- SYNTHESIS OF POLY(ETHYLENE GLYCOL) BLOCK COPOLYMERS AS POTENTIAL WATER-SOLUBLE DRUG CARRIERS
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The synthesis of a model water-soluble drug carrier based on poly(ethylene glycol) (PEG) block copolymers is described.In the copolymers, two blocks of PEG are linked by a biodegradable oligopeptide or amino acid linkage containing the glutamic acid residue. 4-Nitroaniline as a drug model is attached to the γ-carboxyl group of glutamic acid of the polymer carrier via an enzymatically degradable oligopeptide spacer.The oligopeptides used were potential substrates for chymotrypsin.The relationship between the structure of oligopeptides linking two PEG blocks and the rate of chymotrypsin-catalyzed polymer chain degradation as well as the relationship between the structure of the spacer and kinetics of drug model release from the carrier after incubation of chymotrypsin solution is discussed in detail.The results showed that by modifying the structure of oligopeptides in the polymer construct, changes in the rates of both polymer degradation and the drug model release can be achieved in a very broad range.
- Pechar, Michal,Strohalm, Jiri,Ulbrich, Karel
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p. 1765 - 1780
(2007/10/03)
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- α-AMINOACYL DERIVATIVES OF α,ω-DIAMINOPOLY(OXYETHYLENE)
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By reacting p-nitrophenyl esters of L-α-amino acids with α-(3-aminopropyl)-ω-(aminomethyl)poly(oxyethylene), diamides having the structure 2M'x were prepared, X being the protective group Boc or Z, R being residues of glutamic and aspartic acid, phenylalanine and tyrosine, and M'x being the poly(oxyethylene) chain with the (-CH2)3- and -CH2- endgroups.The diamides were characterized by IR and 1H NMR spectroscopy and thin-layer chromatography.After complete removal of tert-butyloxycarbonyl groups from diamides (X=Boc), deprotected α-aminoacyl derivatives were characterized as trifluoroacetic acid salts.
- Masar, Bohumil,Schmidt, Pavel,Pivcova, Hana,Cefelin, Pavel
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p. 1922 - 1927
(2007/10/02)
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