Related Experiment Video
Updated: Jun 16, 2025
10:35
Surface Passivation for Single-molecule Protein Studies
Published on: April 24, 2014
41.8K
A percolation phase transition controls complement protein coating of surfaces.
Zhicheng Wang1, Sahil Kulkarni2, Jia Nong3
1Pulmonary, Allergy, and Critical Care Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Cell
|June 14, 2025
Summary
The body's complement system, a network of blood proteins, activates sharply based on material surface properties. This critical transition explains how the immune system decides to attack foreign materials like nanoparticles and medical devices.
Area of Science:
- Biomaterials Science
- Immunology
- Systems Biology
Background:
- The human body possesses complex protein networks that interact with foreign materials.
- The complement system, comprising approximately 40 blood proteins, plays a crucial role in initiating inflammation upon encountering microbes, nanoparticles, and medical devices.
Purpose of the Study:
- To investigate the mechanism by which the complement system
Main Methods:
- Investigated the relationship between material surface properties and complement activation.
- Utilized computational modeling to analyze complement system behavior.
- Examined diverse engineered and living materials across various scales.
Main Results:
- A sharp threshold for complement activation was identified, dependent on the surface density of complement attachment points.
- This threshold was observed across scales, from nanoparticles to macroscale pathologies.
- Computational models revealed percolation-type critical transitions in the complement response.
Conclusions:
- The complement system's "decision" to attack a material is governed by a critical transition mechanism.
- This criticality switch is explained by a minimal complement subnetwork exhibiting percolation-like behavior.
- Understanding this mechanism is key for designing biocompatible materials and medical devices.
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