A three-phase [nanocrystalline hydroxyapatite (HA), carbon nanotubes (CNT), mixed in a polymeric matrix of polycaprolactone (PCL)] composite scaffold produced by 3D printing is presented. The CNT content varied between 0 and 10 wt % in a 50 wt % PCL matrix, with HA being the balance. With the combination of three well-known materials, these scaffolds aimed at bringing together the properties of all into a unique material to be used in tissue engineering as support for cell growth. The 3D printing technique allows producing composite scaffolds having an interconnected network of square pores in the range of 450-700 μm. The 2 wt % CNT scaffold offers the best combination of mechanical behaviour and electrical conductivity. Its compressive strength of ∼4 MPa is compatible with the trabecular bone. The composites show typical hydroxyapatite bioactivity, good cell adhesion and spreading at the scaffolds surface, this combination of properties indicating that the produced 3D, three-phase, scaffolds are promising materials in the field of bone regenerative medicine. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1210-1219, 2016.

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The present work reports on a novel needle type oxygen microsensor based on boron doped diamond (BDD) with tailored surface aiming in better electrochemical performance. The microelectrodes are produced by growing diamond films using HFCVD (Hot Filament Chemical Vapor Deposition) on top of electrochemically sharpened tungsten filaments. The diamond is functionalized using CF 4 RF-plasma post-treatments resulting in fluorine termination of the surface. The quantitative detection of the dissolved oxygen (DO) is demonstrated and supported with successful fitting to the theoretical values calculated for diffusion limited current on hemicylinder shape electrode. The developed MEs were calibrated and tested as probes for microamperometric mapping of dissolved oxygen in a Zn-Fe wire-electrode model galvanic couple immersed in 50 mM NaCl. Modified diamond MEs show a fast and stable response towards oxygen mapping, as well as stability for several days of measurements.

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