ORCID Profile
0000-0001-5653-5491
Current Organisations
University of Wollongong
,
Friedrich-Alexander-Universität Erlangen-Nürnberg
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Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5AN02534F
Abstract: The use of capacitively coupled contactless conductivity detection (C 4 D) for the characterisation of thin conductive graphene fibres, graphene composite fibres, and graphene coated fibrous materials is demonstrated for the first time.
Publisher: Elsevier BV
Date: 08-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8SM01227J
Abstract: Using ultrasound, we provide a simple and rapid contactless approach for the mechanical characterization of photocrosslinked hydrogels with swelling properties.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7AN00442G
Abstract: The application of a capacitively coupled contactless conductivity sensor for the quantitative characterization of conductive fibers.
Publisher: Wiley
Date: 29-07-2010
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.ACTBIO.2019.04.055
Abstract: In the present work we have revisited the application of quantitative ultrasound imaging (QUI) to cellular hydrogels, by using the reference phantom method (RPM) in combination with a local attenuation compensation algorithm. The investigated biological s les consisted of cell-laden collagen hydrogels with PC12 neural cells. These cell-laden hydrogels were used to calibrate the integrated backscattering coefficient (IBC) as a function of cell density, which was then used to generate parametric images of local cell density. The image resolution used for QUI and its impact on the relative IBC error was also investigated. Another important contribution of our work was the monitoring of PC12 cell proliferation. The cell number estimates obtained via the calibrated IBC compared well with data obtained using a conventional quantitative method, the MTS assay. Evaluation of spectral changes as a function of culture time also provided additional information on the cell cluster size, which was found to be in close agreement with that observed by microscopy. Last but not least, we also applied QUI on a 3D printed cellular construct in order to illustrate its capabilities for the evaluation of bioprinted structures. STATEMENT OF SIGNIFICANCE: While there is intensive research in the areas of polymer science, biology, and 3D bio-printing, there exists a gap in available characterisation tools for the non-destructive inspection of biological constructs in the three-dimensional domain, on the macroscopic scale, and with fast data acquisition times. Quantitative ultrasound imaging is a suitable characterization technique for providing essential information on the development of tissue engineered constructs. These results provide a detailed and comprehensive guide on the capabilities and limitations of the technique.
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.ACTBIO.2022.05.037
Abstract: In this work we present a standardised quantitative ultrasound imaging (SQUI) approach for the non-destructive three-dimensional imaging and quantification of cartilage formation in hydrogel based bioscaffolds. The standardised concept involves the processing of ultrasound backscatter data with respect to an acellular phantom in combination with the compensation of sound speed mismatch diffraction effects between the bioscaffold and the phantom. As a proof-of-concept, the SQUI approach was tested on a variety of bioscaffolds with varying degree of neocartilage formation. These were composed of Gelatine Methacryloyl (GelMA) hydrogels laden with human adipose-derived stem cells (hADSCs). These were cultured under chondrogenic stimulation following a previously established protocol, where the degree of the neocartilage formation was modulated using different GelMA network densities (6, 8, 10 % w/v) and culture time (0, 14, 28 days). Using the SQUI approach we were able to detect marked acoustic and morphological changes occurring in the bioscaffolds a result of their different chondrogenic outcome. We defined an acoustic neocartilage indicator, the sonomarker, for the selective imaging and quantification of neocartilage formation. The sonomarker, of backscatter intensity logIBC -2.4, was found to correlate with data obtained via standard destructive bioassays. The ultrasonic evaluation of human specimens confirmed the sonomarker as a relevant intensity, although it was found to shift to higher intensity values in proportion to the cartilage condition as inferred from sound speed measurements. This study demonstrates the potential of the SQUI approach for the realization of non-destructive analysis of cartilage regeneration over-time. STATEMENT OF SIGNIFICANCE: As tissue engineering strategies for neocartilage regeneration evolve towards clinical implementation, alternative characterisation approaches that allow the non-destructive monitoring of extracellular matrix formation in implantable hydrogel based bioscaffolds are needed. In this work we present an innovative standardized quantitative ultrasound imaging (SQUI) approach that allows the non-destructive, volumetric, and quantitative evaluation of neocartilage formation in hydrogel based bioscaffolds. The standardised concept aims to provide a robust approach that accounts for the dynamic changes occurring during the conversion from a cellular bioscaffold towards the formation of a neocartilage construct. We believe that the SQUI approach will be of great benefit for the evaluation of constructs developing neocartilage, not only for in-vitro applications but also potentially applicable to in-vivo applications.
Publisher: Wiley
Date: 10-06-2010
Publisher: American Chemical Society (ACS)
Date: 07-02-2013
DOI: 10.1021/LA3047609
Abstract: We have investigated the role of linker molecules in quantum-dot-sensitized solar cells (QDSSCs) using density-functional theory (DFT) and experiments. Linkers not only govern the number of attached QDs but also influence charge separation, recombination, and transport. Understanding their behavior is therefore not straightforward. DFT calculations show that mercaptopropionic acid (MPA) and cysteine (Cys) exhibit characteristic binding configurations on TiO(2) surfaces. This information is used to optimize the cell assembly process, yielding Cys-based cells that significantly outperform MPA cells, and reach power conversion efficiencies (PCE) as high as 2.7% under AM 1.5 illumination. Importantly, the structural information from theory also helps understand the cause for this improved performance.
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6TC04308A
Abstract: PCE is improved owing to the enhanced J SC , resulting from larger light harvesting and higher charge generation.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1LC00538C
Abstract: Wireless bipolar electrochemistry on a surface-accessible textile-based electrofluidic 3D construct.
Publisher: American Chemical Society (ACS)
Date: 02-12-2013
DOI: 10.1021/LA403633E
Abstract: We present a series of non-stoichiometric cadmium sulfide quantum-dot (QD) models. Using density functional theory (DFT) and semi-empirical molecular orbital (MO) calculations, we explore the ligand binding and exchange chemistry of these models. Their surface morphology allows for these processes to be rationalized on the atomic scale. This is corroborated by ultraviolet-visible (UV-vis), infrared (IR), and inductively coupled plasma-optical emission spectroscopy (ICP-OES).
Publisher: Wiley
Date: 08-09-2011
No related grants have been discovered for Andres Ruland.