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Abstract
High intracellular reactive oxygen species (ROS) level is characteristic of cancer cells and could act as a target for the efficient targeted drug delivery for cancer treatment. Consequently, biomaterials that react to excessive levels of ROS are essential for biomedical applications. In this study, a novel ROS-responsive polymer based on D-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS) and poly (β-thioester) (TPGS-PBTE) was synthesized for targeted delivery of the first-line antineoplastic drug, paclitaxel (PTX). The resultant TPGS-PBTE NPs showed good ROS-responsive capability in size change and drug release. Compared to PTX, PTX-loaded nanoparticles (PTX@TPGS-PBTE NPs) showed enhanced cytotoxicity and higher level of apoptosis toward squamous cell carcinoma (SCC-7) cells. Tumor-targeted delivery of the NPs was also observed, especially after being modified with a tumor-targeting peptide, cRGD. Enhanced tumor growth inhibition was also observed in head and neck cancer SCC-7 murine models. In summary, PTX@TPGS-PBTE NPs can achieve good therapeutic effects of PTX against head and neck cancer both in vitro and in vivo, especially when modified by cRGD for active targeting, which enriched the application of ROS responsive system utilized in the delivery of anticancer drugs.
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Affiliation(s)
- Yaqin Tu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Zhang
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Guorun Fan
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chenming Zou
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jie Zhang
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Nan Wu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiahui Ding
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wen Qing Zou
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hongjun Xiao
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Songwei Tan
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Yuan J, Dong Z, Guo JP, McGeehan J, Xiao X, Wang J, Cali I, McGeer PL, Cashman NR, Bessen R, Surewicz WK, Kneale G, Petersen RB, Gambetti P, Zou WQ. Accessibility of a critical prion protein region involved in strain recognition and its implications for the early detection of prions. Cell Mol Life Sci 2008; 65:631-43. [PMID: 18193391 PMCID: PMC7079802 DOI: 10.1007/s00018-007-7478-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human prion diseases are characterized by the accumulation in the brain of proteinase K (PK)-resistant prion protein designated PrP27-30 detectable by the 3F4 antibody against human PrP109-112. We recently identified a new PK-resistant PrP species, designated PrP*20, in uninfected human and animal brains. It was preferentially detected with the 1E4 antibody against human PrP 97-108 but not with the anti-PrP 3F4 antibody, although the 3F4 epitope is adjacent to the 1E4 epitope in the PrP*20 molecule. The present study reveals that removal of the N-terminal amino acids up to residue 91 significantly increases accessibility of the 1E4 antibody to PrP of brains and cultured cells. In contrast to cells expressing wild-type PrP, cells expressing pathogenic mutant PrP accumulate not only PrP*20 but also a small amount of 3F4-detected PK-resistant PrP27-30. Remarkably, during the course of human prion disease, a transition from an increase in 1E4-detected PrP*20 to the occurrence of the 3F4-detected PrP27-30 was observed. Our study suggests that an increase in the level of PrP*20 characterizes the early stages of prion diseases.
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Affiliation(s)
- J Yuan
- Department of Pathology and National Prion Disease Pathology Surveillance Center, Case Western Reserve University, 2085 Adelbert Road, Cleveland, OH 44106, USA
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Lu ZL, Zou WQ, Lv LY, Liu XC, Li SD, Zhu JM, Zhang FM, Du YW. Large Low-Field Magnetoresistance in Nanocrystalline Magnetite Prepared by Sol−Gel Method. J Phys Chem B 2006; 110:23817-20. [PMID: 17125346 DOI: 10.1021/jp0608325] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nanocrystalline magnetite Fe3O4 samples with a grain size of about 40 nm have been synthesized by an optimized sol-gel method. The single phase of spinel magnetite was confirmed by both X-ray diffraction and transmission electron microscopy. It has been found that the magnetoresistance of the samples at low field (LFMR) is relatively large, and with the decrease of temperature its value at a field of 0.5 T changes dramatically from -2.5% at 300 K to -17.0% at 55 K. With the further decrease of temperature a sharp drop occurs for the magnitude of the magnetoresistance (MR), regarded as a spin (cluster) glass transition in the surface region of the grains that can be confirmed by the zero-field-cooled and field-cooled magnetization and ac susceptibility measurement. The mechanism of the magnetic and transport properties was discussed.
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Affiliation(s)
- Z L Lu
- Jiangsu Provincial Laboratory for Nanotechnology, National Laboratory of Solid State Microstructure and Department of Physics, Nanjing University, Nanjing 210093, China
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Abstract
Amyloid proteins and peptides comprise a diverse group of molecules that vary both in size and amino-acid sequence, yet assemble into amyloid fibrils that have a common core structure. Kinetic studies of amyloid fibrillogenesis have revealed that certain amyloid proteins form oligomeric intermediates prior to fibril formation. We have investigated fibril formation with a peptide corresponding to residues 195-213 of the human prion protein. Through a combination of kinetic and equilibrium studies, we have found that the fibrillogenesis of this peptide proceeds as an all-or-none reaction where oligomeric intermediates are not stably populated. This variation in whether oligomeric intermediates are stably populated during fibril formation indicates that amyloid proteins assemble into a common fibrillar structure; however, they do so through different pathways.
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Affiliation(s)
- W Q Zou
- Centre for Research in Neurodegenerative Diseases, University of Toronto, Ontario, Canada
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Lin ST, Zou WQ, Chen J, Li P. [Stress and dietary salt intake in the pathogenesis of hypertension: role of the renal and sympathetic nervous system]. Sheng Li Xue Bao 1999; 51:7-13. [PMID: 11972168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Using the methods of electrophysiology, biochemistry, radioimmunoassay, and electron microscopy, changes of sympathetic nervous system and renal function in hypertensive SD rats induced by stress and high-salt intake were investigated. The results are as follows: (1) Renal plasma flow (RPF) and urinary sodium excretion obviously increased in salt-loading rats. Stress could result in marked reduction of RPF. (2) Electron micrography showed a dramatic increase in cell and mitochondrial volume in the proximal and distal convoluted tubules of high-salt diet rats. After stress of two weeks, the cells of the tubule became atrophic and mitochondrial volume decreased. (3) The same recovery from the declining renal cortical Na-K-ATPase activity in high-salt diet rats could be observed by maintained stress. (4) Low frequency (0.2-0.9 Hz) of BP variability was higher in stress rats as compared to control. (5) Both plasma renin activity (PRA) and angiotensin II (ANG II) levels increased in stress rats, but the decrease in high-salt diet rats gradually reached the high level of the former in two weeks. (6) Increase of BP, fall in RPF, or augment in PRA and ANG II were not observed in stress rats subjected to bilateral renal denervation. The above results indicate that the renal mechanism mediated by increased renal sympathetic nervous system plays an important role in stress- and salt-induced hypertension pathogenesis.
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Affiliation(s)
- S T Lin
- Department of Nephrology, Huashan Hospital, Shanghai Medical University, Shanghai 200040
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