title: Synthesis and characterization of monodispersed P(St-co-DMAEMA) nanoparticles as pH-sensitive drug delivery system.
abstract: Monodispersed poly(styrene-co-N,N'-dimethylaminoethyl methacrylate) nanoparticles (P(St-co-DMAEMA) NPs) were synthesized by emulsion polymerization. Zeta potential, volume swelling ratio and in vitro release of fluorescer coumarin-6 from the NPs were determined in buffer of various pH. With an optimized formulation, the diameter of NPs is 100 nm approximately and the polydispersity index (PI) is less than 0.1. The NPs have a hydrophilic surface and alterable surface charge which is almost neutral at normal physiological pH, but becomes much more positive under acidic conditions. The volume swelling ratios and in vitro release of coumarin-6 are highly dependent on pH, which are significantly increased at the lower pH and higher DMAEMA/St molar ratio. More than 70% of the loaded coumarin-6 could be released in 24 h at pH2, which is 2.3-folds higher than that at normal physiological pH. The P(St-co-DMAEMA) NPs show promising applications to targeted drug delivery to tumors.
authors.affiliation: Department of Chemical Engineering, Key Laboratory of Advanced Materials of Ministry of Education, Tsinghua University, Beijing 100084, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Chemical Engineering, Key Laboratory of Advanced Materials of Ministry of Education, Tsinghua University, Beijing 100084, PR China.
authors.forename: Jishuai
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Chemical Engineering, Key Laboratory of Advanced Materials of Ministry of Education, Tsinghua University, Beijing 100084, PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Chemical Engineering, Key Laboratory of Industrial Biocatalysis of Ministry of Education, Tsinghua University, Beijing 100084, PR China. Electronic address: jianggq@mail.tsinghua.edu.cn.
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Jiang
authors.affiliation: Department of Chemical Engineering, Key Laboratory of Advanced Materials of Ministry of Education, Tsinghua University, Beijing 100084, PR China. Electronic address: kancy@mail.tsinghua.edu.cn.
authors.forename: Chengyou
authors.initials: C
authors.lastname: Kan
mesh_terms: D003374:Coumarins / Q000737:chemistry / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008689:Methacrylates / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors
chemical_list: D003374:Coumarins; D004337:Drug Carriers; D008689:Methacrylates; D011108:Polymers; D011137:Polystyrenes; C049840:2-(dimethylamino)ethyl methacrylate
keywords: Drug release; Emulsion polymerization; N,N′-dimethylaminoethyl methacrylate; Tertiary amine groups; Volume swelling; pH-Sensitive nanoparticles