goh , and gcooh � ����� dendrimers at ph n = , rsd encapsulation efficiency of eda core ����� dendrimer ? g i �jii rdl jri i id at i� u e ?c o � v a v at l tris motilium manufacturer sue nh peg pyr ae coona surface functionality fig encapsulation efficiency into famam dendrimers generations with amino nh, polyethyene glycol motilium manufacturer peg, carbomethoxypyrrolidinone fyr, amidoethanol ae, sodium carboxylate coona, succinamic acid suc, and tris hydroxy me thy ammomethane tris surface motilium manufacturer groups core and amino surface g = , or ester surface g = at ph , and , the solubility enhancement of nifedipine was higher in the presence of esterterminated dendrimers than their aminoterminated analogues, possessing the same number of surface groups the motilium manufacturer nifedipine solubility ex pec ted lv increased with the size of the dendrimers for ph , the sequence g g g motilium manufacturer g g g go was reported in another approach, the nonsteroidal antiinflammatory drug naproxen was covalently attached to unsymmetrical polyarylester dendrimers to prepare a complex with enhanced water solubility of the drug and access for hydrplytic cleavage e t motilium manufacturer ek k k k concentration mmolecular weight fig aqueous paclitaxel solubility as a function of the polyglycerol dendrimer concentration mean motilium manufacturer � sd, n = g circle, g triangle, g square, and peg diamond left molecular weight dependency of dendrimers closed circle and peg open circle on the aqueous paclitaxel solubility the concentration of dendrimers and peg was wt reproduced with permission from ref copyright american chemical society of the bond between drug and carrier detailed results on the biological evaluation of these complexes have not been reported the anticancer drug paclitaxel, which is being used to treat metastatic breast motilium manufacturer and ovarian cancers and kaposis sarcoma, has poor water solubility to enhance its bioavailability, paclitaxel has been encapsulated into motilium manufacturer polyglycerol dendrimers, resulting in a ,fold improved water solubility compared with the pure drug, which is much higher than that motilium manufacturer found for peg, a commonly used linear chain cosolvent or hydrotropic agent fig the drug release rate was a function motilium manufacturer of the dendrimer generation generation ����� dendrimers with hydroxy surface have been utilized to improve the bioavailability of the corticosteroid methylprednisolone, which decreases inflammation by stabilizing leukocyte lysosomal membrane by connecting the drug to the dendrimer using glutaric acid motilium manufacturer as the spacer, a payload of wt was achieved the drugdendrimer complex was taken up by a human lung epithelial motilium manufacturer carcinoma cells and mostly localized in the cytosol the complex showed a pharmacological activity comparable to the free drug as motilium manufacturer measured by the inhibition of the prostaglandin secretion doxorubicin and camptothecin � selfimmolative dendritic prodrugs an exciting new approach to motilium manufacturer dendritic drug delivery involves the utilization of a drug as a part of the dendritic molecule selfimmolative dendrimers have motilium manufacturer recently been developed and introduced as a potential platform for a multiprodrug these unique structural dendrimers can release all of their outer branch units through fig mechanism of dimeric prodrug activation by a single enzymatic cleavage reproduced with permission from motilium manufacturer ref copyright american chemical society a selfimmolative chain fragmentation, initiated by a single cleavage at the den drimers core motilium manufacturer incorporation of drug molecules as these outer branch units and an enzyme substrate as the trigger can generate a multiprodrug motilium manufacturer unit that will be activated with a single enzymatic cleavage fig the first generation of dendritic prodrugs with doxorubicin and motilium manufacturer camptothecin as branch units and retromichael focal trigger, which can be cleaved by the catalytic antibody c, has been reported bioactivation of the dendritic prodrugs was evaluated in cellgrowth inhibition assay with the molt leukemia cell line in the motilium manufacturer presence and absence of antibody c a remarkable increase in toxicity was observed dependent on the linker molecule, different numbers motilium manufacturer of drug molecules can be released in one single activation step in a more classical approach to deliver doxorubicin, two motilium manufacturer polyesterbased dendrimers generation with trisphenolic core were synthesized, one carrying a hydroxy surface, the other a triethylene glycol monomethyl ether surface these dendrimers were compared with a arm polyethylene oxide star polymer, carrying g = dendritic polyester units at motilium manufacturer the surface the star polymer gave the most promising results regarding cytotoxicity and systemic circulatory halflife hrs therefore, the anticancer motilium manufacturer drug doxorubicin was