Sánchez-Salcedo Sandra, Colilla Montserrat, Izquierdo-Barba Isabel, Vallet-Regí María
Departamento de Química Inorgánica y Bioinorgánica, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza Ramón y Cajal s/n, 28040 Madrid, Spain.
J Mater Chem B. 2013 Mar 21;1(11):1595-1606. doi: 10.1039/c3tb00122a. Epub 2013 Feb 1.
This study reports the design and preparation of zwitterionic nanocrystalline hydroxyapatite (HA) capable of inhibiting bacterial adhesion while allowing osteoblast cell colonization. The surface functionalization of HA powders was carried out by post-synthesis grafting of 3-aminopropyltriethoxysilane (APTES) and carboxyethylsilanetriol sodium salt (CES) as amine and carboxylate precursors, respectively. The successful functionalization of HA surfaces was assessed by elemental chemical analysis, FTIR, Si, P and C solid state CP/MAS NMR and ζ-potential measurements, and the zwitterionic nature of the synthesized HA was proved through the presence of -NH /-COO pairs on the material surfaces. With the aim of evaluating the feasibility of this functionalization strategy in HA shaped in different physical forms, HA 3D macroporous scaffolds were fabricated by rapid prototyping and then provided with zwitterionic character. The effect of the simultaneous presence of -NH /-COOzwitterionic pairs on the surface of HA on its behaviour regarding bacterial adhesion was tested using E. coli as model bacteria. The in vitro biocompatibility of these materials was investigated with cultured human HOS cells. The results indicate that it is possible to provide HA shaped in different physical forms (particles, granules, coatings, dense blocks, 3D scaffolds, etc.) with bacterial anti-adhesive properties via the "zwitterionization" process without affecting its biocompatibility. These findings open up promising expectations in many clinical fields including dentistry, maxillofacial surgery and otolaryngology, where a decrease in the bacterial adherence onto the implant surface would reduce the infection rates after implantation surgery.
本研究报道了一种两性离子纳米晶羟基磷灰石（HA）的设计与制备方法，该材料能够抑制细菌黏附，同时允许成骨细胞定植。HA粉末的表面功能化通过分别以3-氨丙基三乙氧基硅烷（APTES）和羧乙基硅三醇钠盐（CES）作为胺和羧酸盐前体进行合成后接枝来实现。通过元素化学分析、傅里叶变换红外光谱（FTIR）、硅、磷和碳的固态交叉极化/魔角旋转核磁共振（Si、P和C固体状态CP/MAS NMR）以及ζ电位测量来评估HA表面的成功功能化，并通过材料表面存在-NH /-COO对证明了合成的HA的两性离子性质。为了评估这种功能化策略在不同物理形态的HA中的可行性，通过快速成型制备了HA三维大孔支架，然后赋予其两性离子特性。以大肠杆菌为模型细菌，测试了HA表面同时存在的-NH /-COO两性离子对其细菌黏附行为的影响。用培养的人HOS细胞研究了这些材料的体外生物相容性。结果表明，通过“两性离子化”过程可以使不同物理形态（颗粒、颗粒、涂层、致密块、三维支架等）的HA具有细菌抗黏附性能，而不影响其生物相容性。这些发现为包括牙科、颌面外科和耳鼻喉科在内的许多临床领域带来了有希望的期望，在这些领域中，植入物表面细菌黏附的减少将降低植入手术后的感染率。
