Porphyrins have been used successfully to treat and diagnose cancer, yet the mechanism of how porphyrins are selectively taken up and how they are retained by cancer cells compared to other cells remains poorly understood. Knowledge about the cellular uptake and retention mechanisms of porphyrins can be used to design more effective porphyrin-based diagnostics and therapeutics.
Sputum consists of a complex mixture of mucus from the lungs and a variety of cell types including cancer cells if a tumor is present. Sputum can be collected non-invasively with no patient side-effects which makes it an ideal specimen for diagnostic purposes. Sputum cytology was for decades the only tool available to diagnose lung cancer.
Porphyrins are dynamic molecules involved in many biological processes, including oxygen and electron transport. Porphyrins have also been known to incorporate more readily into cancer cells compared to non-cancerous cells, and this property of porphyrins is being explored for diagnostic and therapeutic applications in cancer patients.