Spontaneous Phase Separation Enables Rapid, Polymerization-Free Fabrication of Gels
Namrata Priyadarshinee1, Vidhi Saxena2, Aniruddha Kambekar1
1Chemical Engineering, IIT Gandhinagar, Gandhinagar 382055, Gujarat, India.
Langmuir : the ACS Journal of Surfaces and Colloids
|July 1, 2026
Summary
This study introduces a novel, cross-linker-free method for creating advanced hydrogels using aqueous two-phase systems (ATPS). This technique enables scalable fabrication of multifunctional gels for diverse applications.
Area of Science:
- Materials Science
- Polymer Chemistry
- Biotechnology
Background:
- Hydrogels are versatile polymeric networks widely used in drug delivery, tissue engineering, and biosensing.
- Current hydrogel fabrication often relies on covalent modifications, limiting scalability and functionality.
- Living cells and biomolecules can be incorporated into hydrogels, expanding their applications.
Purpose of the Study:
- To develop a scalable, cross-linker-free hydrogel fabrication method using aqueous two-phase systems (ATPS).
- To investigate the phase separation behavior of poly(ethylene glycol) (PEG) and dextran (DEX) systems.
- To demonstrate the utility of ATPS-fabricated hydrogels for encapsulating various payloads.
Main Methods:
- Utilized a model system of poly(ethylene glycol) (PEG) and dextran (DEX) far from the binodal boundary to induce phase separation.
- Performed rheological studies to analyze viscoelastic properties.
- Characterized hydrogel composition and solvent content using colorimetric assays, FTIR, MALDI-TOF, and TGA.
- Employed coarse-grained (CG) simulations to understand phase separation mechanisms and the role of DEX molecular weight.
Main Results:
- Demonstrated direct transition to viscoelastic liquids or gels by controlling polymer phase separation.
- Rheological studies provided insights into the viscoelastic behavior of the fabricated gels.
- CG simulations elucidated the mechanistic origins of phase separation and predicted the influence of DEX molecular weight on partitioning.
- Successfully encapsulated live cells, antibiotics, and plant seeds within the hydrogels.
Conclusions:
- The ATPS-based fabrication technique offers a scalable, cross-linker-free route to multifunctional hydrogels.
- This method enables the creation of advanced materials for drug delivery, responsive systems, and tissue engineering.
- The ability to encapsulate diverse payloads highlights the potential of this technique for various biotechnological applications.
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