Article pubs.acs.org/Biomac
NIR-Responsive and Lectin-Binding Doxorubicin-Loaded Nanomedicine from Janus-Type Dendritic PAMAM Amphiphiles Lin Sun,† Xiaofei Ma,‡ Chang-Ming Dong,*,† Bangshang Zhu,*,‡ and Xinyuan Zhu†,‡ †
Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, and ‡Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai 200240, China S Supporting Information *
ABSTRACT: Janus-type dendritic poly(amido amine) (PAMAM) amphiphiles Dm-Lac-D3DNQ were synthesized by connecting hydrophobic diazonaphthoquinone (DNQ)-decorated PAMAM dendron D3 (generation 3) and hydrophilic lactose (Lac)-decorated PAMAM dendrons Dm (generations 0−2, m = 0−2) via click chemistry. They self-assembled into the DNQ-cored micelles dangled by densely free Lac groups in aqueous solution. Irradiated by 808 nm laser and 365 nm lamp, both NIR- and UVsensitivity of micelles were characterized by time-resolved UV−vis spectroscopy. The characteristic absorption intensity of DNQ progressively decreased and then leveled off. Moreover, the bigger the micelles, the more the irradiation time for finishing Wolff rearrangement of DNQ. TEM further confirmed that most of the micelles disassembled after 30 min of 808 nm laser irradiation. The Lac-coated micelles showed binding with RCA120 lectin, as monitored by UV−vis and DLS. The apparent drug-release rate of doxorubicin (DOX) loaded nanomedicine nearly doubled after 10 min of 808 nm laser irradiation, presenting a NIR-triggered drug-release profile. Moreover, the DOX-loaded nanomedicine presented a phototriggered cytotoxicity that was close to free DOX, and they could quickly enter into HeLa cells, as evidenced by MTT assay, flow cytometry, and CLSM. Importantly, this work provides a versatile strategy for the fabrication of NIR-responsive and lectin-binding dendrimer nanomedicine, opening a new avenue for “on-demand” and spatiotemporal drug delivery.
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INTRODUCTION The polymeric nanomedicines that load drugs, proteins, and DNA/siRNA into micelles and polymersomes, increasingly received much attention for advanced drug delivery systems (DDSs) and clinical medicine including cancer therapy, as they not only reduce drug cytotoxicity, drug resistance, and clearance from reticuloendothelial system, but improve drug pharmacokinetics and biodistribution in vivo.1−10 For example, some commercial nanomedicines such as Doxil (doxorubicinloaded PEGylated liposome) and Abranxane (paclitaxel-loaded albumin nanoparticle) have been approved by U.S. FDA for clinical trials, demonstrating improved therapeutic efficacy.11−13 However, most polymeric nanomedicines can not deliver drugs into the diseased sites or cells on-demand, while some diseases including diabetes and cancer often need timing- or chronoadministration. Thereby, the stimuli-responsive polymeric nanomedicines that are triggered by the external stimuli such as pH, temperature, light, biomolecules and enzyme, can realize on-demand dosing, and might be translated into clinical trials. In this case, the light-responsive nanomedicines that achieve spatiotemporal dosing in the diseased sites are appealing for cancer therapy as both photodynamic and photothermal therapies entered into clinical trials.14−20 Especially, the nearinfrared (NIR) light between 750 and 1000 nm can penetrate several millimeter up to centimeter depth of tissues, enabling © 2012 American Chemical Society
the NIR-sensitive nanomedicines great potential as a noninvasive clinical therapy. On the other hand, how to realize the efficient accumulation of drugs in diseased sites or cells is another crucial step for chemotherapy. Fortunately, the polymeric nanomedicines often present the enhanced permeation and retention effect in tumors.11,12 In this case, combining active targeting (e.g., aptamer/antibody/sugar-triggered accumulation) and passive targeting into nanomedicines are expected to solve this problem and are intensively studied for advanced DDSs.21 Taking aforementioned considerations into account, developing the polymeric nanomedicines that simultaneously have NIRsensitivity and active targeting effect looks imperative for cancer therapy, which might accelerate their translation from bench to bedside. Besides breaking the roughly spherical symmetry of most dendrimers with a single type of terminal groups, “Janus” dendrimers with two (or more) types of terminal groups can combine multiple properties in a single molecule and selfassemble into various nanostructures (e.g., dendrimersomes, disks, tubular vesicles, and helical ribbons).23,24 Owing to their Received: July 5, 2012 Revised: September 24, 2012 Published: September 27, 2012 3581
dx.doi.org/10.1021/bm3010325 | Biomacromolecules 2012, 13, 3581−3591
Biomacromolecules
Article
Scheme 1. (A) Synthesis of Janus Dendritic PAMAM Amphiphiles Dm-Lac-D3DNQ (m = 0, 1, and 2) by Click Chemistry; (B) Wolff Rearrangement of DNQ-Containing Compound Irradiated Using NIR- or UV-Light
Scheme 2. Illustration of the Self-Assembled DOX-Loaded Nanomedicine of Dm-Lac-D3DNQ, the Cellular Uptake, and UV-/ NIR-Sensitive Disassembly and DOX Drug Release
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dx.doi.org/10.1021/bm3010325 | Biomacromolecules 2012, 13, 3581−3591
Biomacromolecules
Article
Tosoh Corporation) and a double-path, double-flow refractive index (RI) detector (Bryce) at 30 °C. The injection volume and concentration of polymers was 20 μL and 2 mg/mL, respectively. The elution phase was DMF-LiBr (0.01 mol·L−1) with an elution rate of 0.6 mL·min−1 and a series of polymethyl methacrylate was used as the calibration standard. Fourier transform infrared (FT−IR) spectra were recorded on a Perkin Elmer Paragon 1000 spectrometer at frequencies ranging from 400 to 4000 cm−1 at room temperature, and powder samples were thoroughly mixed with KBr crystal and pressed into pellet form. Fluorescent spectra were recorded at room temperature using a Perkin-Elmer LS 50B luminescence spectrometer. The fluorescence measurements were taken at an excitation wave length of 550 nm and the emission monitored from 560 nm to 700 nm, and the slit widths were maintained at 5 nm. Ultraviolet−visible (UV−vis) spectra of samples were recorded at room temperature using a Spectrumlab54 UV−visible spectrophotometer. The mean size of nanoparticles was determined by dynamic light scattering (DLS) using a Malvern Nano_S instrument (Malvern, U.K.). The solution of nanoparticles was performed at a scattering angle of 90° and at room temperature of 25 °C, and the concentration and pH value was about 0.5 mg/mL and pH = 7, respectively. All the measurements were repeated three times, and the average values reported are the mean diameter ± standard deviation. Transmission electron microscopy (TEM) was performed using a JEM-2010/INCA OXFORD TEM (JEOL/OXFORD) at a 200 kV accelerating voltage. Samples were deposited onto the surface of 300 mesh Formvar-carbon film-coated copper grids. Excess solution was quickly wicked away with a filter paper. For the UV-light irradiation, the sample (about 2 mL solution) was put vertically under the high-pressure mercury lamp (wavelength, 365 nm; power, 125 W), and the distance was kept at 5 cm. For the NIR-light irradiation, the sample was put in the focal point of an infrared laser (LIMO (Germany), repetition rate: 500 Hz, pulse time:
