School of Materials Science and Engineering, P.O. Box 433, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
Acta Biomater. 2010 Jun;6(6):2212-8. doi: 10.1016/j.actbio.2009.12.014. Epub 2009 Dec 22.
Hydroxyapatite (HA) hollow nanoparticles (HNPs) have great potential in nanoscaled delivery devices due to their small size, excellent biocompatibility and expected high capacity. However, the preparation of HA HNPs for their application in a drug delivery system has rarely been reported because HA has a complicated crystal structure and it is difficult to obtain stable HA HNPs with hollows that are only nanoscaled in size. In the present study, HA HNPs were successfully produced through a novel polymeric micelle-templating method. The micelles were structured with completely insoluble Pluronic P123 molecules at cloud point as the core and Tween-60 molecules as the shell by the hydrophobic interaction of the alkyl chains with the insoluble P123 core. The morphology of the HA HNPs could be transformed from nanospheres to nanotubes by adding citric acid as a cosurfactant. The prepared HA HNPs had a much higher drug payload than traditional nanoparticles, using vancomycin as the model drug. Most importantly, the HA nanotubes were coupled with a layer of citrate molecules on the HA surfaces, which could further improve the drug load efficiency and could form an excellent pH-controlled open/closed gate for drug release with the addition of cationic polyelectrolytes.
羟基磷灰石（HA）中空纳米粒子（HNPs）由于其尺寸小、生物相容性好、预期载药量高，在纳米级给药装置中有很大的应用潜力。然而，由于 HA 具有复杂的晶体结构，很难获得具有纳米级尺寸空腔的稳定 HA HNPs，因此将其应用于药物传递系统的报道很少。在本研究中，通过一种新颖的聚合物胶束模板法成功制备了 HA HNPs。胶束由完全不溶的 Pluronic P123 分子在浊点时形成，以疏水性烷基链与不溶性 P123 核的相互作用作为核，以 Tween-60 分子作为壳。通过添加柠檬酸作为助表面活性剂，HA HNPs 的形态可以从纳米球转变为纳米管。与传统纳米粒子相比，所制备的 HA HNPs 具有更高的载药量，以万古霉素为模型药物。最重要的是，HA 纳米管表面结合了一层柠檬酸分子，这可以进一步提高药物负载效率，并在添加阳离子聚电解质时形成一个极好的 pH 控制开/关药物释放的门。
