Performance of calcium deficient hydroxyapatite-polyglycolic acid composites: An in vitro study

The strategic incorporation of bioresorbable polymeric additives to calcium-deficient hydroxyapatite cement may provide short-term structural reinforcement and modify the modulus to closer match bone. The longer-term resorption properties may also be improved, creating pathways for bone in-growth. The aim of this study was to investigate the resorption process of a calcium phosphate cement system containing either in polyglycolic acid tri-methylene carbonate particles or polyglycolic acid fibres. This was achieved by in vitro aging in physiological conditions (phosphate buffered solution at 37°C) over 12 weeks. The unreinforced CPC exhibited an increase in compressive strength at 12 weeks, however catastrophic failure was observed above a critical loading. The fracture behaviour of cement was improved by the incorporation of PGA fibres; the cement retained its cohesive structure after critical loading. Gravimetric analysis and scanning electron microscopy showed a large proportion of the fibres had resorbed after 12 weeks allowing for the increased cement porosity, which could facilitate cell infiltration and faster integration of natural bone. Incorporating the particulate additives in the cement did not provide any mechanism for mechanical property augmentation or did not demonstrate any appreciable level of resorption after 12 weeks.

China’s New Approach to CSR in Congo: Is the leverage turning to China?

China has been the world’s fastest growing economy in the past 30 years with its enterprises rapidly emerging and becoming leading players globally. In particular, the progressive integration into the international system has been spurred by China’s entry into the global trading regime of the World Trade Organization (WTO) in 2001. The 'go global' policy has been facilitating the rapidly growing engagement on the African continent of Chinese multinational companies (MNCs). As a promising tri-polar global economic entity, its growth of relations with Africa has been both unprecedented and impressive. As the Sino-Africa economic and business partnership surges forward, the matter of corporate social responsibility (CSR) is increasingly becoming an imperative ingredient for any successful business. It is noteworthy that responsible corporate citizens should take account of the impact of their investment on both economic and social arenas. However, it still remains uncertain what role Chinese MNCs have been playing in the continent’s sustainable development.
A Sino-Congo deal seems a positive way forward, accelerating the Democratic Republic of Congo’s (hereinafter referred to as Congo) regional economy, depressed due to years of war. Meanwhile, the escalating investment into Congo has raised controversies for its no-attachment policy, with increasing pressure imposed on China’s MNCs to take CSR more seriously. Particular concerns are focused on the multinationals’ inadequate environmental and human rights protection. The recent massive infrastructure investment is arguably perceived as a different interpretation of CSR, which has aroused a hot debate about whether China is heading for status as a responsible stakeholder in the international community. It is conducive to clarifying the paradoxical issue by addressing whether China’s recent approaches have the potential to facilitate CSR initiatives or hinder them in the long run.

Structure-based design of selective high-affinity telomeric quadruplex-binding ligands.

A library of triazole-based telomeric quadruplex-selective ligands has been developed that mimic an established family of tri-substituted acridine-based ligands, using crystal structure data as a starting-point for computer-based design. Binding affinities, estimated by electrospray mass spectrometry, are in accord with the design concept.