scholarly journals Impedance-Based Monitoring of Mesenchymal Stromal Cell Three-Dimensional Proliferation Using Aerosol Jet Printed Sensors: A Tissue Engineering Application

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2231 ◽  
Author(s):  
Sarah Tonello ◽  
Andrea Bianchetti ◽  
Simona Braga ◽  
Camillo Almici ◽  
Mirella Marini ◽  
...  

One of the main hurdles to improving scaffolds for regenerative medicine is the development of non-invasive methods to monitor cell proliferation within three-dimensional environments. Recently, an electrical impedance-based approach has been identified as promising for three-dimensional proliferation assays. A low-cost impedance-based solution, easily integrable with multi-well plates, is here presented. Sensors were developed using biocompatible carbon-based ink on foldable polyimide substrates by means of a novel aerosol jet printing technique. The setup was tested to monitor the proliferation of human mesenchymal stromal cells into previously validated gelatin-chitosan hybrid hydrogel scaffolds. Reliability of the methodology was assessed comparing variations of the electrical impedance parameters with the outcomes of enzymatic proliferation assay. Results obtained showed a magnitude increase and a phase angle decrease at 4 kHz (maximum of 2.5 kΩ and −9 degrees) and an exponential increase of the modeled resistance and capacitance components due to the cell proliferation (maximum of 1.5 kΩ and 200 nF). A statistically significant relationship with enzymatic assay outcomes could be detected for both phase angle and electric model parameters. Overall, these findings support the potentiality of this non-invasive approach for continuous monitoring of scaffold-based cultures, being also promising in the perspective of optimizing the scaffold-culture system.

2020 ◽  
Vol 10 (12) ◽  
pp. 1010
Author(s):  
Deepika Konakanchi ◽  
Amy L. de Jongh Curry ◽  
Robert S. Waters ◽  
Shalini Narayana

Transcranial magnetic stimulation (TMS) is a promising, non-invasive approach in the diagnosis and treatment of several neurological conditions. However, the specific results in the cortex of the magnitude and spatial distribution of the secondary electrical field (E-field) resulting from TMS at different stimulation sites/orientations and varied TMS parameters are not clearly understood. The objective of this study is to identify the impact of TMS stimulation site and coil orientation on the induced E-field, including spatial distribution and the volume of activation in the cortex across brain areas, and hence demonstrate the need for customized optimization, using a three-dimensional finite element model (FEM). A considerable difference was noted in E-field values and distribution at different brain areas. We observed that the volume of activated cortex varied from 3000 to 7000 mm3 between the selected nine clinically relevant coil locations. Coil orientation also changed the induced E-field by a maximum of 10%, and we noted the least optimal values at the standard coil orientation pointing to the nose. The volume of gray matter activated varied by 10% on average between stimulation sites in homologous brain areas in the two hemispheres of the brain. This FEM simulation model clearly demonstrates the importance of TMS parameters for optimal results in clinically relevant brain areas. The results show that TMS parameters cannot be interchangeably used between individuals, hemispheres, and brain areas. The focality of the TMS induced E-field along with its optimal magnitude should be considered as critical TMS parameters that should be individually optimized.


Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 247
Author(s):  
Guanhuier Wang ◽  
Yang An ◽  
Xinling Zhang ◽  
Pengbing Ding ◽  
Hongsen Bi ◽  
...  

Three-dimensional cell-laden tissue engineering has become an extensive research direction. This study aimed to evaluate whether chondrocyte spheroids (chondro-spheroids) prepared using the hanging-drop method could develop better cell proliferation and morphology maintenance characteristics, and be optimized as a micro unit for cartilage tissue engineering. Chondro-spheroids were loaded into a cross-linkable hybrid hydrogel of gelatin methacrylate (GelMA) and hyaluronic acid methacrylate (HAMA) in vivo and in vitro. Cell proliferation, aggregation, cell morphology maintenance as well as cartilage-related gene expression and matrix secretion in vitro and in vivo were evaluated. The results indicated that compared with chondrocyte-laden hydrogel, chondro-spheroid-laden hydrogel enhanced proliferation, had better phenotype maintenance, and a more natural morphological structure, which made it appropriate for use as a micro unit in cartilage tissue engineering.


