E. Reddi, ROLE OF DELIVERY VEHICLES FOR PHOTOSENSITIZERS IN THE PHOTODYNAMIC THERAPY OF TUMORS, Journal of photochemistry and photobiology.B, Biology, 37(3), 1997, pp. 189-195
The use of photosensitizing drugs associated with different types of d
elivery vehicle has received strong interest within the field of the p
hotodynamic therapy of tumours. Lipid-based delivery vehicles, such as
liposomes and oil emulsions, allow the administration of water-insolu
ble photosensitizers, widening the choice of photosensitizers potentia
lly useful for treating tumours. In some cases, these delivery vehicle
s increase the selectivity of tumour targeting by favouring photosensi
tizer uptake in tumour tissue. However, a higher selectivity of tumour
targeting could be obtained through the association of photosensitize
rs with delivery vehicles which can interact preferentially or specifi
cally with tumour cells. With this aim in mind, low-density lipoprotei
ns (LDLs) and monoclonal antibodies, in particular, are regarded as th
e most promising delivery systems for anticancer drugs. Some pharmacok
inetic studies with LDL-associated photosensitizers have demonstrated
a higher tumour uptake compared with the same photosensitizers deliver
ed with other formulations. Monoclonal antibody-coupled photosensitize
rs have been tested mainly in vitro, and have shown a high selectivity
towards cells expressing specific antigens. Only a limited number of
reports are available on the biodistribution of immunoconjugated photo
sensitizers and on their selectivity in vivo, so that their importance
for the selectivity of tumour targeting has not yet been defined. (C)
1997 Elsevier Science S.A.