Targeting Devices

The starting point in the single appliance approach is to determine the amount of the target devices that reach China every year. In previous sections data from Zoeteman et al. [1] have been used as a basis for the definition of the global e-waste flow in China. However, for the single appliances approach more specific information on the entering flow of e-waste appliances in China has been found in a report developed by Yang et al. [23]. Therefore, this document has been taken as the basis of the present section. 

The pharmacokinetic processing of macromolecules used as targeting devices or drug carrier systems is different from that of conventional cytotoxic drugs and plays an important role in e.g. the targeting efficiency of these cytotoxic agents coupled to the macromolecules. 

A second example of a toxin that has been used as targeting device is tetanus toxin. Tetanus toxin is a potent neurotoxin, which can undergo uptake in the nerve endings of motor neurones and subsequent retrograde transport into the central nervous system. The nontoxic C-fragment of tetanus toxin (TTC,451 amino acids), has been used to increase the neuronal uptake of the therapeutic protein SOD [57]. Following intravenous infusion, the recombinant hybrid protein reduced the occurrence of ischaemia-induced cerebral infarction in rats [58]. 

The viability and function tests described above are used to evaluate the hepatocytes within the slice. Up to now, tests to measure the viability of the non-parenchymal cells have not been reported. The presence of the latter cell types is one of the conceptual advantages of slices as compared to isolated hepatocytes. As some drug targeting devices are designed to target non-parenchymal cells in the liver, the development of tests for the sinusoidal cell types deserves more attention. For example, the uptake of substrates such as succinylated human serum albumin (Suc-HSA,which is specifically endocytosed by endothelial cells [79]), or hyaluronic acid [80], can be used to assess the functionality of endocytotic pathways in the endothelial cells in the liver [81]. Other modified proteins that are specifically taken up by Kupffer cells such as mannosylated HSA, may be used to assess the functionality of the endocytotic pathway in Kupffer cells [79]. Another parameter which can be used to assess the functionality of these non-parenchymal liver cells, is the excretion of cytokines in response to pro-inflammatory stimuli. Non-parench5mal cell function in liver slices will be described in more detail in the Section 12.7. 

Efficacy Testing of the Drug Targeting Device in the Liver... 

In future, drug targeting devices aimed at other hnman organs may also be stndied nsing precision-cut tissue shces. The latest data/literature on precision-cnt tissne slices can be fonnd at http //www.farm.mg.nl/slice/open.html. 

Fig. 14. Targeting of microparticles (e.g., bubbles and emulsion droplets) destined for molecular imaging and drug delivery Schematic simultaneous binding to a microparticle of a targeting device (antigen-specific ligands), of stealth-providing elements (e.g., PEG strands), and of drugs and markers (e.g., a Gd + chelate for MRI contrast enhancement).

Another beneLt of polymeric surfactants over traditional surfactants is the potential for much lower CMCs. Amphiphiles with a high CMC may not be suitable as drug-targeting devices since they are unstable in an aqueous environment and easily dissociate upon dilution (Jones and Ler-oux, 1999). It must be noted that while some polymers exhibit very low CMCs, for instance, the CMC of poly -benzyl-L-aspartate) (PEO-PBLA), poly(N-isopropylacrylamide-polystyrene (PNIPA-PST), and poly(caprolactone) (PEO-PCL) are between 0.00005% and 0.002% (La etal.,... 

The forward- and backward time hash functions allows the creation of mobile agents that are able to display the content simultaneously on many target devices after certain point in time or the agents carrying the content with expiration date set. 

Last, monoclonal antibodies or antibody fragments with specificity for endothelial transport systems (e.g., endosomal pathways) have been proposed as targeting devices to enhance therapeutic drug delivery or overcome tissue barriers [31]. 

If you have a compatible tape drive installed, it will show up in the list on the left. You can then select it as the target device and click Start Backup to begin the backup. 

If you don t have a tape drive (or don t want to use it), you can select one of the floppy drives as the target device by clicking on its name. The name of the device will appear under Selected Device or Location as the device that has been specified as the target. In either case, select the device you want to back up to and click Start Backup to continue. 

Folate as a Targeting Device for Proteins Utilizing Folate Receptor-Mediated Endocytosis... 

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