Volume 86, Issue 12

Transform growth factor-β1 (TGF-β1) is an extremely powerful protein to induce the chondrogenesis of mesenchymal stem cells (MSCs) both in vitro and in vivo. However, due to the short-life of TGF-β1, the direct application of TGF-β1 may deteriorate its bioactivity and thereby the repair effect. In this study, uniform sulfated chitosan microspheres (SCMs) with a mean diameter of ∼ 2 μm were fabricated by membrane emulsification as a carrier for TGF-β1. The in vitro release study showed that TGF-β1 could be sustainedly released from the microspheres up to 16 days. Under the protection of SCMs, about 13 % TGF-β1 was preserved even after stored for 14 days. The microspheres cytotoxicity was evaluated by coculture of MSCs with different concentrations SCMs and no obvious deterioration of cell viability was observed when the concentration of SCMs is lower than 2 μg/1.0 × 10 4 cells. In comparison with the blank group, the addition of TGF-β1 either in free state or loaded in SCMs inhibited the proliferation trend of MSCs. Quantitative analysis of GAGs production and genes expression of COL II and aggrecan by qRT-PCR revealed that enhanced bioactivity of TGF-β1 was obtained in the group of TGF-β1/SCMs, indicating that SCMs could be functioned as a promising carrier of TGF-β1 for the in vitro chondrogenesis of MSCs.

Alfred Werner was awarded the Nobel Prize in Chemistry just over 100 years ago. We recall briefly the era in which he was working, his co-workers, and the equipment he used in his laboratories. His ideas were ground breaking: not only does a metal ion have a primary valency (“hauptvalenz”, now the oxidation state), but also a secondary valency, the coordination number (“nebenvalenz”). At that time some refused to accept this idea, but he realised that his new thinking would open up new areas of research. Indeed it did. We illustrate this for the emerging field of medicinal metal coordination chemistry, the design of metal-based therapeutic and diagnostic agents. The biological activity of metal complexes depends intimately not only on the metal and its oxidation state, but also on the type and number of coordinated ligands, and the coordination geometry. This provides a rich platform in pharmacological space for structural and electronic diversity. It is necessary to control both the thermodynamics (strengths of metal-ligand bonds) and kinetics of ligand substitution reactions to provide complexes with defined mechanisms of action. Outer-sphere interactions can also play a major role in target recognition. Our current interest is focussed especially on relatively inert metal complexes which were very familiar to Werner (Ru II , Os II , Rh III , Ir III , Pt II , Pt IV ).

Design of micro-patterning of hydrogel is of critical importance in both understanding cellular behaviors and mimicking controlled microenvironments and architectures of diverse well-organized tissues. After micro-patterning of hyaluronic acid (HA) hydrogel on a poly(dimethyl siloxane) substrate, its physical and biological properties have been compared with those of a non-patterned hydrogel for its possible applications in bone tissue engineering. The micro-patterned morphologies of HA hydrogel in both swollen and dehydrated forms have been observed with light microscope and scanning electron microscope, respectively, before and after in vitro cell culture. When MC3T3 bone cells were in vitro cultured on both HA hydrogels, the micro-patterned one shows excellence in cell proliferation and lining for 7 days along the micro-pattern paths over those of the non-patterned one, which have shown less cell-adhesiveness. The cytotoxicity of the micro-patterned HA hydrogels was in vitro evaluated by the assays of MTT, BrdU and Neutral red. The viability and morphology of MC3T3 cells on both HA hydrogels were observed with a fluorescence microscope by the live & dead assay, where their viability was confirmed by staining of F-actin development. The results of their H&E staining showed that both micro-patterned and non-patterned hydrogels induced development of tissue regeneration as observed by cell attachment, proliferation, and survivability, but the micro-patterned one induced distinctive patterning of both better initial cells adhesion on the micro-patterns and subsequently development of their proliferation and extracellular matrix, which were considered as important characteristics in their applications to tissue engineering.

