Biocompatible pH-Degradable Functional Capsules Based on Melamine Cyanurate Self-Assembly

Development of adaptive self-regulating materials and chemical-biological systems-self-healing, self-regulating, etc.-is an advanced modern trend. The very sensitive pH-controlled functionality of supramolecular assemblies is a very useful tool for chemical and biochemical implementations. However, the assembly process can be tuned by various factors that can be used for both better functionality control and further functionalization such as active species, e.g., drugs and dyes, and encapsulation. Here, the effect of a dye, sodium fluorescein (uranine) (FL), on the formation of a self-assembled melamine cyanurate (M-CA) structure is investigated and calculated with density functional theory (DFT) and molecular dynamics. Interestingly, the dye greatly affects the self-assembly process at early stages from the formation of dimers, trimers, and tetramer to nucleation control. The supramolecular structure disassembly and subsequent release of trapped dye occurred under both high- and low-pH conditions. This system can be used for time-prolonged bacterial staining and development of supramolecular capsules for the system chemistry approach.

Automated summary

The study investigates the impact of a dye on the self-assembly process, revealing its crucial role in controlling and regulating the reaction process. The dye is found to influence structure assembly and dye release under both high and low pH conditions. The findings hold promise for applications in bacterial staining and the development of supramolecular capsules.