covalently bound to this carrier via an acidlabile hydrazone linkage the cytotoxicity of doxorubicin was significantly reduced motilium manufacturer and the drug was successfully taken up by several cancer cell lines photodynamic therapy pdt and boron neutron capture therapy motilium manufacturer bnct dendrimers have been used to optimize the antitumor effect in photodynamic therapy pdt and boron neutron capture therapy motilium manufacturer bnct one of the newest developments in the dendrimer field is their application to photodynamic therapy pdt this cancer treatment motilium manufacturer involves the administration of a lightactivated photosensitizing moiety that selectively concentrates in diseased tissue subsequent activation of the photosensitizer leads motilium manufacturer to the generation of reactive oxygen, primarily singlet oxygen, that damages intracellular components such as lipids and amino acid residues through oxidation, ultimately leading to cell death by apoptosis disadvantages of currently used photosensitizers include skin phototoxicity, poor selectivity motilium manufacturer for tumor tissue, poor water solubility, and difficulties in the treatment of solid tumors because of the impermeability of the motilium manufacturer skin and tissues to the visible light required to excite the chromophores in one set of studies, dendrimers have been motilium manufacturer constructed around a light harvesting core ie a porphyrin to reduce the toxicity under nonirradiative conditions dark toxicity and motilium manufacturer to prevent aggregation, and consequently, selfquenching of the porphyrin cores, these dendrimers have been further encapsulated into micelles for example, motilium manufacturer polyethylene glycolbpolyaspartic acid and pegbpolyllysine micelles have been studied in this regard these micelles are stable under physiological conditions ph motilium manufacturer to however, they disintegrate in the acidic intracellular endosomal compartment ph alternatively, dosage of tetracycline for rabbits the photosensitizer aminolevulinic acid has been attached to motilium manufacturer the surface of dendrimers and studied as an agent for pdt of tumorigenic keratinocytes photosensitive dyes have been incorporated into dendrimers and utilized in pdt devices for example, uptake, toxicity, and the mechanism of photosensitization of the dye pheophorbide a pheo was compared with its complex with diaminobutane polypropylene imine dab dendrimers in human leukemia cells in vitroi the motilium manufacturer second therapy, boron neutron capture therapy, is a cancer treatment based on a nuclear capture reaction when b is motilium manufacturer irradiated with low energy or thermal neutrons, highly energetic �particles and li ions are produced, that are toxic to tumor motilium manufacturer cells to achieve the desired effects, it is necessary to deliver b to tumor cells at a concentration of at motilium manufacturer least atoms per cell high levels of boron accumulation in tumor tissue can be achieved by using boronated antibodies that are targeted towards tumor antigens however, this approach can impair the solubility and targeting efficiency of the antibodies one motilium manufacturer study, involving intratumoral injection of a conjugation between a generation ����� dendrimer carrying boron atoms and cetuximab, a monoclonal antibody motilium manufacturer specific for the egf receptor, showed that the conjugate was present fig schematic presentation of an eda core g = motilium manufacturer ����� dendrimer , the boron carrier ������������ , and the targeting ligand folic acid reproduced with permission from ref copyright american chemical motilium manufacturer society at an almost fold higher concentration in brain tumors than in normal brain tissue to reduce the liver uptake observed for boronated ����� dendrimer conjugates, peg chains were attached onto the dendrimer surface, in addition to the borane motilium manufacturer clusters, to provide steric shielding as compared with a dendrimer without peg chains, the amount of liver uptake was found motilium manufacturer to be less for pegconjugated dendrimers with an average of chains of peg but higher for dendrimers with chains of peg folic acid moieties were also conjugated to the ends of the peg chains to enhance the uptake of motilium manufacturer the dendrimers by tumors overexpressing folate receptors although this strategy was successful in enhancing localization of the molecules to tumors in mice bearing jkfbp tumors expressing the folate receptor, it also led to an increase in the uptake of the motilium manufacturer dendrimers by the liver and kidneys nanoscaffolds for targeting ligands the surface of dendrimers provides an excellent platform for motilium manufacturer the attachment of cell specific ligands, solubility modifiers, stealth molecules, reducing the interaction with macromolecules from the body defense system, motilium manufacturer and imaging tags the ability to attach any or all of these molecules in a welldefined and controllable manner