29 research outputs found
Abrasion Induced Volume Loss in Porcine Teeth Measured Using X-Ray Microtomography
Teeth are complex biological structures consisting primarily of enamel and dentin. The mechanical loading of teeth due to the action of brushing provides a complex interaction between applied forces and the biological structure, resulting in volume loss of dental tissue. The volume loss as a resulting of using an ex situ brushing of teeth was measured using x-ray microcomputed tomography (XCT) and corresponding image analyses. Three-dimension reconstructions of teeth reveal a considerably loss of dentin at a rate of over 30 times that of enamel during brushing, as would be expected by the consideration of the corresponding structures. The approach here is flexible and can be applied to a range of brushing, teeth, and environmental conditions
Resilient and agile engineering solutions to address societal challenges such as coronavirus pandemic
The world is witnessing tumultuous times as major economic powers including the US, UK, Russia, India, and most of Europe continue to be in a state of lockdown. The worst-hit sectors due to this lockdown are sales, production (manufacturing), transport (aerospace and automotive) and tourism. Lockdowns became necessary as a preventive measure to avoid the spread of the contagious and infectious “Coronavirus Disease 2019” (COVID-19). This newly identified disease is caused by a new strain of the virus being referred to as Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS CoV-2; formerly called 2019-nCoV). We review the current medical and manufacturing response to COVID-19, including advances in instrumentation, sensing, use of lasers, fumigation chambers and development of novel tools such as lab-on-the-chip using combinatorial additive and subtractive manufacturing techniques and use of molecular modelling and molecular docking in drug and vaccine discovery. We also offer perspectives on future considerations on climate change, outsourced versus indigenous manufacturing, automation, and antimicrobial resistance. Overall, this paper attempts to identify key areas where manufacturing can be employed to address societal challenges such as COVID-19
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Biomimetic generation of the strongest known biomaterial found in limpet tooth
The biomaterial with the highest known tensile strength is a unique composite of chitin and goethite (α-FeO(OH)) present in teeth from the Common Limpet (Patella vulgata). A biomimetic based on limpet tooth, with corresponding high-performance mechanical properties is highly desirable. Here we report on the replication of limpet tooth developmental processes ex vivo, where isolated limpet tissue and cells in culture generate new biomimetic structures. Transcriptomic analysis of each developmental stage of the radula, the organ from which limpet teeth originate, identifies sequential changes in expression of genes related to chitin and iron processing. We quantify iron and chitin metabolic processes in the radula and grow isolated radula cells in vitro. Bioinspired material can be developed with electrospun chitin mineralised by conditioned media from cultured radula cells. Our results inform molecular processes behind the generation of limpet tooth and establish a platform for development of a novel biomimetic with comparable properties
3D imaging of cell interactions with electrospun PLGA nanofiber membranes for bone regeneration
We acknowledge funding from the QMUL Pump-Priming
Research Funding for Cross-Faculty Initiatives 2011-12 (EPSRC
Fibre-matrix interactions in model glass fibre-thermoplastic composities
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collagen fibrils in antler bone Nanointerfacial strength between non-collagenous protein and References Nanointerfacial strength between non-collagenous protein and collagen fibrils in antler bone
Antler bone displays considerable toughness through the use of a complex nanofibrous structure of mineralized collagen fibrils (MCFs) bound together by non-collagenous proteins (NCPs). While the NCP regions represent a small volume fraction relative to the MCFs, significant surface area is evolved upon failure of the nanointerfaces formed at NCP-collagen fibril boundaries. The mechanical properties of nanointerfaces between the MCFs are investigated directly in this work using an in situ atomic force microscopy technique to pull out individual fibrils from the NCP. Results show that the NCP-fibril interfaces in antler bone are weak, which highlights the propensity for interface failure at the nanoscale in antler bone and extensive fibril pullout observed at antler fracture surfaces. The adhesion between fibrils and NCP is additionally suggested as being rate dependent, with increasing interfacial strength and fracture energy observed when pullout velocity decreases
Evaluation of X-ray tomography contrast agents: A review of production, protocols, and biological applications
X-ray computed tomography is a strong tool that finds many applications both in medical applications and in the investigation of biological and nonbiological samples. In the clinics, X-ray tomography is widely used for diagnostic purposes whose three-dimensional imaging in high resolution helps physicians to obtain detailed image of investigated regions. Researchers in biological sciences and engineering use X-ray tomography because it is a nondestructive method to assess the structure of their samples. In both medical and biological applications, visualization of soft tissues and structures requires special treatment, in which special contrast agents are used. In this detailed report, molecule-based and nanoparticle-based contrast agents used in biological applications to enhance the image quality were compiled and reported. Special contrast agent applications and protocols to enhance the contrast for the biological applications and works to develop nanoparticle contrast agents to enhance the contrast for targeted drug delivery and general imaging applications were also assessed and listed.Turkiye Bilimsel ve Teknolojik Arastirma KurumuTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [2219]Turkiye Bilimsel ve Teknolojik Arastirma Kurumu, Grant/Award Number: 2219 Post Doctoral Scholarship ProgramWOS:0004678620000172-s2.0-85061894342PubMed: 3078609
Adhesion Anisotropy between Contacting Electrospun Fibers
The mechanical properties of electrospun
fiber networks are critical
in a range of applications from filtration to tissue engineering and
are dependent on the adhesion between contacting fibers within the
network. This adhesion is complex as electrospun networks exhibit
a variety of contacts, including both cross-cylinder and parallel
fiber configurations. In situ atomic force microscopy (AFM) was used
to quantify the work of adhesion between a pair of individual electrospun
polyamide fibers using controlled orientations and measurable contact
areas. The work of adhesion was found to depend strongly on the fiber–fiber
contact, with the separation of fibers in a parallel fiber configuration
exhibiting considerably higher work of adhesion across a range of
contact lengths than a cross-cylinder configuration. Our work therefore
highlights direction-dependent adhesion behavior between electrospun
fibers due to a suggested polymer chain orientation mechanism which
increases net van der Waals interactions and indicates the variability
of adhesion within a random electrospun fiber network