Collagen is an abundant structural biopolymer in mammal vertebrates, providing structural support as well as mechanical integrity for connective tissues such as bone, ligament, and tendon. The mechanical behaviours of these tissues are determined by the nanomechanics of their structures at different hierarchies and the role of collagen structures in the extracellular matrix. Some studies revealed that there is significant microstructural difference in the longitudinal direction of the collagen fibril, which challenges the conventional rod-like assumption prevalently adopted in the existing studies. Motivated by this discrepancy, in this study, we investigated the longitudinal heterogeneous nanomechanical properties of type I collagen molecule to probe the origin of the longitudinal heterogeneity of the collagen fibril at the molecular level. A full length type I collagen molecule structure was built based on the experimentally calibrated nanostructure. Then, a suitable strain rate was determined for stretching the three intact 'gap' regions and three intact 'overlap' regions of the collagen molecule. Further, the nanomechanical properties of the six collagen molecule segments were characterized by performing steered molecular dynamics simulations, using the obtained suitable strain rate in modelling. The results indicate that this computational model can be used to capture the mechanical behaviour of the collagen molecule under physiological stress conditions. Moreover, the 'gap' regions show a lower stiffness and undergo a slightly lager strain in the unwinding process, compared to the 'overlap' regions of the collagen molecule. This investigation provides insights into the origin of the longitudinal heterogeneity of collagen fibrils at the molecular level and suggests that it is of significant importance to consider the longitudinal heterogeneous mechanical properties of the collagen molecule in the development of coarse-grained models of collagen-related tissues.
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http://dx.doi.org/10.1007/s10237-016-0870-6 | DOI Listing |
J Tradit Complement Med
November 2024
Orthopedic Research Center, Shahid Kamyab Hospital, Mashhad University of Medical Sciences, Mashhad, Iran.
Background: Post-surgical tendon adhesion formation is a frequent clinical complication with limited treatment options. The aim of this study is to investigate safety and efficacy of orally administration of crocin in attenuating post-operative tendon-sheath adhesion bands in an Achilles tendon rat model.
Methods: Structural, mechanical, histological, and biochemical properties of Achilles tendons were analyzed in the presence and absence of crocin.
Toxicol Rep
June 2025
Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Zagazig University, Egypt.
Extensive uses of silver nanoparticles (Ag NPs) in different industries result in exposure to these nanoparticle imperatives in our daily lives. Resveratrol is found in many plants as a natural compound. The present study aimed to estimate the renal toxic effects of Ag NPs in adult male albino rats and the underlying relevant mechanisms while studying the possible role of resveratrol in ameliorating these effects.
View Article and Find Full Text PDFJ Int Soc Sports Nutr
December 2025
Jiujiang No.1 People's Hospital, Department of Orthopedics, Jiujiang City Key Laboratory of Cell Therapy, Jiujiang, China.
Objective: The aim of this study was to identify the key regulatory mechanisms of cartilage injury and osteoporosis through bioinformatics methods, and to provide a new theoretical basis and molecular targets for the diagnosis and treatment of the disease.
Methods: Microarray data for cartilage injury (GSE129147) and osteoporosis (GSE230665) were first downloaded from the GEO database. Differential expression analysis was applied to identify genes that were significantly up-or down-regulated in the cartilage injury and osteoporosis samples.
Background: Apolipoprotein C3 (apo C3) is primarily secreted by the liver and is involved in promoting sterile inflammation and organ damage under pathological conditions. Previous studies have shown that apo C3 is abundant in the plasma exosomes of patients with aortic dissection (AD), but its specific role in AD remains unclear.
Methods And Results: In vivo, adeno-associated virus was used to knock down hepatic apo C3 expression in an AD mouse model to assess the impact of liver-derived apo C3 on the development of AD.
EMBO Mol Med
January 2025
Sabri Ülker Center for Metabolic Research, Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
Host metabolic fitness is a critical determinant of infectious disease outcomes. Obesity, aging, and other related metabolic disorders are recognized as high-risk disease modifiers for respiratory infections, including coronavirus infections, though the underlying mechanisms remain unknown. Our study highlights fatty acid-binding protein 4 (FABP4), a key regulator of metabolic dysfunction and inflammation, as a modulator of SARS-CoV-2 pathogenesis, correlating strongly with disease severity in COVID-19 patients.
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