Effects of activated state of T cells from human peripheral blood on absorption of photosensitizer hematoporphyrin monomerthyl ether

AIM: To investigate the characterization of absorption of hematoporphyrin monomerthyl ether (HMME), a domestic new generation photosensitizer product, by activated T cells from human peripheral blood. METHODS: Evaluation was performed by flow cytometry on the effects of incubating concentration and time of HMME on absorption by activated T cells. Lymphocytes were separated from human peripheral blood by density gradient centrifugation with Ficoll and T cells were activated with polyclonal stimulators PHA and PDB+Ion. To analyze the effects of HMME incubating doses on the absorption of activated T cells, the cultural lymphocytes were incubated with a serial doses of HMME for 1 h and HMME absorption were measured by FACS after immuno-staining with anti-CD3 antibody. To test the impact of HMME incubating time on the absorption of activated T cells, the cultural lymphocytes were incubated with HMME for various times and HMME absorption were measured by FACS after immuno-staining with anti-CD3 antibody. RESULTS: The HMME absorption-dose curve and absorption-time curve were shifted to right and up in the activated T cells as compared to resting T cells. HMME absorptions of activated T cells were statistic significantly larger than that of resting T cells in the doses between 5 mg/L to 20 mg/L. HMME absorptions of either activated T cells or resting T cells underwent a gradual increase with the incubation-time in HMME at concentration of 10 mg/L. HMME absorptions of activated T cells were statistic significantly larger than that of resting T cells in the incubation-time between 15 to 60 min. CONCLUSION: The differences of HMME absorption between activated T cells and resting T cells depend on the incubation times and doses of HMME. HMME absorption of activated T cells are significantly larger than that of resting T cells in certain incubation-times and doses. These results suggest that incubation time and dose associated with HMME-PDT therapeutic windows will be created for selective deletion of activated T cells.