Photodynamic therapy for cutaneous hemangiosarcoma in dogs.

Cutaneous hemangiosarcoma is a malignant neoplasia that frequently occurs in dogs. The most effective treatment requires wide surgical excision of the tumor. To avoid mutilating surgeries, photodynamic therapy (PDT) could serve as an alternative treatment. This study aimed to treat cutaneous hemangiosarcomas in dogs using PDT with aluminium-chloride-phthalocyanine nanoemulsion (AlClPc-nano) as photosensitizer. Eight dogs with histopathological diagnosis of naturally occurring cutaneous hemangiosarcoma were treated. Animals were given intra and peritumoral injections of AlClPc-nano (13.3 µM). After 15 min, the masses were LED irradiated at a wavelength of 658-662 nm (80 mW potency) for 25 min (120 J/cm2 fluency). The number of sessions was based on lesion observations, with PDT sessions repeated every 7 days until the mass was no longer macroscopically visible. On that occasion, an excisional biopsy of the area was taken for histopathology analysis. Blood was collected from each animal before each PDT session and excisional biopsy for hematological analysis (blood counts; liver and kidney function). The number of PDT sessions varied from 2 to 4, depending on the size of the initial mass. Seven of the eight cases demonstrated complete remission of neoplasia. Microscopic analysis of the excisional biopsies showed necrosis and hemorrhage only, with no cancer cells, except in one case. During the treatment, inflammation and necrosis were macroscopically observed in the treated areas. The dogs did not show any alteration in blood parameters that could be related to the PDT. In conclusion, PDT with AlClPc-nano is a safe and effective treatment for cutaneous hemangiosarcoma in dogs.

Aluminum-chloride-phthalocyanine encapsulated in liposomes: activity against naturally occurring dog breast cancer cells.

Breast tumors represent the most common malignant tumors. Current treatments for humans and pets rely on tumor excision and adjuvant chemotherapy, which may affect both cancer cells and normal cells. Photodynamic therapy (PDT) is an approved treatment modality for a variety of cancers and was recently recommended as a first-line treatment for non-melanoma skin cancers for humans. The main purpose of the present study was to determine the efficacy of PDT using aluminum-chloride-phthalocyanine that is encapsulated in liposomes and LED as a light source to kill naturally occurring female dog breast cancer in vitro. The cytotoxicity behavior of the encapsulated photosensitizer in the dark and under irradiation using the 670 nm laser were investigated using classical trypan blue and MTT cell viability tests, acridine orange and ethidium bromide staining to label organelles, and cell morphology. Cell morphology was evaluated using light and electron microscopy. Our results demonstrate a reduced cell viability that is associated with morphologic alterations. The neoplasic cell destruction was predominantly mediated via a necrotic process, which was assayed using acridine orange and ethidium bromide staining. These findings were confirmed using light and electronic microscopy. The photosensitizer or laser irradiation alone did not induce cytotoxicity or morphological alterations, indicating the safety and efficacy of PDT with chloro-aluminum-phthalocyanine that was encapsulated in liposomes for the treatment of breast cancer cells in vitro.