Gagnon J, Clift M J D, Vanhecke D, Kuhn D A, Weber P, Petri-Fink A, Rothen-Rutishauser B, Fromm K M
Department of Chemistry and Fribourg Center for Nanomaterials, University of Fribourg, Chemin du Musée 9, 1700 Fribourg, Switzerland.
J Mater Chem B. 2015 Mar 7;3(9):1760-1768. doi: 10.1039/c4tb02079k. Epub 2015 Jan 22.
Silver compounds and nanoparticles (NPs) are gaining increasing interest in medical applications, specifically in the treatment and prevention of biomaterial-related infections. However, the silver release from these materials, resulting in a limited antimicrobial activity, is often difficult to control. In this paper, ceria nanocontainers were synthesized by a template-assisted method and were then used to encapsulate silver nitrate (AgNO/CeO nanocontainers). Over the first 30 days, a significant level of silver was released, as determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). A novel type of ceria container containing silver NPs (AgNP/CeO containers) was also developed using two different template removal methods. The presence of AgNPs was confirmed both on the surface and in the interior of the ceria containers by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Upon removal of the template by calcination, the silver was released over a period exceeding three months (>90 days). However, when the template was removed by dissolution, the silver release was shortened to ≤14 days. The antimicrobial activity of the silver-containing CeO containers was observed and the minimum bactericidal concentration (MBC) was determined using the broth dilution method. Investigation on human cells, using a model epithelial barrier cell type (A549 cells), highlighted that all three samples induced a heightened cytotoxicity leading to cell death when exposed to all containers in their raw form. This was attributed to the surface roughness of the CeO nanocontainers and the kinetics of the silver release from the AgNO/CeO and AgNP/CeO nanocontainers. In conclusion, despite the need for further emphasis on their biocompatibility, the concept of the AgNP/CeO nanocontainers offers a potentially alternative long-term antibactericidal strategy for implant materials.
银化合物和纳米颗粒（NPs）在医学应用中越来越受到关注，特别是在治疗和预防生物材料相关感染方面。然而，这些材料中的银释放导致抗菌活性有限，且通常难以控制。在本文中，通过模板辅助法合成了二氧化铈纳米容器，然后用于封装硝酸银（AgNO/CeO纳米容器）。在最初的30天内，使用电感耦合等离子体发射光谱法（ICP-OES）测定发现有大量银释放。还使用两种不同的模板去除方法开发了一种新型的含有银纳米颗粒的二氧化铈容器（AgNP/CeO容器）。通过X射线衍射（XRD）、透射电子显微镜（TEM）和扫描电子显微镜（SEM）证实了二氧化铈容器表面和内部均存在银纳米颗粒。通过煅烧去除模板后，银在超过三个月（>90天）的时间内释放。然而，当通过溶解去除模板时，银释放缩短至≤14天。观察了含银的CeO容器的抗菌活性，并使用肉汤稀释法测定了最低杀菌浓度（MBC）。使用模型上皮屏障细胞类型（A549细胞）对人体细胞进行的研究强调，当以原始形式暴露于所有容器时，所有三个样品均诱导了增强的细胞毒性，导致细胞死亡。这归因于CeO纳米容器的表面粗糙度以及AgNO/CeO和AgNP/CeO纳米容器中银的释放动力学。总之，尽管需要进一步强调其生物相容性，但AgNP/CeO纳米容器的概念为植入材料提供了一种潜在的长期抗菌替代策略。
