1,509 research outputs found

    Silicon Nitride and Metalized Halloysite Nanotube for Enhanced Bacteriostatic Activity, Wound Healing, and Tissue Regeneration

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    Metals such as titanium have been used in implants, but there are often cases of infection and rejection of the implant from the body. In the past decade, the use of metal nanoparticles has seen increasing demand as an alternative treatment for reducing microbial infections, leading to progress in orthopedic surgery and wound healing. Recent investigations have developed new biomaterial bone substitutes with novel structural, biological, and mechanical properties. Advanced ceramic materials, such as Si3N4, may fulfill all the requirements above and represent a promising alternative to metals or polymers. However, the above mentioned materials have limitations because they are not biodegradable, not biocompatible, and do not contain inherent antimicrobial properties. This research is subdivided into three projects. First, it aims to introduce antibacterial properties into fabricated 3D implants by combining antimicrobial and base polymer powders before processing, which will make the material biocompatible and biodegradable. Second, it aims to fabricate multifunctional antimicrobial blow-spun nanocomposite fiber to facilitate wound healing and reduce microbial infection. Third, it aims to fabricate a biodegradable nanocomposite hydrogel patch for the development of chronic wound healing treatment. A patented electrodeposition process was used to coat magnesium (Mg) on the HNT outer surfaces to add additional antimicrobial properties. Gentamicin sulfate was vacuum loaded into the lumen of the HNTs, which had already been coated with Mg. Si3N4 was added to the gentamicin-loaded MgHNT to promote cell adhesion and differentiation, and the resulting composite was then 3D printed/blow-spun into the required shapes according to the testing protocol. FTIR, XRD, and SEM images showed the presence of magnesium on halloysite. cytotoxicity tests show that the fabricated nanocomposites were not toxic to mammalian cells. The results of the antimicrobial activity showed a pronounced inhibition of bacterial growth in all fabricated nanocomposites. Cell proliferation assays showed that Si3N4 enhanced proliferation in all nanocomposites. The porosity test showed that the addition of Si3N4 does not affect the porosity and the cell attachment. The histological staining showed an increase in both calcium and mucopolysaccharides. The nanocomposite shows excellent mechanical properties and a lower contact angle after surface coating with protein. Nanocomposites degraded slowly during the biodegradation test, enabling the growth of new bone cells. Si3N4 gives the cellular surface roughness structure, hydrophilicity, and protein adsorption capability

    Friction of biomechanical interfaces

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    Stem Cells in Domestic Animals

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    Stem cells are an attractive tool for cell-based therapies in regenerative medicine, both for humans and animals. The research and review articles published in this first book of the Collection “Stem Cells in Domestic Animals: Applications in Health and Production” are excellent examples of the recent advances made in the field of stem/stromal cell research in veterinary medicine. In this field, sophisticated and new treatments are now required for improving patients’ quality of life; in livestock animals, the goal of regenerative medicine is to improve not only animal welfare but also the quality of production, aiming to preserve human health. The contributions collected in this book concern both laboratory research and clinical applications of mesenchymal stem/stromal cells. The increasing knowledge of cell-based therapies may constitute an opportunity for researchers, veterinary practitioners, and animal owners to contribute to animal and human health and well-being

    Biofidelic simulations of embryonic joint growth and morphogenesis

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    During skeletal development, the opposing surfaces in the joint mould into interlocking and reciprocal shapes in a process called morphogenesis. Morphogenesis is critical to the health and function of the joint, and yet, little is known about the process of joint morphogenesis. For example, how do different joints acquire their specific shapes? Which cellular processes underlie joint shaping and how are they regulated? However, it is known that fetal movements are critical to joint development, with alterations or absences of movement being implicated in multiple pre- and post-natal musculoskeletal conditions. This doctorate explored the cell-level dynamics governing joint growth and the implication of movements in regulating them, using novel biofidelic and mechanobiological models of joint growth. Cell-level data from wild type zebrafish larvae were tracked and synthesised in a biofidelic simulation of zebrafish jaw joint growth. Growth characteristics were quantified revealing a strong anisotropy (Chapter 3). Next, zebrafish larvae were immobilised using drug treatment. The material properties of the zebrafish jaw cartilage were measured using nano-indentation in the presence or absence of movement showing a delay in cartilage stiffening in immobilised larvae (Chapter 4). Then, I developed a novel mechanobiological model of zebrafish jaw joint growth, which identified a correlation between growth characteristics and the dynamic patterns of mechanical stimuli experienced by joint elements over jaw motion (Chapter 5). Finally, local growth rates were characterised in the mouse elbow in the presence or absence of skeletal muscles. Spatial heterogeneity in the growth rates correlated with the emergence of specific shape features at the level of the condyles. Immobilisation led to disruption of the local growth rates correlated with failed shape differentiation of the condyles. The relative contribution of key cell activities to growth such as cell volume expansion, cell number increases and extracellular matrix expansion, were shown to vary over time in both wild types and muscleless-limbs and to be altered in the absence of skeletal muscles (Chapter 6). This research offers avenues for improvement in simulations of joint development and potentially other organs. It provides fundamental advance in our understanding of mechanoregulation in the developing joint and increases our understanding of the origins of musculoskeletal abnormalities.Open Acces

    Biomaterials for Bone Tissue Engineering 2020

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    This book presents recent advances in the field of bone tissue engineering, including molecular insights, innovative biomaterials with regenerative properties (e.g., osteoinduction and osteoconduction), and physical stimuli to enhance bone regeneration

    International consensus statement on allergy and rhinology: Allergic rhinitis – 2023

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    Background In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document. Methods ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work. Results ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost. Conclusion The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment
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