2016 ◽  
Vol 13 (119) ◽  
pp. 20160073 ◽  
Author(s):  
Jordi Alastruey ◽  
Nan Xiao ◽  
Henry Fok ◽  
Tobias Schaeffter ◽  
C. Alberto Figueroa

Simulation of haemodynamics has become increasingly popular within the research community. Irrespective of the modelling approach (zero-dimensional (0D), one-dimensional (1D) or three-dimensional (3D)), in vivo measurements are required to personalize the arterial geometry, material properties and boundary conditions of the computational model. Limitations in in vivo data acquisition often result in insufficient information to determine all model parameters and, hence, arbitrary modelling assumptions. Our goal was to minimize and understand the impact of modelling assumptions on the simulated blood pressure, flow and luminal area waveforms by studying a small region of the systemic vasculature—the upper aorta—and acquiring a rich array of non-invasive magnetic resonance imaging and tonometry data from a young healthy volunteer. We first investigated the effect of different modelling assumptions for boundary conditions and material parameters in a 1D/0D simulation framework. Strategies were implemented to mitigate the impact of inconsistencies in the in vivo data. Average relative errors smaller than 7% were achieved between simulated and in vivo waveforms. Similar results were obtained in a 3D/0D simulation framework using the same inflow and outflow boundary conditions and consistent geometrical and mechanical properties. We demonstrated that accurate subject-specific 1D/0D and 3D/0D models of aortic haemodynamics can be obtained using non-invasive clinical data while minimizing the number of arbitrary modelling decisions.


2020 ◽  
Vol 12 (9) ◽  
pp. 3831
Author(s):  
Alice Dal Fovo ◽  
Mikel Sanz ◽  
Mohamed Oujja ◽  
Raffaella Fontana ◽  
Sara Mattana ◽  
...  

The non-invasive depth-resolved imaging of pictorial layers in paintings by means of linear optical techniques represents a challenge in the field of Cultural Heritage (CH). The presence of opaque and/or highly-scattering materials may obstruct the penetration of the radiation probe, thus impeding the visualization of the stratigraphy of paintings. Nonlinear Optical Microscopy (NLOM), which makes use of tightly-focused femtosecond pulsed lasers as illumination sources, is an emerging technique for the analysis of painted objects enabling micrometric three-dimensional (3D) resolution with good penetration capability in semi-transparent materials. In this work, we evaluated the potential of NLOM, specifically in the modality of Multi-Photon Excitation Fluorescence (MPEF), to probe the stratigraphy of egg-tempera mock-up paintings. A multi-analytical non-invasive approach, involving ultraviolet-visible-near infrared (UV-Vis-NIR) Fiber Optics Reflectance Spectroscopy, Vis-NIR photoluminescence, and Laser Induced Fluorescence, yielded key-information for the characterization of the constituting materials and for the interpretation of the nonlinear results. Furthermore, the use of three nonlinear optical systems allowed evaluation of the response of the analyzed paints to different excitation wavelengths and photon doses, which proved useful for the definition of the most suitable measurement conditions. The micrometric thickness of the paint layers, which was not measurable by means of Optical Coherence Tomography (OCT), was instead assessed by MPEF, thus demonstrating the effectiveness of this nonlinear modality in probing highly-scattering media, while ensuring the minimal photochemical disturbance to the examined materials.


Holzforschung ◽  
2011 ◽  
Vol 65 (5) ◽  
Author(s):  
Laura Tomppo ◽  
Markku Tiitta ◽  
Tapio Laakso ◽  
Anni Harju ◽  
Martti Venäläinen ◽  
...  

Abstract Scots pine (Pinus sylvestris L.) heartwood samples were measured with electrical impedance spectroscopy (EIS) at frequency range 1 Hz–10 MHz in green and relative humidity (RH) 65% conditioned moisture content (MC) after oven-drying. Complex impedance parameters were studied in relation to the density, moisture, resin acid and stilbene contents. The measurements were conducted in tangential (T) and longitudinal (L) directions with 36 samples in each analysis. For green MC, there were significant correlations between impedance phase angle and contents of stilbenes and resin acids at frequencies below 400 Hz. For the resin acid content, the strongest correlation with phase-angleT was -0.45 (P<0.01) at 100 Hz. Impedance magnitude correlated significantly with MC throughout the frequency range, e.g., at 10 kHz, r was -0.71 (P<0.001) for L-direction. In moisture conditioned state, the correlation between stilbenes and T-measured phase angle was strongest at 250 Hz, (r=-0.56, P<0.001). Equivalent circuit model of two ZARC-Cole elements in series was fitted for the measurements in green MC. Several model parameters correlated with MC (e.g., R1, L r=-0.64, P<0.001), but only one parameter correlated weakly with stilbene content (R2, T r=0.35, P<0.05). The study shows that EIS has a potential for independent determination of resin acid or stilbene contents and MC for green pine heartwood.


