Chitosan adsorption on hydroxyapatite and its role in preventing acid erosion
Chitosan adsorption on hydroxyapatite and its role in preventing acid erosion
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DOI：
10.1016/j.jcis.2012.06.074
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发表时间：
2012-11-01
影响因子：
9.9
通讯作者：
Composto, Russell J.
中科院分区：
文献类型：
--
作者：
Lee, Hyun-Su;Tsai, Shannon;Composto, Russell J.
以壳聚糖为模型聚合物，采用石英晶体微天平（QCM-D）研究了聚合物在人工唾液（AS）表面的吸附。QCM-D以创新的方式用于监测壳聚糖（CH）在羟基磷灰石（HA）涂层晶体上的原位吸附，并检查吸附层在连续暴露于酸性溶液时“保护”HA的能力。在沉积薄AS层（16 nm）后，在pH 5.5下暴露于CH 10 min后，HA基底上的总厚度增加至37 nm。AS）为正，与聚阳离子CH吸附到AS层上或AS层中一致。在暴露于氧化剂时，壳聚糖交联并塌陷，如厚度减小至10 nm和剪切模量增加一个数量级所示。原子力显微镜（AFM）用于确定柠檬酸挑战后涂层和HA表面的表面形态和RMS粗糙度。物理吸附和交联壳聚糖分别被证明可以限制和防止HA的侵蚀。(c)2012 Elsevier Inc. All rights reserved.
Polymer adsorption onto an artificial saliva (AS) layer is investigated using quartz-crystal microbalance with dissipation (QCM-D) and chitosan as the model polymer. QCM-D is utilized in an innovative manner to monitor in situ adsorption of chitosan (CH) onto a hydroxyapatite (HA) coated crystal and to examine the ability of the adsorbed layer to "protect" the HA upon sequential exposure to acidic solutions. After deposition of a thin AS layer (16 nm), the total thickness on the HA substrate increases to 37 nm upon exposure to CH at pH 5.5 for 10 min. Correspondingly, the surface charge changes from negative (i.e., AS) to positive, consistent with the adsorption the polycationic CH onto or into the AS layer. Upon exposure to an oxidizing agent, the chitosan cross-links and collapses as noted by a decrease in thickness to 10 nm and an increase in the shear modulus by an order of magnitude. Atomic force microscopy (AFM) is used to determine the surface morphology and RMS roughness of the coated and HA surfaces after citric acid challenges. Both physisorbed and cross-linked chitosan are demonstrated to limit and prevent the erosion of HA, respectively. (c) 2012 Elsevier Inc. All rights reserved.