Biomedical subjects

T X Neenan

Publications and source records attributed to T X Neenan.

3 recordsLinked to original sources

PubMed1988

Amphiphilic polyphosphazenes as membrane materials: influence of side group on radiation cross-linking.

The amphiphilic mixed-substituent polyphosphazenes, [NP(OCH2CF3)x (NHCH3)y)]n and [NP(OC6H5)x (NHCH3)y]n, have been prepared by the sequential replacement of chlorine in [NPCI2]n by trifluorethoxide or phenoxide and methylamine. Thin films of these species were cross-linked by exposure to gamma radiation and the semipermeability of the resultant membranes was monitored. The radiation-induced cross-linking and membrane-forming properties of these polymers were compared with those of the single substituent polymers, [NP(OCH2CF3)2]n, [NP(OC6H5)2]n, and [NP(NHCH3)2]n. The radiation-cross-linking and appeared to involve free radical reactions at the methyl groups of the methylamino substituents. The possible utility of these materials in biomedical research is discussed.

Biocompatible Materials↗

PubMed1987

Controlled release using a new bioerodible polyphosphazene matrix system.

Polyphosphazenes possess polymer backbones consisting of nitrogen and phosphorous formally separated by alternating single and double bonds. Their potential for biomedical applications stems from the fact that polymers with a wide array of properties can be synthesized using the same starting compound, poly(dichlorophosphazene), through changes in side chain substituents, and that many of these compounds synthesized have been found to biodegrade to harmless products. In this article, studies of a novel monolithic bioerodible polyphosphazene matrix system for controlled drug delivery are presented. Poly(imidazole methylphenoxy)phosphazene is synthesized and shown to be bioerodible. The versatility of drug delivery devices fabricated using this polymer is shown through studies of release of macro-molecules and low molecular weight drugs. Initial histological evaluations of this particular polyphosphazene are also presented.

Aniline Compounds↗

PubMed1982

Synthesis of a heparinized poly(organophosphazene).

The synthesis of a new potential anti-thrombogenic polymer is described. Limited halogenation of an aryloxy-substituted polyphosphazene, followed by quaternization with triethylamine yielded a polymer capable of forming polyelectrolyte complexes with sodium heparin. The results of preliminary clotting tests with bovine blood are presented.

Animals↗