186 results match your criteria subsequent stiffening


Distinct Time Courses and Mechanics of Right Ventricular Hypertrophy and Diastolic Stiffening in a Male Rat Model of Pulmonary Arterial Hypertension.

Am J Physiol Heart Circ Physiol 2021 08 27. Epub 2021 Aug 27.

Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States.

While pulmonary arterial hypertension (PAH) leads to right ventricle (RV) hypertrophy and structural remodeling, the relative contributions of changes in myocardial geometric and mechanical properties to systolic and diastolic chamber dysfunction and their time courses remain unknown. Using measurements of RV hemodynamic and morphological changes over 10 weeks in a male rat model of PAH and a mathematical model of RV mechanics, we discriminated the contributions of RV geometric remodeling and alterations of myocardial material properties to changes in systolic and diastolic chamber function. Significant and rapid RV hypertrophic wall thickening was sufficient to stabilize ejection fraction in response to increased pulmonary arterial pressure by week 4 without significant changes in systolic myofilament activation. Read More

View Article and Full-Text PDF

A stochastic micro to macro mechanical model for the evolution of bone-implant interface stiffness.

Acta Biomater 2021 09 12;131:415-423. Epub 2021 Jun 12.

Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden.

Upon placement of an implant into living bone, an interface is formed through which various biochemical, biological, physical, and mechanical interactions take place. This interface evolves over time as the mechanical properties of peri-implant bone increase. Owing to the multifactorial nature of interfacial processes, it is challenging to devise a comprehensive model for predicting the mechanical behavior of the bone-implant interface. Read More

View Article and Full-Text PDF
September 2021

Elastic tissue disruption is a major pathogenic factor to human vascular disease.

Mol Biol Rep 2021 May 15;48(5):4865-4878. Epub 2021 Jun 15.

Nephrology Division, Internal Medicine Department, Hospital General Juan Cardona, c/ Pardo Bazán s/n, 15406, Ferrol, Spain.

Elastic fibers are essential components of the arterial extracellular matrix. They consist of the protein elastin and an array of microfibrils that support the protein and connect it to the surrounding matrix. The elastin gene encodes tropoelastin, a protein that requires extensive cross-linking to become elastin. Read More

View Article and Full-Text PDF

Dynamic Tuning of Viscoelastic Hydrogels with Carbonyl Iron Microparticles Reveals the Rapid Response of Cells to Three-Dimensional Substrate Mechanics.

ACS Appl Mater Interfaces 2021 May 28;13(18):20947-20959. Epub 2021 Apr 28.

Department of Biomedical Engineering, Rowan University, Glassboro, New Jersey 08028, United States.

Current methods to dynamically tune three-dimensional hydrogel mechanics require specific chemistries and substrates that make modest, slow, and often irreversible changes in their mechanical properties, exclude the use of protein-based scaffolds, or alter the hydrogel microstructure and pore size. Here, we rapidly and reversibly alter the mechanical properties of hydrogels consisting of extracellular matrix proteins and proteoglycans by adding carbonyl iron microparticles (MPs) and applying external magnetic fields. This approach drastically alters hydrogel mechanics: rheology reveals that application of a 4000 Oe magnetic field to a 5 mg/mL collagen hydrogel containing 10 wt % MPs increases the storage modulus from approximately 1. Read More

View Article and Full-Text PDF

Long-Term Treatment of Azathioprine in Rats Induces Vessel Mineralization.

Biomedicines 2021 Mar 23;9(3). Epub 2021 Mar 23.

Department of Nephrology and Medical Intensive Care, Charité-Universitätsmedizin Berlin, 12203 Berlin, Germany.

Medial vascular calcification (mVC) is closely related to cardiovascular disease, especially in patients suffering from chronic kidney disease (CKD). Even after successful kidney transplantation, cardiovascular mortality remains increased. There is evidence that immunosuppressive drugs might influence pathophysiological mechanisms in the vessel wall. Read More

View Article and Full-Text PDF

Research in practice: Towards deciphering the role of epidermal proteases in recessive dystrophic epidermolysis bullosa progression.

J Dtsch Dermatol Ges 2021 06 25;19(6):828-832. Epub 2021 Mar 25.

Department of Dermatology, Medical Center-University of Freiburg, Faculty of Medicine, Freiburg, Germany.

