The Positive Role of Curcumin-Loaded Salmon Nanoliposomes on the Culture of Primary Cortical Neurons

Curcumin (diferuloylmethane) is a natural bioactive compound with many health-promoting benefits. However, its poor water solubility and bioavailability has limited curcumin’s biomedical application. In the present study, we encapsulated curcumin into liposomes, formed from natural sources (salmon lecithin), and characterized its encapsulation efficiency and release profile. The proposed natural carriers increased the solubility and the bioavailability of curcumin. In addition, various physico-chemical properties of the developed soft nanocarriers with and without curcumin were studied. Nanoliposome-encapsulated curcumin increased the viability and network formation in the culture of primary cortical neurons and decreased the rate of apoptosis

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Nonlinear Model for Viscoelastic Behavior of Achilles Tendon

International audienceAlthough the mechanical properties of ligament and tendon are well documented in research literature, very few unified mechanical formulations can describe a wide range of different loadings. The aim of this study was to propose a new model, which can describe tendon responses to various solicitations such as cycles of loading, unloading, and reloading or successive relaxations at different strain levels. In this work, experiments with cycles of loading and reloading at increasing strain level and sequences of relaxation were performed on white New Zealand rabbit Achilles tendons. We presented a local formulation of thermodynamic evolution outside equilibrium at a representative element volume scale to describe the tendon's macroscopic behavior based on the notion of relaxed stress. It was shown that the model corresponds quite well to the experimental data. This work concludes with the complexity of tendons' mechanical properties due to various microphysical mechanisms of deformation involved in loading such as the recruitment of collagen fibers, the rearrangement of the microstructure (i.e., collagens type I and III, proteoglycans, and water), and the evolution of relaxed stress linked to these mechanisms

Fluid–structure interaction simulation of aortic blood flow by ventricular beating: a preliminary model for blunt aortic injuries in vehicle crashes

International audienceBlunt aortic injuries are common and severe in motor vehicle crash accidents (MVCAs), but the injury mechanisms, which can be categorised as kinematics and hydrodynamics aspects, remain to be uncertain. In this study, a finite element model was developed for the aorta-heart system with fluid–structure interaction methods, aimed to study both kinds of mechanisms simultaneously. The aortic blood flow was generated by simulating left ventricle contraction. This model was further integrated with a human body model to reconstruct a real car crash case. The aorta-heart model was validated against ventricular volume, blood pressure, velocity, flow rate and wall shear stress. The integrated model predicted aorta isthmus laceration and other injuries consistent with the case injury reports. The cardiac output during the accident was more intense than the physiological output, proving the ability of current simulation approach to capture the blood flow modification by the thoracic compressive loadings during accidents

A novel bioreactor for ligament tissue engineering

Bioreactors are defined as devices in which biological and/or biochemical processes develop under closely monitored and tightly controlled environmental and operating conditions (e.g. pH, temperature, mechanical conditions, nutrient supply and waste removal). In functional tissue engineering of musculoskeletal tissues, a bioreactor capable of controlling dynamic loading plays a determinant role. It has been shown that mechanical stretching promotes the expression of type I and III collagens, fibronectin, tenascin-C in cultured ligament fibroblasts (J.C.-H. Goh et al., Tissue Eng. 9 (2003), S31) and that human bone marrow mesenchymal stem cells (hBMMSC) – even in the absence of biochemical regulators – could be induced to differentiate into ligament-like fibroblast by the application of physiologically relevant cyclic strains (G. Vunjak-Novakovic et al., Ann. Rev. Biomed. Eng. 6 (2004), 131; H.A. Awad et al., Tissue Eng. 5 (1999), 267; R.G. Young et al., J. Orthop. Res. 16 (1998), 406). Different bioreactors are commercially available but they are too generic to be used for a given tissue, each tissue showing specific mechanical loading properties. In the case of ligament tissue engineering, the design of a bioreactor is still an open question. Our group proposes a bioreactor allowing cyclic traction–torsion on a scaffold seeded with stem cells

Composite Hydrogels of Pectin and Alginate

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Soft Nanobiomaterials (Nanoliposomes) for Biomedical Applications

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Comparison of capsule strain through different liver pressure states

22nd Congress of the European Society of Biomechanics (ESB), LYON, FRANCE, 10-/07/2016 - 13/07/2016Due to its location and anatomy, the liver is a key organ to model for applications in car safety and in computer aided surgical procedures. Its dual blood supply, venous and arterial, involves the vital prognosis of the individual when it is injured. The mechanical behavior of its brittle parenchyma and the Glisson's capsule, which surrounds parenchyma, is a major issue in numerical simulation. Thus, many researches are focusing on the characterization of the Glisson's capsule through tensile tests. Under these test conditions, the initial state of strain corresponds to the sample placed between two jaws and therefore seems far from the initial state of the capsule in - vivo. In order to define the state of strain for tensile test sample of Glisson's capsule, we have measured the strain field of this structure on liver under different pressure levels in portal vein and hepatic artery

Effect of uniaxial stretching on rat bone mesenchymal stem cell: Orientation and expressions of collagen types I and III and tenascin-C

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Effects of nanoliposomes based on soya, rapeseed and fish lecithins on chitosan thin films designed for tissue engineering

International audienceThis work addresses the preparation of chitosan thin films functionalized in volume by nanoliposomes based on plant and marine lecithins, and then characterizes their properties by various physicochemical techniques. Firstly, the main fatty acid compositions of lecithins was analyzed by gas chromatography, secondly the stability of nanoliposomes and nanoliposomes/chitosan blends was determined by zetasizer, tensiometer, Transmission Electron Microscopy and rheometer. Finally, different properties of chitosan and the nanoliposomes/chitosan blend thin films were characterized by water contact angle, Fourier Transform Infrared Spectroscopy, Dynamic-Mechanical Thermal Analysis, Wide-Angle X-ray Scattering and Scanning Probe Microscopy in HarmoniX™ mode. From these experiments, the influences of nanoliposomes on thin films wettability, morphology, viscosity, mechanical properties and structural alteration were determined. The addition of nanoliposomes to chitosan and resulting nanoliposomes/chitosan blend thin films provides greater possibility of producing new materials for potential tissue engineering application