by pX ORFs I and II, to viral replication and pathogenesis remained unclear. Proviral clones that are mutated in either pX ORF I or II, while fully competent in cell culture, are severely limited in their replicative capacity in a rabbit model. Emerging evidence indicates that the HTLV-1 accessory proteins are critical for establishment of viral infectivity, enhance T-lymphocyte activation, and potentially alter gene transcription and mitochondrial function. HTLV-1 pX ORF I expression is critical to the viral infectivity in resting primary lymphocytes, suggesting a role for p12I in lymphocyte activation. The endoplasmic reticulum and cis-Golgi localizing p12I, encoded from pX ORF I, activates NFAT, a key T-cell transcription factor, through calcium-mediated signaling pathways and may lower the threshold of lymphocyte activation via the JAK/STAT pathway. In contrast p30II localizes to the nucleus and represses viral promoter activity, but may regulate cellular gene expression through p300/CBP or related coactivators of transcription. p13II targets mitochondrial proteins, where it alters the organelle morphology and may influence energy metabolism. Collectively, studies of the molecular functions of the HTLV-1 accessory proteins provide insight into strategies used by retroviruses that are associated with lymphoproliferative diseases.

scholarly journals Gıda Bileşenlerinin Enkapsülasyonunda Nanoemülsiyonların Kullanımı

2020 ◽  
Vol 8 (1) ◽  
pp. 130
Author(s):  
İsmail Tontul
Keyword(s):  
Controlled Release ◽  
New Products ◽  
Active Material ◽  
Core Material ◽  
Loading Capacity ◽  
Food Technology ◽  
Active Materials ◽  
Immiscible Liquids ◽  
The Core ◽  
Food Components

The increase in consumers' demands for safer and healthier food has led to the development of many new products in food technology. For this reason, micro- or nanoencapsulation has become an important area in order to protect food components with functional properties against environmental conditions and to provide controlled release in recent years. As a matter of fact, many encapsulation techniques have been developed and many different active materials have been encapsulated. Nanoemulsions, a nanoencapsulation technique, are the process of encapsulating core material in two immiscible liquids. Nanoemulsions have higher stability and loading capacity compared to normal emulsions. It also increases the bioavailability of the core materials because of the increased absorption of the active material in the digestive tract. In this review, the required materials for nanoemulsion preparation, the nanoemulsification methods, and the studies on the encapsulation of various food components in nanoemulsions have been reviewed.

scholarly journals Material Characterization of PCL:PLLA Electrospun Fibers Following Six Months Degradation In Vitro

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 700 ◽  
Author(s):  
Alyah H. Shamsah ◽  
Sarah H. Cartmell ◽  
Stephen M. Richardson ◽  
Lucy A. Bosworth
Keyword(s):  
Tissue Regeneration ◽  
Annulus Fibrosus ◽  
Hydrolytic Degradation ◽  
Electrospun Nanofibers ◽  
Polymer Chains ◽  
Poly Lactic Acid ◽  
Fiber Morphology ◽  
Phosphate Buffered Saline

The annulus fibrosus—one of the two tissues comprising the intervertebral disc—is susceptible to injury and disease, leading to chronic pain and rupture. A synthetic, biodegradable material could provide a suitable scaffold that alleviates this pain and supports repair through tissue regeneration. The transfer of properties, particularly biomechanical, from scaffold to new tissue is essential and should occur at the same rate to prevent graft failure post-implantation. This study outlines the effect of hydrolytic degradation on the material properties of a novel blend of polycaprolactone and poly(lactic acid) electrospun nanofibers (50:50) over a six-month period following storage in phosphate buffered saline solution at 37 °C. As expected, the molecular weight distribution for this blend decreased over the 180-day period. This was in line with significant changes to fiber morphology, which appeared swollen and merged following observation using Scanning Electron Microscopy. Similarly, hydrolysis resulted in considerable remodeling of the scaffolds’ polymer chains as demonstrated by sharp increases in percentage crystallinity and tensile properties becoming stiffer, stronger and more brittle over time. These mechanical data remained within the range reported for human annulus fibrosus tissue and their long-term efficacy further supports this novel blend as a potential scaffold to support tissue regeneration.

