105 research outputs found
Validity and reliability of a photoelectric cells system for the evaluation of change of direction and lateral jumping abilities in collegiate basketball athletes
The validity and reliability of the Optojump system were investigated for jumping height and flight time in vertical jump tests. Conversely, the purpose of the present study was to investigate the validity and reliability of the Optojump system for measuring contact time and lateral displacement in change of direction and lateral jump tests. Thirty basketball collegiate athletes were tested on two 10 m sprints with a 60Β° (COD60) or 180Β° (COD180) change of direction, lateral controlled (CLRJ) and maximal (MLRJ) rebound jump, and lateral countermovement (LCMJ) and squat (LSJ) jump with the concomitant use of two force plates and the Optojump system for the measurement of contact time in COD60, COD180, CLRJ, MLRJ, and lateral jumping distance in all the lateral jump tests. Almost perfect coefficients (r β₯ 0.95) emerged for contact time in COD60, COD180, CLRJ, MLRJ, although a systematic bias was found for COD60 (-0.01 s). Good-to-excellent reliability was found for almost all the measurements of contact time and lateral jumping distance for change of direction and lateral jump tests. Therefore, the use of Optojump system for testing change of direction and lateral jumping abilities should be executed with caution, avoiding misinterpretation of data
Shell cross-linked polymeric micelles as Camptothecin nanocarriers for anti-HCV therapy
A suitable carrier for camptothecin to act as therapy against the hepatitis C virus is presented. The carrier relies on an amphiphilic hybrid dendriticβlinearβdendritic block copolymer, derived from pluronic F127 and bis-MPA dendrons, that forms micelles in aqueous solution. The dendrons admit the incorporation of multiple photoreactive groups that allow the clean and effective preparation of covalently cross-linked polymeric micelles (CLPM), susceptible of loading hydrophilic and lipophilic molecules. Cell-uptake experiments using a newly designed fluorophore, derived from rhodamine B, demonstrate that the carrier favors the accumulation of its cargo within the cell. Furthermore, loaded with camptothecin, it is efficient in fighting against the hepatitis C virus while shows lower cytotoxicity than the free drug
Synthesis of Ξ²βCyclodextrin Containing Copolymer via βClickβ Chemistry and Its SelfβAssembly in the Presence of Guest Compounds
We report the synthesis of a hydrophilic copolymer with one polyethylene glycol (PEG) block and one Ξ²βcyclodextrin (Ξ²βCD) containing block by a βclickβ reaction between azidoβsubstituted Ξ²βCD and propargyl flanking copolymer. 1 H NMR study suggested a highly efficient conjugation of Ξ²βCD units by this approach. The obtained copolymer was used as a host macromolecule to construct assemblies in the presence of hydrophobic guests. For assemblies containing a hydrophobic polymer, their size can be simply adjusted by simply changing the content of hydrophobic component. By serving as a guest molecule, hydrophobic drugs can also be loaded accompanying the formation of nanoparticles, and the drug payload is releasable. Therefore, the copolymer synthesized herein can be employed as a carrier for drug delivery. The synthesis of Ξ²βcyclodextrin containing block copolymer via a βclickβ reaction is reported. The selfβassembly of this newly synthesized copolymer in the presence of guest compounds can lead to the formation of coreβshell structured nanoparticles. These assemblies can be employed as novel delivery vehicles for therapeutics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91173/1/marc_201100814_sm_suppl.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/91173/2/664_ftp.pd
Polymeric Micelles in Anticancer Therapy: Targeting, Imaging and Triggered Release
Micelles are colloidal particles with a size around 5β100Β nm which are currently under investigation as carriers for hydrophobic drugs in anticancer therapy. Currently, five micellar formulations for anticancer therapy are under clinical evaluation, of which Genexol-PM has been FDA approved for use in patients with breast cancer. Micelle-based drug delivery, however, can be improved in different ways. Targeting ligands can be attached to the micelles which specifically recognize and bind to receptors overexpressed in tumor cells, and chelation or incorporation of imaging moieties enables tracking micelles in vivo for biodistribution studies. Moreover, pH-, thermo-, ultrasound-, or light-sensitive block copolymers allow for controlled micelle dissociation and triggered drug release. The combination of these approaches will further improve specificity and efficacy of micelle-based drug delivery and brings the development of a βmagic bulletβ a major step forward
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