Department of Morphology, Federal University of Minas Gerais, Av. Antônio Carlos 6627, Belo Horizonte, MG, Brazil.
Life Sci. 2010 Aug 14;87(7-8):215-22. doi: 10.1016/j.lfs.2010.06.010. Epub 2010 Jun 23.
Sodium hyaluronate (HY) accelerates the repair of bone defects. However, the weak stability of HY formulations in aqueous environments has hindered its wide utilization. The functionalization of carbon nanotubes (SWCNT) with HY (HY-SWCNT) results in a reinforced hydrogel with an increased stability. Nevertheless, the biological effects of HY-SWCNT have not been explored. Thus, our objective was to evaluate whether this biomaterial preserves the bioactivity of the HY.
Wistar rats were subjected to molar extraction and the sockets were treated with SWCNT (50-400 microg/mL), 1% HY, HY-SWCNT (50-400 microg/mL) or carbopol (vehicle). After seven days of surgery, histological and morphometric analyses were performed to evaluate the trabecular bone formation and the number of cell nuclei in the sockets. Expression of collagen types I and III was determined by immunohistochemistry.
Treatment with SWCNT did not alter the bone deposition, as well as the cell nuclei counting. Additionally, no significant evidence of toxicity was observed in SWCNT-treated sockets. Contrastingly, both HY and HY-SWCNT induced a marked increase in the bone formation (HY: 10.10+/-1.99%; HY-SWCNT 100 microg/mL: 10.90+/-1.13%; control: 3.69+/-1.17%) and decreased the cell nuclei amount in the sockets. Moreover, collagen type I expression was more pronounced in HY- and HY-SWCNT-treated sockets. No significant differences were viewed in the expression of collagen type III.
Our results indicate that SWCNT is a feasible material to deliver HY to bone defects. Importantly, the functionalization of SWCNT with HY preserved the beneficial biological properties of HY in the healing process, thereby suggesting that HY-SWCNT scaffolds are potentially useful biomaterials for the restoration of bone defects.
透明质酸钠（HY）可加速骨缺损的修复。然而，HY 制剂在水介质环境中的稳定性差，限制了其广泛应用。通过将 HY 功能化到碳纳米管（SWCNT）上，可以得到稳定性增强的水凝胶。然而，HY-SWCNT 的生物学效应尚未被探索。因此，本研究旨在评估该生物材料是否保留了 HY 的生物活性。
将 Wistar 大鼠的磨牙拔出，将牙窝用 SWCNT（50-400μg/ml）、1%HY、HY-SWCNT（50-400μg/ml）或卡波姆（载体）处理。手术后 7 天，进行组织学和形态计量学分析，以评估牙槽骨的小梁骨形成和牙槽骨中的细胞核数量。通过免疫组织化学检测 I 型和 III 型胶原的表达。
SWCNT 处理并未改变骨沉积和细胞核计数。此外，在 SWCNT 处理的牙窝中未观察到明显的毒性证据。相反，HY 和 HY-SWCNT 均显著增加了骨形成（HY：10.10±1.99%；HY-SWCNT 100μg/ml：10.90±1.13%；对照组：3.69±1.17%），并减少了牙窝中的细胞核数量。此外，HY 和 HY-SWCNT 处理的牙窝中 I 型胶原表达更为明显。III 型胶原的表达无显著差异。
我们的结果表明，SWCNT 是一种向骨缺损递送 HY 的可行材料。重要的是，SWCNT 与 HY 的功能化保留了 HY 在愈合过程中的有益生物学特性，这表明 HY-SWCNT 支架可能是修复骨缺损的有前途的生物材料。
