Hybrid materials for meniscus replacement in the knee

The meniscus is cartilage that not only prevents the bones in knee joints to grind together but acts as a joint stabiliser. Many athletes and older people suffer from meniscus tears and degeneration. Meniscal tear treatments have been through meniscal suture or by partial meniscectomy (removal). These treatments may cause changes in loading or decreased contact area and increased contact stress. Consequently, the ultimate result is a total meniscectomy that potentially leads to osteoarthritis (OA). These current surgical strategies have lower success rates in younger patients. There are no successful artificial meniscus replacement devices for young patients, therefore, new materials for meniscus replacement are required. Here, the aim was to develop a novel biomimetic meniscus device made of a silica/polytetrahydrofuran (SiO2/polyTHF) inorganic/organic hybrid material. The device is biomimetic in terms of its structural design, mechanical properties, and integration with the host tissue. The device should delay onset of OA. The hybrid has unique properties in that is a bouncy material which has comparable mechanical properties to knee cartilage. Two pot hybrid synthesis was used to synthesise the SiO2/polyTHF hybrid and casting mould was developed based on the shrinkage factor of the hybrid. The hybrid synthesis modifications were conducted by controlling compositions and drying processes. Biological fixation of the hybrid meniscus was achieved by titanium anchors with gyroid porous architecture which can provide initial mechanical fixation and secondary biological fixation on the tibia. The architecture was designed using Solidworks and Rhinoceros software and printed by the Additive Manufacturing technique of selective laser melting (SLM). Mechanical testing of the device included compression, cyclic loading, shear strength and long-term 90 days in-vitro mechanical testing, tribology against living bovine 2 cartilage, and cell studies. The results suggest that combination of hybrid and Ti gyroid has potential to be meniscus implant due to comparable mechanical properties, low friction coefficient, and non-cytotoxicity.Open Acces

Engineering Dynamics and Life Sciences

From Preface: This is the fourteenth time when the conference “Dynamical Systems: Theory and Applications” gathers a numerous group of outstanding scientists and engineers, who deal with widely understood problems of theoretical and applied dynamics. Organization of the conference would not have been possible without a great effort of the staff of the Department of Automation, Biomechanics and Mechatronics. The patronage over the conference has been taken by the Committee of Mechanics of the Polish Academy of Sciences and Ministry of Science and Higher Education of Poland. It is a great pleasure that our invitation has been accepted by recording in the history of our conference number of people, including good colleagues and friends as well as a large group of researchers and scientists, who decided to participate in the conference for the first time. With proud and satisfaction we welcomed over 180 persons from 31 countries all over the world. They decided to share the results of their research and many years experiences in a discipline of dynamical systems by submitting many very interesting papers. This year, the DSTA Conference Proceedings were split into three volumes entitled “Dynamical Systems” with respective subtitles: Vibration, Control and Stability of Dynamical Systems; Mathematical and Numerical Aspects of Dynamical System Analysis and Engineering Dynamics and Life Sciences. Additionally, there will be also published two volumes of Springer Proceedings in Mathematics and Statistics entitled “Dynamical Systems in Theoretical Perspective” and “Dynamical Systems in Applications”

Exploring the Multifaceted Roles of Glycosaminoglycans (GAGs) - New Advances and Further Challenges

Glycosaminoglycans are linear, anionic polysaccharides (GAGs) consisting of repeating disaccharides. GAGs are ubiquitously localized throughout the extracellular matrix (ECM) and to the cell membranes of cells in all tissues. They are either conjugated to protein cores in the form of proteoglycans, e.g., chondroitin/dermatan sulfate (CS/DS), heparin/heparan sulfate (Hep/HS) and keratan sulfate (KS), as well as non-sulfated hyaluronan (HA). By modulating biological signaling GAGs participate in the regulation of homeostasis and also participate in disease progression. The book, entitled “Exploring the multifaceted roles of glycosaminoglycans (GAGs)—new advances and further challenges”, features original research and review articles. These articles cover several GAG-related timely topics in structural biology and imaging; morphogenesis, cancer, and other disease therapy and drug developments; tissue engineering; and metabolic engineering. This book also includes an article illustrating how metabolic engineering can be used to create the novel chondroitin-like polysaccharide.A prerequisite for communicating in any discipline and across disciplines is familiarity with the appropriate terminology. Several nomenclature rules exist in the field of biochemistry. The historical description of GAGs follows IUPAC and IUB nomenclature. New structural depictions such as the structural nomenclature for glycan and their translation into machine-readable formats have opened the route for cross-references with popular bioinformatics resources and further connections with other exciting “omics” fields

