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Injectable Oxygen Sensitive Chitosan Complex with High Oxygen Sensitivity and Stability to Oxidoreductants
Chao Li1, Zheng Huang1, Ning Gao1,2
1Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210, United States.
ACS Biomaterials Science & Engineering
|August 29, 2020
Summary
A new injectable polymeric probe using chitosan and a tetrathiatriarylmethyl (TAM) radical allows for stable, long-term monitoring of tissue oxygen levels during vascularization therapies. This overcomes limitations of current methods for evaluating treatment efficacy.
Area of Science:
- Biomaterials Science
- Medical Imaging
- Tissue Engineering
Background:
- Evaluating therapeutic efficacy in tissue vascularization requires precise, reproducible monitoring of oxygen concentration changes.
- Current noninvasive spectroscopic methods lack the stability and minimally invasive delivery needed for long-term tracking.
- Electron paramagnetic resonance (EPR) offers potential but is limited by existing probes' instability and delivery challenges.
Purpose of the Study:
- To develop an injectable, degradable polymeric EPR probe for stable, long-term monitoring of tissue oxygen concentration.
- To overcome the limitations of small molecule EPR probes in maintaining consistent tissue concentration and enabling minimally invasive delivery.
- To assess the oxygen sensitivity, stability, and biocompatibility of the novel probe for therapeutic monitoring.
Main Methods:
- Development of a polymeric EPR probe based on a complex of chitosan and tetrathiatriarylmethyl (TAM) radical.
- In vitro and in vivo evaluation of the probe's oxygen sensitivity, signal stability over time (4 weeks), and reproducibility.
- Assessment of the probe's stability against common oxidoreductants found in diseased tissues.
- Evaluation of the probe's biocompatibility.
Main Results:
- The developed chitosan/TAM complex probe demonstrated high oxygen sensitivity and reproducibility.
- The probe exhibited enhanced stability compared to free TAM radicals when exposed to oxidoreductants.
- Consistent EPR signal intensity was maintained for 4 weeks both in vitro and in vivo without compromising oxygen sensitivity.
- The probe showed excellent biocompatibility.
Conclusions:
- The injectable, degradable TAM/chitosan complex represents a significant advancement for EPR-based tissue oxygen monitoring.
- This novel probe addresses key limitations of existing methods, enabling stable and reproducible measurements during vascularization therapies.
- The developed probe holds promise for long-term detection of tissue oxygen content, aiding in the evaluation of therapeutic efficacy.
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