Epicardial cells derived from human embryonic stem cells augment cardiomyocyte-driven heart regeneration.

The epicardium and its derivatives provide trophic and structural support for the developing and adult heart. Here we tested the ability of human embryonic stem cell (hESC)-derived epicardium to augment the structure and function of engineered heart tissue in vitro and to improve efficacy of hESC-cardiomyocyte grafts in infarcted athymic rat hearts. Epicardial cells markedly enhanced the contractility, myofibril structure and calcium handling of human engineered heart tissues, while reducing passive stiffness compared with mesenchymal stromal cells. Transplanted epicardial cells formed persistent fibroblast grafts in infarcted hearts. Cotransplantation of hESC-derived epicardial cells and cardiomyocytes doubled graft cardiomyocyte proliferation rates in vivo, resulting in 2.6-fold greater cardiac graft size and simultaneously augmenting graft and host vascularization. Notably, cotransplantation improved systolic function compared with hearts receiving either cardiomyocytes alone, epicardial cells alone or vehicle. The ability of epicardial cells to enhance cardiac graft size and function makes them a promising adjuvant therapeutic for cardiac repair.: This work was supported by the British Heart Foundation (BHF; Grants NH/11/1/28922, G1000847, FS/13/29/30024 and FS/18/46/33663), Oxford-Cambridge Centre for Regenerative Medicine (RM/13/3/30159), the UK Medical Research Council (MRC) and the Cambridge Hospitals National Institute for Health Research Biomedical Research Centre funding (SS), as well as National Institutes of Health Grants P01HL094374, P01GM081619, R01HL12836 and a grant from the Fondation Leducq Transatlantic Network of Excellence (CEM). J.B. was supported by a Cambridge National Institute for Health Research Biomedical Research Centre Cardiovascular Clinical Research Fellowship and subsequently, by a BHF Studentship (Grant FS/13/65/30441). DI received a University of Cambridge Commonwealth Scholarship. LG is supported by BHF Award RM/l3/3/30159 and LPO is funded by a Wellcome Trust Fellowship (203568/Z/16/Z). NF was supported by BHF grants RG/13/14/30314. NL was supported by the Biotechnology and Biological Sciences Research Council (Institute Strategic Programmes BBS/E/B/000C0419 and BBS/E/B/000C0434). SS and MB were supported by the British Heart Foundation Centre for Cardiovascular Research Excellence. Core support was provided by the Wellcome-MRC Cambridge Stem Cell Institute (203151/Z/16/Z), The authors thank Osiris for provision of the primary mesenchymal stem cells (59

Ceramic mineral waste-forms for nuclear waste immobilization

Crystalline ceramics are intensively investigated as effective materials in various nuclear energy applications, such as inert matrix and accident tolerant fuels and nuclear waste immobilization. This paper presents an analysis of the current status of work in this field of material sciences. We have considered inorganic materials characterized by different structures, including simple oxides with fluorite structure, complex oxides (pyrochlore, murataite, zirconolite, perovskite, hollandite, garnet, crichtonite, freudenbergite, and P-pollucite), simple silicates (zircon/thorite/coffinite, titanite (sphen), britholite), framework silicates (zeolite, pollucite, nepheline /leucite, sodalite, cancrinite, micas structures), phosphates (monazite, xenotime, apatite, kosnarite (NZP), langbeinite, thorium phosphate diphosphate, struvite, meta-ankoleite), and aluminates with a magnetoplumbite structure. These materials can contain in their composition various cations in different combinations and ratios: Li–Cs, Tl, Ag, Be–Ba, Pb, Mn, Co, Ni, Cu, Cd, B, Al, Fe, Ga, Sc, Cr, V, Sb, Nb, Ta, La, Ce, rare-earth elements (REEs), Si, Ti, Zr, Hf, Sn, Bi, Nb, Th, U, Np, Pu, Am and Cm. They can be prepared in the form of powders, including nano-powders, as well as in form of monolith (bulk) ceramics. To produce ceramics, cold pressing and sintering (frittage), hot pressing, hot isostatic pressing and spark plasma sintering (SPS) can be used. The SPS method is now considered as one of most promising in applications with actual radioactive substances, enabling a densification of up to 98–99.9% to be achieved in a few minutes. Characteristics of the structures obtained (e.g., syngony, unit cell parameters, drawings) are described based upon an analysis of 462 publications

