The effect of ionic versus covalent functionalization of polyoxometalate hybrid materials with coordinating subunits on their stability and interaction with DNA

Inorganic-organic hybrid materials that combine both Polyoxometalates (POMs) and metal ion coordinating subunits (CSUs) represent promising multifunctional materials. Though their individual components are often biologically active, utilization of hybrid materials in bioassays significantly depends on the functionalization method and thus resulting stability of the system. Quite intriguingly, these aspects were very scarcely studied in hybrid materials based on Wells-Dawson POM (WD POM) scaffold and remain unknown. We chose two model WD POM hybrid systems to establish how the functionalization mode (ionic vs covalent) affects their stability in biological medium and interaction with nucleic acids. The synthetic scope and limitations of the covalent POM-terpyridine hybrids were demonstrated and compared with the ionic Complex-Decorated Surfactant Encapsulated-Clusters (CD-SECs) hybrids. The nature of POM and CSU binding can be utilized to modulate the stability of the hybrid and the extent of DNA binding. The above systems show the potential to behave as the model cargo-platforms of potential utilization in medicine and pharmacy.同时整合多金属氧酸盐（Polyoxometalates, POMs）与金属离子配位亚基（metal ion coordinating subunits, CSUs）的无机-有机杂化材料，是一类极具开发潜力的多功能材料。尽管其单独组分通常均具有生物活性，但这类杂化材料在生物分析检测中的应用效果，显著取决于其功能化修饰方法以及由此赋予的体系稳定性。尤为值得关注的是，针对基于Wells-Dawson型多金属氧酸盐（Wells-Dawson POM, WD POM）骨架的杂化材料，相关研究极为匮乏，相关机制仍未明确。本研究选取两类经典WD POM杂化体系，旨在阐明功能化修饰模式（离子键结合与共价键结合）对其在生物介质中的稳定性以及与核酸相互作用的影响规律。本研究阐明了共价型POM-三联吡啶杂化材料的合成适用范围与局限性，并将其与离子型复合物修饰表面活性剂包裹簇（Complex-Decorated Surfactant Encapsulated-Clusters, CD-SECs）杂化材料进行了对比分析。POM与CSUs的结合模式可用于调控杂化材料的稳定性，以及其与DNA结合的亲和程度。上述杂化体系具备作为模型载运平台的潜力，有望在医药与制药领域实现应用。