[Show abstract][Hide abstract]ABSTRACT: We present a facile one-step procedure for solvothermal synthesis of highly water-dispersible magnetic Fe3O4 nanoparticles mediated by cucurbit[n]urils (CB[n]s). A layer of CB[n]s was coated on MNP surface via the portal carbonyl groups to avoid MNP agglomeration, and served as stabilizer to impart the nanoparticles with exceptional dispersibility and stability. Significantly, the nanoparticle sizes can be controlled and fine-tuned by varying the molar ratios of CB[n]s and FeCl3 in solution. The biocompatibility of the materials was investigated by MTT assay using normal human embryonic kidney 293T cells. The synergetic effects of combining supramolecular chemistry with magnetic nanoparticles are promising for clinical diagnosis and transportation of drugs, proteins, viruses, bacteria, etc., which offers important advantageous features for their real applications.
Full-text Article · Mar 2015 · Journal of Materials Chemistry C
[Show abstract][Hide abstract]ABSTRACT: A facile strategy to prepare snap-top magnetic nanocarriers has been developed where ultrasmall superparamagnetic Fe3O4 nanoparticles were used as the core with mesoporous silica as the shell followed by the covalent installation of a layer of β-cyclodextrins on the outer surfaces. The smart hybrid nanomaterials showed remarkable pH- and sugar-responsive cargo release property and low cytotoxicity as proved by an MTT assay with HEK293T cell lines.
Full-text Article · Feb 2015 · Chemical Communications
[Show abstract][Hide abstract]ABSTRACT: β-Cyclodextrins (β-CDs) were grafted onto star-shaped poly(glycidyl methacrylate)s (S5-PGMAs) with a straightforward and efficient ring-opening addition of amine groups to result in PGMA–CDs, which not only possess good water-solubility and biocompatibility, but also can serve as polymeric supramolecular hosts to form inclusion complexes with suitable guests. They can be easily assembled on the surface of azobenzene-functionalized mesoporous silica nanoparticles (MSNs) via host–guest interactions to obtain MSN@PGMA–CD hybrid nanoparticles, which have been fully characterized by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and elemental analysis. The experimental results showed that these types of inorganic–organic hybrid mesoporous nanocomposites possess good cargo encapsulation and release properties, as compared with the simple supramolecular nanovalves with β-CD itself as the gating component, upon activation by light, temperature variation, and competitive binding agents. In addition, the extremely low cytotoxicity of the nanocomposites demonstrated by MTT assay can further broaden their applications in controlled drug release.
[Show abstract][Hide abstract]ABSTRACT: Acetylcholine (ACh), a neurotransmitter located in cholinergic synapses, can trigger cargo release from mesoporous silica nanoparticles equipped with calixarene- or pillarene-based nanovalves by removing macrocycles from the stalk components. The amount and speed of cargo release can be controlled by varying the concentration of ACh in solution or changing the type of gating macrocycle. Although this proof-of-concept study is far from a real-life application, it provides a possible route to treat diseases related to the central nervous system.
Full-text Article · Mar 2014 · Chemistry - A European Journal
[Show abstract][Hide abstract]ABSTRACT: Ethnopharmacological relevance:
The dried fruit of Psoralea corylifolia L. has been used to prevent and treat vitiligo, osteoporosis, arthralgia and asthma in Traditional Chinese Medicine for some 1600 years. Psoralen (P), isopsoralen (IP), psoralenoside (PO) and isopsoralenoside (IPO) are the major coumarins and coumarin-related benzofuran glycosides in Psoraleae Fructus, which have been reported to show estrogen-like activity, osteoblastic proliferation accelerating activity, antitumor effects and antibacterial activity. The first aim of this study is to develop a rapid, sensitive and selective ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) approach for simultaneous determination of PO, IPO, P and IP in rat plasma and samples collected from in vitro incubation experiments. The second aim is to investigate the pharmacokinetic properties of PO, IPO, P and IP after oral administration of Psoralea corylifolia extract (PCE) to rats. The third aim is to confirm the biotransformation of PO to P or IPO to IP under gastrointestinal conditions.
