Hydrophilic Comonomers Research Articles

Synthesis and first in vitro cytotoxicity studies of bis(2-chloroethyl) amino group containing polymers. Pharmacologically active polymers: 22

Monomers containing the cytotoxic bis(2-chloroethyl)amino group (nor-nitrogen mustard), linked in deactivated form via urethane and O-acylated hydroxamic acid bonds to polymerizable methacrylic acid derivatives, have been prepared. Besides the homopolymerization, these monomers were copolymerized with hydrophilic comonomers to obtain water-soluble polymers. The linkages used are expected to undergo intracellular enzymatic or hydrolytic cleavage, releasing the cytotoxic bis(2-chloroethyl)amino moiety from the polymeric carrier. Preliminary in vitro cytotoxicity data for the polymers against three rat and mouse experimental tumour lines (Walker 256 carcinosarcoma, L1210 murine leukaemia and ADJ/PC6A plasma cell tumour) are reported. An approximately 10 2 fold difference in cytotoxic potency was found, depending on the type of the cleavable spacer group.

Immobilization of Enzymes by Radiation-Induced Copolymerization of 2-Hydroxyethyl Methacrylate and Other Hydrophilic or Hydrophobic Comonomers

Abstract Immobilization of enzymes by radiation-induced copolymerization was studied at low temperatures by use of various comonomer systems consisting of 2-hydroxyethyl methacrylate and other more hydrophilic or hydrophobic comonomers. The matrices obtained by copolymerization with more hydrophilic and more hydrophobic comonomers decreased the porosity in the matrix equally. However, the activity yield of the immobilized enzyme showed different changes with repeated use in the more hydrophilic and more hydrophobic matrices. That is, the initial activity decreased rapidly with repeated use owing to the enzyme leakage from the matrix, in the increased hydrophilic matrices. On the other hand, in the more hydrophobic matrices enzyme leakage was completely retarded and activity did not change with repeated use. Moreover, the activity yield showed a maximum at a certain monomer composition in the copolymerization with hydrophobic comonomer. Finally, it was found that the maximum activity yield of the hydrophob...

Studies on Acrylonitrile-Hydrozyalkyl-Methacrylate Copolymer Fibers

The effect cf wet spinning conditions on the properties of acrylonitrile-2-hydroxyethyl methacrylate (AN-HEMA) and acrylonitrile-2-hydroxypropyl methacrylate (AN-HPMA) copolymer fibers were studied. Copolymers containing 1 to 4.8 mole% hydroxyalkylmethacrylate comonomer were synthesized by slurry polymerization using redox initiator. The spinning dope used was a 15% solution of polymer in dimethylformamide. The spinning conditions studied were: extrusion pressure, coagulating bath temperature, take-up velocity, and draw ratio. Low coagulating bath temperature and high draw ratio gave fiber with better strength properties. Sonic modulus and x-ray diffraction were used for study ing the molecular orientation and crystalline organization. The influence of hydrophilic comonomers in polyacrylonitrile on moisture sorption, dyeability, and tensile properties was considered.

The effect of the method of fixation of proteolytic enzymes in polymeric hydrogels on the blood-compatibility of modified polymers

The possibility of increasing the blood-compatibility of polymers by fixation on the surface of the latter, of the proteolytic enzymes trypsin, chimotrypsin, fibrinolysin and the protease from actinomycetes, has been studied. Methods have been developed for fixation of the enzymes on polymers. It is shown that fixation of fibrinolysin and protease by grafting these enzymes modified with acrylyl chloride, to polymers in the presence of a hydrophilic comonomer, results in formation of highly active, stable preparations, displaying high compatibility with blood.

Enzyme immobilization by radiation‐induced polymerization of hydrophobic glass‐forming monomers at low temperatures

Enzyme immobilization was studied by means of radiation-induced polymerization of hydrophobic glass-forming monomers at low temperatures. The polymerized hydrophobic composite was generally obtained in microspheric form. Enzymatic activity showed little decrease with repeated use in these systems. The particle size of the microsphere increased with increasing monomer concentration, and activity yield had a maximum at an optimum monomer concentration. Immobilization by copolymerization of hydrophilic and hydrophobic comonomers was also investigated and a maximum activity yield was found at a certain monomer concentration. A model scheme for immobilization at low temperatures was proposed and discussed.