Drug delivery dendrimers

Dendrimer micelles of this type have been formulated as drug delivery vehicles. Dendrimers with a hydrophobic interior have been used to entrap a hydrophobic drug such as indomethacin. This is retained because of the hydrophilic periphery containing ethylene glycol functional groups, and is released slowly because of the collapsed configuration of the interior, through which molecular diffusion is obstructed. 

An important property of dendrimers is the presence of internal cavities in which ions or neutral molecules can be hosted [68]. Such a property can potentially be exploited for a variety of purposes, which include catalysis and drug delivery. 

Shabat, D. Self-immolative dendrimers as novel drug delivery platforms. J. Polym. Sci. A Polym. Chem. 2006, 44, 1569-1578. 

Host-guest systems made from dendritic materials have potential in the areas of membrane transport and drug delivery [68, 84, 85]. In a recent report [136] Tomalia and coworkers investigated structural aspects of a series of PAM AM bolaamphiphiles (e.g., 50) with a hydrophobic diamino do decane core unit. Fluorescence emission of added dye (nile red) was significantly enhanced in an aqueous medium in the presence of 50 unlike the cases when 51 and 52 were added (Fig. 23). Addition of anion surfactants to this mixture generated supramolecular assemblies which enhanced their ability (ca.by 10-fold) to accommodate nile red (53). Further increase in emission was noted by decreasing the pH from the normal value of 11 for PAMAM dendrimers to 7. At lower pH values the... 

R. Esfand and D. A. Tomalia, Poly(amidoamine) (PAMAM) dendrimers From biomimicry to drug delivery and biomedical applications, Drug Discov. Today, 6 (2001) 427 136. 

Fig. 8 Nanosystems that may function as simultaneous drug delivery and imaging agents for targeting T cells (a) liposomal systems, (b) solid biodegradable nanoparticulates, and (c) macro-molecular dendrimer complexes. PEG polyethylene glycol, Gd-DTPA gadolininum-diethylene triamine penta acetic acid. (Adapted from [48])...

See also Luminescent dendrimers antibacterial, 26 799 biocompatibility studies of, 26 800-801 in catalysis, 26 805-806 in cell targeting, 26 797-798 as chelators, 26 806-807 core and interior shells of, 26 789 cytotoxicity of, 26 800-801 in drug delivery, 26 792-795 in gene transfection, 26 791-792 as imaging agents, 26 795-797 luminescent, 26 801-804 medical applications of, 26 791-801 micelle-mimetic behavior of, 26 789 multiphoton applications of, 26 803-804... 

An important application of polymers in medicine is in advanced drug-delivery systems. These materials control the drug concentration and delivery rate in the body. Hyperbranched polyesters have been suggested for such systems [111]. However, most applications within this field, described in the literature, deal with dendrimers and not with hyperbranched polymers. 

Darbre T, Reymond J-L. Peptide dendrimers as artificial enzymes, receptors, and drug-delivery agents. Acc Chem Res 2006 39 925-934. 

The application of dendritic polymers as drug delivery systems has gained interest mainly due to their inertness relative to temperature, solvent, and pH extremes [38]. However, dendritic polymers require further improvements in biocompability and biodistribution profiles. The cytotoxicity of dendrimers currently has been primarily studied in vitro. 

Dendrimers are a special class of arborescent monodisperse nanometer sized molecules that have been used in the synthesis of Au NPs as surface stabilizers or nanoreactor/templates for nanoparticle growth. Moreover, these hybrid nanomaterials have great potential for application in different fields such as sensors, imaging in cells, electrooptical devices, catalysis, drug delivery agents, and so on. 

Novel dendrimers have novel and unique properties that make them promising candidates for use in the development of nanoscale devices and in drug delivery systems. 

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