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Updated: May 12, 2026
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Composite Scaffolds of Interfacial Polyelectrolyte Fibers for Temporally Controlled Release of Biomolecules
Published on: August 19, 2015
Layer-by-layer polyelectrolyte deposition: a mechanism for forming biocomposite materials
Yerpeng Tan1, Umit Hakan Yildiz, Wei Wei
1Biomolecular Science and Engineering Program, University of California, Santa Barbara , Santa Barbara, California 93106, United States.
Biomacromolecules
|April 23, 2013
Summary
Complex coacervates of poly(aspartic acid) and poly-l-histidine form fluid layers, unlike precipitates. These coacervates show potential for layer-by-layer applications and biomaterial formation.
Area of Science:
- Materials Science
- Biomaterials Engineering
- Polymer Chemistry
Background:
- Biological structures like squid beaks form from metastable protein phases.
- Complex coacervates are liquid-liquid phase-separated polymer solutions.
- Polyelectrolyte complexation can lead to either coacervates or precipitates.
Purpose of the Study:
- To model biological structure formation using synthetic coacervates.
- To compare the properties of coacervate-forming and precipitate-forming polyelectrolyte systems.
- To investigate the potential of coacervates in layer-by-layer (LbL) assembly.
Main Methods:
- Preparation of poly(aspartic acid) (polyAsp) and poly-l-histidine (polyHis) coacervates.
- Preparation of poly-l-glutamic acid (polyGlu) and polyHis precipitates.
- Fabrication of Layer-by-Layer (LbL) structures on gold substrates.
- Characterization using surface-sensitive techniques like in-situ Surface Plasmon Resonance (iSPR) and Quartz Crystal Microbalance with Dissipation monitoring (QCM-D).
Main Results:
- PolyHis-polyAsp formed coacervates, while polyHis-polyGlu formed precipitates.
- PolyHis-polyAsp LbL structures were stiffer than polyHis-polyGlu LbL structures.
- Most water was expelled from the coacervate LbL, but interfacial water remained, allowing molecular rearrangement.
- The resulting coacervate layer exhibited fluidity and spreading capabilities over diverse surfaces.
Conclusions:
- Coacervate-forming polyelectrolytes are promising for LbL applications.
- LbL assembly is a key process in biological material formation.
- The fluid nature of coacervate films facilitates their role in creating complex biological structures.
