Department of Oral and Craniofacial Sciences, UMKC School of Dentistry, University of Missouri-Kansas City, Kansas City, MO 64108, USA.
Acta Biomater. 2013 Aug;9(8):8015-26. doi: 10.1016/j.actbio.2013.04.043. Epub 2013 May 2.
Borate bioactive glasses are biocompatible and enhance new bone formation, but the effect of their microstructure on bone regeneration has received little attention. In this study scaffolds of borate bioactive glass (1393B3) with three different microstructures (trabecular, fibrous, and oriented) were compared for their capacity to regenerate bone in a rat calvarial defect model. 12weeks post-implantation the amount of new bone, mineralization, and blood vessel area in the scaffolds were evaluated using histomorphometric analysis and scanning electron microscopy. The amount of new bone formed was 33%, 23%, and 15%, respectively, of the total defect area for the trabecular, oriented, and fibrous microstructures. In comparison, the percent new bone formed in implants composed of silicate 45S5 bioactive glass particles (250-300μm) was 19%. Doping the borate glass with copper (0.4 wt.% CuO) had little effect on bone regeneration in the trabecular and oriented scaffolds, but significantly enhanced bone regeneration in the fibrous scaffolds (from 15 to 33%). The scaffolds were completely converted to hydroxyapatite within the 12week implantation. The amount of hydroxyapatite formed, 22%, 35%, and 48%, respectively, for the trabecular, oriented, and fibrous scaffolds, increased with increasing volume fraction of glass in the as-fabricated scaffold. Blood vessels infiltrated into all the scaffolds, but the trabecular scaffolds had a higher average blood vessel area compared with the oriented and fibrous scaffolds. While all three scaffold microstructures were effective in supporting bone regeneration, the trabecular scaffolds supported more bone formation and may be more promising in bone repair.
硼酸盐生物活性玻璃具有生物相容性，能增强新骨形成，但它们的微观结构对骨再生的影响却很少受到关注。在这项研究中，比较了具有三种不同微观结构（小梁状、纤维状和定向）的硼酸盐生物活性玻璃（1393B3）支架在大鼠颅骨缺损模型中再生骨的能力。植入后 12 周，通过组织形态计量分析和扫描电子显微镜评估支架中新骨、矿化和血管面积的含量。小梁状、定向和纤维状微观结构形成的新骨量分别占总缺损面积的 33%、23%和 15%。相比之下，由硅酸 45S5 生物活性玻璃颗粒（250-300μm）组成的植入物中形成的新骨量为 19%。在小梁状和定向支架中，硼酸盐玻璃中掺杂铜（0.4wt.%CuO）对骨再生的影响很小，但在纤维支架中显著增强了骨再生（从 15%增加到 33%）。植入物在 12 周内完全转化为羟基磷灰石。形成的羟基磷灰石量分别为小梁状、定向和纤维状支架的 22%、35%和 48%，随着预制支架中玻璃体积分数的增加而增加。血管渗透到所有支架中，但小梁状支架的平均血管面积高于定向和纤维状支架。虽然这三种支架微观结构都能有效促进骨再生，但小梁状支架能促进更多的骨形成，在骨修复中可能更有前途。
