title: pH-Reversible Cationic RNase A Conjugates for Enhanced Cellular Delivery and Tumor Cell Killing.
abstract: Intracellularly-acting therapeutic proteins are considered promising alternatives for the treatment of various diseases. Major limitations of their application are low efficiency of intracellular delivery and possible reduction of protein activity during derivatization. Herein, we report pH-sensitive covalent modification of proteins with a histidine-rich cationic oligomer (689) for efficient intracellular transduction and traceless release of functional proteins. Enhanced Green fluorescent protein (EGFP), as model for the visualization of protein transduction, and RNase A, as therapeutic protein with antitumoral effect, were modified with the pH-sensitive bifunctional AzMMMan linker and varying amounts of cationic oligomer. The modification degree showed impact on the internalization and cellular distribution of EGFP as well as the biological effect of RNase A conjugates, which mediated considerable toxicity against cancer cells at optimal ratio. The presented conjugates demonstrate their qualification to achieve efficient intracellular delivery and controlled release without protein inactivation and potential prospective applications in protein-based therapies.
authors.affiliation: Pharmaceutical Biotechnology, Center for System-based Drug Research, Ludwig-Maximilians University Munich , Butenandstrasse 5-13, D-81377 Munich, Germany.
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Liu
authors.affiliation: Pharmaceutical Biotechnology, Center for System-based Drug Research, Ludwig-Maximilians University Munich , Butenandstrasse 5-13, D-81377 Munich, Germany.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Pharmaceutical Biotechnology, Center for System-based Drug Research, Ludwig-Maximilians University Munich , Butenandstrasse 5-13, D-81377 Munich, Germany.|Nanosystems Initiative Munich, Schellingstrasse 4, D-80799 Munich, Germany.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: He
authors.affiliation: Pharmaceutical Biotechnology, Center for System-based Drug Research, Ludwig-Maximilians University Munich , Butenandstrasse 5-13, D-81377 Munich, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rödl
authors.affiliation: Faculty of Physics and Center for NanoScience (CeNS), Ludwig-Maximilians University Munich , Geschwister-Scholl-Platz 1, 80539 Munich, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Preiß
authors.affiliation: Faculty of Physics and Center for NanoScience (CeNS), Ludwig-Maximilians University Munich , Geschwister-Scholl-Platz 1, 80539 Munich, Germany.|Nanosystems Initiative Munich, Schellingstrasse 4, D-80799 Munich, Germany.
authors.forename: Joachim O
authors.initials: JO
authors.lastname: Rädler
authors.affiliation: Pharmaceutical Biotechnology, Center for System-based Drug Research, Ludwig-Maximilians University Munich , Butenandstrasse 5-13, D-81377 Munich, Germany.|Nanosystems Initiative Munich, Schellingstrasse 4, D-80799 Munich, Germany.
authors.forename: Ernst
authors.initials: E
authors.lastname: Wagner
authors.affiliation: Pharmaceutical Biotechnology, Center for System-based Drug Research, Ludwig-Maximilians University Munich , Butenandstrasse 5-13, D-81377 Munich, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Lächelt
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000378:metabolism*; D002412:Cations / Q000737:chemistry*; D045744:Cell Line, Tumor; D016503:Drug Delivery Systems / Q000379:methods; D049452:Green Fluorescent Proteins / Q000737:chemistry* / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D012259:Ribonuclease, Pancreatic / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D002412:Cations; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D012259:Ribonuclease, Pancreatic