Recessive dystrophic epidermolysis bullosa (RDEB) is an incurable severe skin disease caused by loss of collagen VII, an extracellular protein that ensures skin cohesion. It manifests in skin blistering and unresolved cycles of wounding and healing that progressively lead to dermal stiffening and early development of aggressive cutaneous squamous cell carcinomas. Inflammation and subsequent tissue fibrosis highly contribute to RDEB pathogenicity and targeting them could provide new therapeutic options. Read More

View Article and Full-Text PDF

Effect of penetration enhancer with novel corneal cross-linking using recombinant human decoron in porcine eyes.

Exp Eye Res 2021 05 17;206:108542. Epub 2021 Mar 17.

Department of Ophthalmology & Visual Sciences, William H. Havener Eye Institute, 915 Olentangy River Rd, Suite 5000, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Biomedical Engineering, 140 W. 19th Ave., Fontana Labs the Ohio State University, Columbus, OH, USA. Electronic address:

The aim of the study was to investigate the effectiveness of exogenous recombinant human decoron and an accompanying penetration-enhancing solution in stiffening ex-vivo porcine corneas both transepithelially and after de-epithelialization. Eight porcine paired eyes were treated transepithelially: one eye with a pre-treatment solution (Pre-Tx), penetration enhancing solution (PE), and decoron while the fellow eye was treated by the same protocol but without decoron. A second group included 4 de-epithelialized pairs treated identically. Read More

View Article and Full-Text PDF

Stimulation of vascular smooth muscle cell proliferation by stiff matrix via the IK channel-dependent Ca signaling.

J Cell Physiol 2021 Oct 1;236(10):6897-6906. Epub 2021 Mar 1.

Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China.

Vascular stiffening, an early and common characteristic of cardiovascular diseases (CVDs), stimulates vascular smooth muscle cell (VSMC) proliferation which reciprocally accelerates the progression of CVDs. However, the mechanisms by which extracellular matrix stiffness accompanying vascular stiffening regulates VSMC proliferation remain largely unknown. In the present study, we examined the role of the intermediate-conductance Ca -activated K  (IK ) channel in the matrix stiffness regulation of VSMC proliferation by growing A7r5 cells on soft and stiff polydimethylsiloxane substrates with stiffness close to these of arteries under physiological and pathological conditions, respectively. Read More

View Article and Full-Text PDF
October 2021

Side-specific valvular endothelial-interstitial cell mechano-communication via cadherin-11.

J Biomech 2021 04 10;119:110253. Epub 2021 Feb 10.

Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States. Electronic address:

Calcific aortic valve disease (CAVD) is a condition causing stiffening of the aortic valve, impeding cardiac function and resulting in significant morbidity worldwide. CAVD is thought to be driven by the persistent activation of the predominant cell type in the valve, aortic valve interstitial cells (AVICs), into myofibroblasts, resulting in subsequent calcification and stenosis of the valve. Although much of the research into CAVD focuses on AVICs, the aortic valve endothelial cells (AVECs) have been shown to regulate AVICs and maintain tissue homeostasis. Read More

View Article and Full-Text PDF

Chronic kidney disease, atherosclerotic plaque characteristics on carotid magnetic resonance imaging, and cardiovascular outcomes.

BMC Nephrol 2021 02 24;22(1):69. Epub 2021 Feb 24.

Department of Radiology, Vascular Imaging Lab, University of Washington, Seattle, WA, USA.

Background: It is unclear whether faster progression of atherosclerosis explains the higher risk of cardiovascular events in CKD. The objectives of this study were to 1. Characterize the associations of CKD with presence and morphology of atherosclerotic plaques on carotid magnetic resonance imaging (MRI) and 2. Read More

View Article and Full-Text PDF
February 2021

Longitudinal associations of blood pressure with aortic stiffness and pulsatility: the Atherosclerosis Risk in Communities Study.

J Hypertens 2021 05;39(5):987-993

Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.

Objective: To characterize the longitudinal relationships between blood pressure measured over 24 years and arterial stiffness in late life measured as pulse wave velocity (PWV).

Methods: Carotid--femoral (cf) and femoral--ankle (fa) PWV were measured in 4166 adults at the visit 5 Atherosclerosis Risk in Communities study cohort examination (2011-2013). Participants were categorized into tertiles of PWV measurements. Read More

View Article and Full-Text PDF

Intrinsic Disorder in the T Cell Receptor Creates Cooperativity and Controls ZAP70 Binding.

Biophys J 2021 01 5;120(2):379-392. Epub 2020 Dec 5.

