Thomas Reardon Philip James, Handoko Albertus Denny, Li Lin, Huang Jie, Tang Junwang
Department of Chemical Engineering, UCL, London, WC1E 7JE, UK.
J Mater Chem B. 2013 Nov 28;1(44):6170-6176. doi: 10.1039/c3tb21073a. Epub 2013 Oct 10.
Nanostructured biomaterials with controlled morphology and composition are of high interest for bone tissue regeneration. As resorbable and biocompatible materials for bone tissue engineering, calcium phosphate nanowires and nanoneedles with different aspect ratios and compositions have been first synthesized without the use of any toxic surfactants via an energy efficient microwave assisted process. Correlation between solvent composition, mixing methodology and reagent stoichiometric ratios was investigated with the aim of producing orientated growth and varied biphasic composition, resulting in dimensionally controlled growth of materials containing varying hydroxyapatite (HA)/monetite quantities. It was observed that the HA/monetite content and dimensionality could be manipulated by changing the initial ethanol (EtOH) volume in the HO/EtOH solvent mixture. Three dimensional particles with minute amounts of HA were produced when a HO/EtOH volumetric ratio of 20/80 was used. Conversely, high aspect ratio (ca. 54) nanowires containing ca. 38 wt% HA were obtained with a 60/40 HO/EtOH volumetric ratio. Importantly, the quantity of HA in the high aspect ratio nanowires/needles was controlled by varying the stoichiometric ratio of the reactants, demonstrating that one-dimensional materials with close to 100% HA can be achieved when the Ca/P ratio is increased to 1.67. Additionally, significant correlation between the extent of orientated growth of the materials and the point of EtOH addition during the mixing method was observed. The findings highlight that solvent composition, reactant stoichiometric ratio and mixing procedure can be used in tandem to tailor the morphology and composition of calcium phosphate materials, which are of very high importance in developing excellent materials suitable for bone tissue regeneration.
具有可控形态和组成的纳米结构生物材料在骨组织再生方面备受关注。作为骨组织工程中可吸收且生物相容的材料，具有不同长径比和组成的磷酸钙纳米线和纳米针首先通过节能微波辅助工艺合成，且未使用任何有毒表面活性剂。研究了溶剂组成、混合方法和试剂化学计量比之间的相关性，目的是实现定向生长和改变双相组成，从而使含有不同量羟基磷灰石（HA）/磷酸二钙的材料在尺寸上得到可控生长。观察到可以通过改变HO/EtOH溶剂混合物中初始乙醇（EtOH）的体积来控制HA/磷酸二钙的含量和尺寸。当使用20/80的HO/EtOH体积比时，会生成含有少量HA的三维颗粒。相反，当HO/EtOH体积比为60/40时，可获得含有约38 wt% HA、长径比约为54的纳米线。重要的是，通过改变反应物的化学计量比，可以控制高长径比纳米线/纳米针中HA的含量，这表明当Ca/P比增加到1.67时，可以获得接近100% HA的一维材料。此外，还观察到材料的定向生长程度与混合方法中EtOH添加点之间存在显著相关性。这些发现突出表明，溶剂组成、反应物化学计量比和混合程序可以协同使用，以定制磷酸钙材料的形态和组成，这对于开发适用于骨组织再生的优质材料非常重要。
