Browsing by Author "Tsai, Jin-Sheng"

Now showing 1 - 2 of 2

A Unique and Potent Protein Binding Nature of Liposome Containing Polyethylenimine and Polyethylene Glycol: A Nondisplaceable Property
(2011-06-01)
Liu, Yen-Ku
;
Lin, Yu-Ling
;
Chen, Chia-Hung
;
Lin, Ching-Min
;
Ma, Kuan-Lun
Most of the currently available targeting vectors are produced via the linkage of targeting molecules. However, the coupling process is complicated, and the covalent linkage may attenuate the activity of certain targeting molecules. In this study, we have developed a cationic liposome complexed with polyethylenimine and polyethylene glycol polymers (LPPC) that can capture various proteins without covalent conjugation. Characterizations of prepared LPPC revealed that the maximal-binding capacity was about 170 mu g of bovine serum albumin to 40 mu g of sphere-shaped LPPC (180 nm). The proteins were essentially located at or near the surface when analyzed by atomic force or transmission electron microscopy. We demonstrate that polyethylenimine was an essential component to bind the proteins. Upon the saturation of captured proteins, a given protein could not be displaced by other additional proteins and still retained its biological activity. Using a variety of functional proteins, we show some typical examples of the utility of incorporated beta-glucuronidase and antibodies onto the LPPC. The beta-glucuronidase can be used for the study of antigen-antibody interactions, whereas in studies with the antibody complex, we used anti-CD3 as an agonist to stimulate the proliferation of peripheral blood mononuclear cells via a receptor-mediated mechanism and anti-VEGFR for cell staining. In conclusion, the prepared LPPC can provide a platform to capture biologically and biochemically functional proteins on its surface for various applications, such as cell signaling, cell profiling, noncovalent enzyme-linked immunoassays, and others not mentioned. Biotechnol. Bioeng. Biotechnol. Bioeng. 2011; 108: 1318-1327. (C) 2010 Wiley Periodicals, Inc.
Laser induced popcornlike conformational transition of nanodiamond as a nanoknife
(2008-07-21)
Chang, Chia-Ching
;
Chen, Pei-Hsin
;
Chu, Hsueh-Liang
;
Lee, Tzu-Cheng
;
Chou, Ching-Chung
Nanodiamond (ND) is surrounded by layers of graphite on its surface. This unique structure feature creates unusual fluorescence spectra, which can be used as an indicator to monitor its surface modification. Meanwhile, the impurity, nitroso (C - N = O) inside the ND can be photolyzed by two-photon absorption, releasing NO to facilitate the formation of a sp(3) diamond structure in the core of ND and transforming it into a sp(2) graphite structure. Such a conformational transition enlarges the size of ND from 8 to 90 nm, resulting in a popcornlike structure. This transition reaction may be useful as nanoknives in biomedical application. (c) 2008 American Institute of Physics.