Biodegradable porous biomaterial scaffolds play a critical role in bone regeneration. In this study, the porous nano-hydroxyapatite/collagen/poly(lactic-co-glycolic acid)/graphene oxide (nHAC/PLGA/GO) composite scaffolds containing different amount of GO were fabricated by freeze-drying method. The results show that the synthesized scaffolds possess a three-dimensional porous structure. GO slightly improves the hydrophilicity of the scaffolds and reinforces their mechanical strength. Young’s modulus of the 1.5 wt% GO incorporated scaffold is greatly increased compared to the control sample. The in vitro experiments show that the nHAC/PLGA/GO (1.5 wt%) scaffolds significantly cell adhesion and proliferation of osteoblast cells (MC3T3-E1). This present study indicates that the nHAC/PLGA/GO scaffolds have excellent cytocompatibility and bone regeneration ability, thus it has high potential to be used as scaffolds in the field of bone tissue engineering.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2432-6) contains supplementary material, which is available to authorized users.

In this study, a novel photocatalyst composed of N-doped TiO 2 (N-TiO 2 ) and (Ca, Y)F 2 :Yb 3+ , Tm 3+ was prepared by simple dealloying followed by a hydrothermal method. The composite exhibits a homogeneous nanoporous structure consisting of large quantities of the spindle-like N-doped TiO 2 nanorods, on which the (Ca, Y)F 2 :Yb 3+ , Tm 3+ particles with a diameter of around 5 nm are uniformly dispersed. In addition, morphology and property of the N-TiO 2 can be controlled by adjusting the dealloying period. Results show that a short immersion time leads to a small size, large surface area and low band gap. As a result, the N-TiO 2 / (Ca, Y)F 2 :Yb 3+ , Tm 3+ composite after dealloying for 48 h (TiO 2 -48-C) exhibits higher degradation rates (65.6% for 10 h irradiation by 980 nm NIR) than others after dealloying for 60 h (TiO 2 -60-C) and 72 h (TiO 2 -72-C), indicating its excellent potential for practical applications.

Highly pure magnesium borate (Mg 2 B 2 O 5 ) nanowires with an average diameter of ∼ 30 nm, an average length of ∼ 15 µm, and a high aspect ratio of ∼ 500 have been synthesized on a large scale via a two-step method. MgBO 2 (OH) nanowires with high aspect ratios were first prepared via a PVP-assisted hydrothermal technique. Using these nanowires as precursors, single crystalline Mg 2 B 2 O 5 nanowires were synthesized by post-annealing treatment at a relatively low temperature of 700 • C. The important effect of the MgBO 2 (OH)-Mg 2 B 2 O 5 conversion process on the morphology of the Mg 2 B 2 O 5 nanowires was investigated and it was indicated that the recrystallization process plays an important role in the protection of the one-dimensional (1D) nanostructure. Moreover, the rigidity and the toughness of the Mg 2 B 2 O 5 nanowirereinforced PHA composites were tremendously improved compared to those of the pure PHA. Our results demonstrate the effectiveness of Mg 2 B 2 O 5 nanowires for reinforcement applications in polymer composites.

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