Dually functionalized dendrimers by temperature-sensitive surface modification and gold nanoparticle loading for biomedical application

Kono, Kenji; Takeda, Keishi; Li, Xiaojie; Yuba, Eiji; Harada, Atsushi; Ozaki, Tomoatsu; Mori, Shigeo

doi:10.1039/c4ra03947e

Cited by 6 publications

(5 citation statements)

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“…The unique optical properties of semiconductor nanostructures have been extensively studied in the aspect of quantum confinement effects: when the dimensions of semiconductors are put at or below the characteristic size like exciton Bohr radius, the band gap becomes larger in comparison with the relevant bulk material, followed by a blue shift of the optical absorption onset. Such phenomenon is caused by localization of electrons and holes in a confined space that results in observable quantization of the energy levels of the electrons. − In this case, the optical properties of nanomaterials present a series of features that the bulk materials do not possess and have been widely applied in biomedicine, − sensors, photonics, , and photovoltaics. , However, other geometrical factors excluding the quantum effects that influence the optical band gap of semiconductors are rarely reported. , …”

Section: Introductionmentioning

confidence: 99%

Dimensional Dependence of the Optical Absorption Band Edge of TiO₂ Nanotube Arrays beyond the Quantum Effect

Al‐Haddad

Wang

et al. 2015

J. Phys. Chem. C

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Instead of investigating the quantum effect that influences the absorption band edge of TiO 2 nanostructures, herein we report that geometrical parameters can also be utilized to manipulate the optical band gap of the TiO 2 nanotube arrays. Hexagonal arrays of TiO 2 nanotubes with an excellent crystalline quality were fabricated by techniques combining anodic aluminum oxide templates and atomic layer deposition. Through absorption spectroscopic analysis we observed that the optical absorption band edge of the TiO 2 nanotube arrays exhibited a red shift as the diameter of the nanotube was tuned to be larger and the distance between two nanotubes became smaller accordingly, while the wall thickness of the nanotube was kept constant. Subsequent finite-difference time-domain simulations supported the observation from theoretical aspect and revealed a large near-field enhancement around the outer space of the nanotubes for the arrays with densely distributed nanotubes when the corresponding arrays were exposed to the illuminations. Thus, this paper provides a new perspective for the shift of the optical band gap, which is of great significance to the research in photoelectronics. ■ INTRODUCTIONThe unique optical properties of semiconductor nanostructures have been extensively studied in the aspect of quantum confinement effects: when the dimensions of semiconductors are put at or below the characteristic size like exciton Bohr radius, the band gap becomes larger in comparison with the relevant bulk material, followed by a blue shift of the optical absorption onset. Such phenomenon is caused by localization of electrons and holes in a confined space that results in observable quantization of the energy levels of the electrons. 1−3 In this case, the optical properties of nanomaterials present a series of features that the bulk materials do not possess and have been widely applied in biomedicine, 4−6 sensors, 7 photonics, 8,9 and photovoltaics. 8,10 However, other geometrical factors excluding the quantum effects that influence the optical band gap of semiconductors are rarely reported. 11,12 These days, the development of technologies for precisely controlling morphological parameters of nanostructures and the corresponding arrays enables us with sufficient approaches to turn back to reexamine the renowned optical band gap shift of semiconductors. Specifically, the technique based on anodic aluminum oxide (AAO) template has been proven to be one of the most popular methodologies to fabricate nanostructure arrays with perfectly manipulatable morphologies, owing to the advantages in low cost, easy fabrication, and high manipulation. 13−16 Accordingly, a large diversity of nanostructure arrays, including nanopores, nanodots, nanorods, nanotubes, and even the nanocones, has been realized. 13−22 In consideration of the attractive property of TiO 2 that has been broadly utilized in dye-sensitized solar cells, 23,24 photocatalysts, 25 and photonics, 26,27 in this paper, we focus on the optical band gap modulation of TiO 2 na...

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Section: Introductionmentioning

confidence: 99%

Dimensional Dependence of the Optical Absorption Band Edge of TiO₂ Nanotube Arrays beyond the Quantum Effect

Al‐Haddad

Wang

et al. 2015

J. Phys. Chem. C

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“…Merck Kieselgel 60 (230-400 mesh) (Merck KGaA, Darmstadt, Germany) was used for silica gel column chromatography. 4-Nitrophenyl chloroformate-functionalized alkoxy diethylene glycol (EDEG-4-nitrophenyl chloroformate, MDEG-4-nitrophenyl chloroformate) was synthesized as reported [21]. DL−G1−S and DL−G2−S were synthesized according to previous report [22].…”

Section: Methodsmentioning

confidence: 99%

Temperature-Responsive Molecular Assemblies Using Oligo(Ethylene Glycol)-Attached Polyamidoamine Dendron Lipids and their Functions as Drug Carriers

