We here report an improved experimental technique for the determination of Young׳s modulus and uniaxial strength of extracellular bone matrix at the single micrometer scale, giving direct access to the (homogeneous) deformation (or strain) states of the tested samples and to the corresponding mechanically recoverable energy, called potential or elastic energy. Therefore, a new protocol for Focused Ion Beam milling of prismatic non-tapered micropillars, and attaching them to a rigid substrate, was developed. Uniaxial strength turns out as at least twice that measured macroscopically, and respective ultimate stresses are preceded by hardening elastoplastic states, already at very low load levels. The unloading portion of quasi-static load-displacement curves revealed Young׳s modulus of 29GPa in bovine extracellular bone matrix. This value is impressively confirmed by the corresponding prediction of a multiscale mechanics model for bone, which has been comprehensively validated at various other observation scales, across tissues from the entire vertebrate animal kingdom.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.jmbbm.2015.03.001 | DOI Listing |
Inflamm Res
January 2025
Department of Orthopedics and Traumatology, The Affiliated Traditional Chinese Medicine Hospital, Southwest Medical University, Luzhou, Sichuan Province, China.
Background: One of the etiologic components of degenerative spinal illnesses is intervertebral disc degeneration (IVDD), and the accompanying lower back pain is progressively turning into a significant public health problem. Important pathologic characteristics of IVDD include inflammation and acidic microenvironment, albeit it is unclear how these factors contribute to the disease.
Purpose: To clarify the functions of inflammation and the acidic environment in IVDD, identify the critical connections facilitating glycolytic crosstalk and nucleus pulposus cells (NPCs) pyroptosis, and offer novel approaches to IVDD prevention and therapy.
Acta Biomater
January 2025
Biomedical Engineering, College of Engineering, Mathematics and Physical Sciences, University of Exeter, UK. Electronic address:
The biomechanical properties of articular cartilage arise from a complex bioenvironment comprising hierarchically organised collagen networks within the extracellular matrix (ECM) that interact with the proteoglycan-rich interstitial fluid. This network features a depth-dependent fibril organisation across different zones. Understanding how collagen fibrils respond to external loading is key to elucidating the mechanisms behind lesion and managing degenerative conditions like osteoarthritis.
View Article and Find Full Text PDFACS Biomater Sci Eng
January 2025
J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611, United States.
The complexation of nucleic acids and collagen forms a platform biomaterial greater than the sum of its parts. This union of biomacromolecules merges the extracellular matrix functionality of collagen with the designable bioactivity of nucleic acids, enabling advances in regenerative medicine, tissue engineering, gene delivery, and targeted therapy. This review traces the historical foundations and critical applications of DNA-collagen complexes and highlights their capabilities, demonstrating them as biocompatible, bioactive, and tunable platform materials.
View Article and Find Full Text PDFMol Biol Rep
January 2025
Medical Sociology and Psychobiology, Department of Health and Physical Activity, University of Potsdam, 14469, Potsdam, Germany.
Background: Depression constitutes a risk factor for osteoporosis, but underlying molecular and cellular mechanisms are not fully understood. MiRNAs influence gene expression and are carried by extracellular vesicles (EV), affecting cell-cell communication.
Aims: (1) Identify the difference in miRNA expression between depressed patients and healthy controls; (2) Analyze associations of these miRNAs with bone turnover markers; (3) Analyze target genes of differentially regulated miRNAs and predict associated pathways regarding depression and bone metabolism.
J Extracell Vesicles
January 2025
Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
Microglial phagocytosis of haematomas is crucial for neural functional recovery following intracerebral haemorrhage (ICH), a process regulated by various factors from within and outside the central nervous system (CNS). Extracellular vesicles (EVs), significant mediators of intercellular communication, have been demonstrated to play a pivotal role in the pathogenesis and progression of CNS diseases. However, the regulatory role of endogenous EVs on the phagocytic capacity of microglia post-ICH remains elusive.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!