Experimental bladder regeneration using a poly-L-lactide/silk fibroin scaffold seeded with nanoparticle-labeled allogenic bone marrow stromal cells

Natalia M Yudintceva,1 Yulia A Nashchekina,1,2 Miralda I Blinova,1 Nadezhda V Orlova,3 Alexandr N Muraviov,3 Tatiana I Vinogradova,3 Magomed G Sheykhov,3 Elena Y Shapkova,3 Dmitriy V Emeljannikov,3 Petr K Yablonskii,3,4 Igor A Samusenko,5 Anastasiya L Mikhrina,6 Artem V Pakhomov,7 Maxim A Shevtsov1,7,8 1Department of Cell Culture, Institute of Cytology of the Russian Academy of Sciences (RAS), 2Nanotechnology and Telecommunications, Institute of Physics, Peter the Great St Petersburg Polytechnic University, 3Department of Urology, Federal State Institution Saint Petersburg Research Institute of Phthisiopulmonology, Ministry of Health of Russia, 4Faculty of Medicine, Federal State Budgetary Institute, 5Department of Pathology, Federal State Budgetary Institute “Nikiforov Russian Centre of Emergency and Radiation Medicine” of the Ministry of Health of Russia, 6Department of Pathomorphology, I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Science, 7Department of Radiology, Federal Almazov North-West Medical Research Center, 8Department of Experimental Medicine, First I.P. Pavlov State Medical University of St Petersburg, St Petersburg, Russia Abstract: In the present study, a poly-L-lactide/silk fibroin (PL-SF) bilayer scaffold seeded with allogenic bone marrow stromal cells (BMSCs) was investigated as a potential approach for bladder tissue engineering in a model of partial bladder wall cystectomy in rabbits. The inner porous layer of the scaffold produced from silk fibroin was designed to promote cell proliferation and the outer layer produced from poly-L-lactic acid to serve as a waterproof barrier. To compare the feasibility and efficacy of BMSC application in the reconstruction of bladder defects, 12 adult male rabbits were divided into experimental and control groups (six animals each) that received a scaffold seeded with BMSCs or an acellular one, respectively. For BMSC tracking in the graft in in vivo studies using magnetic resonance imaging, cells were labeled with superparamagnetic iron oxide nanoparticles. In vitro studies demonstrated high intracellular incorporation of nanoparticles and the absence of a toxic influence on BMSC viability and proliferation. Following implantation of the graft with BMSCs into the bladder, we observed integration of the scaffold with surrounding bladder tissues (as detected by magnetic resonance imaging). During the follow-up period of 12 weeks, labeled BMSCs resided in the implanted scaffold. The functional activity of the reconstructed bladder was confirmed by electromyo­graphy. Subsequent histological assay demonstrated enhanced biointegrative properties of the PL-SF scaffold with cells in comparison to the control graft, as related to complete regener­ation of the smooth muscle and urothelium tissues in the implant. Confocal microscopy studies confirmed the presence of the superparamagnetic iron oxide nanoparticle-labeled BMSCs in newly formed bladder layers, thus indicating the role of stem cells in bladder regeneration. The results of this study demonstrate that application of a PL-SF scaffold seeded with allogenic BMSCs can enhance biointegration of the graft in vivo and support bladder tissue regeneration and function. Keywords: bladder, bone marrow stromal cells, scaffold, superparamagnetic iron oxide nanoparticles, tissue engineering, stem cell