Hashimoto

Hirai

Yuba

et al. 2020

JFB

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Temperature-responsive nanocarrier systems using external stimuli are one of the most widely investigated stimuli-responsive strategies because heat is easy and safe to use for hyperthermia and controlled drug delivery. Polyamidoamine dendron lipids (PAMAM-DLs) composed of PAMAM dendron as head group and two alkyl chains can exhibit temperature-responsive morphological change through the attachment of suitable moieties to terminal of PAMAM dendron. In this study, oligo(ethylene glycol)s including ethoxy- or methoxy-diethylene glycols were attached to the terminals of PAMAM-DL, and temperature-responsive properties of their self-assemblies were evaluated by calorimetric and turbidity measurements. In the evaluation of temperature-responsive properties, ethoxy diethylene glycol (EDEG)-attached PAMAM-DL composed of two saturated alkyl chains and PAMAM dendron with 1st generation had lipid bilayer structure and suitable cloud point for the application as drug carrier. In vitro performances of the assemblies combining EDEG-attached PAMAM-DLs with cholesteryl-oxy-poly(ethylene glycol) (PEG-Chol) was evaluated using doxorubicin (DOX) as an anticancer drug. Cellular uptake of DOX-loaded EDEG-attached PAMAM-DL/PEG-Chol assemblies was promoted at 42 °C rather than 37 °C, resulting in an effective decrease in cell viability.

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“…PAMAM G1 dendron-bearing lipid having two oleyl groups (DL) was synthesized as previously described [26]. Ethoxydiethylene glycol (EDEG)-modification to PAMAM G2 dendron-bearing lipid having two octadecyl groups (DL−S−G2) was performed by the reaction of amino groups of DL−S−G2 and EDEG-4-nitrophenyl chloroformate according to previous reports [27] (See also Scheme S1 in Supplementary Materials). Synthesized EDEG−DL was characterized using NMR.…”

Section: Methodsmentioning

confidence: 99%

Light-Activatable Transfection System Using Hybrid Vectors Composed of Thermosensitive Dendron Lipids and Gold Nanorods

et al. 2020

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Background: Gene delivery to target cells is crucially important to establish gene therapy and regenerative medicine. Although various virus-based and synthetic molecule-based gene vectors have been developed to date, selective transfection in a site or a cell level is still challenging. For this study, both light-responsive and temperature-responsive synthetic gene vectors were designed for spatiotemporal control of a transfection system. Methods: 11-Mercaptoundecanoic acid-coated gold nanorods were mixed with polyamidoamine dendron-bearing lipids of two types having amino-terminus or ethoxydiethylene glycol-terminus to obtain hybrid vectors. Hybrid vectors were mixed further with pDNA. Then we investigated their physicochemical properties and transfection efficacy with or without near infrared laser irradiation. Results: Hybrid vectors formed complexes with pDNA and exhibited enhanced photothermal property under near infrared laser irradiation compared with parent gold nanorods. Transfection efficacy of complexes was promoted considerably by brief laser irradiation soon after complex application to the cells. Analysis of intracellular distribution revealed that laser irradiation promoted the adsorption of complexes to the cells and cytosolic release of pDNA, which is derived from the change in surface hydrophobicity of complexes through dehydration of temperature-responsive groups. Conclusions: Hybrid vector is promising as a light-activatable transfection system.

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Dually functionalized dendrimers by temperature-sensitive surface modification and gold nanoparticle loading for biomedical application

Abstract: Stimuli-sensitive dendrimers of a new type were developed through dual functionalization of polyamidoamine (PAMAM) dendrimers with temperature-sensitive surface modification using propoxy diethylene glycol (PDEG) and Au nanoparticle (AuNP) loading.

Cited by 6 publications

References 54 publications

Dimensional Dependence of the Optical Absorption Band Edge of TiO₂ Nanotube Arrays beyond the Quantum Effect

Dimensional Dependence of the Optical Absorption Band Edge of TiO₂ Nanotube Arrays beyond the Quantum Effect

Temperature-Responsive Molecular Assemblies Using Oligo(Ethylene Glycol)-Attached Polyamidoamine Dendron Lipids and their Functions as Drug Carriers

Light-Activatable Transfection System Using Hybrid Vectors Composed of Thermosensitive Dendron Lipids and Gold Nanorods

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Dually functionalized dendrimers by temperature-sensitive surface modification and gold nanoparticle loading for biomedical application

Abstract: Stimuli-sensitive dendrimers of a new type were developed through dual functionalization of polyamidoamine (PAMAM) dendrimers with temperature-sensitive surface modification using propoxy diethylene glycol (PDEG) and Au nanoparticle (AuNP) loading.

Cited by 6 publications

References 54 publications

Dimensional Dependence of the Optical Absorption Band Edge of TiO2 Nanotube Arrays beyond the Quantum Effect

Dimensional Dependence of the Optical Absorption Band Edge of TiO2 Nanotube Arrays beyond the Quantum Effect

Temperature-Responsive Molecular Assemblies Using Oligo(Ethylene Glycol)-Attached Polyamidoamine Dendron Lipids and their Functions as Drug Carriers

Light-Activatable Transfection System Using Hybrid Vectors Composed of Thermosensitive Dendron Lipids and Gold Nanorods

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Dimensional Dependence of the Optical Absorption Band Edge of TiO₂ Nanotube Arrays beyond the Quantum Effect

Dimensional Dependence of the Optical Absorption Band Edge of TiO₂ Nanotube Arrays beyond the Quantum Effect