Stretchable Printed Device for the Simultaneous Sensing of Temperature and Strain Validated in a Mouse Wound Healing Model

Author(s):  
Wim Deferme ◽  
Manoj Jose ◽  
Annelies Bronckaers ◽  
Rachith S N ◽  
Dieter Reenaers ◽  
...  

Abstract Temperature and strain are two vital parameters that play a significant role in wound diagnosis and healing. As periodic temperature measurements with a custom thermometer or strain measurements with conventional metallic gauges became less feasible for the modern competent health monitoring, individual temperature and strain measurement modalities incorporated into wearables and patches were developed. The proposed research in the article shows the development of a single sensor solution which can simultaneously measure both the above mentioned parameters. This work integrates a thermoelectric principle based temperature measurement approach into wearables, ensuring flexibility and bendability properties without affecting its thermo-generated voltage. The modified thermoelectric material helped to achieve stretchability of the sensor, thanks to its superior mechano-transduction properties. Moreover, the stretch-induced resistance changes become an additional marker for strain measurements so that both the parameters can be measured with the same sensor. Due to the independent measurement parameters (open circuit voltage and sensor resistance ), the sensing model is greatly attractive for measurements without cross-sensitivity. The highly resilient temperature and strain sensor show excellent linearity, repeatability and good sensitivity. Besides, due to the compatibility of the fabrication scheme to low temperature processing of the flexible materials and to mass volume production, printed fabrication methodologies were adopted to realize the sensor. This promises low cost production and a disposable nature (single use) of the sensor patch. The temperature-strain dual parameter semi-transparent sensor has been further tested on mice wounds in vivo. The preliminary experiments on mice wounds offer prospects for developing smart, i.e. sensorized, wound dressings for clinical applications.

Author(s):  
R.J. Mount ◽  
R.V. Harrison

The sensory end organ of the ear, the organ of Corti, rests on a thin basilar membrane which lies between the bone of the central modiolus and the bony wall of the cochlea. In vivo, the organ of Corti is protected by the bony wall which totally surrounds it. In order to examine the sensory epithelium by scanning electron microscopy it is necessary to dissect away the protective bone and expose the region of interest (Fig. 1). This leaves the fragile organ of Corti susceptible to physical damage during subsequent handling. In our laboratory cochlear specimens, after dissection, are routinely prepared by the O-T- O-T-O technique, critical point dried and then lightly sputter coated with gold. This processing involves considerable specimen handling including several hours on a rotator during which the organ of Corti is at risk of being physically damaged. The following procedure uses low cost, readily available materials to hold the specimen during processing ,preventing physical damage while allowing an unhindered exchange of fluids.Following fixation, the cochlea is dehydrated to 70% ethanol then dissected under ethanol to prevent air drying. The holder is prepared by punching a hole in the flexible snap cap of a Wheaton vial with a paper hole punch. A small amount of two component epoxy putty is well mixed then pushed through the hole in the cap. The putty on the inner cap is formed into a “cup” to hold the specimen (Fig. 2), the putty on the outside is smoothed into a “button” to give good attachment even when the cap is flexed during handling (Fig. 3). The cap is submerged in the 70% ethanol, the bone at the base of the cochlea is seated into the cup and the sides of the cup squeezed with forceps to grip it (Fig.4). Several types of epoxy putty have been tried, most are either soluble in ethanol to some degree or do not set in ethanol. The only putty we find successful is “DUROtm MASTERMENDtm Epoxy Extra Strength Ribbon” (Loctite Corp., Cleveland, Ohio), this is a blue and yellow ribbon which is kneaded to form a green putty, it is available at many hardware stores.


2019 ◽  
Vol 33 (9) ◽  
pp. 1285-1297 ◽  
Author(s):  
Cornelia Wiegand ◽  
Martin Abel ◽  
Uta-Christina Hipler ◽  
Peter Elsner ◽  
Michael Zieger ◽  
...  

Background Application of controlled in vitro techniques can be used as a screening tool for the development of new hemostatic agents allowing quantitative assessment of overall hemostatic potential. Materials and methods Several tests were selected to evaluate the efficacy of cotton gauze, collagen, and oxidized regenerated cellulose for enhancing blood clotting, coagulation, and platelet activation. Results Visual inspection of dressings after blood contact proved the formation of blood clots. Scanning electron microscopy demonstrated the adsorption of blood cells and plasma proteins. Significantly enhanced blood clot formation was observed for collagen together with β-thromboglobulin increase and platelet count reduction. Oxidized regenerated cellulose demonstrated slower clotting rates not yielding any thrombin generation; yet, led to significantly increased thrombin-anti-thrombin-III complex levels compared to the other dressings. As hemostyptica ought to function without triggering any adverse events, induction of hemolysis, instigation of inflammatory reactions, and initiation of the innate complement system were also tested. Here, cotton gauze provoked high PMN elastase and elevated SC5b-9 concentrations. Conclusions A range of tests for desired and undesired effects of materials need to be combined to gain some degree of predictability of the in vivo situation. Collagen-based dressings demonstrated the highest hemostyptic properties with lowest adverse reactions whereas gauze did not induce high coagulation activation but rather activated leukocytes and complement.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Woo Seok Kim ◽  
Sungcheol Hong ◽  
Milenka Gamero ◽  
Vivekanand Jeevakumar ◽  
Clay M. Smithhart ◽  
...  

