Apoptotic cell death induced by dendritic derivatives of aminolevulinic acid in endothelial and foam cells co-cultures

Photodynamic therapy (PDT) is an effective procedure for the treatment of lesions diseases based on the selectivity of a photosensitising compound with the ability to accumulate in the target cell. Atherosclerotic plaque is a suitable target for PDT because of the preferential accumulation of photosensitisers in atherosclerotic plaques. Dendrimers are hyperbranched polymers conjugated to drugs. The dendrimers of ALA hold ester bonds that inside the cells are cleaved and release ALA, yielding PpIX production. The dendrimer 6m-ALA was chosen to perform this study since in previous studies it induced the highest porphyrin macrophage: endothelial cell ratio (Rodriguez et al. in Photochem Photobiol Sci 14:1617–1627, 2015). We transformed Raw 264.7 macrophages to foam cells by exposure to oxidised LDLs, and we employed a co-culture model of HMEC-1 endothelial cells and foam cells to study the affinity of ALA dendrimers for the foam cells. In this work it was proposed an in vitro model of atheromatous plaque, the aim was to study the selectivity of an ALA dendrimer for the foam cells as compared to the endothelial cells in a co-culture system and the type of cell death triggered by the photodynamic treatment. The ALA dendrimer 6m-ALA showed selectivity PDT response for foam cells against endothelial cells. A light dose of 1 J/cm² eliminate foam cells, whereas less than 50% of HMEC-1 is killed, and apoptosis cell death is involved in this process, and no necrosis is present. We propose the use of ALA dendrimers as pro-photosensitisers to be employed in photoangioplasty to aid in the treatment of obstructive cardiovascular diseases, and these molecules can also be employed as a theranostic agent.Facultad de Ciencias MédicasInstituto de Investigaciones Bioquímicas de La Plat

Light fractionated ALA-PDT enhances therapeutic efficacy in vitro; The influence of PpIX concentration and illumination parameters

Light fractionation, with a long dark interval, significantly increases the response to ALA-PDT in pre-clinical models and in non-melanoma skin cancer. We investigated if this increase in efficacy can be replicated in PAM 212 cells in vitro. The results show a significant decrease in cell survival after light fractionation which is dependent on the PpIX concentration and light dose of the first light fraction. This study supports the hypothesis that an underlying cellular mechanism is involved in the response to light fractionation in which a first light fraction leads to sub-lethally damaged cells that are sensitised to a second light fraction 2 hours later. The current study reveals the in vitro circumstances under which we can investigate the cellular pathways involved.Fil: De Bruijn, Henriëtte S.. Erasmus MC; Países BajosFil: Casas, Adriana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; ArgentinaFil: Di Venosa, Gabriela Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; ArgentinaFil: Gándara, Lautaro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; ArgentinaFil: Sterenborg, Henricus J. C. M.. Erasmus MC; Países BajosFil: Batlle, Alcira María del C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; ArgentinaFil: Robinson, Dominic J.. Erasmus MC; Países Bajo

The use of dipeptide derivatives of 5-aminolaevulinic acid promotes their entry to tumor cells and improves tumor selectivity of photodynamic therapy

The use of endogenous protoporphyrin IX generated after administration of 5-aminolaevulinic acid (ALA) has led to many applications in photodynamic therapy (PDT). However, the bioavailability of ALA is limited by its hydrophilic properties and limited cell uptake. A promising approach to optimize the efficacy of ALA-PDT is to deliver ALA in the form of prodrugs to mask its hydrophilic nature. The aim of this work was to evaluate the potential of two ALA dipeptide derivatives, N-acetyl terminated leucinyl-ALA methyl ester (Ac-Leu-ALA-Me) and phenylalanyl-ALA methyl ester (Ac-Phe-ALA-Me), for their use in PDT of cancer, by investigating the generation of protoporphyrin IX in an oncogenic cell line (PAM212-Ras), and in a subcutaneous tumor model. In our in vitro studies, both derivatives were more effective than ALA in PDT treatment, at inducing the same protoporphyrin IX levels but at 50- to 100-fold lower concentrations, with the phenylalanyl derivative being the most effective. The efficient release of ALA from Ac-Phe-ALA-Me appears to be consistent with the reported substrate and inhibitor preferences of acylpeptide hydrolase. In vivo studies revealed that topical application of the peptide prodrug Ac-Phe-ALA-Me gave greater selectivity than with ALA itself, and induced tumor photodamage, whereas systemic administration improved ALA-induced porphyrin generation in terms of equivalent doses administered, without induction of toxic effects. Our data support the possibility of using particularly Ac-Phe-ALA-Me both for topical treatment of basal cell carcinomas and for systemic administration. Further chemical fine-tuning of this prodrug template should yield additional compounds for enhanced ALA-PDT with potential for translation to the clinic.Fil: Di Venosa, Gabriela Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Vallecorsa, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Giuntini, Francesca. University of Bath; Reino UnidoFil: Mamone, Leandro Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Batlle, Alcira María del C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Vanzuli, Silvia. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Juarranz, Ángeles. Universidad Autónoma de Madrid. Facultad de Ciencias; EspañaFil: MacRobert, Alexander J.. University College London; Estados UnidosFil: Egglestone, Ian M.. University of Bath; Reino UnidoFil: Casas, Adriana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentin