Abstract: The present invention is directed to methods of preparing high purity polyalkylene oxide carboxylic acids. The methods include reacting a polyalkylene oxide such as polyethylene glycol with a t-butyl haloacetate in the presence of a base followed by treatment with an acid such as trifluoroacetic acid. The resultant polymer carboxylic acids are of sufficient purity so that expensive and time containing purification steps required for pharmaceutical grade polymers are avoided.

Abstract: The use of hemoglobin-polymer conjugates to enhance antitumor therapy in mammals is disclosed. The methods include administering an effective amount of an antitumor therapy such as radiation in combination with hemoglobin conjugated to a substantially non-antigenic polymer.

Abstract: Polyalkylene oxide-conjugated hemoglobin solutions having a molecular weight greater than about 85,000 daltons and a degree of substitution of which substantially avoids clinically significant nephrotoxicity associated with hemoglobinuria in mammals. A method of simultaneously fractionating and purifying polyalkylene oxide-conjugated hemoglobins is al so disclosed.

Abstract: Branched, substantially non-antigenic polymers are disclosed. Conjugates prepared with the polymers and biologically active molecules such as proteins and peptides demonstrate extended circulating life in vivo. Substantially fewer sites on the biologically active material are used as attachment sites. Methods of forming the polymer, conjugating the polymers with biologically active moieties and methods of using the conjugates are also disclosed.

Abstract: Water-soluble aryl imidate activated polyalkylene oxides having improved hydrolytic stability and conjugates of the aryl imidate activated polyalkylene oxides with biologically active nucleophiles are disclosed. Methods of preparing the activated polyalkylene oxides and conjugates thereof are also disclosed.

Abstract: 2'- and/or 7'- substituted taxoid derivatives having improved water-solubility and/or enhanced therapeutic activity and methods of making the same are disclosed.

Abstract: Conjugates containing glucocerebrosidase and non-antigenic polymers such as polyethylene glycol are disclosed. The conjugates circulate for extended times and have prolonged activity in vivo when compared to unmodified enzymes. The conjugates are useful in the treatment of Gaucher's Disease and have improved enzyme activity at the pH ranges associated with lysosomal, arterial and capillary regions.

Abstract: Water-soluble prodrugs of the formula: ##STR1## wherein: D is a biologically active nucleophile;M is X or Q;x is an electron withdrawing group;Q is a moiety containing a free electron pair positioned five or six atoms from Y';Y and Y' are oxygen or sulfur;R is a polyalkylene oxide; andZ is OH, C.sub.1-4 alkyl moieties or ##STR2## are disclosed.

Abstract: Poly(ethylene glycol)-N-succinimide carbonate and its preparation are disclosed. Polyethylene glycol (PEG) is converted into its N-succinimide carbonate derivative. This form of the polymer reacts readily with amino groups of proteins in aqueous buffers. The modified proteins have PEG-chains grafted onto the polypeptide backbone by means of stable, hydrolysis-resistant urethane (carbamate) linkages.

Abstract: The present invention is directed to methods of preparing high purity polyalkylene oxide carboxylic acids. The methods include reacting a polyalkylene oxide such as polyethylene glycol with a t-butyl haloacetate in the presence of a base followed by treatment with an acid such as trifluoroacetic acid. The resultant polymer carboxylic acids are of sufficient purity so that expensive and time consuming purification steps required for pharmaceutical grade polymers are avoided.

Abstract: Water-soluble azlactone activated polyalkylene oxides having improved hydrolytic stability and conjugates of the azlactone activated polyalkylene oxides with biologically active nucleophiles are disclosed. Methods of forming and conjugating the activated polyalkylene oxides with biologically active nucleophiles are also disclosed.

Abstract: The present invention relates to chemically modified hemoglobin produced by a novel and efficient method in which stroma-free hemoglobin is first effectively deoxygenated and reduced and then conjugated with a polyalkylene oxide such as polyethylene glycol (PEG) under conditions which maintain the structural integrity of the heme oxygen binding site. In specific, preferred embodiments of the invention, the deoxygenation and reduction is performed under an inert atmosphere by the amino acid cysteine. In additional specific, preferred embodiments, the structural integrity of the heme oxygen binding site is maintained by a high anionic concentration in the reaction mixture. In further preferred specific emodiments of the invention, the polyalkylene oxide is polyethylene glycol; in still further preferred specific embodiments of the invention, the polyalkylene oxide is linked to hemoglobin via a urethane (carbamate) linkage.

Abstract: Water-soluble cyclic imide thione activated polyalkylene oxides having improved hydrolytic stability are disclosed. Methods of forming and conjugating the activated polyalkylene oxides with biologically active nucleophiles are also disclosed.

Abstract: Poly(ethylene glycol)-N-succinimide carbonate and its preparation are disclosed. Polyethylene glycol (PEG) is converted into its N-succinimide carbonate derivative. This form of the polymer reacts readily with amino groups of proteins in aqueous buffers. The modified proteins have PEG-chains grafted onto the polypeptide backbone by means of stable, hydrolysis-resistant urethane (carbamate) linkages.

Abstract: Water-soluble azlactone activated polyalkylene oxides having improved hydrolytic stability and conjugates of the azlactone activated polyalkylene oxides with biologically active nucleophiles are disclosed. Methods of forming and conjugating the activated polyalkylene oxides with biologically active nucleophiles are also disclosed.

Abstract: Hemoglobin-containing solutions containing polyalkylene oxide-conjugated hemoglobin having a molecular weight greater than about 85,000 daltons and a degree of substitution of at least five polyalkylene oxide conjugates per hemoglobin molecule are described that are not associated with hemoglobinuria in mammals. A method of simultaneously fractionating and purifying polyalkylene oxide-conjugated hemoglobins is also disclosed.

Abstract: Water-soluble aryl imidate activated polyalkylene oxides having improved hydrolytic stability and conjugates of the aryl imidate activated polyalkylene oxides with biologically active nucleophiles are disclosed. Methods of preparing the activated polyalkylene oxides and conjugates thereof are also disclosed.