Abstract：
Vertical bone augmentation to create host bone prior to implant placement is one of the most challenging regenerative procedures. The objective of this study is to evaluate the capacity of a UV-photofunctionalized titanium microfiber scaffold to recruit osteoblasts, generate intra-scaffold bone, and integrate with host bone in a vertical augmentation model with unidirectional, limited blood supply. Scaffolds were fabricated by molding and sintering grade 1 commercially pure titanium microfibers (20 μm diameter) and treated with UVC light (200-280 nm wavelength) emitted from a low-pressure mercury lamp for 20 min immediately before experiments. The scaffolds had an even and dense fiber network with 87% porosity and 20-50 mm inter-fiber distance. Surface carbon reduced from 30% on untreated scaffold to 10% after UV treatment, which corresponded to hydro-repellent to superhydrophilic conversion. Vertical infiltration testing revealed that UV-treated scaffolds absorbed 4-, 14-, and 15-times more blood, water, and glycerol than untreated scaffolds, respectively. In vitro, four-times more osteoblasts attached to UV-treated scaffolds than untreated scaffolds three hours after seeding. On day 2, there were 70% more osteoblasts on UV-treated scaffolds. Fluorescent microscopy visualized confluent osteoblasts on UV-treated microfibers two days after seeding but sparse and separated cells on untreated microfibers. Alkaline phosphatase activity and osteocalcin gene expression were significantly greater in osteoblasts grown on UV-treated microfiber scaffolds. In an in vivo model of vertical augmentation on rat femoral cortical bone, the interfacial strength between innate cortical bone and UV-treated microfiber scaffold after two weeks of healing was double that observed between bone and untreated scaffold. Morphological and chemical analysis confirmed seamless integration of the innate cortical and regenerated bone within microfiber networks for UV-treated scaffolds. These results indicate synergy between titanium microfiber scaffolds and UV photofunctionalization to provide a novel and effective strategy for vertical bone augmentation.
摘要：
在植入物放置之前创建宿主骨的垂直骨增强是最具挑战性的再生程序之一。这项研究的目的是评估紫外光功能化的钛微纤维支架招募成骨细胞的能力，生成支架内骨，并与宿主骨骼集成在一个单向的垂直增强模型中，血液供应有限。通过模制和烧结1级商业纯钛微纤维(20μm直径)制造支架,并且在实验前立即用从低压汞灯发射的UVC光(200-280nm波长)处理20分钟。支架具有均匀且致密的纤维网络,具有87%的孔隙率和20-50mm的纤维间距离。表面碳从未经处理的支架上的30%减少到紫外线处理后的10%，这对应于防水到超亲水转化。垂直渗透测试表明，紫外线处理的支架吸收4-，14-,还有15倍的血,水,和甘油比未处理的支架，分别。体外，接种后三小时，附着在紫外线处理支架上的成骨细胞是未处理支架的四倍。在第2天,在UV处理的支架上存在70%以上的成骨细胞。接种两天后，荧光显微镜观察了UV处理的微纤维上的融合成骨细胞，但未处理的微纤维上的细胞稀疏且分离。在紫外线处理的超细纤维支架上生长的成骨细胞中，碱性磷酸酶活性和骨钙蛋白基因表达明显更高。在大鼠股骨皮质骨垂直增强的体内模型中，愈合两周后，先天皮质骨和紫外线处理的超细纤维支架之间的界面强度是骨和未处理支架之间观察到的两倍。形态学和化学分析证实了用于UV处理的支架的微纤维网络内的先天皮质和再生骨的无缝整合。这些结果表明钛微纤维支架和紫外光功能化之间的协同作用，为垂直骨增强提供了一种新颖有效的策略。
