title: Radiosensitizer-eluting nanocoatings on gold fiducials for biological in-situ image-guided radio therapy (BIS-IGRT).
abstract: Image-guided radiation treatments (IGRT) routinely utilize radio-opaque implantable devices, such as fiducials or brachytherapy spacers, for improved spatial accuracy. The therapeutic efficiency of IGRT can be further enhanced by biological in situ dose painting (BIS-IGRT) of radiosensitizers through localized delivery within the tumor using gold fiducial markers that have been coated with nanoporous polymer matrices loaded with nanoparticles (NPs). In this work, two approaches were studied: (i) a free drug release system consisting of Doxorubicin (Dox), a hydrophilic drug, loaded into a non-degradable polymer poly(methyl methacrylate) (PMMA) coating and (ii) poly(d,l-lactic-co-glycolic acid) (PLGA) NPs loaded with fluorescent Coumarin-6, serving as a model for a hydrophobic drug, in a biodegradable chitosan matrix. Temporal release kinetics measurements in buffer were carried out using fluorescence spectroscopy. In the first case of free Dox release, an initial release within the first few hours was followed by a sustained release over the course of the next 3 months. In the second platform, release of NPs and the free drug was controlled by the degradation rate of the chitosan matrix and PLGA. The results show that dosage and rate of release of these radiosensitizers coated on gold fiducials for IGRT can be precisely tailored to achieve the desired release profile for radiation therapy of cancer.
authors.affiliation: Electronic Materials Research Institute and Department of Physics, Northeastern University, Boston, MA 02115, USA.
authors.forename: D K
authors.initials: DK
authors.lastname: Nagesha
authors.forename: D B
authors.initials: DB
authors.lastname: Tada
authors.forename: C K K
authors.initials: CK
authors.lastname: Stambaugh
authors.forename: E
authors.initials: E
authors.lastname: Gultepe
authors.forename: E
authors.initials: E
authors.lastname: Jost
authors.forename: C O
authors.initials: CO
authors.lastname: Levy
authors.forename: R
authors.initials: R
authors.lastname: Cormack
authors.forename: G M
authors.initials: GM
authors.lastname: Makrigiorgos
authors.forename: S
authors.initials: S
authors.lastname: Sridhar
mesh_terms: D048271:Chitosan / Q000737:chemistry; D004317:Doxorubicin / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry*; D057918:Fiducial Markers; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D053758:Nanoparticles / Q000737:chemistry*; D019904:Polymethyl Methacrylate / Q000737:chemistry; D011838:Radiation-Sensitizing Agents / Q000737:chemistry*; D011880:Radiotherapy Planning, Computer-Assisted / Q000592:standards*
chemical_list: D004337:Drug Carriers; D011838:Radiation-Sensitizing Agents; D006046:Gold; D004317:Doxorubicin; D019904:Polymethyl Methacrylate; D048271:Chitosan