Biological performance of novel phosphate-based glass microspheres for mesenchymal stem cell therapy in osteoporotic patients

In this study, degradable phosphate-based bulk or porous glass microspheres (BGMS or PGMS), with nominal molar compositions of P45-(45P2O5-16CaO-24MgO-11Na2O-4Fe2O3) and P40-(40P2O5-16CaO-24MgO-20Na2O), were evaluated for cytotoxicity, cytocompatibility and osteogenic potential for Mesenchymal stem cell (MSC)-based therapy in osteoporotic patients. Evaluations were performed using direct-contact and indirect-contact bone marrow derived human MSC (hMSC)-based experiments, in addition to material characterisations such as morphology, elemental composition and degradation behaviour, which were correlated to the hMSC experiments. Degradation of microspheres (MS) was measured using a novel method where Scanning Electron micrographs was used to assess the number of MS with surface damage (cracks and peeling effect), over 42 days of degradation in culture medium. Results showed that after 42 days, 2%, 46% and 29% of P45 BGMS, P40 BGMS and P40 PGMS, respectively, had cracks or peeling off surfaces. The results for direct-contact hMSC-experiments showed that P45 BGMS supported 1.4 times more hMSCs than P40 BGMS over 31 days of culture period. However, P45 BGMS were not osteoinductive, possibly due to hydrophobic nature of this glass and its slower dissolution rate. On the other hand, in comparison to P45 BGMS, hMSCs seeded on P40 BGMS showed up to 1.7 times higher alkaline phosphatase (ALP) activity on Day 7, up to 1.5 times more collagen and at least 6 times more Ca deposited in extracellular matrix, in addition to osteocalcin on Day 21 of culture, which strongly indicated the osteoinductive nature of P40 BGMS. This effect was also confirmed through indirect-contact experiments where there was higher collagen and Ca production by hMSCs was observed after 25 days of culture in P40 BGMS-conditioned medium as compared to control (no MS) or P45-conditioned medium. Elemental analysis using Energy Dispersive X-Ray Spectroscopic (EDS) analysis revealed that the Ca-based porogen used in the manufacturing of PGMS, may have been retained on the edges of the pores in PGMS. Therefore, an acid-washing step was introduced at the end of manufacturing process in order to remove the porogen and limit the possible cytotoxic effect of porogen and excess calcium. Characterisation results indicated that acid washing changed the physicality of these microspheres without changing their chemical composition. For example, mean and mode pore window sizes on the surface of PGMS increased from 2.63 μm to 2.73 μm and from 1.15 μm to 1.53 μm, respectively, and closed porosity decreased by 27%, as a result of acid washing. However, more detailed EDS analysis revealed that the Ca-based porogen was not being completely removed from PGMS even after acid washing and this may need further investigation. Cytotoxicity evaluations over 7 days of elution (indirect-contact hMSC experiments) suggested that there was marked improvement in hMSC membrane integrity and metabolic activity in PGMS neat extracts after acid washing. Moreover, direct-contact hMSC experiments also showed higher DNA content on acid washed (AW) P40 PGMS over 7 days of culture. Therefore, based on these results, it was hypothesised that acid washing may have opened up some of the pores and removed some of the glass fragments from PGMS surface, which may have been responsible for cytotoxicity in non-AW PGMS. Direct-contact experiments also showed that over 42-day culture period, there was up to 1.6 times higher hMSC numbers in AW P40 PGMS as compared to P40 BGMS. However, this increase was much lower than the expected range as there was more than 10-fold increase in surface area after the introduction of porosity. This was probably due to presence of <5 μm and <10 μm pore window sizes and interconnection sizes, respectively, in these microspheres, which allowed limited penetration of hMSCs into the porous structures. There was also evidence of at least 2 times more ALP activity up to day 42 of culture and up to 1.7 times more collagen production by day 21 of culture, in case of AW P40 PGMS as compared to P40 BGMS, which strongly indicated a positive effect of porosity on osteogenesis. Interestingly, there was also lower Ca and P deposited by hMSCs in porous microspheres, which was in line with the observations made through indirect-contact experiments, where there was lower collagen and Ca production by hMSCs in P40 PGMS-conditioned medium as compared to P40 BGMS-conditioned medium. This negative effect of PGMS was hypothesised due to excess release of glass fragments/particulates and calcium ions into the medium, possibly leading to cytotoxicity. Based on the results shown here, there is a potential of P40 BGMS and AW P40 PGMS for hMSC-based bone repair therapy. However, future work needs to be done in order to limit the delamination of glass surfaces and release of glass fragments/particulates from these MS, as a result of degradation

Recent Results from LHD Experiment with Emphasis on Relation to Theory from Experimentalist’s View

he Large Helical Device (LHD) has been extending an operational regime of net-current free plasmas towardsthe fusion relevant condition with taking advantage of a net current-free heliotron concept and employing a superconducting coil system. Heating capability has exceeded 10 MW and the central ion and electron temperatureshave reached 7 and 10 keV, respectively. The maximum value of β and pulse length have been extended to 3.2% and 150 s, respectively. Many encouraging physical findings have been obtained. Topics from recent experiments, which should be emphasized from the aspect of theoretical approaches, are reviewed. Those are (1) Prominent features in the inward shifted configuration, i.e., mitigation of an ideal interchange mode in the configuration with magnetic hill, and confinement improvement due to suppression of both anomalous and neoclassical transport, (2) Demonstration ofbifurcation of radial electric field and associated formation of an internal transport barrier, and (3) Dynamics of magnetic islands and clarification of the role of separatrix

