Ultrasonication-assisted one-step self-assembly preparation of biocompatible fluorescent-magnetic nanobeads for rare cancer cell detection.

Multifunctional nanomaterials simultaneously possessing attractive properties, such as strong fluorescent intensity, excellent superparamagnetic behavior, easy modification and good biocompatibility, are always desired in a wide range of applications. In this work, we present a facile ultrasonication-assisted one-step self-assembly strategy for the fabrication of smart fluorescent-magnetic nanobeads (FMNBs) without using a matrix. Via one-step ultrasonication, organic-soluble superparamagnetic nanoparticles (MNPs) and quantum dots (QDs) were automatically encapsulated by amphiphilic (2-hydroxyl-3-dodecanoxyl) propylcarboxymethylchitosans (HDP-CMCHSs) through hydrophobic interaction to form hydrophilic FMNBs, presenting a good QD fluorescent property and a strong MNP magnetic response.

Rational modification of oligoarginine for highly efficient siRNA delivery: structure-activity relationship and mechanism of intracellular trafficking of siRNA.

Unlabelled: Recently, cell-penetrating peptides (CPPs) have received much attention for cellular delivery of therapeutic molecules. However, in the case of CPPs as carriers for siRNA delivery, their utility is often restricted by low cellular uptake and/or entrapment in endosomes. Here, in order to deliver siRNAs with high efficiency, oligoarginine, a prominent member in CPPs, is rationally modified with oligohistidine and stearyl moieties (STR-) by fully taking into account the formation of nanoparticles, uptake and intracellular trafficking.

pH-responsive mechanism of a deoxycholic acid and folate comodified chitosan micelle under cancerous environment.

Smart pH-responsive polymeric micelles have attracted much attention as one of the most promising drug delivery candidates. In this paper, a different substitution of deoxycholic acid (DCA) and folic acid (FA) comodified hydroxypropyl chitosans (HPCHS) were synthesized for doxorubicin (DOX) targeted delivery and controllable release. The results indicate that the DOX-release behavior is pH-responsive and closely related with the grafting proportions of the two hydrophobic ingredients.

Shell modulation by tailoring substituents in chitosan for LbL-assembled microcapsules.

By AFM we report the successful modulation of shell structure (morphology and shell thickness) of microcapsules through tailoring molecular substituents of chitosan. The shell thickness of hollow (HPCS/SA)(n) (n=5, 7, 9) capsules is more than 3 times that of the (QACS/SA)(n) (n=5, 7, 9) capsules, due to less charges carried by the neutral -NH(2) substituent group and the induced coily conformation in HPCS, while more charges carried by the positively charged -N(CH(3))(3)(+) substituent and the induced extended conformation in QACS (HPCS: hydroxyl propyl chitosan; QACS: quaternary ammonium chitosan; SA: sodium alginate). The ultrathin shells of microcapsules assembled in this work by the layer-by-layer (LbL) self-assembly technique rather than the traditional method of mixing CS, SA and CaCl(2) enable the thickness modulation characterization by AFM on the atomic scale.

Synthesis and characterization of carboxymethyl-polyaminate chitosan and its adsorption behavior toward a reactive dye.

Carboxymethyl-polyaminate chitosan (DETA-CMCHS), a novel kind of amphoteric chitosan derivative, was prepared and characterized by elemental analysis, and by IR and (1)H NMR spectroscopy. The adsorption behavior of Reactive Blue (RB2) on DETA-CMCHS was also studied. Results showed that the maximum value of adsorption capacity was 1185.

Preparation and properties of chitosan chondroitin sulfate complex microcapsules.

The chitosan (CHS) chondroitin sulfate (CS) complex microcapsules were prepared by emulsion-chemical crosslink method, with the chitosan and chondroitin sulfate as the wall materials and the low molecular weight heparin (LMWH) as the core materials. The microcapsules were characterized by Fourier transform infrared (IR) spectrometry, scanning electron microscope (SEM), size distribution and thermal analysis. The in vitro drug release behavior of the microcapsules was studied by spectrophotometry.

Self-assembly of an amphiphilic derivative of chitosan and micellar solubilization of puerarin.

A kind of amphiphilic derivatives of chitosan (2-hydroxyl-3-butoxyl)-propylcarboxymethyl-chitosan (HBP-CMCHS), has been synthesized, and the critical micelle concentration (cmc) of HBP-CMCHS was detected by the fluorescence method. The puerarin-loaded HBP-CMCHS micellar system was prepared by physical entrapped method. Result showed that when adding the same amount of puerarin, the solubilizing capacity was enhanced by increasing the concentration of HBP-CMCHS and temperature.

Surface and aggregate properties of an amphiphilic derivative of carboxymethylchitosan.

A new kind of amphiphilic derivative of carboxymethylchitosan, a group of (2-hydroxyl-3-butoxyl)propylcarboxymethylchitosans (HBP-CMCHS), has been synthesized, and the surface and aggregate properties have been studied by means of surface tension, surface pressure and fluorescence measurements. HBP-CMCHS can adsorb on the surface to decrease the surface tension of the solution. The adsorption film was quite stable, which can make the relative compressed pressure increase dramatically with the decrease of the surface area.