# Butyrylcholinesterase-Loaded Liposomes and Polymersomes: Catalytic Parameters for Three Types of Substrates

## TL;DR

This paper explores how nano-compartments containing the enzyme butyrylcholinesterase can detoxify harmful esters, with polymersomes showing better performance than liposomes.

## Contribution

The study introduces BChE-loaded polymersomes with higher encapsulation efficiency and enhanced catalytic activity for detoxifying ester substrates.

## Key findings

- BChE-polymersomes have 95% encapsulation efficiency and release enzymes over more than 7 days.
- Polymersomes based on diblock PEG-PPS showed a kcat three times higher than non-encapsulated BChE for neutral phenyl acetate.
- Catalytic performance varied with ester substrate polarity and nano-compartment formulation.

## Abstract

The nano-technological approach and supramolecular chemistry principles relation to the encapsulation of enzymes pave the way for creating next-generation nano-system-functionalized nano-compartments. The most promising approach for prophylaxis and the treatment of organophosphate (OP) poisoning is the use of stable, bioavailable nano-compartments containing OP-scavenging enzymes. Such enzymes, like butyrylcholinesterase (BChE), wild type and mutants, could also be used for the detoxification of other poisonous esters. There are two types of IRD-labeled human BChE-containing nano-scavengers: PEGylated liposomes and polyethyleneglycol–polypropylenesulfide polymersomes, which were developed with diameter close to 100 nm. BChE-polymersomes have higher encapsulation efficiency (95%) and slower release rate of enzymes (more than 7 days) compared to BChE-liposomes. The catalytic properties of encapsulated enzymes were analyzed for nano-compartment formulations, lipophilicity, the structure of block copolymers, and for different ester substrate polarity: positively charged butyrylthiocholine iodide, neutral phenyl acetate, and negatively charged aspirin. The highest kcat (more than three times) compared to non-encapsulated BChE was for polymersomes based on diblock PEG-PPS polymersomes towards the neutral phenyl acetate substrate.