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Assembly-Controlled Permeability of Layer-by-Layer Polymeric Microcapsules Using a Tapered Fluidized Bed
Ka Fung Noi1, Ali Roozmand1, Mattias Björnmalm1
1Australian Research Council (ARC) Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
A new tapered fluidized bed (TFB) method enables scalable, automated production of advanced polymer microcapsules using layer-by-layer (LbL) assembly. This technique improves capsule properties for potential drug delivery applications.
Area of Science:
- Materials Science
- Chemical Engineering
- Nanotechnology
Background:
- Layer-by-layer (LbL) assembly is crucial for creating functional nano- and microcapsules for diverse applications.
- Traditional centrifugation-based LbL assembly is a batch process, limiting automation and scalability.
- Previous fluidized bed methods struggled with small particle sizes.
Purpose of the Study:
- To introduce and evaluate a tapered fluidized bed (TFB) system for scalable LbL assembly of polymer microcapsules.
- To expand the range of materials compatible with fluidized bed LbL assembly.
- To compare the properties of microcapsules produced by TFB LbL assembly versus traditional centrifugation methods.
Main Methods:
- Utilized a tapered fluidized bed (TFB) for layer-by-layer (LbL) assembly of polymer microcapsules.
- Successfully fluidized particles smaller than 3 μm, an improvement over cylindrical fluidized beds (CFB).
- Employed both electrostatic (PAH/PSS) and hydrogen-bonding (PMASH/PVPON) polymer pairs for capsule fabrication.
Main Results:
- TFB LbL assembly demonstrated compatibility with sub-3 μm particles, enabling efficient fluidization.
- Microcapsules produced via TFB exhibited increased film thickness and roughness compared to centrifugation methods.
- PMASH microcapsules fabricated using TFB showed reduced swelling and permeability, indicating enhanced deposition and cross-linking.
Conclusions:
- Tapered fluidized bed (TFB) offers a scalable and automatable approach for layer-by-layer (LbL) assembly of polymer microcapsules.
- TFB-fabricated microcapsules possess enhanced structural properties suitable for improved payload encapsulation.
- These advanced microcapsules hold promise for drug delivery applications, particularly for retaining and releasing low molecular weight biomacromolecules.
