title: Shieldable tumor targeting based on pH responsive self-assembly/disassembly of gold nanoparticles.
abstract: A new approach to shield/deshield ligands for controllable tumor targeting was reported, which was based on amphiphilic self-assembly and disassembly of gold nanoparticles (Au NPs). Thanks to the excellent pH response of the system, glycyrrhetinic acid (GA) ligands can be buried inside the Au NPs' assembly at normal tissue pH (pH 7.4), while exposed when the nanostructure is disassembled at tumor extracellular pH (pHe 6.8). Hydrophobic GA molecules not only acted as ligands targeting tumor cells but also provided the major interparticle attractive force for Au NPs' assembling. An ordered assembly of Au NPs with regular shape, proper size and ultrasharp pH sensitivity (ΔpH ∼ 0.2) was achieved by fine-tuning of materials modified on Au NPs. Mechanism studies for assembly and disassembly of Au NPs indicated the possibility of a GA shield when the assembly formed, which was further demonstrated by bovine serum albumin absorption and cellular uptake. The assembly/disassembly process was reversible within extrinsic pH changes, which provides a perspective for reversible tumor targeting.
authors.affiliation: Key Laboratory of Functional Polymer Materials of Ministry of Education and Institute of Polymer Chemistry, Nankai University Collaborative Innovation Center of Chemical Science and Engineering , Tianjin 300071, China.
authors.forename: Zhiqing
authors.initials: Z
authors.lastname: Tian
authors.forename: Chengling
authors.initials: C
authors.lastname: Yang
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Yuan
mesh_terms: D016503:Drug Delivery Systems; D004705:Endocytosis; D005453:Fluorescence; D006034:Glycyrrhetinic Acid / Q000138:chemical synthesis / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D056945:Hep G2 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry*; D009369:Neoplasms / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry; D066244:Proton Magnetic Resonance Spectroscopy; D012542:Scattering, Radiation; D012710:Serum Albumin, Bovine / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D008063:Thioctic Acid / Q000737:chemistry
chemical_list: D008024:Ligands; D012710:Serum Albumin, Bovine; D011092:Polyethylene Glycols; D008063:Thioctic Acid; D006046:Gold; C028210:monomethoxypolyethylene glycol; D006034:Glycyrrhetinic Acid
keywords: drug delivery; gold nanoparticle; pH-responsive; self-assembly; tumor targeting