Effects of shear stress on mesenchymal stem cells of patients with osteogenesis imperfecta.

Introduction: Osteogenesis imperfecta (OI) is a rare genetic bone disorder, mainly caused by autosomal dominant mutations of the COL1A1 or COL1A2 genes that encode the alpha chains of type 1 collagen. In severe forms and in nonambulatory patients, for whom physical exercise is difficult, exposing the bone to mechanical stimuli by promoting movement, especially with physiotherapy and mobility aids, is an essential part of clinical practice. However, the effects of mechanical stimulation at the cellular level remain unknown for this disease.

Analysis of a Chronic Lateral Ankle Instability Model in the Rat: Conclusions and Suggestions for Future Research.

The purpose of this study was to evaluate potential osteoarthritic alterations within the ankle using a surgically-induced chronic lateral ankle instability (CLAI) model. Twelve rats were assigned randomly to either the control ( = 4) or CLAI group ( = 8). Surgery was performed on the right ankle.

Porosity and surface curvature effects on the permeability and wall shear stress of trabecular bone: Guidelines for biomimetic scaffolds for bone repair.

Scaffolds are an essential component of bone tissue engineering to provide support and create a physiological environment for cells. Biomimetic scaffolds are a promising approach to fulfill the requirements. Bone allografts are widely used scaffolds due to their mechanical and structural characteristics.

In Vivo Assessment of Skin Surface Pattern: Exploring Its Potential as an Indicator of Bone Biomechanical Properties.

The mechanical properties of bone tissue are the result of a complex process involving collagen-crystal interactions. The mineral density of the bone tissue is correlated with bone strength, whereas the characteristics of collagen are often associated with the ductility and toughness of the bone. From a clinical perspective, bone mineral density alone does not satisfactorily explain skeletal fragility.

A New Microarchitecture-Based Parameter to Predict the Micromechanical Properties of Bone Allografts.

Scaffolds are an essential component of bone tissue engineering. They provide support and create a physiological environment for cells to proliferate and differentiate. Bone allografts extracted from human donors are promising scaffolds due to their mechanical and structural characteristics.

Early impairment of cartilage poroelastic properties in an animal model of ACL tear.

Background: In more than 50% of cases, anterior cruciate ligament (ACL) lesions lead to post-traumatic osteoarthritis. Ligament reconstruction stabilizes the joint, but the tear seems to impair the poroelasticity of the cartilage: synovial membrane fluid inflammation is observed 3 weeks after tearing. There have been some descriptions of visible cartilage changes, but poroelasticity has never been analyzed at this early stage.

Correlation between skin and bone parameters in women with postmenopausal osteoporosis: A systematic review.

Skin and bone share similarities in terms of biochemical composition.Some authors have hypothesized that their properties could evolve concomitantly with age, allowing the estimation of the parameters of one from those of the other.We performed a systematic review of studies reporting the correlation between skin and bone parameters in women with postmenopausal osteoporosis.

Mechanical alterations of the bone-cartilage unit in a rabbit model of early osteoarthrosis.

Objective: The purpose of this study was to assess mechanical properties along with microstructural modifications of the hyaline cartilage (HC), calcified cartilage (CC) and cortical plate (Ct.Pt), in an anterior cruciate ligament transection (ACLT) model. Medial femoral condyles of six healthy rabbits (control group) and of six ACLT rabbits 6 weeks after OA induction were explanted.

Characterization of the anisotropic mechanical behavior of human abdominal wall connective tissues.

Abdominal wall sheathing tissues are commonly involved in hernia formation. However, there is very limited work studying mechanics of all tissues from the same donor which prevents a complete understanding of the abdominal wall behavior and the differences in these tissues. The aim of this study was to investigate the differences between the mechanical properties of the linea alba and the anterior and posterior rectus sheaths from a macroscopic point of view.

Contra-lateral hip fracture in the elderly: are decreased body mass index and skin thickness predictive factors?

Purpose: A correlation between soft tissue thickness and osteoporosis has been suggested. We aimed to estimate if a low body mass index (BMI) and/or a decrease of skin thickness could estimate the risk of contra-lateral hip fracture.

Methods: First, we performed a retrospective analysis of 1268 patients treated for a hip fracture.

Predictive model for tensile strength of pharmaceutical tablets based on local hardness measurements.

In the pharmaceutical field, tablets are the most common dosage forms for oral administration. During the manufacture of tablets, measures are taken to assure that they possess a suitable mechanical strength to avoid crumbling or breaking when handling while ensuring disintegration after administration. Accordingly, the tensile strength is an essential parameter to consider.

Microstructure and compressive mechanical properties of cortical bone in children with osteogenesis imperfecta treated with bisphosphonates compared with healthy children.

Osteogenesis imperfecta (OI) is a genetic disorder characterized by a change in bone tissue quality, but little data are available to describe the factors involved at the macroscopic scale. To better understand the effect of microstructure alterations on the mechanical properties at the sample scale, we studied the structural and mechanical properties of six cortical bone samples from children with OI treated with bisphosphonates and compared them to the properties of three controls. Scanning electron microscopy, high resolution computed tomography and compression testing were used to assess these properties.

Numerical Study of Granular Scaffold Efficiency to Convert Fluid Flow into Mechanical Stimulation in Bone Tissue Engineering.

Controlling the mechanical environment in bioreactors represents a key element in the reactors' optimization. Positive effects of fluid flow in three-dimensional bioreactors have been observed, but local stresses at cell scale remain unknown. These effects led to the development of numerical tools to assess the micromechanical environment of cells in bioreactors.

Mechanical and mineral properties of osteogenesis imperfecta human bones at the tissue level.

Osteogenesis imperfecta (OI) is a genetic disorder characterized by an increase in bone fragility on the macroscopic scale, but few data are available to describe the mechanisms involved on the tissue scale and the possible correlations between these scales. To better understand the effects of OI on the properties of human bone, we studied the mechanical and chemical properties of eight bone samples from children suffering from OI and compared them to the properties of three controls. High-resolution computed tomography, nanoindentation and Raman microspectroscopy were used to assess those properties.

Digital image correlation of bone sequential microscopic observations.

A method of image correlation is presented to study sequential microscopic observations of human Haversian cortical bone. Imaging biological tissues is sometimes challenging owing to their complex microstructures in particular when microcracks appear. Bone microfractures can be studied in micro compression tests where the progressive growth of small cracks is imaged by light microscopy.