Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States.
McGowan Institute for Regenerative Medicine, Pittsburgh, Pennsylvania 15219, United States.
Langmuir. 2023 Jun 6;39(22):7912-7921. doi: 10.1021/acs.langmuir.3c00753. Epub 2023 May 25.
An oral sorbent to remove NH within the small intestine of end-stage kidney disease (ESKD) patients could reduce blood urea levels and diminish their dialysis treatment burden. But current sorbent materials like amorphous zirconium phosphate particles Zr(HPO)·HO (ZrP) lack the selectivity to remove NH in water solution with other competing ions. Our previous work found that a gas-permeable, hydrophobic polydimethylsiloxane (PDMS) coating on ZrP improved the material's selectivity for NH. However, a competing ion Ca was still removed by PDMS-coated ZrP sorbent, and the permeability of the PDMS coating to Ca was increased after low-pH stomach-like condition exposure. An alternative hydrophobic and gas permeable coating has been investigated─perfluorooctyltriethoxysilane (FOTS). The coating was attached in place of PDMS to a tetraethyl orthosilicate-coated ZrP surface. Surface atomic composition analysis and scanning electron microscopy observation verified the successful application of the FOTS coating. Water contact angle analysis validated the FOTS coating was hydrophobic (145.0 ± 3.2°). competing ion studies indicated the FOTS coating attached to ZrP increased NH removal by 53% versus uncoated ZrP. FOTS offers complete selectivity for NH over Ca with similar NH capacity as the previous PDMS coating. Moreover, FOTS-coated ZrP maintained NH removal capacity and selectivity after the acid exposure study, indicating excellent acid resistance while NH selectivity of ZrP-PDMS decreased by 72%. The results suggested that FOTS-coated ZrP is promising as an oral sorbent for ESKD patients.
一种可在终末期肾病 (ESKD) 患者的小肠内吸附 NH 的口服吸附剂，可降低血液尿素水平，减轻其透析治疗负担。但目前的吸附材料，如无定形磷酸锆颗粒 Zr(HPO)·HO (ZrP)，缺乏在水溶液中选择性去除 NH 的能力，因为存在其他竞争离子。我们之前的工作发现，ZrP 表面涂覆透气疏水性聚二甲基硅氧烷 (PDMS) 可以提高材料对 NH 的选择性。然而，涂覆 PDMS 的 ZrP 吸附剂仍会去除竞争离子 Ca，且在模拟低 pH 胃液条件下暴露后，PDMS 涂层对 Ca 的通透性增加。我们研究了一种替代的疏水性和透气涂层——全氟辛基三乙氧基硅烷 (FOTS)。将该涂层涂覆到正硅酸乙酯涂覆的 ZrP 表面，取代 PDMS。表面原子组成分析和扫描电子显微镜观察证实了 FOTS 涂层的成功应用。水接触角分析验证了 FOTS 涂层具有疏水性（145.0 ± 3.2°）。竞争离子研究表明，与未涂覆的 ZrP 相比，附着在 ZrP 上的 FOTS 涂层使 NH 的去除率提高了 53%。FOTS 涂层对 NH 具有完全的选择性，而对 Ca 则没有，且其 NH 容量与之前的 PDMS 涂层相似。此外，FOTS 涂层 ZrP 在酸暴露研究后仍保持 NH 去除能力和选择性，表明其具有优异的耐酸性，而 ZrP-PDMS 的 NH 选择性则降低了 72%。结果表明，FOTS 涂层 ZrP 有望成为 ESKD 患者的口服吸附剂。