AbstractThe vagus nerve supports diverse autonomic functions and behaviors important for health and survival. To understand how specific components of the vagus contribute to behaviors and long-term physiological effects, it is critical to modulate their activity with anatomical specificity in awake, freely behaving conditions using reliable methods. Here, we introduce an organ-specific scalable, multimodal, wireless optoelectronic device for precise and chronic optogenetic manipulations in vivo. When combined with an advanced, coil-antenna system and a multiplexing strategy for powering 8 individual homecages using a single RF transmitter, the proposed wireless telemetry enables low cost, high-throughput, and precise functional mapping of peripheral neural circuits, including long-term behavioral and physiological measurements. Deployment of these technologies reveals an unexpected role for stomach, non-stretch vagal sensory fibers in suppressing appetite and demonstrates the durability of the miniature wireless device inside harsh gastric conditions.


Author(s):  
Laura Wienands ◽  
Franziska Theiß ◽  
James Eills ◽  
Lorenz Rösler ◽  
Stephan Knecht ◽  
...  

AbstractParahydrogen-induced polarization is a hyperpolarization method for enhancing nuclear magnetic resonance signals by chemical reactions/interactions involving the para spin isomer of hydrogen gas. This method has allowed for biomolecules to be hyperpolarized to such a level that they can be used for real time in vivo metabolic imaging. One particularly promising example is fumarate, which can be rapidly and efficiently hyperpolarized at low cost by hydrogenating an acetylene dicarboxylate precursor molecule using parahydrogen. The reaction is relatively slow compared to the timescale on which the hyperpolarization relaxes back to thermal equilibrium, and an undesirable 2nd hydrogenation step can convert the fumarate into succinate. To date, the hydrogenation chemistry has not been thoroughly investigated, so previous work has been inconsistent in the chosen reaction conditions in the search for ever-higher reaction rate and yield. In this work we investigate the solution preparation protocols and the reaction conditions on the rate and yield of fumarate formation. We report conditions to reproducibly yield over 100 mM fumarate on a short timescale, and discuss aspects of the protocol that hinder the formation of fumarate or lead to irreproducible results. We also provide experimental procedures and recommendations for performing reproducible kinetics experiments in which hydrogen gas is repeatedly bubbled into an aqueous solution, overcoming challenges related to the viscosity and surface tension of the water.


2020 ◽  
Author(s):  
Joost van Haasteren ◽  
Altar M Munis ◽  
Deborah R Gill ◽  
Stephen C Hyde

Abstract The gene and cell therapy fields are advancing rapidly, with a potential to treat and cure a wide range of diseases, and lentivirus-based gene transfer agents are the vector of choice for many investigators. Early cases of insertional mutagenesis caused by gammaretroviral vectors highlighted that integration site (IS) analysis was a major safety and quality control checkpoint for lentiviral applications. The methods established to detect lentiviral integrations using next-generation sequencing (NGS) are limited by short read length, inadvertent PCR bias, low yield, or lengthy protocols. Here, we describe a new method to sequence IS using Amplification-free Integration Site sequencing (AFIS-Seq). AFIS-Seq is based on amplification-free, Cas9-mediated enrichment of high-molecular-weight chromosomal DNA suitable for long-range Nanopore MinION sequencing. This accessible and low-cost approach generates long reads enabling IS mapping with high certainty within a single day. We demonstrate proof-of-concept by mapping IS of lentiviral vectors in a variety of cell models and report up to 1600-fold enrichment of the signal. This method can be further extended to sequencing of Cas9-mediated integration of genes and to in vivo analysis of IS. AFIS-Seq uses long-read sequencing to facilitate safety evaluation of preclinical lentiviral vector gene therapies by providing IS analysis with improved confidence.


2020 ◽  
Vol 18 ◽  
pp. 228080002097517
Author(s):  
Yuan-ming Geng ◽  
Dong-ni Ren ◽  
Shu-yi Li ◽  
Zong-yi Li ◽  
Xiao-qing Shen ◽  
...  

