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Implantable Tin Porphyrin-PEG Hydrogels with pH-Responsive Fluorescence
Haoyuan Huang1, Saurabh Chauhan1, Jumin Geng1
1Department of Biomedical Engineering and ‡Department of Chemistry, University at Buffalo, State University of New York , Buffalo, New York 14260, United States.
Biomacromolecules
|February 2, 2017
Summary
Tin porphyrin hydrogels offer intense, pH-responsive near-infrared fluorescence for transdermal imaging. These novel materials show promise for sensitive, noninvasive in vivo monitoring in the physiological pH range.
Area of Science:
- Biomaterials Science
- Polymer Chemistry
- Medical Imaging
Background:
- Tetracarboxy porphyrins can be polymerized with polyethylene glycol (PEG) diamines to create hydrogels.
- These hydrogels exhibit intense, near-infrared, and transdermal fluorescence after subcutaneous implantation.
- Chelating preformed polymer porphyrins with tin enhances their properties.
Purpose of the Study:
- To investigate the pH-responsive fluorescence properties of tin-chelated porphyrin hydrogels.
- To evaluate the potential of these hydrogels for in vivo transdermal fluorescence imaging.
Main Methods:
- Polymerization of tetracarboxy porphyrins with PEG diamines.
- Chelation of tin into the porphyrin hydrogel structure.
- Characterization of hydrogel fluorescence properties across a pH range (1-10).
- In vivo subcutaneous implantation in mice for transdermal fluorescence imaging.
Main Results:
- Tin porphyrin hydrogels displayed increasing emission intensity, ratios, and lifetimes from pH 1 to 10.
- The fluorescence emission was highly reversible and exhibited pH responsiveness within the physiological range (pH 6-8).
- Noninvasive transdermal fluorescence imaging in vivo successfully detected pH-sensitive emission.
Conclusions:
- Tin-chelated porphyrin hydrogels are a promising platform for pH-sensitive fluorescent biomaterials.
- These hydrogels demonstrate potential for noninvasive, real-time monitoring of physiological pH changes in vivo.
- The reversible and tunable fluorescence offers new avenues for diagnostic and therapeutic applications.
