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Implantable sensor for local Cherenkov-excited luminescence imaging of tumor pO2 during radiotherapy
- Source :
- Journal of Biomedical Optics
- Publication Year :
- 2020
- Publisher :
- SPIE-Intl Soc Optical Eng, 2020.
-
Abstract
- Significance: The necessity to use exogenous probes for optical oxygen measurements in radiotherapy poses challenges for clinical applications. Options for implantable probe biotechnology need to be improved to alleviate toxicity concerns in human use and facilitate translation to clinical trial use. Aim: To develop an implantable oxygen sensor containing a phosphorescent oxygen probe such that the overall administered dose of the probe would be below the Federal Drug Administration (FDA)-prescribed microdose level, and the sensor would provide local high-intensity signal for longitudinal measurements of tissue pO2. Approach: PtG4, an oxygen quenched dendritic molecule, was mixed into an agarose matrix at 100 μM concentration, allowing for local injection into tumors at the total dose of 10 nmol per animal, forming a gel at the site of injection. Cherenkov-excited luminescence imaging (CELI) was used to acquire the phosphorescence and provide intratumoral pO2. Results: Although PtG4 does not form covalent bonds with agarose and gradually leaches out into the surrounding tissue, its retention time within the gel was sufficiently long to demonstrate the capability to measure intratumoral pO2 with the implantable gel sensors. The sensor’s performance was first evaluated in vitro in tissue simulation phantoms, and then the sensor was used to measure changes in oxygen in MDA-MB-231 tumors during hypofractionated radiotherapy. Conclusions: Our study demonstrates that implantable oxygen sensors in combination with CELI present a promising approach for quantifying oxygen changes during the course of radiation therapy and thus for evaluating the tumor response to radiation. By improving the design of the gel–probe composition in order to prevent leaching of the probe into the tissue, biosensors can be created that should allow longitudinal oxygen measurements in tumors by means of CELI while using FDA-compliant microdose levels of the probe and thus lowering toxicity concerns.
- Subjects :
- Paper
Luminescence
Materials science
medicine.medical_treatment
Biomedical Engineering
chemistry.chemical_element
01 natural sciences
Oxygen
010309 optics
Biomaterials
chemistry.chemical_compound
MicroDose
Neoplasms
0103 physical sciences
Special Series on Wearable, Implantable, Mobile, and Remote Biomedical Optics and Photonics
medicine
Animals
Humans
Cherenkov
Image sensor
radiotherapy
medicine.diagnostic_test
hypoxia
Phantoms, Imaging
Optical Imaging
Atomic and Molecular Physics, and Optics
Electronic, Optical and Magnetic Materials
Radiation therapy
chemistry
Positron emission tomography
Agarose
Oxygen sensor
Biosensor
oxygen imaging
implantable probe
Biomedical engineering
Subjects
Details
- ISSN :
- 10833668
- Volume :
- 25
- Database :
- OpenAIRE
- Journal :
- Journal of Biomedical Optics
- Accession number :
- edsair.doi.dedup.....7f0751c2a5547923142d1892a7adce99