Ultrasound Luminescence Chemical Imaging for implant infection
ORAL
Abstract
We present a hybrid ultrasound luminescent chemical imaging (ULCI) technique to probe the chemical environment on an implant surface. ULCI allows surface-specific chemical sensitivity through tissue, as opposed to diffused visible light scattering, e.g., that spreads to >1 cm through ~1 cm of tissue. On UV light excitation, we generated green luminescence with a long afterglow in mechanoluminescent SrAl2O4:Eu,Dy microphosphors encapsulated in a biocompatible polymer film. On focusing modulated ultrasound pulses, a bright spot was generated with a ~23-fold higher luminescence intensity above the afterglow background. For imaging, we scanned the ultrasound-modulated luminescence from a target area and obtained a knife-edge spatial resolution of ~3 mm (limited by the focused ultrasound spot size) through optically scattering tissue phantoms. For chemical imaging, we developed a pH sensor by adding red fluorescent dye to the green emitting film (to reduce attenuation of light through scattering media) and a pH indicator to modulate the red-light transmittance via pH-dependent absorbance. The films were sensitive to biologically relevant changes in pH (6.0-8.0) and were imaged through optically scattering media that mimic tissue. Our results depicted that a pH-sensitive dye can modulate the ultrasound luminescent films to elucidate the physiological information of implant infection. The ULCI technique will further enable imaging of other relevant chemical species in the future.
*The research was supported by pilot projects supported by the South Carolina Bioengineering Center of Regeneration and Formation of Tissues (SC BioCRAFT) funded through the NIH grant # 5P30GM131959 and the Prisma Health Transformative Research Seed Grant program. The XELCI scanner which was used for the ULCI imaging was developed with funding from NIH NIAMS R01 AR070305-01.
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Publication:"Ultrasound Luminescence Chemical Imaging: A Tool for Detection of Implant Infection via Monitoring of pH Changes at Implant Surface", Bhattacharya S., Schober G., Uzair U., Reel M., Behlow H., Abbaraju L. V., Rao A.M., Anker J.N., Preprint from ChemRxiv, 24 Nov 2020 [DOI: 10.26434/chemrxiv.13275254.v1]
"Development of pH Sensitive Film for Detection of Implant Infection via Ultrasound Luminescent Chemical Imaging", Gretchen B. Schober, Unaiza Uzair, Morgan Reel, Vigjna Abbaraju, Herbert Behlow, Apparao M. Rao, Sriparna Bhattacharya, Jeffrey N. Anker (to be submitted)
