Prodrugs combining macromolecular delivery systems with site-selective drug release represent a powerful strategy to increase selectivity of anticancer agents. We have adapted this strategy to develop new polymeric photosensitizer prodrugs (PPP) sensitive to urokinase-like plasminogen activator (uPA). In these compounds (to be referred to as uPA-PPPs) multiple copies of pheophorbide a are attached to a polymeric carrier via peptide linkers that can be cleaved by uPA, a protease overexpressed in prostate cancer (PCa). uPA-PPPs are non-phototoxic in their native state but become fluorescent and produce singlet oxygen after uPA-mediated activation. In the present work, we studied the influence of side-chain modifications, molecular weight, and overall charge on the photoactivity and pharmacokinetics of uPA-PPPs. An in vitro promising candidate with convertible phototoxicity was then further investigated in vivo. Systemic administration resulted in a selective accumulation and activation of the prodrug in luc...
Authors:
Maria-Fernanda Zuluaga; Doris Gabriel; Norbert Lange
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