ABSTRACT
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ABSTRACT
One of the greatest enigmas of modern biology is how the geometry of muscular and skeletal structures are created and how their development is controlled during growth and regeneration. Scaling and shaping of vertebrate muscles and skeletal elements has always been enigmatic and required an advanced technical level in order to analyse the cell distribution in 3D. In this work, synchrotron X-ray computed microtomography (µCT) and chemical contrasting has been exploited for a quantitative analysis of the 3D-cell distribution in tissues of a developing salamander (Pleurodeles waltl) limb - a key model organism for vertebrate regeneration studies. We mapped the limb muscles, their size and shape as well as the number and density of cells within the extracellular matrix of the developing cartilage. By using tomographic approach, we explored the polarity of the cells in 3D, in relation to the structure of developing joints. We found that the polarity of chondrocytes correlates with the planes in joint surfaces and also changes along the length of the cartilaginous elements. Our approach generates data for the precise computer simulations of muscle-skeletal regeneration using cell dynamics models, which is necessary for the understanding how anisotropic growth results in the precise shapes of skeletal structures.
Subject(s)
Muscle Development/physiology , Muscle, Skeletal/diagnostic imaging , Regeneration/physiology , Synchrotrons , X-Ray Microtomography/methods , Animals , UrodelaABSTRACT
Sparsely tested group of platinum nanoparticles (PtNPs) may have a comparable effect as complex platinum compounds. The aim of this study was to observe the effect of PtNPs in in vitro amplification of DNA fragment of phage λ, on the bacterial cultures (Staphylococcus aureus), human foreskin fibroblasts and erythrocytes. In vitro synthesized PtNPs were characterized by dynamic light scattering (PtNPs size range 4.8-11.7 nm), zeta potential measurements (-15 mV at pH 7.4), X-ray fluorescence, UV/vis spectrophotometry and atomic absorption spectrometry. The PtNPs inhibited the DNA replication and affected the secondary structure of DNA at higher concentrations, which was confirmed by polymerase chain reaction, DNA sequencing and DNA denaturation experiments. Further, cisplatin (CisPt), as traditional chemotherapy agent, was used in all parallel experiments. Moreover, the encapsulation of PtNPs in liposomes (LipoPtNPs) caused an approximately 2.4x higher of DNA damage in comparison with CisPt, LipoCisPt and PtNPs. The encapsulation of PtNPs in liposomes also increased their antibacterial, cytostatic and cytotoxic effect, which was determined by the method of growth curves on S. aureus and HFF cells. In addition, both the bare and encapsulated PtNPs caused lower oxidative stress (determined by GSH/GSSG ratio) in the human erythrocytes compared to the bare and encapsulated CisPt. CisPt was used in all parallel experiments as traditional chemotherapy agent.
Subject(s)
DNA Damage , DNA Replication , Metal Nanoparticles/adverse effects , Cell Line , Cells, Cultured , Erythrocytes/drug effects , Fibroblasts/drug effects , Humans , Metal Nanoparticles/chemistry , Oxidative Stress , Platinum/adverse effects , Platinum/chemistry , Staphylococcus aureus/drug effects , Staphylococcus aureus/geneticsABSTRACT
The aim of this study was to synthesize cadmium telluride nanoparticles (CdTe NPs) modified apoferritin, and examine if apoferritin is able to accommodate CdTe NPs. Primarily, the thermostability of horse spleen apoferritin was tested and it's unfolding at 70 °C was observed. Cadmium telluride nanoparticles (CdTe NPs) were synthesized both within apoferritin protein cage and on its surface. The thermal treatment of apoferritin with CdTe NPs resulted in the aggregation of cores, which was indicated by changes in the absorption spectra and the shape of apoferritin tryptophan fluorescence. The apoferritin modified with CdTe NPs was additionally modified with gold nanoparticles and attached to magnetic particles via oligonucleotide using gold affinity to thiol group. This anchor system was used to separate the construct using external magnetic field and to analyse the molecules attached to apoferritin.