Tumor Phantom with Incorporated SERS Tags: Detectability in a Turbid Medium

Abstract

Surface-enhanced Raman scattering (SERS) tags have proven to be excellent labels for tissue bioimaging because of their low interference from biological matrices, high photostability, and possibility for using as theranostic agents. Although SERS tags are widely used for the imaging of tumors in vivo, in practice, the low contrast of the tag accumulation in the tissue and strong light scattering can significantly affect their detectability. In this work, we studied these effects by using a phantom of tumor tissue with incorporated SERS tags. The phantom is a 2 mm sphere of calcium alginate with incorporated SERS tags at a concentration of 0.625 × 108–2 × 109 cm−3. To simulate the surrounding medium with differing turbidities, the phantom was placed in a 4 mm thick agarose gel containing intralipid at a concentration of 0–1%. SERS bioimaging was carried out using standard backscattering geometry with different light focusing conditions. We found that shielding the phantom with a turbid medium led not only to a decrease in detectability but also to a decrease in the apparent size of the imaging object. Our results can help develop more accurate algorithms for processing SERS data for bioimaging.

Ex vivo confocal Raman microspectroscopy of porcinedura matersupported by optical clearing

“…Also, the optical clearing method in assisting SERS is a promising approach for the extension of the clinical applications to deeper tissues for instance using nanotags to detect metastatic sentinel lymph nodes. [75, 76]…”

“…Also, the optical clearing method in assisting SERS is a promising approach for the extension of the clinical applications to deeper tissues for instance using nanotags to detect metastatic sentinel lymph nodes. [75,76] 4 | CONCLUSIONS Ex vivo investigation of optical clearing of porcine DM with glycerol was performed by using confocal Raman microspectroscopy, including the detailed spectroscopic depth profiling of the tissue. The results show that by using glycerol as an OCA for 30 min treatment time the information depth of porcine DM can be extended to 250 μm.…”