title: A smart multifunctional nanocomposite for intracellular targeted drug delivery and self-release.
abstract: A multifunctional 'all-in-one' nanocomposite is fabricated using a colloid, template and surface-modification method. This material encompasses magnetic induced target delivery, cell uptake promotion and controlled drug release in one system. The nanocomposite is characterized by scanning electron microscopy, transmission electron microscopy, x-ray diffraction, N(2) adsorption and vibrating sample magnetometry. The prepared material has a diameter of 350-400 nm, a high surface area of 420.29 m(2) g(-1), a pore size of 1.91 nm and a saturation magnetization of 32 emu g(-1). Doxorubicin (DOX) is loaded in mesopores and acid-sensitive blockers are introduced onto the orifices of the mesopores by a Schiff base linker to implement pH-dependent self-release. Folate was also introduced to improve DOX targeted delivery and endocytosis. The linkers remained intact to block pores with ferrocene valves and inhibit the diffusion of DOX at neutral pH. However, in lysosomes of cancer cells, which have a weak acidic pH, hydrolysis of the Schiff base group removes the nanovalves and allows the trapped DOX to be released. These processes are demonstrated by UV-visible absorption spectra, confocal fluorescence microscopy images and methyl thiazolyl tetrazolium assays in vitro, which suggest that the smart nanocomposite successfully integrates targeted drug delivery with internal stimulus induced self-release and is a potentially useful material for nanobiomedicine.
authors.affiliation: School of Chemical Engineering, Dalian University of Technology, Dalian, Liaoning, People's Republic of China.
authors.forename: Chan
authors.initials: C
authors.lastname: Wang
authors.forename: Piping
authors.initials: P
authors.lastname: Lv
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Shengyang
authors.initials: S
authors.lastname: Tao
authors.forename: Tao
authors.initials: T
authors.lastname: Hu
authors.forename: Jingbang
authors.initials: J
authors.lastname: Yang
authors.forename: Changgong
authors.initials: C
authors.lastname: Meng
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage* / Q000494:pharmacology; D001943:Breast Neoplasms / Q000188:drug therapy; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004317:Doxorubicin / Q000008:administration & dosage* / Q000494:pharmacology; D016503:Drug Delivery Systems / Q000295:instrumentation / Q000379:methods*; D004705:Endocytosis; D005260:Female; D006801:Humans; D059346:Magnets; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D016062:Porosity
chemical_list: D000903:Antibiotics, Antineoplastic; D004317:Doxorubicin