Non-Invasively Quantitative Raman Imaging for Calculation of Lymphatic Transport Kinetics of Micelles in Mice

Raman spectroscopy based on surface enhanced Raman scattering (SERS) has received great interest in biological and medical applications owing to its high specificity and sensitivity. However, a reliable and quantitative SERS analysis in vivo is a great challenge since SERS is affected by the unevenly distributed field enhancement in hot spots of nanoparticle substrate and unpredictable nanoparticle aggregation in the complex biological environment. Here, we present non-invasively quantitative Raman imaging through stacking-induced intermolecular charge transfer-enhanced Raman scattering (SICTERS) without relying on substrate. Based on the Raman imaging with SICTERS micelles, a quantitative method is established to accurately calculate the concentration of micelles in draining lymph nodes (DLNs) following subcutaneous administration. A physiologically based pharmacokinetic model is generated to fit the concentration-time curve of the SICTERS micelles in DLNs (R² > 0.99), which calculates the pharmacokinetic parameters of the lymphatic transport of micelles with different sizes and surface charges. The optimized SICTERS micelles loading ovalbumin (OVA) as model antigen exhibits significant anti-tumor effect in mice bearing B16-OVA melanoma following vaccination. This study demonstrates a quantitative in vivo Raman imaging platform based on SICTERS for image-based pharmacokinetic modeling of micellar transport in lymphatics.