Degradation Kinetics of Disulfide Cross-Linked Microgels: Real-Time Monitoring by Confocal Microscopy.
Iris G Mercer1, Angelina N Italiano1, Irina G Gazaryan1
1Department of Chemistry and Physical Sciences, Pace University, Pleasantville, NY 10570, USA.
Gels (Basel, Switzerland)
|October 27, 2023
Summary
Biodegradable microgels with disulfide bonds degrade via swelling and erosion. Their degradation rate, dependent on glutathione, differs in cancer versus normal cells, impacting drug release kinetics.
Area of Science:
- Polymer Chemistry
- Materials Science
- Biomedical Engineering
Background:
- Biodegradable microgels are promising for drug delivery.
- Understanding microgel degradation kinetics is crucial for controlled drug release.
Purpose of the Study:
- To quantitatively study the degradation kinetics and mechanism of disulfide-crosslinked microgels.
- To investigate the influence of glutathione concentration on microgel degradation.
Main Methods:
- Synthesis of fluorescently labeled polyacrylamide-acrylonitrile microgels with disulfide cross-linkers (PAAm-AN-BAC-FA).
- Confocal microscopy to monitor microgel swelling and erosion at varying glutathione concentrations (0.06–91.8 mM).
Main Results:
- Microgel degradation involves overlapping diffusion-driven swelling and dissolution-driven erosion.
- Swelling and erosion kinetics are distinct and depend on glutathione concentration.
- Degradation is faster at higher glutathione levels, mimicking intracellular environments.
Conclusions:
- Microgel degradation is redox-sensitive, with faster rates in higher reductant environments.
- This suggests tunable drug release profiles for targeted delivery, especially in cancer cells.
- These microgels can potentially quantify reducing agent concentrations in vitro and in vivo.
