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Your search keyword '"Wang, Junxin"' showing total 3 results
Start Over Author "Wang, Junxin" Topic photoacoustic imaging
3 results on '"Wang, Junxin"'

1. Copper Sulfide Nanodisks and Nanoprisms for Photoacoustic Ovarian Tumor Imaging.

Author

Wang, Junxin, Hsu, Su-Wen, Gonzalez-Pech, Natalia, Jhunjhunwala, Anamik, Chen, Fang, Hariri, Ali, Grassian, Vicki, Tao, Andrea, and Jokerst, Jesse

Subjects
Photoacoustic imaging, copper sulfide nanoparticles, ovarian cancer
Abstract

Transvaginal ultrasound is widely used for ovarian cancer screening but has a high false positive rate. Photoacoustic imaging provides additional optical contrast to supplement ultrasound and might be able to improve the accuracy of screening. Here, we report two copper sulfide (CuS) nanoparticles types (nanodisks and triangular nanoprisms) as the photoacoustic contrast agents for imaging ovarian cancer. Both CuS nanoprisms and nanodisks were ~6 nm thick and ~26 nm wide and were coated with poly(ethylene glycol) to make them colloidally stable in phosphate buffered saline (PBS) for at least 2 weeks. The CuS nanodisks and nanoprisms revealed strong localized surface plasmon resonances with peak maxima at 1145 nm and 1098 nm, respectively. Both nanoparticles types had strong and stable photoacoustic intensity with detection limits below 120 pM. The circular CuS nanodisk remained in the circulation of nude mice (n=4) and xenograft 2008 ovarian tumors (n=4) 17.9-fold and 1.8-fold more than the triangular nanoprisms, respectively. Finally, the photoacoustic intensity of the tumors from the mice (n=3) treated with CuS nanodisks was 3.0-fold higher than the baseline. The tumors treated with nanodisks had a characteristic peak at 920 nm in the spectrum to potentially differentiate the tumor from adjacent tissues.

Published
2019

2. A cellulose-based photoacoustic sensor to measure heparin concentration and activity in human blood samples

Author

Jeevarathinam, Ananthakrishnan Soundaram, Pai, Navin, Huang, Kevin, Hariri, Ali, Wang, Junxin, Bai, Yuting, Wang, Lu, Hancock, Tiffany, Keys, Stanley, Penny, William, and Jokerst, Jesse V

Subjects
Hematology, Detection, screening and diagnosis, 4.1 Discovery and preclinical testing of markers and technologies, Anticoagulants, Biosensing Techniques, Cellulose, Heparin, Humans, Optical Imaging, Partial Thromboplastin Time, Photoacoustic Techniques, Heparin sensing, Photoacoustic imaging, Ultrasound, Anticoagulation therapy, Cellulose based sensor, Analytical Chemistry, Biomedical Engineering, Nanotechnology, Bioinformatics
Abstract

Heparin is an indispensable drug in anticoagulation therapy but with a narrow therapeutic window, which dictates regular testing and dose adjustment. However, current monitoring tools have a long turnaround time or are operator intensive. In this work, we describe a cellulose-based photoacoustic sensor for heparin. The sensors have a turnaround time of 6 min for whole blood samples and 3 min for plasma samples regardless of heparin concentration. These sensors have a limit of detection of 0.28 U/ml heparin in human plasma and 0.29 U/ml in whole blood with a linear response (Pearson's r = 0.99) from 0 to 2 U/ml heparin in plasma and blood samples. The relative standard deviation was

Published
2019

3. Photoacoustic Monitoring of Anticoagulant Therapy and Other Imaging Applications

Author

Wang, Junxin

Subjects
Nanotechnology, drug monitoring, nanoparticles, photoacoustic imaging
Abstract

Photoacoustic imaging uses nanosecond laser pulses to excite materials and generate acoustic waves. This “light in, sound out” technique can extend the applications of traditional ultrasound by harnessing the optical properties of materials. These features can be used for the non-invasive monitoring of drugs, molecular interaction, and diseases. In this dissertation, I will present three case studies that use photoacoustic imaging in tandem with nanoparticle contrast agents. The first case leverages photoacoustic imaging for heparin and clotting time monitoring via phenothiazine dyes embedded in nanomaterials. The heparin concentration and clotting time could be determined by the photoacoustic intensity of methylene blue increased by heparin, and this signal enhancement was due to the aggregation between the two molecules. To translate this technique for clinical use, we developed a cellulose sensor loaded with Nile blue A for finger-prick diagnostics. Human studies using 78 blood samples revealed that the photoacoustic intensity of the sensor was strongly correlated to the activated clotting time (Pearson’s r=0.86), which was the gold standard for clotting time measurement. In addition to direct measurements of therapeutic, the second study used photoacoustic imaging to monitor the micellization of sodium dodecyl sulfate (SDS). The micellization can be determined because the photoacoustic intensity of methylene blue shows 492-fold enhancement upon addition of 3.47 mM SDS due to fluorescent quenching, which is caused by the aggregation between methylene blue and SDS. Higher concentrations above the SDS critical micelle concentration at 8.67 mM decreases the intensity signal by 54-fold because of the disassociation of the aggregates. The final case evaluated copper sulfide (CuS) nanodisk and nanoprism as the photoacoustic contrast agents for ovarian tumor detection. We found that the nanodisks have 1.8-fold higher accumulation than nanoprisms in the ovarian tumors indicating the importance of nanoparticle shape for tumor penetration. Versus baseline, the tumors treated with nanodisk revealed three-fold stronger photoacoustic intensity with a characteristic intensity peak at 920 nm. These three photoacoustic applications could improve healthcare because photoacoustic imaging is faster and more cost-effective than most of the imaging modalities in medicine.

Published
2019

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