Center for Complex Biological Systems, University of California Irvine, Irvine, California; Department of Mathematics and Department of Physics and Astronomy, University of California Irvine, Irvine, California. Electronic address:

Many immunoreceptors have cytoplasmic domains that are intrinsically disordered (i.e., have high configurational entropy), have multiple sites of posttranslational modification (e. Read More

View Article and Full-Text PDF
January 2021

Fall inducing movable platform (FIMP) for overground trips and slips.

J Neuroeng Rehabil 2020 12 3;17(1):161. Epub 2020 Dec 3.

Nanyang Technological University, Rehabilitation Research Institute of Singapore, 11 Mandalay Road, #14-03, 308232, Singapore, Singapore.

Background: The study of falls and fall prevention/intervention devices requires the recording of true falls incidence. However, true falls are rare, random, and difficult to collect in real world settings. A system capable of producing falls in an ecologically valid manner will be very helpful in collecting the data necessary to advance our understanding of the neuro and musculoskeletal mechanisms underpinning real-world falls events. Read More

View Article and Full-Text PDF
December 2020

Self-Strengthening Adhesive Force Promotes Cell Mechanotransduction.

Adv Mater 2020 Dec 18;32(52):e2006986. Epub 2020 Nov 18.

Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, Berlin, 14195, Germany.

The extracellular matrix (ECM) undergoes dynamic remodeling and progressive stiffening during tissue regeneration and disease progression. However, most of the artificial ECMs and in vitro disease models are mechanically static. Here, a self-strengthening polymer coating mimicking the dynamic nature of native ECM is designed to study the cellular response to dynamic biophysical cues and promote cell mechanical sensitive response. Read More

View Article and Full-Text PDF
December 2020

Nuclear plasticity increases susceptibility to damage during confined migration.

PLoS Comput Biol 2020 10 9;16(10):e1008300. Epub 2020 Oct 9.

Dept. of Biosciences & Bioengineering, IIT Bombay, Mumbai, India.

Large nuclear deformations during migration through confined spaces have been associated with nuclear membrane rupture and DNA damage. However, the stresses associated with nuclear damage remain unclear. Here, using a quasi-static plane strain finite element model, we map evolution of nuclear shape and stresses during confined migration of a cell through a deformable matrix. Read More

View Article and Full-Text PDF
October 2020

Dry vs. wet: Properties and performance of collagen films. Part II. Cyclic and time-dependent behaviours.

J Mech Behav Biomed Mater 2020 12 20;112:104040. Epub 2020 Aug 20.

Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK. Electronic address:

Collagen constitutes one-third of human-body proteins, providing mechanical strength and structural stability. Films of collagen are widely used in tissue engineering as scaffolds for wound healing and corneal implants, among other applications, presupposing the investigation of their mechanical properties and performance under various loading and environmental conditions. Part I of this research (Bose et al. Read More

View Article and Full-Text PDF
December 2020

Consensus on Indications for Isolated Subtalar Joint Fusion and Naviculocuneiform Fusions for Progressive Collapsing Foot Deformity.

Foot Ankle Int 2020 Oct 27;41(10):1295-1298. Epub 2020 Aug 27.

Mercy Medical Center, Baltimore, MD, USA.

Recommendation: Peritalar subluxation represents an important hindfoot component of progressive collapsing foot deformity, which can be associated with a breakdown of the medial longitudinal arch. It results in a complex 3-dimensional deformity with varying degrees of hindfoot valgus, forefoot abduction, and pronation. Loss of peritalar stability allows the talus to rotate and translate on the calcaneal and navicular bone surfaces, typically moving medially and anteriorly, which may result in sinus tarsi and subfibular impingement. Read More

View Article and Full-Text PDF
October 2020

Deformation of leukaemia cell lines in hyperbolic microchannels: investigating the role of shear and extensional components.

Lab Chip 2020 07;20(14):2539-2548

Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, piazza Leonardo da Vinci, 32 - 20133 Milan, Italy.

The mechanical properties of cells are of enormous interest in a diverse range of physio and pathological situations of clinical relevance. Unsurprisingly, a variety of microfluidic platforms have been developed in recent years to study the deformability of cells, most commonly employing pure shear or extensional flows, with and without direct contact of the cells with channel walls. Herein, we investigate the effects of shear and extensional flow components on fluid-induced cell deformation by means of three microchannel geometries. Read More

View Article and Full-Text PDF

Wnt Activation After Inhibition Restores Trabecular Meshwork Cells Toward a Normal Phenotype.

Invest Ophthalmol Vis Sci 2020 06;61(6):30

,.