Materials and methods:
A UPLC-MS/MS method with a C18 column and a mobile phase of methanol-0.1% aqueous formic acid was validated according to the criteria in FDA guidelines about bioanalytical method, which was developed to investigate the pharmacokinetic behavior of PO, IPO, P and IP from PCE and the metabolic pathways of PO to P or IPO to IP.
The criteria for establishment of a new UPLC-MS/MS method including selectivity, linearity, accuracy, precision, extraction recovery, matrix effect and stability were validated. This method was successfully applied to the quantitative determination of PO, IPO, P and IP in biological samples collected from both in vitro incubations and in vivo rat experiments. After oral administration of PCE to rat, pharmacokinetic parameters of these four compounds indicated that in vivo biotransformation may occur between PO and P or IPO and IP. Purified benzofuran glycosides fraction (PBGF), containing only PO and IPO, was orally administered to rats to further confirm the biotransformation of PO to P or IPO to IP under gastrointestinal conditions. An in vitro incubation study elucidated that PO and IPO were metabolized to P and IP by intestinal microflora through de-glucosylation.
This paper developed a rapid, sensitive and selective UPLC-MS/MS method for simultaneous determination of PO, IPO, P and IP from PCE in biological samples, and investigated on their comprehensive in vivo and in vitro pharmacokinetic studies. These obtained results showed that the metabolism by intestinal bacteria plays an important role in pharmacological effects of orally administered PCE.
[Show abstract][Hide abstract]ABSTRACT: Considering the high reactivity of the C–H bonds in fluorobenzenes for direct arylation and special properties of fluorinated polymers, herein, synthesis of fluorinated porous organic polymers via direct C–H arylation polycondensation is explored. The obtained polymers (FPOP-1 and FPOP-2) are well characterized and show high porosities with Brunauer–Emmett–Teller specific surface area of above 1000 m2 g–1. Different pore size distribution (PSD) profiles of porous polymers can be obtained by selecting different core constructing monomers. FPOP-2 exhibits a relatively narrower PSD with the dominant pore size at about 0.63 nm, which is more suitable for adsorption of small gas molecules (H2, CO2, and CH4) than FPOP-1. As a porous fluorinated hydrophobic material, FPOP-2 possesses high adsorption ability for toluene (976 mg g–1 at saturated vapor pressure and room temperature) due to its high porosities and binding affinities between the guest molecules and the host network. The good sorption capacity of FPOP-2 for toluene makes it show potential applications in elimination of harmful small aromatic molecules in the environment.
[Show abstract][Hide abstract]ABSTRACT: With an aggregation-induced emission feature, a suspension of imidazole-bearing tetraphenylethylene in a tetrahydrofuran–water mixture with a high water fraction is highly emissive, and can be completely quenched by Fe3+ ions due to the coordination between imidazole moieties and the Fe3+ ion.
Full-text Article · Aug 2011 · New Journal of Chemistry
[Show abstract][Hide abstract]ABSTRACT: The effect of 2-hydroxypropyl-β-cyclodextrin (HPβCD) on solubility, stability and oral bioavailability of curcumin by external factors adjustment, was investigated with an aim of a simple, stable and effective formulation. The phase solubility studies showed the solubility of curcumin increased slightly with increasing pH. However, the apparent stability constant (K
S) were found to decrease with increasing pH from 1.29 × 104 M−1 at pH 3.0 to 5.22 × 103 M−1 at pH 7.0. The thermodynamic parameters were calculated for inclusion complex formation in aqueous solution. Interestingly, it could be concluded that the degrees of curcumin stability improved by HPβCD grew with increasing drug–cyclodextrin binding ability. Furthermore, in vivo study not only revealed that the bioavailability of curcumin after oral administration to rats was significantly improved by curcumin/HPβCD inclusion complex, but also showed more dramatic changes in the plasma concentration–time curve (1752.76–866.70 ng mL−1 h) and the peak plasma concentration (370.10–178.11 ng mL−1) of drug by formation of complexes in pH 3–7 solution.
