Fabrication and characterization of Ag- and Ga-doped mesoporous glass-coated scaffolds based on natural marine sponges with improved mechanical properties

Natural marine sponges were used as sacrificial template for the fabrication of bioactive glassbased scaffolds. After sintering at 1050 ºC, the resulting samples were additionally coated with a sol silicate solution containing biologically active ions (Ag and Ga), well-known for their antibacterial properties in comparison with standard scaffolds made by PU foam templates. The produced scaffolds were characterized by superior mechanical properties (maximum compressive strength of 4 MPa) and total porosity of ~80%. Direct cell culture tests performed on the uncoated and coated samples showed positive results in terms of adhesion, proliferation, and differentiation of MC3T3-E1 cells. Moreover, vascular endothelial growth factor (VEGF) secretion from cells in contact with scaffold dissolution products was measured after 7 and 10 days of incubation, showing promising angiogenic results for bone tissue engineering applications. The antibacterial potential of the produced samples was assessed by performing agar diffusion tests against both Gram-positive and Gram-negative bacteria.EU Horizon 2020 project COACH 64255

Silica-Encapsulated Efficient and Stable Si Quantum Dots with High Biocompatibility

A facile fabrication method to produce biocompatible semiconductor Quantum Dots encapsulated in high quality and thick thermal oxide is presented. The process employs sonication of porous Si/SiO2 structures to produce flakes with dimension in the 50–200 nm range. These flakes show a coral-like SiO2 skeleton with Si nanocrystals embedded in and are suitable for functionalization with other diagnostic or therapeutic agents. Silicon is a biocompatible material, efficiently cleared from the human body. The Photoluminescence emission falls in the transparency window for living tissues and is found to be bright and stable for hours in the aggressive biological environment

Development and characterization of 5% mol Zn bioceramic in granular form

Hydroxyapatite (HA) is capable of accepting substitute ions within its lattice, including zinc ions. Zinc is a trace element that activates the osteogenesis of osteoblastic cells and therefore plays an important role in the activity of alkaline phosphatase enzyme. The purpose of this work was to produce and characterize 5% mol Zn bioceramic in granular form (Zn-granules) for clinical applications and compare it with granules made from HA by using the same production route. Granules with addition of porogen agents were produced from powders of HA and zinc-containing HA by uniaxial pressing and heat treatment. The granules were subsequently ground and sieved. The results indicated that zinc contributed to the reduction of sample crystallinity and formed a biphasic structure after calcination at 1200 °C. Additionally, zinc release from granular material may have clinical applications as bone graft