ABSTRACT
In the present study, we aimed to demonstrate the differentiating properties of platelet-rich plasma releasates (PRPr) on human chondrocytes seeded on a polygtlycolic acid (PGA) 3D scaffold. Gene expression and biochemical analysis were carried out to assess the improved quality of our PGA-based cartilage constructs supplemented with PRPr. We observed that the use of PRPr as cell cultures supplementation to PGA-chondrocyte constructs may promote chondrocyte differentiation, and thus may contribute to maintaining the chondrogenic phenotype longer than conventional supplementation by increasing high levels of important chondrogenic markers (e.g. sox9, aggrecan and type II collagen), without induction of type I collagen. Moreover, our constructs were analysed for the secretion and deposition of important ECM molecules (sGAG, type II collagen, etc.). Our results indicate that PRPr supplementation may synergize with PGA-based scaffolds to stimulate human articular chondrocyte differentiation, maturation and phenotypic maintenance.
ABSTRACT
Mathematical modelling analysis of experimental data, obtained with in vivo NMR spectroscopy and 13C-labelled substrates, allowed us to describe how the fermentative metabolism in Saccharomyces cerevisiae, taken as eukaryotic cell model, is influenced by stress factors. Experiments on cellular cultures subject to increasing concentrations of ferric ions were conducted in order to study the effect of oxidative stress on the dynamics of the fermentative process. The developed mathematical model was able to simulate the cellular activity, the metabolic yield and the main metabolic fluxes occurring during fermentation and to describe how these are modulated by the presence of ferric ions.
ABSTRACT
The highly toxic Aβ(25-35) is a peculiar peptide that differs from all the other commonly studied β-amyloid peptides because of its extremely rapid aggregation properties and enhanced neurotoxicity. We investigated Aβ(25-35) aggregation in H 2 O at pH 3.0 and at pH 7.4 by means of in-solution analyses. Adopting UV spectroscopy, Congo red spectrophotometry and thiofl avin T fl uorimetry, we were able to quantify, in water, the very fast assembling time necessary for Aβ(25-35) to form stable insoluble aggregates and their ability to seed or not seed fi bril growth. Our quantitative results, which confi rm a very rapid assembly leading to stable insoluble aggregates of Aβ(25-35) only when incubated at pH 7.4, might be helpful for designing novel aggregation inhibitors and to shed light on the in vivo environment in which fi bril formation takes place.