We are experts in the determination of protein/enzyme locations and membrane permeability for polymeric vesicles by various analytical methods. Thus, the preferred location of biomacromolecules determined orchestrates the potential application of polymeric vesicles (Figure 1). Beside this, the pH-responsiveness of polymeric vesicles membrane plays an important role to use enzymatic nanoreactors for switch on and off enzymatic reactions.

The unification of both key characteristics, e.g. enzyme location at polymeric vesicles and pH-responsiveness of polymeric vesicles, is required to establish active artificial organelles with different pH-responsiveness. Here preferred location of enzymes is 1, but very few in location 3 (Figure 1). The self-regulating ability is a basic characteristic of biologic systems and it is always cyclic in nature. To mimic this self-regulation process, it is a challenge for the construction of artificial cell structures and functions. We have established a self-regulated artificial organelles system consisting of coexisting enzyme (glucose oxidase (GOx) and urease) loaded pH-responsive polymersomes A (GOx-Psomes A) and B (Urease-Psomes B) with orthogonal-responsive membranes (Figure 2).

Further investigations are in progress:

• Clustered artificial organelles for spatially separated enzymatic cascade reactions.
• Modulate membrane permeability or release by different stimuli.

Unifying different enzymes and artificial organelles in larger compartments such as proteinosomes or hollow capsules allow the design and fabrication of eukaryotic cell biomimetics to study spatiotemporal and spatially separated enzymatic cascade reactions as well competitive enzyme reactions triggered by orthogonal-responsive membranes with/without skeleton-like scaffolds. A first study focused on the design and fabrication of eukaryotic cell biomimetics for the pH-dependent release insulin derivative through the variation of glucose concentration.

Further investigations are in progress:

• Clustered artificial organelles for spatially separated enzymatic cascade reactions.
• Triggering cytosolic pH in eukaryotic cell biomimetics by oscillating pH switches.
• Coacervate compartments as dynamic scaffolds for enzyme reactions

(1) Advanced Science 6 (2019) 1801299. DOI: 10.1002/advs.201801299

(2) Small 16 (2020) 2002135. DOI: 10.1002/smll.202002135

(3) Advanced Science 8 (2021) 2004263. DOI: 10.1002/advs.202004263

(4) Small 17 (2021) 2005749. DOI: 10.1002/smll.202005749

(5) Chemical Communications 57 (2021) 8019-8022. DOI: 10.1039/D1CC03422G