ABSTRACT
Objective To evaluate the targeting and photodynamic activity of photosensitizer Ⅰ (PSⅠ)for laryngocarcinoma Hep-2 cells.Methods The photostability of PSⅠ was measured by bleaching assay.The cellular uptake of PSⅠ by Hep-2 cells were evaluated by fluorescence spectroscopy,the effects of PSⅠconcentration,irradiation dose and etc on the viability of Hep-2 cells were investigated by MTT assay.Results After irradiation of 50 min,the OD value of PS Ⅰ decreased 11％,which indicated that the stability of PSⅠ can meet the requirement of PDT.The cellular uptake of PS Ⅰ by Hep-2 cells increased with the concentration of PSⅠ and can be obviously inhibited by the presence of excessive free folic acid (P ＜ 0.01).The results of MTT assays demonstrated that the viability of Hep-2 showed negative correlation with the PSⅠ concentration and irradiation dose.The viability of Hep-2 was only 34 ％ after PDT with 14 μ mol/L of the PS Ⅰ and 18 J/cm2 of irradiation.However,the viability of Hep-2 was still 100 ％ without irradiation,even though the concentration of PS Ⅰ was up to 1 10 μmol/L.The PDT carried out after 24 h of PSⅠ administration can efficiently inhibited the growth of Hep-2 with the survival rate of 32 ％.Conclusion The PS Ⅰ posses satisfactory photostability and lower dark cytotoxicity,and displays significant targeting and photocytotoxicity for Hep-2 cells.
ABSTRACT
The nanocomposites of poly-diallyldimethylammonium chloride (PDADMAC) and CdTe quantum dots (QDs) (i.e.QDs-PDADMAC nanocomposites) have been prepared based on electrostatic interaction and their fluorescence stability in aqueous solution has been investigated. MTT method(3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazoliumbromide method) was used to study their cytotoxicity and A549 lung cancer cell as a model cell was also used to evaluate their cellular imaging.It was shown that the fluorescence stability of QDs-PDADMAC nanocomposites was much better than that of bare QDs both in aqueous solution and cell.Meanwhile,QDs-PDADMAC nanocomposites display very low cytotoxicity in the low concentrations and better staining ability compared with QDs.QDs-PDADMAC nanocomposites will have great advantage on the cell analysis detection and imaging.