97 research outputs found
Incorporating I-131 into a PAMAM (G5.0) dendrimerconjugate: design of a theranostic nanosensor for medullary thyroid carcinoma
No full textCitation: He, R., Wang, H., Su, Y., Chen, C., Xie, L., Chen, L., . . . Bossmann, S. H. (2017). Incorporating I-131 into a PAMAM (G5.0) dendrimerconjugate: design of a theranostic nanosensor for medullary thyroid carcinoma. Rsc Advances, 7(26), 16181-16188. doi:10.1039/c7ra00604gWe report the synthesis and purification of a targeting probe for Medullary Thyroid Carcinoma (MTC) by incorporating I-131 into PAMAM (G5.0) dendrimers. Both the I-131 labeled control dendrimer (I-131-PAMAM (G5.0) without attached targeting peptide) and the MTC-targeting dendrimer (I-131-PAMAM (G5.0) attached to VTP (vascular targeting peptide)) were labeled with the radioisotope I-131 by applying the iodogen method. The resulting G5.0 dendrimers were purified by means of ultracentrifugation. The labelling efficiencies and radiochemical purities vs. time were determined by paper chromatography. The radiolabeling efficiencies of I-131-PAMAM (G5.0) and I-131-PAMAM (G5.0) were 93 +/- 1% and 85 +/- 2%, respectively. I-131-PAMAM (G5.0) did exhibit small, but significant changes in radiochemical purity as a function of time after labelling. The highest observed highest purity was 82 +/- 2%. I-131-PAMAM (G5.0)VTP did display larger changes in radiochemical purity as a function of time after labelling, maximally 80 +/- 2%. The stability of the two probes and their binding behavior to the human medullary thyroid cancer cell line (TT) were observed in vitro. Compared to the negative control group (consisting of (NaI)-I-131), the TT cell binding rate of 131I-PAMAM (G5.0)-VTP was significantly increased at 48 h and 72 h (P 0.05). These findings have been confirmed by performing MTT assays. These results confirm earlier findings, which demonstrated fast uptake of PAMAM (G5.0) by various cell types
Elucidation of Acceptor-Acceptor Interactions in a Ru(II) Supramolecular Photosynthetic Model Complex
No full textSynthesis and Characterization of Nitroxide-Linked Ruthenium Complexes as Molecular Probes for Microheterogeneous Environments
No full textPhysico-Chemical Studies on the Adsorption Properties of Asbestos.2. an EPR and Fluorescence Study on the Adsorption of Pyrene
No full textNitroxide-Labeled Ru(II) Polypyridyl Complexes as EPR Probes of Organized Systems. 3. Characterization of Starburst Dendrimers and Comparison to Photophysical Measurements
No full textPhase Separation of Poly(N-isopropylacrylamide) in Mixtures of Water and Methanol: A Spectroscopic Study of a Polymer Tagged with a Fluorescent Dye and a Spin Label
No full textMicrostructural characterization of porous thermal barrier coatings by IR gas porosimetry and sintering forecasts
No full textIt is known that the thermal diffusivity of plasma sprayed coatings is quite sensitive to the operating conditions, namely the composition and pressure of the operating atmosphere. This makes it possible, in principle, to obtain information, in a non-destructive way, on the microstructure of thermal barrier coatings (TBCs) from thermal diffusivity measurements. An experimental assessment of this idea is presented in this paper. The microstructure of as-sprayed and sintered free-standing atmospheric plasma sprayed YPSZ TBC samples have been characterized by a new technique, named infrared (IR) gas porosimetry, as well as by mercury intrusion porosimetry and image analysis. The results from these different techniques have been compared. Furthermore, the microstructure and thermal diffusivity of sintered samples have been compared with the sintering forecasts produced by Cipitria’s sintering code coupled with the Bruggeman model for thermal diffusivity estimation. Sample-to-sample variations have been discussed and uncertainties in experimental techniques have been analysed. Conditions for accurate microstructural estimations have been obtained and suggestions on the reliability of the statistical evaluation are provide
Early breast cancer screening using iron/iron oxide-based nanoplatforms with sub-femtomolar limits of detection
No full textCitation: Udukala, D. N., Wang, H. W., Wendel, S. O., Malalasekera, A. P., Samarakoon, T. N., Yapa, A. S., . . . Bossmann, S. H. (2016). Early breast cancer screening using iron/iron oxide-based nanoplatforms with sub-femtomolar limits of detection. Beilstein Journal of Nanotechnology, 7, 364-373. doi:10.3762/bjnano.7.33Additional Authors: Ortega, R.;Toledo, Y.;Bossmann, L.;Robinson, C.;Janik, K. E.;Koper, O. B.;Motamedi, M.;Zhu, G. H.Proteases, including matrix metalloproteinases (MMPs), tissue serine proteases, and cathepsins (CTS) exhibit numerous functions in tumor biology. Solid tumors are characterized by changes in protease expression levels by tumor and surrounding tissue. Therefore, monitoring protease levels in tissue samples and liquid biopsies is a vital strategy for early cancer detection. Water-dispersable Fe/Fe3O4-core/shell based nanoplatforms for protease detection are capable of detecting protease activity down to sub-femtomolar limits of detection. They feature one dye (tetrakis(carboxyphenyl) porphyrin (TCPP)) that is tethered to the central nanoparticle by means of a protease-cleavable consensus sequence and a second dye (Cy 5.5) that is directly linked. Based on the protease activities of urokinase plasminogen activator (uPA), MMPs 1, 2, 3, 7, 9, and 13, as well as CTS B and L, human breast cancer can be detected at stage I by means of a simple serum test. By monitoring CTS B and L stage 0 detection may be achieved. This initial study, comprised of 46 breast cancer patients and 20 apparently healthy human subjects, demonstrates the feasibility of protease-activity-based liquid biopsies for early cancer diagnosis
Cononsolvency of Poly-(N-isopropylacrylamide): A look at Spin-labeled Polymers in Mixtures of Water and Tetrahydrofuran
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