Exploring Quadrupolar Interactions of 23Na and 35Cl with Triple-Quantum MRS/MRI

Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) can be used to investigate the quadrupolar nuclei 23Na and 35Cl, each with a nuclear spin of 3/2. The Na+ cations and Cl- anions are involved in cellular functions and can undergo quadrupolar interactions with oppositely charged macromolecules. These interactions give rise to triple-quantum (TQ) signals. Compromised physiological functions change the macromolecular composition and ion content, which can be investigated with TQ MRI/MRS. The goal was to develop a sequence to acquire single-quantum (SQ) and TQ images and to map relaxation parameters in vivo within one measurement. First, a density-adapted radial MRI technique (DA-R) was implemented at a 9.4 T scanner. Phantom images demonstrated superior image quality and measurement time efficiency. High-resolution 23Na and 35Cl images allowed for distinction of anatomical features in rat. Second, TQ spectroscopy with time-proportional phase incrementation (TQ-TPPI) was used to acquire data in cells and in rat head. The results revealed interesting discrepancies in 23Na and 35Cl TQ signals, uncovering differences in the quadrupolar interactions of Na+ and Cl- on a molecular level. Finally, TQ-TPPI was combined with DA-R to create TQ and SQ TPPI imaging (TASTI). The sequence was sucsessfully applied to rat head. For the first time, localized ratios between TQ and SQ signal were mapped in different head regions. Furthermore, it enabled the distinction between TQ signal fractions in the intra- and extracellular space. With its ability to analyze local changes in ion content, relaxation times and TQ signal, the TASTI sequence has the potential to become the one tool to combine all major approaches to address 23Na NMR

Applied Mathematics to Mechanisms and Machines

This book brings together all 16 articles published in the Special Issue "Applied Mathematics to Mechanisms and Machines" of the MDPI Mathematics journal, in the section “Engineering Mathematics”. The subject matter covered by these works is varied, but they all have mechanisms as the object of study and mathematics as the basis of the methodology used. In fact, the synthesis, design and optimization of mechanisms, robotics, automotives, maintenance 4.0, machine vibrations, control, biomechanics and medical devices are among the topics covered in this book. This volume may be of interest to all who work in the field of mechanism and machine science and we hope that it will contribute to the development of both mechanical engineering and applied mathematics

Models and analysis of vocal emissions for biomedical applications

This book of Proceedings collects the papers presented at the 3rd International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2003, held 10-12 December 2003, Firenze, Italy. The workshop is organised every two years, and aims to stimulate contacts between specialists active in research and industrial developments, in the area of voice analysis for biomedical applications. The scope of the Workshop includes all aspects of voice modelling and analysis, ranging from fundamental research to all kinds of biomedical applications and related established and advanced technologies

Diseases of the Brain, Head and Neck, Spine 2020–2023

This open access book offers an essential overview of brain, head and neck, and spine imaging. Over the last few years, there have been considerable advances in this area, driven by both clinical and technological developments. Written by leading international experts and teachers, the chapters are disease-oriented and cover all relevant imaging modalities, with a focus on magnetic resonance imaging and computed tomography. The book also includes a synopsis of pediatric imaging. IDKD books are rewritten (not merely updated) every four years, which means they offer a comprehensive review of the state-of-the-art in imaging. The book is clearly structured and features learning objectives, abstracts, subheadings, tables and take-home points, supported by design elements to help readers navigate the text. It will particularly appeal to general radiologists, radiology residents, and interventional radiologists who want to update their diagnostic expertise, as well as clinicians from other specialties who are interested in imaging for their patient care