Full-text Article · Aug 2011 · Journal of Inclusion Phenomena
[Show abstract][Hide abstract]ABSTRACT: We demonstrated the synthesis of five kinds of microporous organic polymers based on aldol self-condensation of di- and multiacetyl-containing building blocks catalyzed by thionyl chloride. The α,β-unsaturated ketone (dimerization) and 1,3,5-trisubstituted benzene (cyclotrimerization) can be observed in the resulting polymers by Fourier transform infrared and solid-state 13C CP/MAS NMR spectroscopy. The regular spheres and nanometer-scaled cavities were also seen from scanning electron microscopy and high-resolution transmission electron microscopy images. The highest Brunauer–Emmet–Teller specific surface area up to 832 m2 g–1 was obtained for the resulting polymers with a pore volume of 0.48 cm3 g–1. The polymers show great hydrogen storage capacities (up to 1.56 wt %) at 77 K and 1 bar. These excellent characteristics would make them become promising candidates for heterogeneous catalysis, separation, and gas storage.
[Show abstract][Hide abstract]ABSTRACT: The p-sulfonatocalix[n]arenes are supposed to show potential application in the clinical treatment of viologen poisoning. In the present study, p-sulfonatocalixarene (C4AS), the most common derivative of p-sulfonatocalix[n]arenes, is used to study the antidotic mechanism for paraquat (PQ) by pharmacokinetics in vivo. A high-performance liquid chromatography (HPLC) method was established to determine the concentration of PQ in rat plasma. The results showed that the peak plasma concentration (C(max)) and area under the plasma concentration-time curve (AUC(0-t)) were significantly lower after C4AS intervention than in the PQ intoxication group. It was considered that C4AS has great effective detoxication to PQ poisoning, and the results of in vitro intestinal absorption studies showed that C4AS can inhibit the absorption of PQ via oral administration by forming a stable inclusion constant.
Full-text Article · Mar 2011 · Journal of Agricultural and Food Chemistry
[Show abstract][Hide abstract]ABSTRACT: Neutral sugar-bearing tetraphenylethenes (TPE) are designed and prepared as "turn-on" luminescent sensors for lectins and glycosidases based on aggregation-induced emission. Through aggregation derived from carbohydrate-lectin binding, multivalent mannosyl-bearing TPE shows a good selectivity and sensitivity to Con A by switching on the fluorescence of water-soluble tetraphenylethylene-based glyco-conjugates in aqueous solution. Meanwhile, cellobiosyl-bearing TPE can be used to investigate enzymatic hydrolysis based on emission enhancing by glycosidase-induced aggregation.
Full-text Article · Feb 2011 · Organic & Biomolecular Chemistry
[Show abstract][Hide abstract]ABSTRACT: The hydrolytic kinetics and degradation mechanism of 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glycoside (THSG) extracted from Radix Polygoni Multiflori (a commonly used official Chinese herbal Heshouwu), were investigated using reversed-phase high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). The influences of pH (1.5-9.9), temperature (25-60°C) and irradiation on the hydrolysis of THSG were studied in aqueous solutions. The results showed that the degradation of THSG was pH-, temperature- and irradiation-dependent and all followed first-order kinetics. The effect of temperature on the rate of THSG degradation was characterized using the Arrhenius equation. Maximum stability of THSG was found at pH 1.5 (t(0.5)=47.57 d). THSG was unstable in alkaline and irradiation conditions. The active energy (E(a)) of THSG degradation in aqueous solution at pH 6.8 (most frequently adopted extract solvent) under lucifugal and irradiation conditions was 47.7kJmol(-1) and 25.3kJmol(-1), respectively. Three hydrolytic products of THSG were identified by LC-MS. Cis-trans isomerism took place under irradiation, and hydrolysis took place in acid-base conditions. Moreover, further oxidation on aglycon occurred after hydrolytic cleavage of phenolic glycoside in acidic conditions. The possible hydrolytic pathways of THSG are proposed.
Full-text Article · Dec 2010 · Journal of pharmaceutical and biomedical analysis
[Show abstract][Hide abstract]ABSTRACT: Grafting of glucosamine hydrochloride moieties to tetraphenylethylene (TPE) motif furnished a novel cationic water-soluble tetraphenylethylene derivative (GH-TPE). With aggregation-induced emission properties, GH-TPE was used for fluorometric detection to alkaline phosphatase through enzyme-triggered de-aggregation of the ensemble of GH-TPE and substrate.
Full-text Article · Jun 2010 · Chemical Communications