CORRELATION BETWEEN SITE II-SPECIFIC HUMAN SERUM-ALBUMIN (HSA) BINDING-AFFINITY AND MURINE IN-VIVO PHOTOSENSITIZING EFFICACY OF SOME PHOTOFRIN(R) COMPONENTS
T. Tsuchida et al., CORRELATION BETWEEN SITE II-SPECIFIC HUMAN SERUM-ALBUMIN (HSA) BINDING-AFFINITY AND MURINE IN-VIVO PHOTOSENSITIZING EFFICACY OF SOME PHOTOFRIN(R) COMPONENTS, Photochemistry and photobiology, 66(2), 1997, pp. 224-228
Human serum albumin (HSA) is one of the key components in human blood
that may influence drug distribution. As such, it is important to know
the affinity of any drug for albumin, Previously, Photofrin(R) a mixt
ure of monomeric, dimeric and oligomeric porphyrins, has been subjecte
d to HSA binding studies. However, due to its complex nature, binding
studies on Photofrin or other hematoporphyrin derivatives with HSA are
inconclusive. In this report, the binding properties of some componen
ts (dimers and trimers) of Photofrin(R) and the relationship between m
urine photosensitizing efficacy and those binding properties were inve
stigated, The interaction of these porphyrins with HSA mas investigate
d by direct ultrafiltration and fluorescent titration techniques with
fluorescent probes such as dansyl-L-proline (DP), which is known to in
teract selectively with site II on HSA. Porphyrins also were tested fo
r antitumor activity in a mouse model following intravenous administra
tion and exposure to laser light. Together, the results suggest that t
he photosensitizers that were preferentially bound to site II of HSA w
ere most effective at controlling muring tumor regrowth.