Photodynamic therapy with intratumoral administration of Lipid‐Based mTHPC in a model of breast cancer recurrence

Abstract

The weak intratumoral fluorescence at early time points could be explained by concentration quenching within the liposomes as evidenced from fluorescence polarization studies. Progressive mTHPC redistribution from liposomes and its further incorporation into tumor tissue resulted in fluorescence build-up over time with a maximum at 24 hours post-injection. This correlates perfectly with the best therapeutic effect at this time point. The absence of total cure can be attributed to inhomogeneous photosensitizer distribution. mTHPC is reabsorbed into the blood stream but the total administered amount is much reduced as opposed to systemic administration so that repeated PDT sessions might be favorable in terms of side effects and tumor response.

Cellular and molecular effects of the liposomal mTHPC derivative Foslipos in prostate carcinoma cells in vitro

“…In this context, liposomal photosensitizer preparations are of interest mainly for two reasons: on the one hand they may serve as useful carriers for hydrophobic photoactive molecules in biosystems and on the other hand, they may possess a high payload for targeting molecules. Among others, the photosensitizer mTHPC had been incorporated into different types of liposomes and successfully applied in PDT protocols in-vitro and in-vivo [5,6,8,[21][22][23][24]. However, the lack of information on molecular effects prompted us to explore cellular mechanisms in PDT with the DDPG/DDPC liposomal mTHPC derivative Foslipos, using the prostate carcinoma cell line PC-3 as model.…”

Nanodrug applications in photodynamic therapy

“…These include studies on the putative absence of side effects [47], efficacy and reduced damage of healthy tissue compared to the non-liposomal formulation Foscan ® [48,49]. Newer studies are related to the potential use of an intratumoral injection of a liposomal formulation of Foslip in a mouse model of local recurrence of breast cancer [129] and its photothrombic activity [130].…”

“…Various studies have been reported on Foslip  , such as on side effects [47], photodynamic efficiency, toxicity, decreased damage of healthy tissue [48,49], tumor selectivity [164] or skin delivery [165]. Not long ago, the potential use of a liposomal formulation of Foslip  was studied in a mouse model for the local recurrence of breast cancer [129]. Likewise, its photothrombic activity was investigated [130].…”

Photodynamic therapy of cancer — Challenges of multidrug resistance

“…The use of lipid-based PS (e.g., Foscan) and nanocarriers might improve the PS distribution and retention in targeted tumor. 80 An e®ective control of cancer might require the selective destruction of parenchymal and/or stromal tissue. It is well known that the generation of a reactive stroma environment can promote tumorigenesis.…”