Hyperthermia and local drug delivery have been proposed as potential therapeutic approaches for bone defects resulting from malignant bone tumors. The development of bioactive materials with magnetic and drug delivery properties may potentially meet this target. The aim of this study was to develop a multifunctional mesoporous bioactive glass (MBG) scaffold system for both hyperthermic and local drug delivery applications. To this end iron (Fe)-containing MBG (Fe-MBG) scaffolds with a hierarchical large pores structure (300-500 μm) and fingerprint-like mesopores (4.5 nm) have been prepared. The effects of Fe on the mesopore structure and physiochemical, magnetic, drug delivery and biological properties of MBG scaffolds have been systematically investigated. The results show that the morphology of the mesopores varied from straight channels to curved fingerprint-like channels after incorporation of Fe into MBG scaffolds. The magnetism of MBG scaffolds can be tailored by controlling the Fe content. Furthermore, the incorporation of Fe into mesoporous MBG glass scaffolds enhanced the mitochondrial activity and the expression of bone-related genes (ALP and OCN) in human bone marrow mesenchymal stem cells (BMSC) attached to the scaffolds. The Fe-MBG scaffolds obtained also possessed high specific surface areas and demonstrated sustained drug delivery. Thus Fe-MBG scaffolds are magnetic, degradable and bioactive. The multifunctionality of Fe-MBG scaffolds suggests that there is great potential for their use in the treatment and regeneration of large-bone defects caused by malignant bone tumors through a combination of hyperthermia, local drug delivery and osteoconductivity.

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The surface properties of poly(dimethyl siloxane) (PDMS) layers screen printed onto silicon wafers were studied after oxygen and ammonia plasma treatments and subsequent grafting of poly(ethylene -alt-maleic anhydride) (PEMA) using X-ray photoelectron spectroscopy (XPS), roughness analysis, and contact angle and electrokinetic measurements. In the case of oxygen-plasma-treated PDMS, a hydrophilic, brittle, silica-like surface layer containing reactive silanol groups was obtained. These surfaces indicate a strong tendency for "hydrophobic recovery" due to the surface segregation of low-molecular-weight PDMS species. The ammonia plasma treatment of PDMS resulted in the generation of amino-functional surface groups and the formation of a weak boundary layer that could be washed off by polar liquids. To avoid the loss of the plasma modification effect and to achieve stabilization of the mechanically instable, functionalized PDMS top layer, PEMA was subsequently grafted directly or after using gamma-APS as a coupling agent on the plasma-activated PDMS surfaces. In this way, long-time stable surface functionalization of PDMS was obtained. The reactivity of the PEMA-coated PDMS surface caused by the availability of anhydride groups could be controlled by the number of amino functional surface groups of the PDMS surface necessary for the covalent binding of PEMA. The higher the number of amino functional surface groups available for the grafting-to procedure, the lower the hydrophilicity and hence the lower the reactivity of the PEMA-coated PDMS surface. Additionally, pull-off tests were applied to estimate the effect of surface modification on the adhesion between the silicone rubber and an epoxy resin.

This study reports on a facile approach to the fabrication of nanoporous carbon cathodes for lithium sulfur batteries using gyroid carbon replicas based on use of polystyrene-poly-4-vinylpyridine (PS-P4VP) block copolymers as sacrificial templates. The free-standing gyroid carbon network with a highly ordered and interconnected porous structure has been fabricated by impregnating the carbon precursor solution into the gyroid block copolymer nanotemplates and subsequently carbonizing them. A wide range of analytical tools have been employed to characterize fabricated porous carbon material. Prepared nanostructures are envisioned to have a great potential in myriad areas such as energy storage/conversion devices owing to their fascinating morphology exhibiting high surface area and uniform porosity with interconnected three-dimensional networks. The resulting carbon nanoporous structures infused with elemental sulfur have been found to work as a promising electrode for lithium sulfur batteries demonstrating a high cycling stability over more than 200 cycles.

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