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Published on: January 15, 2018
pH-Sensitive Reversible Programmed Targeting Strategy by the Self-Assembly/Disassembly of Gold Nanoparticles
Jinlong Ma1, Zhenpeng Hu1, Wei Wang1
1Key Laboratory of Functional Polymer Materials of the Ministry of Education, Institute of Polymer Chemistry, College of Chemistry, and ‡Collaborative Innovation Center of Chemical Science and Engineering, Nankai University , Tianjin 300071, China.
This study introduces a novel pH-responsive gold nanoparticle system that reversibly shields and exposes targeting ligands. This strategy enhances tumor accumulation and prolongs circulation time for targeted drug delivery.
Area of Science:
- Nanotechnology
- Biomedical Engineering
- Materials Science
Background:
- Targeted drug delivery systems aim to improve therapeutic efficacy and reduce side effects.
- Achieving high tumor accumulation requires strategies that balance circulation time and cellular uptake.
- Reversible control over nanoparticle surface properties is crucial for optimizing delivery kinetics.
Purpose of the Study:
- To develop a pH-responsive gold nanoparticle (Au NP) system for reversible shielding and exposure of targeting ligands.
- To investigate the self-assembly and disassembly behavior of modified Au NPs based on pH changes.
- To evaluate the potential of this system for enhanced tumor targeting and prolonged blood circulation.
Main Methods:
- Modification of gold nanoparticles (Au NPs) with poly(ethylene glycol) (PEG)-ligand, dibutylamines (Bu), and pyrrolidinamines (Py).
- Utilizing pH-responsive self-assembly driven by hydrophobic interactions and steric repulsion for ligand shielding/deshielding.
- Characterizing self-assembly/disassembly using transmission electron microscopy (TEM) and dynamic light scattering (DLS).
- Assessing ligand accessibility via enzyme-linked immunosorbent assays (ELISA) and cellular uptake studies.
Main Results:
- Precise pH-triggered self-assembly (pH ≥ 7.2) and disassembly (pH ≤ 6.8) of Au NPs were achieved by tuning the Bu/Py molar ratio.
- Ligands were successfully shielded within the assembled NPs and exposed upon disassembly.
- The self-assembly/disassembly process demonstrated reversibility.
- TEM and DLS confirmed the structural changes of Au NPs at different pH values.
Conclusions:
- The developed pH-responsive Au NP system enables reversible control over targeting ligand presentation.
- This strategy holds promise for prolonging blood circulation by shielding ligands in non-tumor environments.
- The system facilitates enhanced tumor accumulation through ligand exposure in the acidic tumor microenvironment.
- This reversible targeting approach offers a new paradigm for optimizing nanoparticle-based drug delivery.
