Laboratorio de Materiales Avanzados, Departamento de Química Inorgánica-IUMA, Universidad de Alicante, E-03690 San Vicente del Raspeig, Spain.
Multifunctional Materials & Composites (MMC) Laboratory, Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, U.K.
ACS Appl Mater Interfaces. 2020 Jul 8;12(27):30189-30197. doi: 10.1021/acsami.0c07517. Epub 2020 Jun 28.
Novel MOF-based polymer nanocomposite films were successfully prepared using Zr-based UiO-67 as a metal-organic framework (MOF) and polyurethane (PU) as a polymeric matrix. Synchrotron X-ray powder diffraction (SXRPD) analysis confirms the improved stability of the UiO-67 embedded nanocrystals, and scanning electron microscopy images confirm their homogeneous distribution (average crystal size ∼100-200 nm) within the 50 μm thick film. Accessibility to the inner porous structure of the embedded MOFs was completely suppressed for N at cryogenic temperatures. However, ethylene adsorption measurements at 25 °C confirm that at least 45% of the MOF crystals are fully accessible for gas-phase adsorption of nonpolar molecules. Although this partial blockage limits the adsorption performance of the embedded MOFs for ocular drugs (e.g., brimonidine tartrate) compared to the pure MOF, an almost 60-fold improvement in the adsorption capacity was observed for the PU matrix after incorporation of the UiO-67 nanocrystals. The UiO-67@PU nanocomposite exhibits a prolonged release of brimonidine (up to 14 days were quantified). Finally, the combined use of SXRPD, thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR) analyses confirmed the presence of the drug in the nanocomposite film, the stability of the MOF framework and the drug upon loading, and the presence of brimonidine in an amorphous phase once adsorbed. These results open the gate toward the application of these polymeric nanocomposite films for drug delivery in ocular therapeutics, either as a component of a contact lens, in the composition of lacrimal stoppers (e.g., punctal plugs), or in subtenon inserts.
新型基于 MOF 的聚合物纳米复合膜是通过使用 Zr 基 UiO-67 作为金属有机骨架（MOF）和聚氨酯（PU）作为聚合物基质成功制备的。同步加速器粉末 X 射线衍射（SXRPD）分析证实了嵌入纳米晶体的 UiO-67 稳定性提高，扫描电子显微镜图像证实了它们在 50μm 厚膜内的均匀分布（平均晶体尺寸约为 100-200nm）。在低温下，N 完全阻止了嵌入 MOF 的内多孔结构的可及性。然而，25°C 的乙烯吸附测量证实，至少 45%的 MOF 晶体对于非极性分子的气相吸附是完全可及的。尽管这种部分阻塞限制了嵌入 MOF 对眼部药物（例如酒石酸溴莫尼定）的吸附性能，与纯 MOF 相比，但在掺入 UiO-67 纳米晶体后，PU 基质的吸附容量提高了近 60 倍。UiO-67@PU 纳米复合材料表现出溴莫尼定的延长释放（定量至 14 天）。最后，SXRPD、热重分析（TGA）和傅里叶变换红外（FTIR）分析的结合证实了药物在纳米复合材料膜中的存在、MOF 框架和药物在负载时的稳定性以及吸附后药物处于无定形相的存在。这些结果为这些聚合物纳米复合材料膜在眼部治疗中的药物输送中的应用开辟了道路，无论是作为隐形眼镜的组成部分，在泪液塞（例如，泪点塞）的组成部分，还是在腱下插入物中。
