Alec Plotkin

Chemical Engineering, '18


Nanoencapsulation of tyrosine kinase inhibitors and their effects on pathway inhibition

Mentor: Ralph Weissleder, MD (Massachusetts General Hospital)

Tyrosine kinase inhibitors such as sunitinib, foretinib, and crizotinib comprise a significant class of cancer-fighting compounds. These molecules function by binding to receptor tyrosine kinases (RTKs) such as MET, VEGFR, and MERTK. This disables phosphorylation in pathways that can lead to oncogenic or inflammatory responses in cancer cells, such as the MAPK pathways ERK and JNK. Despite promising indications, kinase inhibitors have shown results that are highly variable from patient to patient. These discrepancies may be partly due to problems in drug delivery, arising from these molecules’ categorical hydrophobicity. One potential solution is the encapsulation of kinase inhibitors in amphiphilic nanoparticles. Development of a nanoparticle-packaging platform for these molecules would provide the scientific community with an adaptable mechanism for improving drug delivery. Furthermore, nanoparticles can be customized to include tumor or immune targeting moieties, which may enable their use to target specific pathways in immune-tumor interactions. My work will involve identification of successful nano-encapsulation strategies for different kinase inhibitors. Subsequently, nanoparticle performance will be monitored in vitro and vivo. Eventually, the targeting of nanoparticles to interfere with tumor-immune crosstalk will explore the feasibility of employing nanoparticles in immuno-oncology.

Imaging the nuclear and cytosolic fluorescence of green (GFP) and red (RFP) fluorescent protein-bound kinases in murine ovarian cancer cells can yield quantitative data on pathway activity. The hoechst image allows identification of the cells' nuclei, while GFP and RFP label the mitogen-activated protein kinases ERK and JNK. The presence of nuclear localization sequences on the fluorophore-bound proteins allows for measurement of kinase activity by comparing nuclear and cytosolic fluorescence. In this way, pathway function can be compared under varying experimental conditions, like the addition of a kinase inhibitor. This data can be used to investigate the effectiveness of nanoparticle formulations in vitro. Source: