Biomimetic artificial organelles with in vitro and in vivo activity triggered by reduction in microenvironment

TLDR

Stimuli‑responsive enzyme delivery systems have largely remained effective only in vitro, despite extensive development efforts. The authors present a biomimetic strategy that combines biomolecules with artificial compartments to create artificial organelles (AOs) capable of endogenous, stimuli‑triggered enzymatic activity as cellular implants. AOs are fabricated by inserting protein gates—engineered channel porins capped with molecular caps—into polymersome membranes that encapsulate horseradish peroxidase, enabling redox‑responsive control of molecular flow. The AOs retain structural integrity, are activated by intracellular glutathione in vitro, function in vivo within zebrafish embryos, and thus offer a promising platform for patient‑oriented protein therapy.

Abstract

Abstract Despite tremendous efforts to develop stimuli-responsive enzyme delivery systems, their efficacy has been mostly limited to in vitro applications. Here we introduce, by using an approach of combining biomolecules with artificial compartments, a biomimetic strategy to create artificial organelles (AOs) as cellular implants, with endogenous stimuli-triggered enzymatic activity. AOs are produced by inserting protein gates in the membrane of polymersomes containing horseradish peroxidase enzymes selected as a model for natures own enzymes involved in the redox homoeostasis. The inserted protein gates are engineered by attaching molecular caps to genetically modified channel porins in order to induce redox-responsive control of the molecular flow through the membrane. AOs preserve their structure and are activated by intracellular glutathione levels in vitro. Importantly, our biomimetic AOs are functional in vivo in zebrafish embryos, which demonstrates the feasibility of using AOs as cellular implants in living organisms. This opens new perspectives for patient-oriented protein therapy.