onto motilium manufacturer a robust dendritic surface, clearly differentiates dendrimers from other carriers such as micelles, liposomes, emulsion droplets, and engineered particles folic motilium manufacturer acid one example of cellspecific dendritic carriers is a dendrimer modified with folic acid the membraneassociated high affinity folate motilium manufacturer receptor hfr is a folate binding protein that is overexpressed on the surface of a variety of cancer cells, and motilium manufacturer therefore, folatemodified dendrimers would be expected to internalize into these cells preferentially over normal cells via receptormediated endocytosis folate dendrimer motilium manufacturer conjugates have been shown to be wellsuited for targeted, cancer specific drug delivery of cytotoxic substances in a very recent study, branched polylglutamic acid chains were centered around ����� dendrimers generations and and polyethylene imine pei cores to create motilium manufacturer new biodegradable polymers with improved biodistribution and targeting ability these constructs were surfaceterminated with polyethylene glycol chains to enhance their motilium manufacturer biocompatibility, and folic acid ligands to introduce cell specific targeting cell binding studies have been performed using the epidermal carcinoma motilium manufacturer cell line, kb carbohydrates in addition to folates, carbohydrates constitute another important class of biological recognition molecules, displaying a motilium manufacturer wide variety of spatial structures due to their branching possibility and anomericity to achieve sufficiently high binding affinities between simple mono and oligosaccharide ligands and cell membrane receptors, these ligands have to be presented to the receptors in a multivalent motilium manufacturer or cluster fashion the highly functionalized surface of dendrimers provides an excellent platform for such presentations the design, synthesis, and motilium manufacturer biomedical use of glycodendrimers, as well as their application in diagnostic and for vaccinations, have been thoroughly reviewed recently motilium manufacturer for example, the thomsen friedenreich carbohydrate antigen tantigen, jgallagalnac, which has been well documented as an important antigen for the motilium manufacturer detection and immunotherapy of carcinomas, especially relevant to breast cancer, has been attached to the surface of ����� and other motilium manufacturer dendrimers an enhanced binding affinity was observed for all glycodendrimers these constructs could have potential in blocking the metastatic sites motilium manufacturer of invasive tumor cells a series of dendritic cyclodextrin derivatives, bearing multivalent mannosyl ligands, has been prepared and their binding efficiency towards the plant lectin concanavalin a con a and a mammalian mannosespecific cell surface receptor from macrophages has motilium manufacturer been studied the effects of glycodendritic architecture on binding efficiency, molecular inclusion, lectinbinding properties, and the consequence of complex formation motilium manufacturer using the anticancer drug docetaxel on biological recognition were investigated di to tetravalent dendritic galabiosides, carrying galalgal moieties on motilium manufacturer their surfaces, were studied as inhibitors of pathogens based on bacterial species such as e coli and streptococcus suis attachment motilium manufacturer of dendritic galabiosides onto cell surfaces would be expected to inhibit the attachment of bacteria using the same sugar ligandreceptor motilium manufacturer interactions the study revealed a clear enhancement of the binding affinity between glycodendrons and cell surfaces, with an increasing number motilium manufacturer of sugar moieties in a similar approach, glycodendrons carrying two to four jdgalactose moieties on their surface, while the motilium manufacturer dendron core was connected to a proteindegrading enzyme, were synthesized these glycodendriproteins are expected to attach to the surface of motilium manufacturer bacteria, allowing the enzyme to degrade the bacterial adhesin, hence rendering the bacteria incapable of attaching to the cell surfaces motilium manufacturer anionic ����� dendrimers c = were conjugated to dglucosamine and dglucoseamine fisulfate these watersoluble conjugates not only revealed immunomodulatory and motilium manufacturer antian giogenic properties, but synergistically prevented scar tissue formation after glaucoma filtration surgery in a validated and clinically relevant rabbit study, the long term success rate was increased from to using these d end rimerconjugates antibodies and biotinavidin binding motilium manufacturer generation ����� dendrimerendrimers with amino erythromycin opthalmic ointment 0.5 canada pet surface were conjugated to fluorescein isothio cyan ate as a means to analyze cell binding motilium manufacturer and internalization two different antibodies, bca and j, which bind tocd and prostatespecific membrane antigen psma respectively, were used as mode!