A novel approach to monitor photosensitizer accumulation and photobleaching in the course of photodynamic therapy (PDT) with the use of nanoconstructs based on the simultaneous fluorescence (FL) and optoacoustic (OA) imaging is implemented. A liposome nanoconstructs employed in this studies contain benzoporphyrin derivatives (BPD) which serve as a photosensitizer and secondly, as a fluorophore, and the fluorescent IRDye800 dye acting as an additional contrasting agent due to its high quantum yield. FL provides visualization of BPD and IRDye800 distribution, while OA principle allows for BPD-absorption based imaging of tumor and its vascular environment. We demonstrate the results of a preliminary in vivo study with combined FL and OA custom-made setups on a NUDE mouse with human glioblastoma U- 87. The results of this studies show a hemorrhage in the tumor area on the OA images obtained @532 nm after PDT that is not visually detected, but confirmed with the following histological verification. Fast nanoconstructs accumulation (< 10 min) was observed using FL imaging with the concentration in tumor only 10% higher than in surrounding tissues. We believe that the ratio of nanoconstructs accumulation in tumor can be significantly increased using target approach.
We provide direct experimental comparison of the optoacoustic imaging performance of two different 64-element linear detector array (LDA) units based on polyvinylidene difluoride (PVDF) films. The first LDA unit was based on traditional flexible circuit (FC) technology and consisted of an FC glued to the nonmetalized signal surface of a 28-μm-thick PVDF film providing 300 / 80-μm axial resolution/lateral resolution (AR/LR) and 0.4-kPa noise equivalent pressure of its single element. The other LDA unit was manufactured using a technology of low-temperature photolithographic etching (PE) of a signal electrode onto a 25-μm-thick PVDF film providing 300 / 40-μm AR/LR and 1 kPa noise equivalent pressure. As compared with a previously reported LDA unit based on a 100-μm PVDF thick film, the main advantage of using the thinner PVDF films was 10-fold improvement in axial resolution, whereas the main drawback was 10-fold increased noise equivalent pressure. In terms of in vivo imaging performance, higher bandwidth of PE LDA probe was more important than the higher sensitivity of FC LDA unit.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.