Immunotheranostic Polymersomes Modularly Assembled from Tetrablock and Diblock Copolymers with Oxidation-Responsive
Fanfan Du1,2, Yu-Gang Liu1, Evan Alexander Scott1,3,4,2,5
1Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, USA.
Cellular and Molecular Bioengineering
|October 10, 2017
Summary
Engineered immunotheranostic polymersomes track immune cells by changing fluorescence. These polymersomes disassemble in response to reactive oxygen species, enabling visualization of targeted immune cells in vivo.
Area of Science:
- Biomaterials Science
- Immunology
- Nanotechnology
Background:
- Intracellular delivery is crucial for immunotherapy and cellular research.
- Monitoring targeted immune cells is essential for understanding complex immune responses.
- Current methods lack precise tracking of immune cell populations during treatment.
Purpose of the Study:
- To develop an immunotheranostic polymersome system for intracellular delivery.
- To enable fluorescent marking of immune cells after intracellular delivery.
- To monitor specific immune cell populations targeted in immunotherapy.
Main Methods:
- Synthesized tetrablock copolymers (PEG-PPS-PBI-PPS-PEG) via anionic ring-opening polymerization.
- Assembled block copolymers into polymersomes using thin-film hydration.
- Analyzed polymersome uptake and disassembly in mouse lymph nodes via flow cytometry.
Main Results:
- Polymersomes exhibited π-π stacking of the PBI linker, quenching fluorescence.
- Oxidation of PPS blocks by reactive oxygen species disassembled polymersomes.
- A shift in PBI fluorescence from 640 nm to 550 nm indicated polymersome disassembly within phagocytic cells.
- Increased 550 nm emission was observed in lymph node macrophages and dendritic cells over 3 days.
Conclusions:
- Immunotheranostic polymersomes offer a versatile platform for studying immune responses.
- Oxidation-sensitive PPS blocks facilitate polymersome disassembly and fluorescence shifting.
- The red-to-green fluorescence shift in response to reactive oxygen species allows in vitro and in vivo tracking of phagocytic cells.
