title: Functionalized, Long-Circulating, and Ultrasmall Gold Nanocarriers for Overcoming the Barriers of Low Nanoparticle Delivery Efficiency and Poor Tumor Penetration.
abstract: The development of sophisticated nanoplatforms for in vivo targeted delivery of therapeutic agents to solid tumors has the potential for not only improving therapeutic efficacy but also minimizing systemic toxicity. However, the currently low delivery efficiency (about 1% of the injected dose) and the limited tumor penetration of nanoparticles remain two major challenges. Here we report a class of functionalized, long-circulating, and ultrasmall gold nanocarriers (5 nm gold core and 20 nm overall hydrodynamic diameter) for improved drug delivery and deep tumor penetration. By using doxorubicin as a model drug, our design also includes a pH-sensitive hydrazone linkage that is stable at neutral or slightly basic pH but is rapidly cleaved in the acidic tumor microenvironments and intracellular organelles. With a circulation halftime of 1.6 days, the small particle size is an important feature not only for efficient extravasation and accumulation via the enhanced permeability and retention (EPR) effect, but also for faster nanoparticle diffusion and improved tumor penetration. In xenograft animal models, the results demonstrate that up to 8% of the injected nanoparticles can be accumulated at the tumor sites, among the highest nanoparticle delivery efficiencies reported in the literature. Also, histopathological and direct visual examinations reveal dark-colored tumors with deep nanoparticle penetration and distribution throughout the tumor mass. In comparison with pure doxorubicin which is known to cause considerable heart, kidney, and lung toxicity, in vivo animal data indicate that this class of functionalized and ultrasmall gold nanoparticles indeed provides better therapeutic efficacies with no apparent toxicity in vital organs.
authors.affiliation: Departments of Biomedical Engineering and Chemistry, Emory University and Georgia Institute of Technology , Atlanta, Georgia 30322, United States.
authors.forename: Kate Y J
authors.initials: KY
authors.lastname: Lee
authors.affiliation: Departments of Biomedical Engineering and Chemistry, Emory University and Georgia Institute of Technology , Atlanta, Georgia 30322, United States.
authors.forename: Gee Young
authors.initials: GY
authors.lastname: Lee
authors.affiliation: Departments of Biomedical Engineering and Chemistry, Emory University and Georgia Institute of Technology , Atlanta, Georgia 30322, United States.
authors.forename: Lucas A
authors.initials: LA
authors.lastname: Lane
authors.affiliation: Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing, Jiangsu Province 210093, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing, Jiangsu Province 210093, China.
authors.forename: Jianquan
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing, Jiangsu Province 210093, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing, Jiangsu Province 210093, China.|Departments of Biomedical Engineering and Chemistry, Emory University and Georgia Institute of Technology , Atlanta, Georgia 30322, United States.
authors.forename: Yiqing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University , Nanjing, Jiangsu Province 210093, China.|Departments of Biomedical Engineering and Chemistry, Emory University and Georgia Institute of Technology , Atlanta, Georgia 30322, United States.
authors.forename: Shuming
authors.initials: S
authors.lastname: Nie
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage* / Q000493:pharmacokinetics; D004317:Doxorubicin / Q000008:administration & dosage* / Q000493:pharmacokinetics; D004337:Drug Carriers; D006046:Gold / Q000737:chemistry*; D006801:Humans; D013058:Mass Spectrometry; D053768:Metal Nanoparticles / Q000737:chemistry*; D051379:Mice; D046529:Microscopy, Electron, Transmission; D011092:Polyethylene Glycols / Q000737:chemistry; D014018:Tissue Distribution
chemical_list: D000903:Antibiotics, Antineoplastic; D004337:Drug Carriers; D011092:Polyethylene Glycols; D006046:Gold; D004317:Doxorubicin