The terminology of NPU (nomenclature for properties and units) aims at describing properties examined in clinical laboratories for a patient. It was originally jointly approved in 1966 by IUPAC and by the International Federation of Clinical Chemistry (IFCC) and covers multiple disciplines in the field of clinical laboratory sciences, including clinical allergology, clinical chemistry, clinical haematology, clinical immunology and blood banking, clinical microbiology, clinical pharmacology, molecular biology and genetics, reproduction and fertility, thrombosis and haemostasis, and toxicology. The NPU terminology adheres to international standards of metrology and of terminology, in particular the International System of Quantities (ISQ) and International System of Units (SI), the International Vocabulary of Metrology (VIM), and also to ‘An outline for a vocabulary of nominal properties and examinations – basic and general concepts and associated terms,’ recently prepared on behalf of the IFCC-IUPAC Committee-Subcommittee on Nomenclature for Properties and Units. The present document recalls the definitions of the concepts used to express a property of a patient, regarded as a system. The aim is to promote by this comprehensive summary the proper NPU terminology for reliable exchange of patient examination data. The use of this syntax and of SI units enables the translation of these descriptions into other languages without loss of meaning or accuracy. The NPU format is also well adapted for comparative and epidemiological studies. More information will be found in the upcoming 2 nd edition of the Compendium of Terminology and Nomenclature of Properties in Clinical Laboratory Sciences , the IUPAC and IFCC ‘Silver Book’, and in the recently published ‘Properties and units in the clinical laboratory sciences. Part XXIII. The NPU terminology, principles, and implementation: A user’s guide (IUPAC Technical Report)’ (DOI:10.1351/PAC-REP-11-05-03).

The report of an IUPAC Task Group, formed in 2011 on “Intensities and line shapes in high-resolution spectra of water isotopologues from experiment and theory” (Project No. 2011-022-2-100), on line profiles of isolated high-resolution rotational-vibrational transitions perturbed by neutral gas-phase molecules is presented. The well-documented inadequacies of the Voigt profile (VP), used almost universally by databases and radiative-transfer codes, to represent pressure effects and Doppler broadening in isolated vibrational-rotational and pure rotational transitions of the water molecule have resulted in the development of a variety of alternative line-profile models. These models capture more of the physics of the influence of pressure on line shapes but, in general, at the price of greater complexity. The Task Group recommends that the partially Correlated quadratic-Speed-Dependent Hard-Collision profile (pCqSD-HCP) should be adopted as the appropriate model for high-resolution spectroscopy. For simplicity this should be called the Hartmann–Tran profile (HTP). The HTP is sophisticated enough to capture the various collisional contributions to the isolated line shape, can be computed in a straightforward and rapid manner, and reduces to simpler profiles, including the Voigt profile, under certain simplifying assumptions.

The paper addresses techniques for checking the performance of rotational rheometers with cone–plate, plate–plate, or concentric cylinder geometry. We focus on the determination of the viscosity as a function of the shear rate and of the magnitude of the complex viscosity as a function of the angular frequency. After summarizing the relevant definitions and test modes, we show examples of measurements in the linear viscoelastic range, and applications of the Cox–Merz relationship. Sources of reference fluids with defined viscosities are presented, and their use in tests for verification of accuracy is demonstrated. Relevant issues, predominantly for Newtonian reference liquids, are the exploration of measurement limits, related either to the shear rate range or to reliably accessible viscosity levels. Viscoelastic reference samples are also discussed. Prerequisites for sample preparation and loading are addressed. In particular, we present recommendations based on experience from various laboratories. Finally, we discuss the problem of temperature calibration, presenting techniques that allow the determination of the true sample temperature for a given set temperature of the rheometer. This paper summarizes contributions from various industrial and academic laboratories.

This IUPAC Technical Report describes and compares the currently applied methods for measuring and analyzing time-resolved fluorescence traces using phase-modulation fluorometry as well as pulse fluorometry (direct emission decay measurements, single-photon timing, streak camera measurements, fluorescence upconversion, and optical Kerr gating). The paper starts with a brief description of the basic principles for time and frequency domain fluorescence spectroscopy. The fundamental equations are given, and recommendations for adequate use are emphasized. The up-to-date, commonly employed excitation sources and photodetectors are described in detail. The analysis of time-resolved fluorescence data is discussed. Attention is paid to possible artifacts, and remedies are presented on how to avoid them or to account for them. Finally, fluorescence lifetime standards for the nanosecond and picosecond timescales are collected.