E8.5 mouse embryo_1

Data of DNA microarray analysis of E8.5 mouse embryo (whole body

E9.5 mouse embryo_1

Data of DNA microarray analysis of E9.5 mouse embryo (whole body

Data from: Rewiring of embryonic glucose metabolism via suppression of pfk-1/aldolase during mouse chorioallantoic branching

Adapting the energy metabolism state to changing bioenergetic demands is essential for mammalian development accompanying massive cell proliferation and cell differentiation. However, it remains unclear how developing embryos meet the changing bioenergetic demands during the chorioallantoic branching (CB) stage when the maternal-fetal exchange of gases and nutrients is promoted. In this study, using metabolome analysis with mass-labeled glucose, we found that developing embryos redirected glucose carbon flow into the pentose phosphate pathway (PPP) via suppression of the key glycolytic enzymes PFK-1 and aldolase during CB. Concomitantly, embryos had increases in lactate pool size and in the fractional contribution of glycolysis to lactate biosynthesis. Imaging mass spectrometry (IMS) visualized lactate-rich tissues, such as the dorsal or posterior neural tube, somites, and head mesenchyme. Furthermore, we found that the heterochronic gene Lin28a could act as a regulator of the metabolic changes observed during CB. Perturbation of glucose metabolism rewiring by suppressing Lin28a downregulation resulted in perinatal lethality. Thus, our work demonstrates that developing embryos rewire glucose metabolism following CB for normal development

Glycolytic flux-signaling controls mouse embryo mesoderm development.

How cellular metabolic state impacts cellular programs is a fundamental, unresolved question. Here, we investigated how glycolytic flux impacts embryonic development, using presomitic mesoderm (PSM) patterning as the experimental model. First, we identified fructose 1,6-bisphosphate (FBP) as an in vivo sentinel metabolite that mirrors glycolytic flux within PSM cells of post-implantation mouse embryos. We found that medium-supplementation with FBP, but not with other glycolytic metabolites, such as fructose 6-phosphate and 3-phosphoglycerate, impaired mesoderm segmentation. To genetically manipulate glycolytic flux and FBP levels, we generated a mouse model enabling the conditional overexpression of dominant active, cytoplasmic PFKFB3 (cytoPFKFB3). Overexpression of cytoPFKFB3 indeed led to increased glycolytic flux/FBP levels and caused an impairment of mesoderm segmentation, paralleled by the downregulation of Wnt-signaling, reminiscent of the effects seen upon FBP-supplementation. To probe for mechanisms underlying glycolytic flux-signaling, we performed subcellular proteome analysis and revealed that cytoPFKFB3 overexpression altered subcellular localization of certain proteins, including glycolytic enzymes, in PSM cells. Specifically, we revealed that FBP supplementation caused depletion of Pfkl and Aldoa from the nuclear-soluble fraction. Combined, we propose that FBP functions as a flux-signaling metabolite connecting glycolysis and PSM patterning, potentially through modulating subcellular protein localization

Corporate eligibility to conduct initial public offerings in Indonesia: an examination of the disclosure principle

Theoretical thesis.Bibliography: pages 65-70.Chapter I. Introduction -- Chapter II. Regulating publicly listed companies through mandatory disclosure -- Chapter III. Implementing mandatory disclosure requirements in Indonesia -- Chapter IV. Legal non-compliance disclosure -- Chapter V. Conclusion -- Bibliography.In capital markets, disclosure is the main source of information for investors. One of the most important types of information in disclosure is information about a company’s legal non-compliance. Information about a company’s legal non-compliance is not only socially significant but also financially important as it may lead to hefty penalties, loss of contract and other economic effects. However, in contrast to financial information which is quantitatively measured, the consequences of non-compliance often involve a qualitative aspect making it difficult to articulate its materiality.This study is doctrinal legal research and it sets out to evaluate whether the enforcement by the Indonesian Financial Services Authority (OJK) of its disclosure policy on legal non-compliance is sufficient to protect the investing public. The study aims to mitigate the impact of information asymmetry due to incomplete disclosure of corporate legal non-compliance as well as to enhance corporate accountability to shareholders for company illegality. It argues that factors such as materiality, regulatory capture, and the roles of securities lawyers have been creating inconsistencies in OJK’s implementation of its legal non-compliance disclosure policy. The outcome of this study would be useful to articulate lessons for other developing capital markets, particularly those with conditions of legal uncertainty similar to those in Indonesia, in advancing the goal of disclosure.Mode of access: World wide web1 online resource (70 pages

E10.5 mouse embryo_3

Data of DNA microarray analysis of E10.5 mouse embryo (whole body

E8.5 mouse embryo_2

Data of DNA microarray analysis of E8.5 mouse embryo (whole body