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Molecular dynamics (MD) simulations at normal and high temperature were used to study the flexibility and malleability of three microsomal cytochromes P450 (CYPs): CYP3A4, CYP2C9, and CYP2A6. Comparison of B-factors (describing the atomic fluctuations) between X-ray and MD data shows that the X-ray B-factors are significantly lower in the regions where the crystal contacts occur than for other regions. Consequently, the conclusions about CYP flexibility based solely on the X-ray data might be misleading. Comparison of flexibility patterns of the three CYPs enabled common features and variations in flexibility and malleability of the studied CYPs to be identified. The previously described pattern of flexibility in topological elements of microsomal CYPs (a rigid heme binding core, a malleable distal side and intermediately flexible proximal side) was confirmed. These topological features provide an important combination of high stereo- and regio-specificity (mediated by the relative rigidity in the neighborhood of the heme), together with high substrate promiscuity due to the more flexible active site and the malleability of the distal side. The data acquired here show that the malleability of the three studied CYPs correlates with their substrate specificity: CYP2A6 has a narrow substrate range and is the most rigid, CYP3A4 is the most promiscuous CYP known and is the most malleable, and CYP2C9 is intermediate in terms of both its substrate specificity and malleability. Thus, the malleability of CYPs is probably a major determinant of their substrate specificity.

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Objective: Stromal vascular fraction (SVF), containing high amount of stem cells and other regenerative cells, can be easily obtained from loose connective tissue that is associated with adipose tissue. Here we evaluated safety and clinical efficacy of freshly isolated autologous SVF cells in a case control prospective multi-centric non-randomized study in patients with grade 2-4 degenerative osteoarthritis. Methods:A total of 1128 patients underwent standard liposuction under local anesthesia and SVF cells were isolated and prepared for application into 1-4 large joints. A total of 1856 joints, mainly knee and hip joints, were treated with a single dose of SVF cells. 1114 patients were followed for 12.1-54.3 months (median 17.2 months) for safety and efficacy. Modified KOOS/HOOS Clinical Score was used to evaluate clinical effect and was based on pain, non-steroid analgesic usage, limping, extent of joint movement, and joint stiffness evaluation before and at 3,6 and 12 months after the treatment. Results:No serious side effects, systemic infection or cancer was associated with SVF cell therapy. Most patients gradually improved 3-12 months after the treatment. At least 75% Score improvement was noticed in 63% of patients and at least 50% Score improvement was documented in 91% of patients 12 months after SVF cell therapy. Obesity and higher grade of OA were associated with slower healing. Conclusion:Here we report a novel and promising treatment approach for patients with degenerative osteoarthritis that is safe, cost-effective, and relying only on autologous cells.

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Ahead of Print article withdrawn by publisher

Objective Cell therapies have emerged as a promising approach in medicine. The basis of each therapy is the injection of 1–100×10 6 cells with regenerative potential into some part of the body. Mesenchymal stromal cells (MSCs) are the most used cell type in the cell therapy nowadays, but no gold standard for the labeling of the MSCs for magnetic resonance imaging (MRI) is available yet. This work evaluates our newly synthesized uncoated superparamagnetic maghemite nanoparticles (surface-active maghemite nanoparticles – SAMNs) as an MRI contrast intracellular probe usable in a clinical 1.5 T MRI system. Methods MSCs from rat and human donors were isolated, and then incubated at different concentrations (10–200 μg/mL) of SAMN maghemite nanoparticles for 48 hours. Viability, proliferation, and nanoparticle uptake efficiency were tested (using fluorescence microscopy, xCELLigence analysis, atomic absorption spectroscopy, and advanced microscopy techniques). Migration capacity, cluster of differentiation markers, effect of nanoparticles on long-term viability, contrast properties in MRI, and cocultivation of labeled cells with myocytes were also studied. Results SAMNs do not affect MSC viability if the concentration does not exceed 100 μg ferumoxide/mL, and this concentration does not alter their cell phenotype and long-term proliferation profile. After 48 hours of incubation, MSCs labeled with SAMNs show more than double the amount of iron per cell compared to Resovist-labeled cells, which correlates well with the better contrast properties of the SAMN cell sample in T2-weighted MRI. SAMN-labeled MSCs display strong adherence and excellent elasticity in a beating myocyte culture for a minimum of 7 days. Conclusion Detailed in vitro tests and phantom tests on ex vivo tissue show that the new SAMNs are efficient MRI contrast agent probes with exclusive intracellular uptake and high biological safety.