Research Topics | Research Projects
Fluorescence Guided Surgery
The goal of molecular-targeted fluorescence guided surgery (FGS) is to improve the removal of tumor tissue based on the molecular overexpression of cellular proteins. Tumor tissues naturally retain imaging agents and therapeutics longer than normal tissue due to the enhanced permeability and retention effect. Molecular targeted agents are retained even longer in tumor due to the dynamic binding with the receptor of interest, potentially improving the tumor contrast. In the Samkoe Lab, we focus on both single-agent and paired-agent imaging methodologies for FGS.
Paired-Agent Imaging
Although promising, single-agent imaging suffers from long injection-to-imaging time, and modest contrast observed using tumor-to-normal tissue background ratios due to a complex combination of receptor binding, vascular density and perfusion, and inhibited lymphatic clearance. Paired-agent imaging (PAI) is a technique that quantifies receptor-ligand binding through transport kinetics compensation. PAI overcomes the confounding factors observed with single agents by isolating the signals of receptor-targeted and perfusion agents co-administered at microdose levels. PAI significantly improves contrast-to-noise ratios between tumor and normal tissue as compared to single agent antibody agents, even at short time periods, and allows tumor protein receptors to be quantified in vivo, which is traditionally performed with ex vivo methodologies.
Photodynamic Therapy
Photodynamic therapy requires a combination of a photosensitizing drug, light for activation, and the presence of molecular oxygen. The energy provided to the photosensitizing agent is transferred to molecular oxygen to form singlet oxygen, which can then cause damage to surrounding biological structures, such as lipid bilayers and proteins. This rapid onset of cellular damage induces a controlled cell-death pathway, which allows killing of the cancer cells but spares the normal connective tissue.