Effect of soluble copper released from copper oxide nanoparticles solubilisation on growth and photosynthetic processes of Lemna gibba L

Copper oxide nanoparticles (CuO NPs) are used as a biocide in paints, textiles and plastics. Their application may lead to the contamination of aquatic ecosystems, where potential environmental effects remain to be determined. Toxic effects may be related to interactions of NPs with cellular systems or to particles' solubilisation releasing metal ions. In this report, we evaluated CuO NPs and soluble copper effects on photosynthesis of the aquatic macrophyte Lemna gibba L to determine the role of particle solubility in NPs toxicity. When L. gibba plants were exposed 48 h to CuO NPs or soluble copper, inhibition of photosynthetic activity was found, indicated by the inactivation of Photosystem II reaction centers, a decrease in electron transport and an increase of thermal energy dissipation. Toxicity of CuO NPs was mainly driven by copper ions released from particles. However, the bioaccumulation of CuO NPs in plant was shown, indicating the need to evaluate organisms of higher trophic level.     

Effects of inhibiting astrocytes and BET/BRD4 chromatin reader on spatial memory and synaptic proteins in rats with Alzheimer’s disease

Metabolic Brain Disease - Communication between astrocytes and neurons has a profound effect on the pathophysiology of Alzheimer’s disease (AD). Astrocytes regulate homeostasis and increase...     

Simulating osteoarthritis: the effect of the changing thickness of articular cartilage on the kinematics and pathological bone-to-bone contact in a hip joint with femoroacetabular impingement

Femoroacetabular impingement (FAI) is a pathomechanical process by which the human hip can fail. The effect of attenuated cartilage on the kinematics and the pathological bone-to-bone contact of an osteoarthritic hip joint with FAI are still unknown. The current study is aiming to simulate osteoarthritis of a cam-type femoral head with cartilage thinning of varying severity. A three-dimensional model of the left hip joint of a male patient diagnosed with FAI was obtained from preoperative computerised tomography data using density segmentation techniques. The kinematics of FAI was simulated using a finite element method. As the acetabulum and femur came into contact, the penetrations were detected, and the contact constraints were applied according to the penalty constraint enforcement method. The translation and rotation parameters were defined in a single step for each one of three cases: healthy cartilage and 2 mm (one-sided thinning) and 4 mm (two-sided thinning) worn out articular cartilages. The results of the analysis show that thinning of the cartilage at the hip joint adversely affects impingement, as a range of motion decreased with progressive thinning of the articular cartilage. In the presence of attenuated cartilage, equating osteoarthritis, the pathomorphology of the cam lesion, likely determines the extent of damage on the rim of the acetabulum, as well.     

Tri-layered elastomeric scaffolds for engineering heart valve leaflets

Tissue engineered heart valves (TEHVs) that can grow and remodel have the potential to serve as permanent replacements of the current non-viable prosthetic valves particularly for pediatric patients. A major challenge in designing functional TEHVs is to mimic both structural and anisotropic mechanical characteristics of the native valve leaflets. To establish a more biomimetic model of TEHV, we fabricated tri-layered scaffolds by combining electrospinning and microfabrication techniques. These constructs were fabricated by assembling microfabricated poly(glycerol sebacate) (PGS) and fibrous PGS/poly(caprolactone) (PCL) electrospun sheets to develop elastic scaffolds with tunable anisotropic mechanical properties similar to the mechanical characteristics of the native heart valves. The engineered scaffolds supported the growth of valvular interstitial cells (VICs) and mesenchymal stem cells (MSCs) within the 3D structure and promoted the deposition of heart valve extracellular matrix (ECM). MSCs were also organized and aligned along the anisotropic axes of the engineered tri-layered scaffolds. In addition, the fabricated constructs opened and closed properly in an ex vivo model of porcine heart valve leaflet tissue replacement. The engineered tri-layered scaffolds have the potential for successful translation towards TEHV replacements.