Document Detail


Light-responsive polymer nanoreactors: a source of reactive oxygen species on demand.
MedLine Citation:
PMID:  23154601     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
Various domains present the challenges of responding to stimuli in a specific manner, with the desired sensitivity or functionality, and only when required. Stimuli-responsive systems that are appropriately designed can effectively meet these challenges. Here, we introduce nanoreactors that encapsulate photosensitizer-protein conjugates in polymer vesicles as a source of "on demand" reactive oxygen species. Vesicles made of poly(2-methyloxazoline)-poly(dimethylsiloxane)-poly(2-methyloxazoline) successfully encapsulated the photosensitizer Rose Bengal-bovine serum albumin conjugate (RB-BSA) during a self-assembly process, as demonstrated by UV-Vis spectroscopy. A combination of light scattering and transmission electron microscopy indicated that the nanoreactors are stable over time. They serve a dual role: protecting the photosensitizer in the inner cavity and producing in situ reactive oxygen species (ROS) upon irradiation with appropriate electromagnetic radiation. Illumination with appropriate wavelength light allows us to switch on/off and to control the production of ROS. Because of the oxygen-permeable nature of the polymer membrane of vesicles, ROS escape into the environment around vesicles, as established by electron paramagnetic resonance. The light-sensitive nanoreactor is taken up by HeLa cells in a Trojan horse fashion: it is nontoxic and, when irradiated with the appropriate laser light, produces ROS that induce cell death in a precise area corresponding to the irradiation zone. These nanoreactors can be used in theranostic approaches because they can be detected via the fluorescent photosensitizer signal and simultaneously produce ROS efficiently "on demand".
Authors:
Patric Baumann; Vimalkumar Balasubramanian; Ozana Onaca-Fischer; Andrzej Sienkiewicz; Cornelia G Palivan
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-11-15
Journal Detail:
Title:  Nanoscale     Volume:  -     ISSN:  2040-3372     ISO Abbreviation:  Nanoscale     Publication Date:  2012 Nov 
Date Detail:
Created Date:  2012-11-16     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101525249     Medline TA:  Nanoscale     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland. Cornelia.Palivan@unibas.ch.
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