title: Gold-loaded polymeric micelles for computed tomography-guided radiation therapy treatment and radiosensitization.
abstract: Gold nanoparticles (AuNPs) have generated interest as both imaging and therapeutic agents. AuNPs are attractive for imaging applications since they are nontoxic and provide nearly three times greater X-ray attenuation per unit weight than iodine. As therapeutic agents, AuNPs can sensitize tumor cells to ionizing radiation. To create a nanoplatform that could simultaneously exhibit long circulation times, achieve appreciable tumor accumulation, generate computed tomography (CT) image contrast, and serve as a radiosensitizer, gold-loaded polymeric micelles (GPMs) were prepared. Specifically, 1.9 nm AuNPs were encapsulated within the hydrophobic core of micelles formed with the amphiphilic diblock copolymer poly(ethylene glycol)-b-poly(ε-capralactone). GPMs were produced with low polydispersity and mean hydrodynamic diameters ranging from 25 to 150 nm. Following intravenous injection, GPMs provided blood pool contrast for up to 24 h and improved the delineation of tumor margins via CT. Thus, GPM-enhanced CT imaging was used to guide radiation therapy delivered via a small animal radiation research platform. In combination with the radiosensitizing capabilities of gold, tumor-bearing mice exhibited a 1.7-fold improvement in the median survival time, compared with mice receiving radiation alone. It is envisioned that translation of these capabilities to human cancer patients could guide and enhance the efficacy of radiation therapy.
authors.affiliation: Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Ajlan
authors.initials: A
authors.lastname: Al Zaki
authors.forename: Daniel
authors.initials: D
authors.lastname: Joh
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Cheng
authors.forename: André Luís Branco
authors.initials: AL
authors.lastname: De Barros
authors.forename: Gary
authors.initials: G
authors.lastname: Kao
authors.forename: Jay
authors.initials: J
authors.lastname: Dorsey
authors.forename: Andrew
authors.initials: A
authors.lastname: Tsourkas
mesh_terms: D045744:Cell Line, Tumor; D006046:Gold / Q000737:chemistry*; D006801:Humans; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D011108:Polymers / Q000737:chemistry*; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage*; D011878:Radiotherapy / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D008823:Micelles; D011108:Polymers; D011838:Radiation-Sensitizing Agents; D006046:Gold