-
[show abstract]
[hide abstract]
ABSTRACT: A novel folate fluorescent nanoconjugate was synthesized and used for detection of cancer cells overexpressing the folate receptor (FR). The folate conjugate (PCMS-NA-FA) was synthesized by conjugating folic acid (FA) and 4-ethylnyl-N-ethyl-1, 8-naphthalimide (NA) to the polychloromethylstyrene (PCMS) functionalized with azido group (PCMS-N₃) through click reaction. The obtained conjugate had clear structure and could form PCMS-NA-FA nanoparticles with particle size around 86 nm in aqueous solution. Ability of PCMS-NA-FA targeting to cancerous cells was investigated by comparing the uptake of the nanoparticles by human adenocarcinoma HeLa cells and by non-FR expressing human lung carcinoma A549 cells. Specificity of the PCMS-NA-FA nanoparticles targeting on FRs was verified with cellular uptake inhibition assay, in which HeLa cells were incubated with both nanoconjugate and free FA. In addition, the specificity was also confirmed by the collocation of the immunofluorescence staining of anti-FR and the cellular uptake of the PCMS-NA-FA nanoparticles. Furthermore, the organ distribution of this folate nanoconjugate was studied on HeLa cell-bearing mice via frozen slicing, and the results showed that the folate nanoparticles were preferentially accumulated in the tumor site rather than other tissues, indicating the desired specificity for tumor targeting and imaging. All these findings suggested that this practical synthetic strategy can potentially facilitate the preparation of multifunctional imaging probe in biology and diagnosis of disease.
Journal of Biomedical Materials Research Part A 09/2011; 99(4):684-9. · 2.63 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The goal of this paper is to introduce a universal method for quantitative control of the particle size of magnetic cellulose microspheres (MCMS) and to produce an optimal antibody absorption capability as an aid in the research of new applications of MCMS in immunomagnetic capture. In this study, "the smallest critical size theory" (TSCS) was proposed, tested, and confirmed by IgG-carrying capability measurements, magnetic response analysis, immunomagnetic capture, and PCR identification of bacteria. A Gaussian expression was proposed and used to guide the preparation of MCMS of the smallest critical size (SCS). The results showed that the diameter of the SCS of MCMS in this study was 5.82 mum, while the IgG absorption capability of the MCMS with SCS was 186.8 mg/mL. In addition, its high sensitivity and the efficiency of immunomagnetic capture of Salmonella bacteria exhibited another new application for MCMS.
Langmuir 07/2010; 26(13):11266-71. · 4.19 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Glucagon-like peptide-1 (GLP-1) is an important hormone peptide secreted from the gastrointestinal tract in response to nutrient ingestion. Its multifaceted actions make GLP-1 attractive as a candidate for the treatment of type 2 diabetes mellitus. However, its main limitation is an extremely short half-life, which is due to rapid inactivation by a ubiquitous enzyme, dipeptidyl peptidase-IV (DPP-IV). Therefore, here we describe the development of a novel GLP-1 analog, designated KGLP-1. Initial in vitro experiments revealed that KGLP-1 bound to and activated GLP-1R with similar efficacy as native GLP-1. Importantly, KGLP-1 showed marked resistance to inactivation by DPP-IV. Further in vivo studies confirmed that KGLP-1 had antihyperglycemic and insulinotropic actions after intraperitoneal injection to KM mice and alloxan-induced diabetic mice. Finally, we prepared KGLP-1-loaded poly (d,l-lactic-co-glycolic acid) microspheres (PLGA MS) using the solid in oil in oil (s/o/o) solvent extraction method, which achieved controlled release and biological efficacy over a period of 10 days after a single subcutaneous injection in alloxan-induced diabetic rats.