Background: Poly Ether Ether Ketone (PEEK) has been considered as a potential alternative material for endosseous dental implants, for its low elastic modulus, biocompatibility, and low cost in customized device manufacture. Hydroxyapatite-incorporation is supposed to improve the poor osseointegration of PEEK. Methods: In the present study we analyzed the in vivo response of hydroxyapatite-incorporated PEEK (PEEK-HA) implants in canine tibia. PEEK-HA and PEEK implants were implanted and were examined 4 weeks and 12 weeks after implantation with radiology and histology. Commercial titanium dental implants served as controls. Results: The ratio of bone volume to tissue volume of PEEK-HA implants was higher than that of PEEK implants 4 weeks after implantation in the μ-CT analysis. The bone implant contact of PEEK and PEEK-HA implants showed no statistical difference in the histological examination, but newly-formed bone around PEEK-HA implants showed more signs of mineralization than that around PEEK implants. Conclusion: The study suggested that bone formation was improved with hydroxyapatite-incorporation in PEEK. Hydroxyapatite-incorporated PEEK implants may represent a potential material for endosseous dental implant.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Lingyu Yang ◽  
Dehai Xian ◽  
Xia Xiong ◽  
Rui Lai ◽  
Jing Song ◽  
...  

Proanthocyanidins (PCs) are naturally occurring polyphenolic compounds abundant in many vegetables, plant skins (rind/bark), seeds, flowers, fruits, and nuts. Numerousin vitroandin vivostudies have demonstrated myriad effects potentially beneficial to human health, such as antioxidation, anti-inflammation, immunomodulation, DNA repair, and antitumor activity. Accumulation of prooxidants such as reactive oxygen species (ROS) exceeding cellular antioxidant capacity results in oxidative stress (OS), which can damage macromolecules (DNA, lipids, and proteins), organelles (membranes and mitochondria), and whole tissues. OS is implicated in the pathogenesis and exacerbation of many cardiovascular, neurodegenerative, dermatological, and metabolic diseases, both through direct molecular damage and secondary activation of stress-associated signaling pathways. PCs are promising natural agents to safely prevent acute damage and control chronic diseases at relatively low cost. In this review, we summarize the molecules and signaling pathways involved in OS and the corresponding therapeutic mechanisms of PCs.


2021 ◽  
pp. 088532822199601
Author(s):  
Linying Shi ◽  
Fang Lin ◽  
Mou Zhou ◽  
Yanhui Li ◽  
Wendan Li ◽  
...  

The ever-growing threats of bacterial infection and chronic wound healing have provoked an urgent need for novel antibacterial wound dressings. In this study, we developed a wound dressing for the treatment of infected wounds, which can reduce the inflammatory period (through the use of gentamycin sulfate (GS)) and enhance the granulation stage (through the addition of platelet-rich plasma (PRP)). Herein, the sustained antimicrobial CMC/GMs@GS/PRP wound dressings were developed by using gelatin microspheres (GMs) loading GS and PRP, covalent bonding to carboxymethyl chitosan (CMC). The prepared dressings exhibited high water uptake capability, appropriate porosity, excellent mechanical properties, sustain release of PRP and GS. Meanwhile, the wound dressing showed good biocompatibility and excellent antibacterial ability against Gram-negative and Gram-positive bacteria. Moreover, in vivo experiments further demonstrated that the prepared dressings could accelerate the healing process of E. coli and S. aureus-infected full-thickness wounds i n vivo, reepithelialization, collagen deposition and angiogenesis. In addition, the treatment of CMC/GMs@GS/PRP wound dressing could reduce bacterial count, inhibit pro-inflammatory factors (TNF-α, IL-1β and IL-6), and enhance anti-inflammatory factors (TGF-β1). The findings of this study suggested that biocompatible wound dressings with dual release of GS and PRP have great potential in the treatment of chronic and infected wounds.


2003 ◽  
Vol 28 (11) ◽  
pp. 905 ◽  
Author(s):  
A. Unterhuber ◽  
B. Považay ◽  
B. Hermann ◽  
H. Sattmann ◽  
W. Drexler ◽  
...  

1997 ◽  
Vol 496 ◽  
Author(s):  
Y.-I. Jang ◽  
B. Huang ◽  
H. Wang ◽  
Y.-M. Chiang ◽  
D. R. Sadoway

ABSTRACTAluminum is of interest as a constituent for Li battery electrodes due to its low cost and low mass, and because ab initio calculations indicate that solid solution of LiAlO2 with LiMO2 (M = transition metal) in the α-NaFeO2 structure can increase intercalation voltage [1]. In this study, we investigated the effect of Al doping on LiCoO2 and LiMnO2. Single phase LiAlyCo1-yO2 has been synthesized up to y = 0.5 by firing homogenous hydroxide precursors. A systematic increase in the open circuit voltage is observed with Al content. In LiAlyMn1-yO2, the addition of LiAlO2 stabilizes LiMnO2 in the α-NaFeO2 structure under conditions where neither endmember is stable in the structure. High reversible capacity was obtained over both a 4 V and 3 V plateau, indicating that the compound transforms to a spinel-related structure during cycling, but that the cooperative Jahn-Teller distortion is suppressed.


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