# Mobile obstacles accelerates and inhibits the bundle formation in two-patch colloidal particle

## TL;DR

This study investigates how two-patch colloidal particles self-assemble into chains and bundles, and how obstacles and particle interactions influence the kinetics of bundle formation, providing insights into neurodegenerative disease mechanisms.

## Contribution

It introduces a model showing how mobile and immobile obstacles affect bundle formation kinetics in colloidal particles, mimicking neurodegenerative disease processes.

## Key findings

- Inert obstacles slow down bundle formation
- Mobile aggregating particles slightly accelerate formation
- Mobile obstacles with intra-particle attraction inhibit bundle formation

## Abstract

Aggregation of protein into bundles is responsible for many neurodegenerative diseases. In this work, we show how two-patch colloidal particles self assemble into chains and a sudden transition to bundles takes place by tuning the patch size and solvent condition. We study the kinetics of formation of chains, bundles and network like structures using Patchy Brownian cluster dynamics. We also analyse the ways to inhibit and accelerate the formation of these bundles. We show that in presence of inert immobile obstacles, the kinetics of formation of bundles slows down. Whereas, in presence of mobile aggregating particles which exhibit inter-particle attraction and intra-particle repulsion, the kinetics of bundle formation accelerates slightly. We also show that if we introduce mobile obstacles which exhibit intra-particle attraction and inter-particle hard sphere repulsion, the kinetics of formation of bundles is inhibited. This is similar to the inhibitory effect of peptide P4 on the formation of insulin fibres. We are providing a model of mobile obstacles undergoing directional interactions to inhibit the formation of bundles.