Demonstration of synergistic effects of hyperthermia and photodynamic therapy using the chick chorioallantoic membrane model.
The chick chorioallantoic membrane (CAM) model was used to study vascular effects of photodynamic therapy (PDT) and hyperthermia (HPT) and the synergism of these modalities. The CAM is a convenient medium for monitoring the modifications of the vasculature. It is possible to view the CAM and to examine structural changes of individual blood vessels in real time. Moreover, the CAM is a closed system which lends itself to mathematical modeling of the temporal and spatial temperature profile and in which HPT can be performed quantitatively and to a selected depth, using different lasers. A porphyrin-type photosensitizer solution was applied to areas of the CAM, defined by teflon O-rings placed on the surface. Uptake dynamics of the sensitizer into the CAM was determined by analyzing its fluorescence in vivo. The CAM area was irradiated with a dual-wavelength laser system composed of a dye laser at 644 nm (to induce PDT) and a CO2 laser at 10.6 microns (to bring about HPT). Damage to the CAM vasculature, due to combined PDT+HPT, was compared to the outcome of the separate modalities, and a synergistic effect of about 40% was observed.
Kimel
S
S
Beckman Laser Institute and Medical Clinic, Irvine, California 92715.
Svaasand
L O
LO
Hammer-Wilson
M
M
Gottfried
V
V
Cheng
S
S
Svaasand
E
E
Berns
M W
MW
D000482:Allantois / Q000098:blood supply* / Q000187:drug effects / Q000528:radiation effects; D000818:Animals; D001831:Body Temperature / Q000187:drug effects / Q000528:radiation effects; D002245:Carbon Dioxide; D002642:Chick Embryo; D002823:Chorion / Q000098:blood supply* / Q000187:drug effects / Q000528:radiation effects; D003131:Combined Modality Therapy; D004195:Disease Models, Animal; D005290:Ferric Compounds / Q000627:therapeutic use*; D006979:Hyperthermia, Induced / Q000379:methods*; D053685:Laser Therapy; D008833:Microcirculation / Q000187:drug effects / Q000528:radiation effects; D009389:Neovascularization, Pathologic / Q000473:pathology / Q000503:physiopathology; D010778:Photochemotherapy / Q000379:methods*; D011166:Porphyrins / Q000627:therapeutic use*; D011838:Radiation-Sensitizing Agents / Q000627:therapeutic use*; D013997:Time Factors
D005290:Ferric Compounds; D011166:Porphyrins; D011838:Radiation-Sensitizing Agents; D002245:Carbon Dioxide; C016136:tetraphenylporphine sulfonate