Treatment of defects in joint cartilage aims to re-establish normal joint function. In vitro experiments have shown that the application of synthetic scaffolds is a promising alternative to existing therapeutic options. A sheep study was conducted to test the suitability of microporous pure β-tricalcium phosphate (TCP) ceramics as tissue engineering scaffolds for the repair of osteochondral defects. Cylindrical plugs of microporous β-TCP (diameter: 7mm; length: 25mm; porosity: 43.5±2.4%; pore diameter: ~5μm) with interconnecting pores were used. Scaffolds were seeded with autologous chondrocytes in vitro and cultured for 4weeks. A drill hole (diameter 7mm) was placed in both medial femoral condyles of sheep. For the left knee the defect was filled with a TCP plug and for the right knee the defect was left empty. After 6, 12, 26 and 52weeks, seven animals from each group were killed and studied. The samples were examined employing histological, histomorphometric and immunohistological methods as well as various imaging techniques (X-ray, microcomputer tomography and scanning electron microscopy). After explantation the cartilage defects were first assessed macroscopically. There were no signs of infection or inflammation. Histological grading scales were used for assessment of bony integration and cartilage repair. An increasing degradation (81% after 52weeks) of the ceramic with concomitant bone formation was observed. The original structure of cancellous bone was almost completely restored. After 26 and 52weeks, collagen II-positive hyaline cartilage was detected in several samples. New subchondral bone had formed. The formation of cartilage began at the outer edge and proceeded to the middle. According to the O'Driscoll score, values corresponding to healthy cartilage were not reached after 1year. Integration of the newly formed cartilage tissue into the surrounding native cartilage was found. The formation of biomechanical stable cartilage began at the edge and progressed towards the centre of the defect. After 1year this process was still not completed. Microporous β-TCP scaffolds seeded with chondrocytes are suitable for the treatment of osteochondral defects.

Alzheimer’s disease (AD) and Parkinson’s disease (PD), including dementia with Lewy bodies (DLB), account for the majority of dementia cases worldwide. Interestingly, a significant number of patients have clinical and neuropathological features of both AD and PD, i.e., the presence of amyloid deposits and Lewy bodies in the neocortex. The identification of α-synuclein peptides in amyloid plaques in DLB brain led to the hypothesis that both peptides mutually interact with each other to facilitate neurodegeneration. In this article, we report the influence of Aβ(1–42) and pGlu-Aβ(3–42) on the aggregation of α-synuclein in vitro. The aggregation of human recombinant α-synuclein was investigated using thioflavin-T fluorescence assay. Fibrils were investigated by means of antibody conjugated immunogold followed by transmission electron microscopy (TEM). Our data demonstrate a significantly increased aggregation propensity of α-synuclein in the presence of minor concentrations of Aβ(1–42) and pGlu-Aβ(3–42) for the first time, but without effect on toxicity on mouse primary neurons. The analysis of the composition of the fibrils by TEM combined with immunogold labeling of the peptides revealed an interaction of α-synuclein and Aβ in vitro, leading to an accelerated fibril formation. The analysis of kinetic data suggests that significantly enhanced nucleus formation accounts for this effect. Additionally, co-occurrence of α-synuclein and Aβ and pGlu-Aβ, respectively, under pathological conditions was confirmed in vivo by double immunofluorescent labelings in brains of aged transgenic mice with amyloid pathology. These observations imply a cross-talk of the amyloid peptides α-synuclein and Aβ species in neurodegeneration. Such effects might be responsible for the co-occurrence of Lewy bodies and plaques in many dementia cases.

Wood-plastic composites from bio-based polymers and wood fibers (bio-WPC) provide an improved sustainability and carbon footprint compared to conventional composites. Actually, the implementation of this approach into industrial applications is hindered by the missing knowledge on the mechanical and thermo-mechanical properties of such bio-WPC. In this study, the properties of a bio-WPC from bio-based polyamide 11 (PA 11) and chemically modified beech fibers were investigated. The chemical modification of the beech fibers by an alkaline treatment with an aqueous solution of sodium hydroxide (NaOH) was done to support the melt processing and adhesion to the PA 11 matrix. Analysis of the modified fibers by Thermogravimetric Analysis (TGA) proved an increased thermal stability, as identified by an increase of the extrapolated TGA onset temperature from 290 to 330 °C. This improvement resulted from hemicellulose removal, as confirmed through Attenuated Total Reflection Inf rared Spectroscopy (ATR-FTIR). Consequently, mechanical and thermo-mechanical analysis of the processed bio-WPC showed an increase in elastic modulus and storage modulus of the composites by the chemical treatment of the fibers. This effect was attributed to an increased number of hydrogen bonds between the modified beech fibers and the PA 11 matrix. The overall mechanical properties of the investigated bio-WPCs support their use as sustainable construction material for technical applications

These results demonstrate that the commercial collagen membrane holds an osteoconductive competence in a rat calvaria defect model. Soaking collagen membranes with BCM shifts bone formation toward the formation of bony islands rather than new bone connected to the host bone.