Department of Engineering, University of Campania "Luigi Vanvitelli", Via Roma 29, I-81031 Aversa, Italy.
Department of Engineering, University of Campania "Luigi Vanvitelli", Via Roma 29, I-81031 Aversa, Italy.
Mater Sci Eng C Mater Biol Appl. 2019 Jul;100:837-844. doi: 10.1016/j.msec.2019.03.035. Epub 2019 Mar 20.
New organic-inorganic hybrid materials were synthesized by an acid catalysed sol-gel approach, using silicon alkoxide and low molecular weight polyethylene glycol (PEG400) as inorganic and organic precursor, respectively. Chlorogenic acid (CGA), an antioxidant natural phenol compound, enriched further the organic component. Hybrids synthesized, all identical in terms of their starting materials, but differing in terms of their relative proportions, were characterized by means of Fourier Transform InfraRed (FTIR) measurements, UV-Vis spectroscopy, and UHPLC-HRMS analysis. The preservation of the intrinsic chlorogenic acid ability to scavenge, in a dose-dependent manner, radical species was investigated by directly exposing the hybrids to DPPH radical and ABTS radical cation. The relative ratio of both the natural compound and PEG heavily affected the antiradical response, suggesting that chemical interactions in the established network were able, based on components' ratio, to differently mask and/or display the CGA moieties, commonly deemed relevant for antioxidant power exerting. Cell culture MTT assay was used to assess the biocompatibility of hybrid materials towards fibroblast NIH-3 T3 cells and neuroblastoma SH-SY5Y cells. Cells tested appeared differently responsive. In particular, a marked cell viability increase was observed when hybrids with low PEG amount (6%) and high CGA (15%) were directly exposed to fibroblast cells, whose mitochondrial redox activity was negatively affected by hybrid synthesized using the highest organic component rate (both PEG and CGA). Cell viability and morphology of human neuroblastoma SH-SY5Y cells were broadly compromised regardless of organic/inorganic starting materials ratio, suggesting the ability of hybrids to exert pro-oxidant effect towards tumour cells and to selectively interfere with their growth. The hybrids, able to elicit cleverly anti- or proliferative effects, were also shown to be bioactive. In fact, a biologically active hydroxyapatite layer was observed to be formed on the surface of the smart synthesized materials. This feature, which makes them a valuable bonding interface with tissues, opens new scenario aiming at further investigating the employment of natural phenol compounds in versatile sol-gel synthesis routes.
新的有机-无机杂化材料通过酸催化溶胶-凝胶法合成，使用硅烷醇盐和低分子量聚乙二醇（PEG400）作为无机和有机前体。绿原酸（CGA）是一种抗氧化天然酚类化合物，进一步丰富了有机成分。合成的杂化物在起始材料方面完全相同，但在相对比例方面有所不同，通过傅里叶变换红外（FTIR）测量、紫外-可见光谱和 UHPLC-HRMS 分析进行了表征。通过直接将杂化物暴露于 DPPH 自由基和 ABTS 自由基阳离子，研究了内在绿原酸以剂量依赖方式清除自由基的能力的保留情况。天然化合物和 PEG 的相对比例强烈影响抗自由基反应，表明在建立的网络中，基于成分的比例，化学相互作用能够不同程度地掩盖和/或显示 CGA 部分，通常被认为与发挥抗氧化能力有关。细胞培养 MTT 测定法用于评估杂化物对成纤维细胞 NIH-3T3 和神经母细胞瘤 SH-SY5Y 细胞的生物相容性。测试的细胞表现出不同的反应。特别是，当低 PEG 含量（6%）和高 CGA（15%）的杂化物直接暴露于成纤维细胞时，观察到明显的细胞活力增加，而使用最高有机成分（PEG 和 CGA）合成的杂化物则会对其线粒体氧化还原活性产生负面影响。无论有机/无机起始材料的比例如何，人类神经母细胞瘤 SH-SY5Y 细胞的活力和形态都受到广泛损害，这表明杂化物对肿瘤细胞具有促氧化作用，并能选择性干扰其生长。能够引起聪明的抗或增殖作用的杂化物也被证明是生物活性的。事实上，观察到在智能合成材料的表面形成了具有生物活性的羟基磷灰石层。这一特性使它们成为与组织具有良好结合界面的材料，为进一步研究天然酚类化合物在多种溶胶-凝胶合成途径中的应用开辟了新的前景。
