Patterning Nanoroads and Quantum Dots on Fluorinated Graphene

Using ab initio methods we have investigated the fluorination of graphene and find that different stoichiometric phases can be formed without a nucleation barrier, with the complete ＂2D-Teflon＂ CF phase being thermody- namically most stable. The fluorinated graphene is an insulator and turns out to be a perfect matrix-host for patterning nanoroads and quantum dots of pristine graphene. The electronic and magnetic properties of the nanoroads can be tuned by varying the edge orientation and width. The energy gaps between the highest occupied and lowest unoccupied molecular orbitals （HOMO-LUMO） of quantum dots are size-dependent and show a confinement typical of Dirac fermions. Furthermore, we study the effect of different basic coverage of F on graphene （with stoichiometries CF and C4F） on the band gaps, and show the suitability of these materials to host quantum dots of graphene with unique electronic properties.

Au,Pd and maghemite nanofunctionalized hydroxyapatite scaffolds for bone regeneration

Nanotechnology plays a key role in the development of innovative scaffolds for bone tissue engineering(BTE)allowing the incorporation of nanomaterials able to improve cell proliferation and differentiation.In this study,Mg-HA-Coll type I scaffolds(Mg-HA-based scaffolds)were nanofunctionalized with gold nanorods(Au NRs),palladium nanoparticles(Pd NPs)and maghemite nanoparticles(MAG NPs).Nanofunctionalized Mg-HA-based scaffolds(NF-HA-Ss)were tested for their ability to promote both the proliferation and the differentiation of adipose-derived mesenchymal stem cells(hADSCs).Results clearly highlight that MAG nanofunctionalization substantially improves cell proliferation up to 70% compared with the control(Mg-HA-based scaffold),whereas both Au NRs and Pd NPs nanofunctionalization induce a cell growth inhibition of 94% and 89%,respectively.Similar evidences were found for the osteoinductive properties showing relevant calcium deposits(25% higher than the control)for MAG nanofunctionalization,while a decreasing of cell differentiation(20% lower than the control)for both Au NRs and Pd NPs derivatization.These results are in agreement with previous studies that found cytotoxic effects for both Pd NPs and Au NRs.The excellent improvement of both osteoconductivity and osteoinductivity of the MAG NF-HA-S could be attributed to the high intrinsic magnetic field of superparamagnetic MAG NPs.These findings may pave the way for the development of innovative nanostructured scaffolds for BTE.