In situ generation of sodium alginate/hydroxyapatite nanocomposite beads as drug-controlled release matrices.
In situ generation of sodium alginate/hydroxyapatite nanocomposite beads as drug-controlled release matrices.
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DOI：
10.1016/j.actbio.2009.07.001
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发表时间：
2010-02
影响因子：
9.7
通讯作者：
J. Zhang;Q. Wang;A. Wang
中科院分区：
文献类型：
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作者：
J. Zhang;Q. Wang;A. Wang
为了寻找一种减缓药物释放的新途径，解决传统水凝胶基质中药物的爆裂释放问题，在海藻酸钠/羟基磷灰石（SA/HA）微球的溶胶-凝胶过渡过程中，在微球中原位生成HA微粒，制备了一系列新型ph敏感型海藻酸钠/羟基磷灰石（SA/HA）纳米复合微球。利用傅里叶变换红外光谱、x射线荧光光谱、扫描电镜和场发射扫描电镜对SA/HA纳米复合材料进行了表征，以揭示其组成、表面形貌以及原位生成的HA微粒的作用。以双氯芬酸钠（DS）为模型药物，研究了影响SA/HA纳米复合微球的溶胀行为、载药和控释行为的因素。透明质酸微粒在纳米复合材料中作为无机交联剂，可以收缩和限制SA聚合物链的可动性，从而改变表面形貌，降低膨胀比。同时，提高了DS的捕获效率，克服了DS的突发释放。影响HA微粒生长的因素（包括Ca2+浓度、反应时间和温度）对DS的包封效率和释放速率有明显的影响。在此条件下制备的纳米复合微球与原始SA水凝胶微球相比，DS的释放时间延长8h。
In order to find a new way to slow down the release of drugs and to solve the burst release problem of drugs from traditionally used hydrogel matrices, a series of novel pH-sensitive sodium alginate/hydroxyapatite (SA/HA) nanocomposite beads was prepared by the in situ generation of HA micro-particles in the beads during the sol–gel transition process of SA. The SA/HA nanocomposites were characterized by Fourier transform IR spectroscopy, X-ray fluorescence spectrometry, scanning electron microscopy and field emission SEM in order to reveal their composition and surface morphology as well as the role that the in situ generated HA micro-particles play. The factors influencing the swelling behavior, drug loading and controlled release behavior of the SA/HA nanocomposite beads were also investigated using diclofenac sodium (DS) as the model drug. The HA micro-particles act as inorganic crosslinkers in the nanocomposites, which could contract and restrict the movability of the SA polymer chains, and then change the surface morphology and decrease the swell ratio. Meanwhile, the entrapment efficiency of DS was improved, and the burst release of DS was overcome. The factors (including concentration of Ca2+, reaction time and temperature) affecting the growth of HA micro-particles have a clear influence on the entrapment efficiency and release rate of DS. In this work, the nanocomposite beads prepared under optimum condition could prolong the release of DS for 8h more compared with the pristine SA hydrogel beads.