2017 ◽  
Vol 19 (2) ◽  
pp. 216 ◽  
Author(s):  
Paulo Sergio Cossi ◽  
Heron Werner ◽  
Alberto Borges Peixoto ◽  
Wellington P Martins ◽  
Edward Araujo Júnior

Endometrial pathology is frequent in premenopausal women and the diagnostic hysteroscopy is considered the gold standard for assessing endometrial cavity and congenital uterine anomalies. However it is an invasive and uncomfortable procedure. Saline contrast hysterosalgingography and hysterosalpingo-contrast sonography allow detailed assessment of the uterine cavity. We propose a virtual hysteroscopy from three-dimensional saline and three-dimensional hysterosalpingo-contrast sonography scan data to generate a virtual reality as a new noninvasive procedure for assessing the uterine cavity in uterine congenital anomaly and endometrial pathology cases as well.


Author(s):  
M. Campi ◽  
R. Catuogno ◽  
A. di Luggo ◽  
D. Iovane ◽  
D. Palomba

The research illustrated in this paper is part of a wider testing ground, aimed at identifying and developing processes of le arning and development taking place in archaeological contexts. These sites are investigated through the use of advanced technology, based on integrated methods of survey of new generation. The aim is to identify alternative languages of representation, able to read and to represent effectively the analyzed object and to propose alternative enjoyment systems. The case study is the Mithraeum in Santa Maria Capua Vetere, for which were carried out surveys with non-contact techniques, based on the use of instrumentations, for the acquisition of colorimetric and metric informations, that exploit a non-invasive approach. Data coming from laser scanner's sensors, combined with GPS receivers, are processed to define a three-dimensional centimetric space, in a single reference system of individual scans. Purpose of this research is to identify representation techniques able to communicate the sense of the multiple interrelations and of interferences among parties, providing the subsequent insertion of data into a wider project of cataloging, fruition and valuation of cultural heritage. The chance to diffuse Digital surveys is now a possible and implementable reality. The purpose is to spread awareness of World Heritage, in a participatory manner and based on the spiri t of knowledge, conveying all the strength of cultural content that heritage has.


ACTA IMEKO ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 241
Author(s):  
Leila Es Sebar ◽  
Leonardo Iannucci ◽  
Caterina Gori ◽  
Alessandro Re ◽  
Marco Parvis ◽  
...  

<p class="Abstract">This paper presents a long-term in-situ campaign to monitor contemporary bronze statuary exposed outdoors. The case study relates to the characterisation of three sculptures belonging to the Gori Art Collection, located in the Fattoria di Celle: ‘Cavaliere’ and ‘Miracolo – Composizione’ by Marino Marini and ‘Due forme o due ombre n°2’ by Luciano Minguzzi. The overall conservation state of the sculptures was investigated by means of a multi-analytical and non-invasive approach, involving different techniques. Three-dimensional photogrammetry was performed to fully document the artworks. The chemical and microstructural features of the corrosion patinas were then characterised through X-ray fluorescence and Raman spectroscopy. In addition, the stability and the protective effectiveness of the corrosion products were assessed by electrochemical impedance spectroscopy. Thanks to the combined use of these specific techniques, the information extracted through the different analyses could be correlated with each other and with the exposure conditions. The different corrosion products were identified as being primarily copper sulphates and phosphates, and they were correlated with the different microclimate conditions related to their location on the statues. The information gathered from the presented multi-analytical approach represents the fundamental knowledge required to develop a tailored conservation project to assure the long-lasting preservation of these artworks.</p>


Author(s):  
H.W. Deckman ◽  
B.F. Flannery ◽  
J.H. Dunsmuir ◽  
K.D' Amico

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.


2012 ◽  
Vol 153 (40) ◽  
pp. 1570-1577 ◽  
Author(s):  
Attila Nemes ◽  
Anita Kalapos ◽  
Péter Domsik ◽  
Tamás Forster

Three-dimensional speckle-tracking echocardiography is a new cardiac imaging methodology, which allows three-dimensional non-invasive evaluation of the myocardial mechanics. The aim of this review is to present this new tool emphasizing its diagnostic potentials and demonstrating its limitations, as well. Orv. Hetil., 2012, 153, 1570–1577.


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