Active Armoring of Protocell Condensates with Metal-Phenolic Networks

This study presents the use of metal-phenolic networks (MPNs) for the removable membranization of peptide-based condensates, providing a powerful strategy for stabilizing and protecting condensates from chemically harmful agents. It is demonstrated that the redox-active properties of MPNs allow for controlled membrane formation and disassembly, offering tunable regulation of membrane thickness and permeability. Using ferric ion (Fe³⁺) and tannic acid, poly-L-lysine and adenosine triphosphate condensates are successfully coated with MPN membranes, which significantly enhances their structural stability and resistance to fusion. Additionally, it is observed that when exposed to Tris(2-carboxyethyl)phosphine (TCEP), a reducing agent, the MPN membrane acts as a sacrificial layer, preserving the integrity of the encapsulated condensates, whereas non-membranized condensates dissolve. Nuclear magnetic resonance spectroscopy reveals that TCEP is oxidized within the MPN-protected condensates, rendering it non-harmful. By adjusting membrane thickness through varying reagent concentrations, selective permeability is achieved, demonstrating the ability of MPN membranes to mimic key features of biological membranes. These results highlight the potential of MPN membranization for developing stable, functional protocell models that are protected from external chemical threats, offering promising applications in synthetic biology and prebiotic chemistry. This work provides a versatile platform for controlling condensate behavior and improving its utility in various scientific applications.