Garino Nadia, Limongi Tania, Dumontel Bianca, Canta Marta, Racca Luisa, Laurenti Marco, Castellino Micaela, Casu Alberto, Falqui Andrea, Cauda Valentina
Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy.
Istituto Italiano di Tecnologia, Center for Sustainable Future Technologies, Via Livorno 60, 10144 Torino, Italy.
Nanomaterials (Basel). 2019 Feb 6;9(2):212. doi: 10.3390/nano9020212.
Herein we report a novel, easy, fast and reliable microwave-assisted synthesis procedure for the preparation of colloidal zinc oxide nanocrystals (ZnO NCs) optimized for biological applications. ZnO NCs are also prepared by a conventional solvo-thermal approach and the properties of the two families of NCs are compared and discussed. All of the NCs are fully characterized in terms of morphological analysis, crystalline structure, chemical composition and optical properties, both as pristine nanomaterials or after amino-propyl group functionalization. Compared to the conventional approach, the novel microwave-derived ZnO NCs demonstrate outstanding colloidal stability in ethanol and water with long shelf-life. Furthermore, together with their more uniform size, shape and chemical surface properties, this long-term colloidal stability also contributes to the highly reproducible data in terms of biocompatibility. Actually, a significantly different biological behavior of the microwave-synthesized ZnO NCs is reported with respect to NCs prepared by the conventional synthesis procedure. In particular, consistent cytotoxicity and highly reproducible cell uptake toward KB cancer cells are measured with the use of microwave-synthesized ZnO NCs, in contrast to the non-reproducible and scattered data obtained with the conventionally-synthesized ones. Thus, we demonstrate how the synthetic route and, as a consequence, the control over all the nanomaterial properties are prominent points to be considered when dealing with the biological world for the achievement of reproducible and reliable results, and how the use of commercially-available and under-characterized nanomaterials should be discouraged in this view.
在此，我们报告了一种新颖、简便、快速且可靠的微波辅助合成方法，用于制备针对生物应用进行优化的胶体氧化锌纳米晶体（ZnO NCs）。还通过传统的溶剂热法制备了ZnO NCs，并对这两类纳米晶体的性质进行了比较和讨论。所有纳米晶体均在形态分析、晶体结构、化学成分和光学性质方面进行了全面表征，无论是作为原始纳米材料还是在氨基丙基官能化之后。与传统方法相比，新型微波衍生的ZnO NCs在乙醇和水中表现出出色的胶体稳定性，保质期长。此外，除了其更均匀的尺寸、形状和化学表面性质外，这种长期的胶体稳定性也有助于在生物相容性方面获得高度可重复的数据。实际上，据报道，微波合成的ZnO NCs与通过传统合成方法制备的纳米晶体相比，具有显著不同的生物学行为。特别是，使用微波合成的ZnO NCs测量了对KB癌细胞一致的细胞毒性和高度可重复的细胞摄取，这与传统合成的纳米晶体所获得的不可重复且分散的数据形成对比。因此，我们证明了合成路线以及随之而来的对所有纳米材料性质的控制是在与生物领域打交道以获得可重复和可靠结果时需要考虑的突出要点，以及从这个角度应不鼓励使用市售且表征不足的纳米材料。
