Publications - DO NOT EDIT
http://hdl.handle.net/10106/26358
2024-03-29T11:18:10ZAn optical probe for detecting chondrocyte apoptosis in response to mechanical injury
http://hdl.handle.net/10106/27316
An optical probe for detecting chondrocyte apoptosis in response to mechanical injury
Huang, Yihui; Zhou, Jun; Hakamivala, Amirhossein; Wu, Jinglei; Hong, Yi; Borrelli Jr., Joseph; Tang, Liping
Cartilage injury induced by acute excessive contact stress is common and mostly affects young adult. Although early detection of cartilage injury may prevent serious and lifelong arthritic complications, early detection and treatment is not possible due to the lack of a reliable detection method. Since chondrocyte injury and subsequent cell death are the early signs of cartilage injury, it is likely that cartilage cell apoptosis can be used to predict the extent of injury. To test this hypothesis, a near infrared probe was fabricated to have high affinity to apoptotic cells. In vitro tests show that this
apoptosis probe has low toxicity, high specificity, and high affinity to apoptotic cells. In addition, there is a positive relationship between apoptotic cell numbers and fluorescence intensities. Using a mouse xiphoid injury model, we found significant accumulation of the apoptosis probes at the injured xiphoid cartilage site. There was also a positive correlation between probe accumulation and the number of apoptotic chondrocytes within the injured xiphoid cartilage, which was confirmed by TUNEL assay. The results support that the apoptosis probes may serve as a powerful tool to monitor the extent of mechanical force-induced cartilage injury in vivo.
0007-01-01T00:00:00ZA Dual-Modality System for Both Multi-Color Ultrasound-Switchable Fluorescence and Ultrasound Imaging
http://hdl.handle.net/10106/27314
A Dual-Modality System for Both Multi-Color Ultrasound-Switchable Fluorescence and Ultrasound Imaging
Kandukuri, Jayanth; Yu, Shuai; Cheng, Bingbing; Bandi, Venugopal; D’Souza, Francis; Nguyen, Kytai Truong; Hong, Yi; Yuan, Baohong
Gobalakrishnan, Sundaresan; Zweit, Jamal
Simultaneous imaging of multiple targets (SIMT) in opaque biological tissues is an important goal for molecular imaging in the future. Multi-color fluorescence imaging in deep tissues is a promising technology to reach this goal. In this work, we developed a dual-modality imaging system by combining our recently developed ultrasound-switchable fluorescence (USF) imaging technology with the conventional ultrasound (US) B-mode imaging. This dual-modality system can simultaneously image tissue acoustic structure information and multi-color fluorophores in centimeter-deep tissue with comparable spatial resolutions. To conduct USF imaging on the same plane (i.e., x-z plane) as US imaging, we adopted two 90 <degree>-crossed ultrasound transducers with an overlapped focal region, while the US transducer (the third one) was positioned at the center of these two USF transducers. Thus, the axial resolution of USF is close to the lateral resolution, which allows a point-by-point USF scanning on the same plane as the US imaging. Both multi-color USF and
ultrasound imaging of a tissue phantom were demonstrated.
0004-01-01T00:00:00ZThe Mechanisms and Biomedical Applications of an NIR BODIPY-Based Switchable Fluorescent Probe
http://hdl.handle.net/10106/27306
The Mechanisms and Biomedical Applications of an NIR BODIPY-Based Switchable Fluorescent Probe
Cheng, Bingbing; Bandi, Venugopal; Yu, Shuai; D’Souza, Francis; Nguyen, Kytai T.; Hong, Yi; Tang, Liping; Yuan, Baohong
Zweit, Jamal; Gobalakrishnan, Sundaresan; Cho, William Chi-shing
Highly environment-sensitive fluorophores have been desired for many biomedical applications. Because of the noninvasive operation, high sensitivity, and high specificity to the microenvironment change, they can be used as excellent probes for fluorescence sensing/imaging, cell tracking/imaging, molecular imaging for cancer, and so on (i.e., polarity, viscosity, temperature, or pH measurement). In this work, investigations of the switching mechanism of a recently reported near-infrared environment-sensitive fluorophore, ADP(CA)2, were conducted. Besides, multiple
potential biomedical applications of this switchable fluorescent probe have been demonstrated, including wash-free live-cell fluorescence imaging, in vivo tissue fluorescence imaging, temperature sensing, and ultrasound-switchable fluorescence (USF) imaging. The fluorescence of the ADP(CA)2 is extremely sensitive to the microenvironment, especially polarity and viscosity. Our investigations showed that the fluorescence of ADP(CA)2 can be switched on by low polarity, high viscosity, or the presence of protein and surfactants. In wash-free live-cell imaging, the fluorescence of ADP(CA)2 inside cells was found much brighter than the dye-containing medium and was retained for at least
two days. In all of the fluorescence imaging applications conducted in this study, high target-to-noise (>5-fold) was achieved. In addition, a high temperature sensitivity (73-fold per Celsius degree) of ADP(CA)2-based temperature probes was found in temperature sensing.
0011-01-01T00:00:00ZLung protection by inhalation of exogenous solubilized extracellular matrix
http://hdl.handle.net/10106/26359
Lung protection by inhalation of exogenous solubilized extracellular matrix
Wu, Jinglei; Ravikumar, Priya; Nguyen, Kytai Truong; Hsia, Connie C. W.; Hong, Yi
Decellularized extracellular matrix (ECM) contains complex tissue-specific components that
work in concert to promote tissue repair and constructive remodeling and has been used
experimentally and clinically to accelerate epithelial wound repair, leading us to hypothesize
that lung-derived ECM could mitigate acute lung injury. To explore the therapeutic potential
of ECM for noninvasive delivery to the lung, we decellularized and solubilized porcine lung
ECM, then characterized the composition, concentration, particle size and stability of the
preparation. The ECM preparation at 3.2 mg/mL with average particle size <3 μm was
tested in vitro on human A549 lung epithelial cells exposed to 95% O2 for 24 hours, and in
vivo by tracheal instillation or nebulization into the lungs of rats exposed intermittently or
continuously to 90% O2 for a cumulative 72 hours. Our results showed that the preparation
was enriched in collagen, reduced in glycosaminoglycans, and contained various bioactive
molecules. Particle size was concentration-dependent. Compared to the respective controls
treated with cell culture medium in vitro or saline in vivo, ECM inhalation normalized cell survival and alveolar morphology, and reduced hyperoxia-induced apoptosis and oxidative
damage. This proof-of-concept study established the methodology, feasibility and therapeutic potential of exogenous solubilized ECM for pulmonary cytoprotection, possibly as an
adjunct or potentiator of conventional therapy.
2017-02-02T00:00:00Z