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Updated: Feb 8, 2026
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Injectable Supramolecular Polymer-Nanoparticle Hydrogels for Cell and Drug Delivery Applications
Published on: February 7, 2021
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Effect of ionic strength on shear-thinning nanoclay-polymer composite hydrogels
Amir Sheikhi1, Samson Afewerki, Rahmi Oklu
1Biomaterials Innovation Research Center, Division of Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA 02139, USA.
Biomaterials Science
|June 27, 2018
Summary
The study reveals how ions in physiological media affect nanoclay-polymer hydrogels, crucial for injectable biomaterials. Understanding these ion interactions optimizes shear-thinning biomaterial (STB) performance in tissue engineering and drug delivery applications.
Area of Science:
- Biomaterials Science
- Materials Chemistry
- Rheology
Background:
- Nanoclay-polymer composites are vital for biomedical applications like tissue engineering and drug delivery.
- Current evaluations of shear-thinning biomaterials (STBs) often overlook the colloidal properties of layered silicates in physiological conditions.
- Understanding ion effects on STBs is critical for their successful in vitro and in vivo performance.
Purpose of the Study:
- To investigate the impact of common physiological ions (NaCl, CaCl2) on the rheological properties and injectability of nanoclay-gelatin hydrogels.
- To elucidate the role of ion-induced structural changes in nanoclay-polymer composites within physiological media.
- To provide fundamental insights into nanoclay-polymer interactions relevant to designing injectable biomaterials.
Main Methods:
- Rheological characterization of nanoclay-gelatin hydrogels under varying ionic conditions.
- Investigation of structural organization of nanoclay (LAPONITE® XLG-XR) and polymer (gelatin) composites.
- Analysis of ion type (NaCl, CaCl2) and concentration effects on hydrogel properties.
Main Results:
- Ion-induced aggregation of nanoclay-polymer composites was observed, linked to diffuse double layer shrinkage.
- Decreased yield stress and altered structural breakdown were correlated with ion type and concentration.
- Physiological ions significantly impact the rheological behavior and injectability of STBs, independent of STB composition.
Conclusions:
- The study demonstrates that ions in physiological media induce aggregation in nanoclay-gelatin hydrogels, affecting their shear-thinning and injectability.
- These findings are crucial for optimizing the design and performance of injectable clay-based biomaterials for biomedical applications.
- This research offers fundamental insights into nanoclay-polymer interactions in physiological environments, guiding future biomaterial development.
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