Extracorporeal photo-immunotherapy for circulating tumor cells

Area of Science:

• Biomedical Engineering
• Oncology
• Photochemistry

Background:

• Metastasis is a major cause of cancer mortality, driven by circulating tumor cells (CTCs) in the bloodstream.
• Current treatments face challenges in effectively targeting and eliminating CTCs.
• Photodynamic therapy (PDT) offers a light-activated mechanism for cell destruction.

Purpose of the Study:

• To develop and evaluate an novel extracorporeal PDT approach for eliminating CTCs.
• To assess the efficacy of targeting prostate cancer cells (PC-3) using a CD44-targeted photosensitizer.
• To investigate the efficiency of PDT in a blood flow system compared to traditional cell culture methods.

Main Methods:

• Conjugation of Chlorin e6 (Ce6) photosensitizer to CD44 antibodies for targeting PC-3 cells.
• Staining of PC-3 cells with the Ce6-CD44 conjugate.
• Extracorporeal PDT application on whole blood containing spiked, stained PC-3 cells using a transparent tube and 660 nm LED light.
• Evaluation of cancer cell necrosis post-PDT exposure.

Main Results:

• Successful staining of PC-3 cells using the Ce6-CD44 antibody conjugate.
• Achieved selective cancer cell necrosis within two minutes of extracorporeal PDT.
• Demonstrated significantly enhanced cell-killing efficiency compared to traditional PDT in cell cultures.
• Minimized light attenuation by blood, improving PDT efficacy in a flow system.

Conclusions:

• The developed extracorporeal PDT method is effective in eliminating targeted CTCs from blood.
• This approach shows promise for a new therapeutic strategy against CTCs and other blood-borne pathogens.
• Minimizing light attenuation in a flow system enhances PDT efficiency for blood-based therapies.