Purpose Previous studies have shown that blocking the endplate nutritional pathway with bone cement did not result in obvious intervertebral disc degeneration (IDD) in mature animal models. However, there are very few comparable studies in immature animal models. As vertebroplasty currently is beginning to be applied in young, even biologically immature patients, it is important to investigate the effect of cement blocking at the endplate in an immature animal model. Methods Two lumbar intervertebral discs in eight immature pigs were either blocked by cement in both endplate pathways or stabbed with a scalpel in the annulus fibrosus (AF) as a positive control, and with a third disc remaining intact as a normal control. Magnetic resonance imaging (MRI) and histology study were performed. Results After three months, the cement-blocked discs exhibited severe IDD, with the percentage of disc-height index (DHI), nucleus pulposus (NP) area, and NP T2 value significantly lower than the normal control. These IDD changes were histologically confirmed. Post-contrast MRI showed diseased nutritional diffusion patterns in the cement-blocked discs. Moreover, the degenerative changes of the cementblocked discs exceeded those of the injured AF positive controls.Conclusions The endplate nutritional pathway was interfered with and diseased after three months of bone cement intervention in an immature porcine model. Severe interference in the endplate nutritional pathway in an immature porcine model caused IDD. These findings also draw attention to the fact that interference in endplate nutritional pathways in immature or young patients may affect the vitality of adjacent discs.

Purpose Osteoporosis mainly involves cancellous bone, and the spine and hip, with their relatively high cancellous bone to cortical bone ratio, are severely affected. Studies of bone mesenchymal stem cells (BMSCs) from osteoporotic patients and animal models have revealed that osteoporosis is often associated with reduction of BMSCs' proliferation and osteogenic differentiation. Our aim was to test whether polylactic acidpolyglycolic acid copolymer(PLGA)/collagen type I(CoI) microspheres combined with BMSCs could be used as injectable scaffolds to improve bone quality in osteoporotic female rats. Methods PLGA microspheres were coated with CoI. BMSCs of the third passage and were cultured with PLGA/CoI microspheres for seven days. Forty three-month-old female non-pregnant SD rats were ovariectomized to establish osteoporotic animal models. Three months after being ovariectomized, the osteoporotic rats were randomly divided into five groups: SHAM group, PBS group, cell group, microsphere (MS) group, and cell+MS group. Varying materials were injected into the intertrochanters of each group's rats. Twenty rats were sacrificed at one month and three months post-op, respectively. The femora were harvested in order to measure the intertrochanteric bone mineral density (BMD) with DEXA and trabecular thickness (Tb.Th), percentage of trabecular area (%Tb.Ar), bone volume fraction (BV/TV) and trabecular spacing (Tb.Sp) with Micro CT. One-way ANOVA and Kruskal-Wallis tests were used. Results BMSCs seeded on PLGA/CoI microspheres had a nice adhesion and proliferation. At one month post-op, the BMD (0.33 ± 0.01 g/cm 2 ), Tb.Th (459.65 ± 28.31 μm), %Tb.Ar (9.61±0.29 %) and Tb.Sp (2645.81±94.91 μm) of the cell+MS group were better than those of the SHAM group and the cell group. At three months post-op, the BMD (0.32±0.01 g/cm 2 ), Tb.Th (372.81±38.45 μm), %Tb.Ar (6.65 ± 0.25 %), BV/TV (6.62 ± 0.25 %) and Tb.Sp (1559.03±57.06 μm) of the cell+MS group were also better than those of the SHAM group and the cell group. Conclusion The PLGA/CoI microspheres combined with BMSCs can repair bone defects more quickly. This means that PLGA/CoI microspheres combined with BMSCs can promote trabecular reconstruction and improve bone quality in osteoporotic rats. This scaffold can provide a promising minimally invasive surgical tool for enhancement of bone fracture healing or prevention of fracture occurrence which will in turn minimize complications endemic to patients with osteoporosis.

An effective one-pot process of synthesizing 2,5-diformylfuran (DFF) directly from fructose was accomplished over carbon sphere (CS)-supported molybdenum oxides (MoO x /CS) catalysts. The MoO x /CS catalyst was first prepared by a glucose hydrothermal carbonization method and subsequently annealed under different atmospheres. The annealing treatment under air at 275 °C afforded abundant mesopores over the CS and exposed more active sites. Kinetics studies suggested that 5-hydroxymethylfurfural (HMF) was the key intermediate; acid and oxide sites were active toward the dehydration of fructose and aerobic oxidation of HMF to DFF, respectively. A relatively faster dehydration rate compared to oxidation rate was critical for the dehydration of fructose to HMF instead of decomposing fructose under oxidative conditions. Under the optimized reaction conditions, nearly 78% yield of DFF at 100% conversion of fructose was obtained in dimethyl sulfoxide under atmospheric pressure of oxygen at 160 °C within 2 h.

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