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Polyanhydride Microcapsules Exhibiting a Sharp pH Transition at Physiological Conditions for Instantaneous Triggered
Viktor Eriksson1, Leyla Beckerman1, Erik Aerts1
1Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden.
Langmuir : the ACS Journal of Surfaces and Colloids
|November 17, 2023
Summary
New pH-sensitive microcapsules offer instant drug release. These polyanhydride microcapsules release their entire payload within seconds when exposed to a narrow pH change, enabling rapid triggered delivery.
Area of Science:
- Materials Science
- Polymer Chemistry
- Drug Delivery Systems
Background:
- Stimulus-responsive microcapsules enable controlled release of encapsulated substances.
- Polyanhydrides are known for their degradability and potential in controlled release applications.
- Achieving instantaneous release upon external stimuli remains a challenge in microcapsule technology.
Purpose of the Study:
- To develop and characterize pH-controlled stimulus-responsive microcapsules.
- To investigate the instantaneous release capabilities of polyanhydride core-shell microcapsules.
- To correlate microcapsule degradation kinetics with release profiles.
Main Methods:
- Formulation of core-shell microcapsules using poly(bis(2-carboxyphenyl)adipate) as the shell material.
- Encapsulation of pyrene as a model active substance.
- pH-triggered release studies within a narrow pH interval.
- Degradation kinetics analysis using spectrophotometry and quartz crystal microbalance with dissipation monitoring.
Main Results:
- A narrow triggering pH interval (6.4–6.9) was identified for instantaneous release.
- The entire core content was released within seconds upon pH change.
- Degradation kinetics showed excellent correlation with diffusion coefficients derived from release data.
- The microcapsules demonstrated rapid triggered release under mild conditions.
Conclusions:
- The developed polyanhydride core-shell microcapsules provide a platform for almost instantaneous triggered release.
- The precise control over release is attributed to the designed morphology and material properties.
- These microcapsules hold promise for applications requiring rapid delivery of active substances.
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