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Transplanting cell/hydrogel constructs into a bone defect site is an effective strategy to repair the damaged tissues. However, before transplantation, there are various methods to culture cell/hydrogel constructs. Especially, the preferred pre-osteogenic differentiation period to achieve satisfied bone regeneration should be determined. To this end, Bone marrow mesenchymal stem cells (BMSCs) were firstly photo-encapsulated into poly(ethylene glycol)-diacrylate (PEGDA) hydrogel. Then the constructs were implanted in rat calvarial defects after being osteogenically induced for 0, 7, 14, and 21 days. In vitro experiments demonstrated that the proliferation of BMSCs in the hydrogels deceased significantly from 0 day to 7 days. The activity and the gene expression of alkaline phosphatase, besides the gene expression of bone morphogenetic protein-2 peaked at day 14, whereas the gene expression of osteocalcin and the formation of calcium nodules increased with the prolongation of differentiation time. In vivo results showed that limited areas of newly formed bone were found in the day0 and day21 groups. In the day7 group, obvious new bone with bone marrow space was found, while the day14 group nearly achieved complete bone healing. Our data suggested that the period of in vitro pre-osteogenic differentiation played a crucial role for the osteogenesis of BMSCs/PEGDA hydrogels. Furthermore, we found that a pre-differentiation for 14 days is preferable for bone regeneration in the rat cranial defects.

Supplementary data is available online at https://www.sciencedirect.com/science/article/pii/S0167577X22006164#s0035 . The spark plasma sintering (SPS), subsequent cold rolling, and annealing were used to produce Ti-Cu alloys to improve mechanical properties and antibacterial rate against Staphylococcus aureus significantly. The tensile strength, elongation and antibacterial rate reached 683.4 MPa, 21.6% and 95%, respectively. The insights for the improvement have been attributed to the high-density in-situ Ti2Cu precipitates in refined grain structures in the Ti-Cu alloys after rolling and annealing. National Natural Science Foundation of China (Grant No. 51404302 and 51801003); Natural Science Foundation of Hunan Province (Grant No. 2020JJ4732).

To compare the effect of three different surface zirconium oxide treatments on binding strength and fracture patterns between zirconia and veneering ceramics. Methods: A total of 40 zirconia specimens and 10 nickel-chromium alloy were divided into 5 groups (n=10 in each group): a treatment group by zirconium oxide sand-blaste (Group A), a zirconia bonded porcelain group (Group B), a hot-etching solution group (Group C), a non-treatment zirconia (Group D) and a non-treatment nickel-chromium alloy group (Group E). After all treatments, a veneering porcelain (4 mm×4 mm×2 mm) was formed onto the center of all substrate specimens by plastic coating method. Shear bond strength (SBS) test with a universal testing machine was used in each group. Scanning electron microscopy was used to observe the surface morphology of the damaged specimen interface, which was randomly selected from each group. Results: The SBS test showed that there was no significant difference in SBS results between the Group A, the Group B and the Group D (both P0.05), and both of them were significant less than that in the group E (both P0.05). The SBS results in the Group C were significantly higher than that in the Group D, the Group A, and the Group B (all P0.05), but there were no significant difference compared with that in the Group E (P0.05). Conclusion: Sand-blaste and liner application on zirconia ceramic contribute no effect to binding strength between zirconia and veneering ceramics, but hot-etching solution can increase the binding strength between zirconia and veneering ceramics.目的：探讨不同方式处理对氧化锆陶瓷与饰瓷结合强度的影响。方法：制作40个氧化锆瓷块、10个镍铬合金片，并按照表面处理方法分为5组，即喷砂组(A组)、结合瓷组(B组)、热酸蚀组(C组)、氧化锆空白对照组(D组)、镍铬烤瓷对照组(E组)。5组试件处理完成后，采用粉浆涂塑法烧结大小为4 mm×4 mm×2 mm的饰瓷。通过万能试验机对所有试件进行剪切强度测试，每组随机抽取一个样本在电子显微镜下进行界面破坏形貌分析。结果：剪切强度结果显示：与D组相比，A组和B组剪切强度差异均无统计学意义(均P0.05)，且二者均显著小于E组(均P0.05)；C组剪切强度值显著高于D组、A组和B组(均P0.05)，但与E组相比差异无统计学意义(P0.05)。结论：喷砂及烧结的结合瓷层对于增强锆瓷与饰瓷的结合强度无显著作用，热酸蚀可以显著增强锆瓷与饰瓷的结合强度。.

By combining the biocompatibility of Ta and excellent performance of Nb, the β-type Ta-xNb (x = 5, 10, and 15 wt %) alloys with three-dimensional network structure was successfully fabricated. This work was designed to carry out the systematic study of in vitro/vivo biocompatibility of highly porous Ta-Nb alloys. In the present study, the in vitro biological response was characterized by cell attachment, cytotoxicity test, and gene expression. Cells were well distributed on porous alloy surface and both bulk/porous Ta-15Nb alloys showd a 0-1 RGR level. Moreover, the upregulated gene expression may reveal an increase in bone regeneration. An assessment of primary osteogenic response in vivo was achieved by histological evaluation and pull-out test. In vivo results demonstrated that the porous Ta-15Nb alloy showed a higher pull-out force than bulk Ta-15Nb alloy and exhibited a more extensive contact between implants and bones after 12 weeks. Based on the present experiments, porous Ta-Nb alloy scaffolds had a good biocompatibility and were promising for biomedical applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 573-581, 2019.