Purpose: Wnt is a spatiotemporally regulated signaling pathway whose inhibition is associated with glaucoma, elevated intraocular pressure (IOP), and cell stiffening. Whether such changes are permanent or may be reversed is unclear. Here, we determine if activation of Wnt pathway after inhibition reverses the pathologic phenotype. Read More

View Article and Full-Text PDF

Paradoxical aortic stiffening and subsequent cardiac dysfunction in Hutchinson-Gilford progeria syndrome.

J R Soc Interface 2020 05 27;17(166):20200066. Epub 2020 May 27.

Department of Biomedical Engineering, Yale University, New Haven, CT, USA.

Hutchinson-Gilford progeria syndrome (HGPS) is an ultra-rare disorder with devastating sequelae resulting in early death, presently thought to stem primarily from cardiovascular events. We analyse novel longitudinal cardiovascular data from a mouse model of HGPS () using allometric scaling, biomechanical phenotyping, and advanced computational modelling and show that late-stage diastolic dysfunction, with preserved systolic function, emerges with an increase in the pulse wave velocity and an associated loss of aortic function, independent of sex. Specifically, there is a dramatic late-stage loss of smooth muscle function and cells and an excessive accumulation of proteoglycans along the aorta, which result in a loss of biomechanical function (contractility and elastic energy storage) and a marked structural stiffening despite a distinctly low intrinsic material stiffness that is consistent with the lack of functional lamin A. Read More

View Article and Full-Text PDF

Tracking intracellular forces and mechanical property changes in mouse one-cell embryo development.

Nat Mater 2020 10 25;19(10):1114-1123. Epub 2020 May 25.

Laboratory of Mammalian Molecular Embryology, Department of Biology and Biochemistry, University of Bath, Bath, UK.

Cells comprise mechanically active matter that governs their functionality, but intracellular mechanics are difficult to study directly and are poorly understood. However, injected nanodevices open up opportunities to analyse intracellular mechanobiology. Here, we identify a programme of forces and changes to the cytoplasmic mechanical properties required for mouse embryo development from fertilization to the first cell division. Read More

View Article and Full-Text PDF
October 2020

Asymmetric in-plane shear behavior of isolated cadaveric lumbar facet capsular ligaments: Implications for subject specific biomechanical models.

J Biomech 2020 05 22;105:109814. Epub 2020 Apr 22.

University of Minnesota, Biomedical Engineering, 312 Church St. SE, 7-105 Nils Hasselmo Hall, Minneapolis, MN 55455, United States. Electronic address:

The facet capsular ligaments (FCLs) flank the spinous process on the posterior aspect of the spine. The lumbar FCL is collagenous, with collagen fibers aligned primarily bone-to-bone (medial-lateral) and experiences significant shear, especially during spinal flexion and extension. We characterized the mechanical response of the lumbar FCL to in-plane shear, and we evaluated that response in the context of the fiber architecture. Read More

View Article and Full-Text PDF

Morphometric, Hemodynamic, and Multi-Omics Analyses in Heart Failure Rats with Preserved Ejection Fraction.

Int J Mol Sci 2020 May 9;21(9). Epub 2020 May 9.

Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, China.

(1) Background: There are no successive treatments for heart failure with preserved ejection fraction (HFpEF) because of complex interactions between environmental, histological, and genetic risk factors. The objective of the study is to investigate changes in cardiomyocytes and molecular networks associated with HFpEF. (2) Methods: Dahl salt-sensitive (DSS) rats developed HFpEF when fed with a high-salt (HS) diet for 7 weeks, which was confirmed by in vivo and ex vivo measurements. Read More

View Article and Full-Text PDF

Magnetoelastic coupling associated with vacancy ordering and ferrimagnetism in natural pyrrhotite, FeS.

J Phys Condens Matter 2020 May 5;32(38):385401. Epub 2020 May 5.

Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, United Kingdom.

Magnetoelastic coupling associated with the hexagonal-monoclinic transition in a natural sample of the mineral pyrrhotite, FeS, has been analysed in terms of separate coupling of spontaneous strains with two discrete order parameters, q for Fe/vacancy ordering and q for magnetic ordering. Coupling of the two order parameters separately with strain gives rise to two terms for coupling between them, λ [Formula: see text] and λ [Formula: see text], and a pattern of evolution in which q varies continuously and q discontinuously through a single transition point. The transition is ferrimagnetic and ferroelastic but the relatively slow relaxation rate for Fe/vacancy ordering, in comparison with magnetic ordering, results in elastic and anelastic properties which are quite different from those observed in other ferroic or multiferroic materials with two instabilities. Read More

View Article and Full-Text PDF

Laparoscopic approach to early gastric cancer in a patient with a prior history of open right hepatectomy: a case report.

