[Synergetic killing effects of external magnetic fields combined with porphyrin-dextran magnetic nanoparticles on the human bladder cancer cells].
OBJECTIVE
To study the synergetic killing effects of external magnetic fields combined with the photodynamic action of porphyrin-dextran iron oxide  magnetic nanoparticles (PDMN) on human bladder cancer cells in vitro.


METHODS
The PDMN were produced by using the chemical co-precipitation  and redox process and the physicochemical properties were characterized. Methyl thiazolyl tetrazolium (MTT) and flow cytometry were used to determine  the effects of photodynamic therapy of PDMN combined with external pulsed electromagnetic fields (5 mT) on killing human bladder cancer BIU-87 cells  respectively.


RESULTS
The diameters of PDMN were 10-15 nm and the saturation magnetization was 0.20 emu/g. Effective diameter of PDMN was 94.8  nm. PDMN could remarkably inhibit the proliferation and induce the obvious apoptosis of BIU-87 cells, and the rates of growth inhibition and apoptosis  were (17.61±2.73)% and (24.53±5.74)% respectively. Moreover, external pulsed electromagnetic fields (5 mT) could also suppress the proliferation and  induce apoptosis of BIU-87 cells. Furthermore, the photodynamic action of PDMN combined with external magnetic fields significantly inhibited the  proliferation and promote apoptosis of BIU-87 cells, and the rates of growth inhibition and apoptosis was (28.11±4.25)% and (24.53±5.74)%, respectively,  which were significantly higher than those of other groups (P<0.01).


CONCLUSIONS
The chemical modified photodynamic action of PDMN could effectively  inhibit proliferation and induce apoptosis of BIU-87 cells. Moreover, these effects on BIU-87 cells could be strengthened by the combination with external  magnetic fields.
Department of Urology, Dongguan People's Hospital, Dongguan, China. zdluods@126.com
Dao-sheng
DS
Luo
Qi-wu
QW
Mi
Xiang-jun
XJ
Meng
Yong
Y
Gao
Yu-ping
YP
Dai
Chun-hua
CH
Deng
D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D003911:Dextrans; D006801:Humans; D060526:Magnetic Fields; D060328:Magnetic Phenomena; D058185:Magnetite Nanoparticles; D010778:Photochemotherapy; D011166:Porphyrins; D001749:Urinary Bladder Neoplasms / Q000473:pathology*
D003911:Dextrans; D058185:Magnetite Nanoparticles; D011166:Porphyrins