Experimental SectionMeasurements. 1 H NMR (500 MHz) spectra were acquired in CDCl 3 using a Varian INOVA-500 spectrometer at 25 °C. Tetramethylsilane (TMS) was used as an internal reference for 1 H NMR spectroscopy. FT-IR spectra were obtained on a Bruker Tensor 27 system using attenuated total reflectance (ATR) sampling accessories. High resolution mass spectrum was obtained on a ThermoFinnigan MAT XL spectrometer.Matrix-assisted laser desorption/ionization time-of-flight mass spectrometery (MALDI-TOF) was measured on a Bruker Biflex IV (Billerica, MA) MALDI mass spectrometer equipped with a nitrogen laser (λ = 337 nm). Mass spectrum was acquired in the reflection mode with a mass range of 2000-12000 m/z, and the mass scale was calibrated externally using the peaks of peptide calibration standard II purchased from Bruker. Trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile (DCTB, Aldrich; ≥99%) served as matrix and was dissolved in CHCl 3 at a concentration of 20 mg/mL. Sodium trifluoroacetate (NaTFA, Aldrich; ~98%) served as cationizing agent and was dissolved in MeOH/CHCl 3 (1/3, v/v) at a concentration of 10 mg/mL. The polymer was dissolved in CHCl 3 at a concentration of 10 mg/mL. The matrix solution, polymer solution, and NaTFA solution were mixed in the ratio of 10/1/1 (v/v/v). The sample preparation involved depositing 1 μL of the mixture on the steel plate, and allowing the spot to dry.Gel permeation chromatography (GPC) was conducted using Viscotek GPC system equipped with a VE-3580 refractive index (RI) detector, a 270 dual detector system having a viscometer detector and a dual-angle (7 º and 90 º) laser light scattering (LS) detector, a VE 1122 pump, and two mixed-bed organic columns (PAS-103M with exclusion limit of 70 kDa and PAS-105M with exclusion limit of 4 MDa). N,N'-dimethylformamide (HPLC grade) with 0.1 M
A novel approach for the preparation of nanomaterials is developed by tuning miniemulsion reaction systems to be transparent in order to enable highly efficient photoreactions. Biodegradable nanoparticles and nanocapsules are obtained by UV‐induced thiol‐ene cross‐linking of polylactide (PLA)‐based precursor polymers preassembled in transparent miniemulsions. These well‐defined nanomaterials may potentially serve as ideal scaffolds for drug delivery.
A nanoparticle coated with sialic acid activates Siglec receptors on macrophages, improving survival from sepsis in mice and reducing inflammation in human tissues.
Representing a new category of polymer-drug conjugates, brush polymer-drug conjugates were prepared by ring-opening metathesis copolymerization. Following judicious structural design, these conjugates exhibited well-shielded drug moieties, significant water solubility, well-defined nanostructures, and acid-triggered drug release.
Diblock
copolymer vesicles are tagged with pH-responsive Nile Blue-based
labels and used as a new type of pH-responsive colorimetric/fluorescent
biosensor for far-red and near-infrared imaging of live cells. The
diblock copolymer vesicles described herein are based on poly(2-(methacryloyloxy)ethyl
phosphorylcholine-block-2-(diisopropylamino)ethyl methacrylate) [PMPC-PDPA]:
the biomimetic PMPC block is known to facilitate rapid cell uptake
for a wide range of cell lines, while the PDPA block constitutes the
pH-responsive component that enables facile vesicle self-assembly
in aqueous solution. These biocompatible vesicles can be utilized
to detect interstitial hypoxic/acidic regions in a tumor model via
a pH-dependent colorimetric shift. In addition, they are also useful
for selective intracellular staining of lysosomes and early endosomes
via subtle changes in fluorescence emission. Such nanoparticles combine
efficient cellular uptake with a pH-responsive Nile Blue dye label
to produce a highly versatile dual capability probe. This is in marked
contrast to small molecule dyes, which are usually poorly uptaken
by cells, frequently exhibit cytotoxicity, and are characterized by
intracellular distributions invariably dictated by their hydrophilic/hydrophobic
balance.
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