Non-cytotoxic polymer vesicles for rapid and efficient intracellular delivery
Hannah Lomas1, Marzia Massignani, Khairuddin A Abdullah
1Biomaterials and Tissue Engineering Group, Department of Engineering Materials, University of Sheffield, The Kroto Research Institute, Broad Lane, Sheffield, UK S3 7HQ.
Faraday Discussions
|December 4, 2008
Summary
Novel pH-sensitive polymersomes made from poly(2-(methacryloyloxy)ethylphosphorylcholine)-co-poly(2-(diisopropylamino)ethylmethacrylate) (PMPC-PDPA) enable efficient nucleic acid delivery into cells. These PMPC-PDPA vesicles are stable at physiological pH but break down in acidic conditions, enhancing intracellular release.
Area of Science:
- Biomaterials Science
- Polymer Chemistry
- Cellular Biology
Background:
- Developing effective intracellular delivery systems for nucleic acids is crucial for gene therapy and molecular medicine.
- pH-sensitive polymers offer potential for triggered release in acidic cellular compartments.
- Polymersomes are self-assembled vesicular structures with tunable properties for drug and nucleic acid delivery.
Purpose of the Study:
- To develop and characterize pH-sensitive poly(2-(methacryloyloxy)ethylphosphorylcholine)-co-poly(2-(diisopropylamino)ethylmethacrylate) (PMPC-PDPA) diblock copolymers for efficient cytosolic delivery.
- To investigate the self-assembly, pH-triggered dissociation, and intracellular delivery capabilities of PMPC-PDPA polymersomes.
- To evaluate the biocompatibility and inflammatory potential of PMPC-PDPA polymersomes in primary human cells.
Main Methods:
- Synthesis and characterization of PMPC-PDPA diblock copolymers.
- Formation and pH-dependent stability studies of PMPC-PDPA polymersomes.
- Encapsulation of nucleic acids within PMPC-PDPA polymersomes.
- Confocal laser scanning microscopy and fluorescence flow cytometry for cellular uptake analysis.
- Cell viability assays and assessment of inflammatory responses in human dermal fibroblasts (HDFs).
Main Results:
- PMPC-PDPA diblock copolymers self-assemble into stable polymersomes at physiological pH.
- Polymersomes rapidly dissociate into unimers below pH 6, facilitating release.
- Efficient cellular uptake and cytosolic delivery of encapsulated nucleic acids were demonstrated.
- PMPC-PDPA polymersomes showed no significant adverse effects on human dermal fibroblast viability or inflammatory response.
Conclusions:
- PMPC-PDPA polymersomes represent a promising platform for pH-triggered, efficient cytosolic delivery of nucleic acids.
- The pH-sensitive nature of these polymersomes allows for controlled release within the acidic endosomal pathway.
- The demonstrated biocompatibility supports their potential application in therapeutic delivery systems.