Surg Case Rep 2020 Apr 26;6(1):84. Epub 2020 Apr 26.

Division of Gastric Surgery, Shizuoka Cancer Center, 1007 Shimonagakubo, Nagaizumi-cho, Sunto-gun, Shizuoka, 411-8777, Japan.

Background: Laparoscopic gastrectomy is regarded a standard treatment procedure for early gastric cancer and is widely used in clinical practice. However, the feasibility of laparoscopic gastrectomy for patients with a prior history of open surgery, especially in the case of a complicated operation, remains unclear. Here, we report a laparoscopic gastrectomy case with a prior history of right hepatectomy. Read More

View Article and Full-Text PDF

Centrosome anchoring regulates progenitor properties and cortical formation.

Nature 2020 04 25;580(7801):106-112. Epub 2020 Mar 25.

Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Centre, New York, NY, USA.

Radial glial progenitor cells (RGPs) are the major neural progenitor cells that generate neurons and glia in the developing mammalian cerebral cortex. In RGPs, the centrosome is positioned away from the nucleus at the apical surface of the ventricular zone of the cerebral cortex. However, the molecular basis and precise function of this distinctive subcellular organization of the centrosome are largely unknown. Read More

View Article and Full-Text PDF

Increasing the Potential Interacting Area of Nanomedicine Enhances Its Homotypic Cancer Targeting Efficacy.

ACS Nano 2020 03 21;14(3):3259-3271. Epub 2020 Feb 21.

Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 Singapore.

The cancer cell membrane contains an arsenal of highly specific homotypic moieties that can be used to recognize its own kind. These cell membranes are often used to coat spherical nanoparticles to enhance nanomedicines' targeting specificities and uptakes. A sphere, however, has only a point contact with a surface at any given time. Read More

View Article and Full-Text PDF

Mechanics-Controlled Dynamic Cell Niches Guided Osteogenic Differentiation of Stem Cells via Preserved Cellular Mechanical Memory.

ACS Appl Mater Interfaces 2020 Jan 20;12(1):260-274. Epub 2019 Dec 20.

Chengdu Konjin Biotech Co., Ltd. , Chengdu 611100 , Sichuan , P. R. China.

Stem cells sense and respond to their local dynamic mechanical niches, which further regulate the cellular behaviors. While in naturally, instead of instantly responding to real-time mechanical changes of their surrounding niches, stem cells often present a delayed cellular response over a time scale, namely cellular mechanical memory, which may finally influence their lineage choice. Here, we aim to build a dynamic mechanical niche model with alginate-based hydrogel, therein the dynamic mechanical switching can be easily realized via the introduce or removal of Ca. Read More

View Article and Full-Text PDF
January 2020

Effect of preferred walking speed on the upper body range of motion and mechanical work during gait before and after spinal fusion for patients with idiopathic scoliosis.

Clin Biomech (Bristol, Avon) 2019 Dec 9;70:265-269. Epub 2019 Nov 9.

Laboratoire d'Analyse du Mouvement, Centre de l'Arche, Pole Régional du Handicap, 72650 St Saturnin, France.

Background: Scoliosis may have an effect on gait parameters, the kinematics of the lower limbs and the spine, and mechanical work with specific gait speed. Imposed gait speed may influence these effects. Following spinal fusion in the case of idiopathic scoliosis, patients fear subsequent and considerable back stiffness and kinetic consequences. Read More

View Article and Full-Text PDF
December 2019

Instant Thermal Switching from Soft Hydrogel to Rigid Plastics Inspired by Thermophile Proteins.

Adv Mater 2020 Jan 18;32(4):e1905878. Epub 2019 Nov 18.

Faculty of Advanced Life Science, Global Station for Soft Matter, Global Institution for Collaborative Research and Education (GSS, GI-CoRE), Hokkaido University, Kita-21 Nishi-11, Kita-ku, Sapporo, 001-0021, Japan.

Proteins of thermophiles are thermally stable in a high-temperature environment, adopting a strategy of enhancing the electrostatic interaction in hydrophobic media at high temperature. Herein, inspired by the molecular mechanism of thermally stable proteins, the synthesis of novel polymer materials that undergo ultrarapid, isochoric, and reversible switching from soft hydrogels to rigid plastics at elevated temperature is reported. The materials are developed from versatile, inexpensive, and nontoxic poly(acrylic acid) hydrogels containing calcium acetate. Read More

View Article and Full-Text PDF
January 2020