Framework Structures for Mg Battery Cathodes

2016 ◽  
Vol 879 ◽  
pp. 2150-2152
Author(s):  
Shunsuke Yagi ◽  
Masaaki Fukuda ◽  
Tetsu Ichitsubo ◽  
Eiichiro Matsubara
Keyword(s):  
Prussian Blue ◽  
Room Temperature ◽  
Active Material ◽  
Electrochemical Quartz Crystal Microbalance ◽  
High Energy ◽  
Rechargeable Batteries ◽  
High Energy Density ◽  
Active Materials ◽  
Large Space ◽  
Extraction Behavior

Rechargeable Mg batteries have received intensive attention as affordable rechargeable batteries with high electromotive force, high energy density, and high safety. Mg possesses two valence electrons and has the lowest standard electrode potential (ca. -2.36 V vs. SHE) among the air-stable metals. There is another advantage that Mg metal can be used as an active material because Mg metal hardly forms dendrites. However, the slow diffusion of Mg ions in solid crystals prevents the realization of active materials for Mg rechargeable batteries at room temperature. Although some complex oxides have been reported to work as active materials at higher temperatures, Chevrel compounds are still the gold standards, which work at room temperature. However, the working voltage of the Mg battery using a Chevrel compound for the cathode is only ca. 1.2 V, which is far below that of Li-ion batteries (3-5 V). Nevertheless, Chevrel compounds have the significant advantage that a relatively large space exists in the crystal structure, which allows for fast Mg ion diffusion. In the present study, we investigated some materials with framework structures as cathodes for Mg batteries, which can alleviate the electrostatic constraint between Mg ions and cathode constituents. Specifically, we investigated the redox behavior of the thin films of Prussian blue and Prussian blue analogues in electrolytes containing an Mg salt using electrochemical quartz crystal microbalance and X-ray absorption spectroscopy. In addition, we discuss the electrochemical insertion/extraction behavior of Mg ions and their solvation structures.

scholarly journals Mechanical Integrity of Conductive Carbon-Black-Filled Aqueous Polymer Binder in Composite Electrode for Lithium-Ion Battery

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1460
Author(s):  
Kehua Peng ◽  
Yaolong He ◽  
Hongjiu Hu ◽  
Shufeng Li ◽  
Bao Tao
Keyword(s):  
Carbon Black ◽  
Composite Electrode ◽  
Mechanical Stability ◽  
Critical Role ◽  
Active Material ◽  
Mechanical Damage ◽  
Lithium Ion ◽  
Spherical Particles ◽  
Inorganic Filler ◽  
Composite Electrodes

The mechanical stability of aqueous binder and conductive composites (BCC) is the basis of the long-term service of composite electrodes in advanced secondary batteries. To evaluate the stress evolution of BCC in composite electrodes during electrochemical operation, we established an electrochemical–mechanical model for multilayer spherical particles that consists of an active material and a solid-electrolyte-interface (SEI)-enclosed BCC. The lithium-diffusion-induced stress distribution was studied in detail by coupling the influence of SEI and the viscoelasticity of inorganic-filler-doped polymeric bonding material. It was found that tensile hoop stress plays a critical role in determining whether a composite electrode is damaged or not—and circumferential cracks may primarily initiate in BCC, rather than in other electrode components. Further, the peak tensile stress of BCC is at the interface with SEI and does not occur at full lithiation due to the relaxation nature of polymer composite. Moreover, mechanical damage would be greatly misled if neglecting the existence of SEI. Finally, the structure integrity of the binder and conductive system can be effectively improved by (1) increasing the carbon black content as much as possible in the context of meeting cell capacity requirements—it is greater than 27% and 50% for sodium alginate and the mixtures of carboxy styrene butadiene latex and sodium carboxymethyl cellulose, respectively, for composite graphite anode; (2) reducing the elastic modulus of SEI to less than that of BCC; (3) decreasing the lithiation rate.

Rehabilitation After Oswestry Autologous-Chondrocyte Implantation: The OsCell Protocol

2003 ◽  
Vol 12 (2) ◽  
pp. 104-118 ◽  
Author(s):  
Andrea Bailey ◽  
Nicola Goodstone ◽  
Sharon Roberts ◽  
Jane Hughes ◽  
Simon Roberts ◽  
...  
Keyword(s):  
Autologous Chondrocyte Implantation ◽  
Weight Bearing ◽  
Critical Role ◽  
Data Sources ◽  
Cartilage Defects ◽  
Postoperative Rehabilitation ◽  
Data Synthesis ◽  
Chondrocyte Implantation ◽  
Type Data ◽  
Autologous Chondrocyte

Objective:To develop a postoperative rehabilitation protocol for patients receiving autologous-chondrocyte implantation (ACI) to repair articular-cartilage defects of the knee.Data Sources:careful review of both basic science and clinical literature, personal communication with colleagues dealing with similar cases, and the authors’ experience and expertise in rehabilitating numerous patients with knee pathologies, injuries, and trauma.Data Synthesis:Postoperative rehabilitation of the ACI patient plays a critical role in the outcome of the procedure. The goals are to improve function and reduce discomfort by focusing on 3 key elements: weight bearing, range of motion, and strengthening.Conclusions:The authors present 2 flexible postoperative protocols to rehabilitate patients after an ACI procedure to the knee.

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