Peptides 08/2009; 30(10):1874-81. · 2.43 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The monomeric CuII complex, [Cu(TLA)C2O4].2O (1), and dimeric CuII complex, [Cu2(TLA)2(C4O4)](ClO4)2
(1), where TLA=[tris(6-methyl-2-pyridyl)methyl]amine, have been synthesized and characterized. Both complexes have been obtained as single crystals and their structures were determined by X-ray diffraction analysis. The configuration of (1) is pseudo-octahedral owing to the fact that one of the Cu-Npyridyl bonds is much longer than the others. Two molecules of (1) link via hydrogen bonding to the oxalic oxygen in the unit cell. The copper complex (2) dimer is obtained, using the squarate ion as a bridging ligand, from a monomer copper complex, [Cu(TLA)N3].4ClO4
(3). By comparison of the configurations of (1), (2) with that of (3), the copper center is coordinated with TLA first, and then with secondary ligands, such as the azido group, squaric acid, or oxalate ion. The configurations of the transition metal complexes are affected by the smaller ions, as is further discussed below. The variable temperature magnetic susceptibilities of (2) have been studied, and the exchange integral is J=–2.5474cm-, g=2.061, indicating the existence of a weaker anti-ferromagnetic interaction between the two copper ions in compound (2). The spectral behavior of the title complexes in solution has been studied by u.v.–vis. and i.r. techniques, and the results are discussed.
Transition Metal Chemistry 08/2004; 29(6):590-595. · 1.02 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Two new CuII complexes, (CuL1N3)ClO4 (1) and (CuL2N3)ClO4 (2), have been synthesized and characterized in the presence of NaN3, where L1 = tris[2-(6-methylpyridyl)methyl]amine and L2 = tris[(3,5-dimethylpyrazol-l-yl)methyl]amine, and their crystal structures have been determined by X-ray diffraction methods. Compound 1 crystallizes in the triclinic space group P–1, with a = 8.258(2) , b = 11.481(2) , c = 14.158(3) , = 72.30(3), = 79.05(3), = 86.08(3), V = 1255.4(5) 3. Compound 2 crystallizes in the monoclinic space group C2/c, with a = 26.752(2) , b = 10.561(2) , c = 21.059(4) , = 120.51(3), V = 5126(3) 3. In both compounds, each CuII center is in a distorted trigonal–bipyramidal coordinated environment with four nitrogen atoms from the tripodal ligand and one nitrogen atom from the azide group. The coordination geometry around CuII center of 1 is axially compressed trigonal bipyramid, while that of 2 is an axially elongated trigonal bipyramid. The coordinated azide group is in the axial site in both complexes. A quasi-dimeric structure of 1 has been formed in the unit cell through hydrogen bonding. The electronic spectra of two complexes in solution have been further studied by UV–vis technique, and the coordination properties have been discussed.
Journal of Chemical Crystallography 01/2004; 34(2):119-125. · 0.57 Impact Factor
-
Polyhedron 28(16):3491-3498. · 2.06 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Two new binuclear complexes bridged by end-to-end azido, [Ni2(TLA)2(N3)3]·(ClO4) (1) and [Mn2(TLA)2(N3)3]·(ClO4) (2), where TLA is tris(6-methyl-2-pyridylmethyl)amine, have been synthesized and characterized. The structures of the two complexes have been studied by X-ray diffraction analysis. The complex 1 cation is a dimeric structure consisting of two [(TLA)Ni(N3)]+ units linked by an end-to-end (μ-1,3-N3 −) bridging azide anion. There is an inversion center at the center N(2) of the bridged azido group. Each of the NiII atoms is in a distorted octahedral configuration. The crystal structure of 2 is very similar to that of 1, in which the MnII atoms by bridging the azide group are also in the distorted octahedral environment. The variable temperature magnetic susceptibilities of the title complexes have been studied. For 1, the exchange integral is J=−20.45 cm−1, g=2.23; for 2, J=−2.99 cm−1, g=2.04, indicating the existence of an intramolecular antiferromagnetic interaction between the two metal ions in both complexes. The spectral properties of the two complexes have been studied further by UV–Vis techniques, and the results have been discussed in detail.
Polyhedron 19(13):1559-1566. · 2.06 Impact Factor
