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Teixo R, Laranjo M, Abrantes AM, Brites G, Serra A, Proença R, Botelho MF. Retinoblastoma: might photodynamic therapy be an option? Cancer Metastasis Rev 2016; 34:563-73. [PMID: 25579236 DOI: 10.1007/s10555-014-9544-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Retinoblastoma is a tumor that mainly affects children under 5 years, all over the world. The origin of these tumors is related with mutations in the RB1 gene, which may result from genetic alterations in cells of the germ line or in retinal somatic cells. In developing countries, the number of retinoblastoma-related deaths is higher due to less access to treatment, unlike what happens in developed countries where survival rates are higher. However, treatments such as chemotherapy and radiotherapy, although quite effective in treating this type of cancer, do not avoid high indices of mortality due to secondary malignances which are quite frequent in these patients. Additionally, treatments such as cryotherapy, thermotherapy, thermochemotherapy, or brachytherapy represent other options for retinoblastoma. When all these approaches fail, enucleation is the last option. Photodynamic therapy might be considered as an alternative, particularly because of its non-mutagenic character. Photodynamic therapy is a treatment modality based on the administration of photosensitizing molecules that only upon irradiation of the tumor with a light source of appropriate wavelength are activated, triggering its antitumor action. This activity may be not only due to direct damage to tumor cells but also due to damage caused to the blood vessels responsible for the vascular supply of the tumor. Over the past decades, several in vitro and in vivo studies were conducted to assess the effectiveness of photodynamic therapy in the treatment of retinoblastoma, and very promising results were achieved.
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Affiliation(s)
- Ricardo Teixo
- Unit of Biophysics, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548, Coimbra, Portugal
| | - Mafalda Laranjo
- Unit of Biophysics, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548, Coimbra, Portugal. .,CIMAGO, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548, Coimbra, Portugal. .,IBILI, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548, Coimbra, Portugal.
| | - Ana Margarida Abrantes
- Unit of Biophysics, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548, Coimbra, Portugal.,CIMAGO, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548, Coimbra, Portugal.,IBILI, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548, Coimbra, Portugal
| | - Gonçalo Brites
- Unit of Biophysics, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548, Coimbra, Portugal
| | - Arménio Serra
- Chemical Engineering Department, Faculty of Science and Technology, University of Coimbra, Pólo II, Pinhal de Marrocos, 3030-290, Coimbra, Portugal
| | - Rui Proença
- IBILI, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548, Coimbra, Portugal.,Centre for Integrated Responsibility in Ophthalmology, Coimbra Hospital and University Centre (CRIO-CHUC), Praceta Mota Pinto, 3000-075, Coimbra, Portugal
| | - Maria Filomena Botelho
- Unit of Biophysics, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548, Coimbra, Portugal.,CIMAGO, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548, Coimbra, Portugal.,IBILI, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, 3000-548, Coimbra, Portugal
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Georgiou S, Papazoglou T, Dafnomili D, Coutsolelos AG, Kouklaki V, Tosca A. Photophysical characterization of hematoporphyrin incorporated within collagen gels. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1994; 22:45-50. [PMID: 8151455 DOI: 10.1016/1011-1344(93)06950-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Physical properties of hematoporphyrin-enriched collagen gels relevant to the photodynamic treatment of cancer are characterized. The incorporation of the sensitizer within the gels does not affect either the structure of the gel or the absorption and fluorescence spectra of the sensitizer. The gel-embedded sensitizer photodegrades efficiently with the formation of a product emitting near 635 nm. Differences in the collagen scattering are observed following sensitization vs. prolonged irradiation with Ar+ laser, indicating contrasting structural modifications effected to the biopolymer matrix in the two cases. The results correspond well to in vivo observations, suggesting that hematoporphyrin-enriched collagen gels may be appropriate systems for modeling the influence of the semisolid nature of tissues, and in particular of the tumour stroma collagen, on the photodynamic phenomenon.
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Affiliation(s)
- S Georgiou
- Foundation for Research and Technology-Hellas, Institute of Electronic Structure and Lasers, Heraklion, Crete, Greece
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