Abstract: A chemical sensor for detecting an analyte in a fluid, useful for the production of an apparatus for the analysis of odours (an electronic nose), comprises a film of composite material formed by a matrix of a non-conductive polymer constituted by a polyamidoamine and a conductive filler, e.g. carbon black. In preferred embodiments, the polyamidoamine is formed as the adduct of bisacrylamidoacetic (BAC) and N, N?-dimethylethylenediamide (DMEDA) else N, N?-ethlenediaminoaceticacid (EDDA), and can include copper or cobalt ions as complexes.

Abstract: PEG-chitosan conjugates comprising chitosan and polyethylene glycol moieties or derivatives thereof which are bonded together and their use in medicine is described. In one embodiment, the conjugate comprises a chitosan moiety or a derivative thereof and a polyethylene glycol moiety or a derivative thereof which are bonded together via the amino function on the chitosan by the use of an activated chitosan species. In another embodiment, the conjugate comprises a chitosan moiety or a derivative thereof and a polyethylene glycol moiety or a derivative thereof which are bonded together, the chitosan portion of the conjugate having a molecular weight in the range of from 10 kilodaltons to 1000 kilodaltons.

Abstract: A nucleic acid complex for delivering a nucleic acid or a derivative thereof to a cell comprises the components: A. a nucleic acid or a derivative thereof; B. a cationic polymer; and C. a preformed polyethylene glycol-cationic polymer copolymer. The complex has a conformation in which the nucleic acid or derivative thereof is condensed and wherein component C is bound to component A such that the poylethylene glycol groups of component C are located at the surface of the complex. The complexes which are stable to aggregation are useful for the delivery of nucleic acids or derivatives thereof to cells in biological systems.

Abstract: PEG-chitosan conjugates comprising chitosan and polyethylene glycol moieties or derivatives thereof which are bonded together and their use in medicine is described. In one embodiment, the conjugate comprises a chitosan moiety or a derivative thereof and a polyethylene glycol moiety or a derivative thereof which are bonded together via the amino function on the chitosan by the use of an activated chitosan species. In another embodiment, the conjugate comprises a chitosan moiety or a derivative thereof and a polyethylene glycol moiety or a derivative thereof which are bonded together, the chitosan portion of the conjugate having a molecular weight in the range of from 10 kilodaltons to 1000 kilodaltons.

Abstract: A process for attaching a polyethylene glycol compound to a macromolecule to prepare a conjugate or adduct between the polyethylene glycol compound and the macromolecule is described. The process comprises the steps of (1) preparing an activated PEG or an activated PEG derivative by incorporating an acrylic ester, an acrylic thioester or an acrylamido group into the PEG or PEG derivative; (2) reacting the activated PEG or PEG derivative with a macromolecular material comprising one or more sulphydryl groups, primary amino groups and/or secondary amino groups and (3) recovering the conjugate of the PEG or PEG derivative and the macromolecular material.

Abstract: PEG-chitosan conjugates comprising chitosan and polyethylene glycol moieties or derivatives thereof which are bonded together and their use in medicine is described. In one embodiment, the conjugate comprises a chitosan moiety or a derivative thereof and a polyethylene glycol moiety or a derivative thereof which are bonded together via the amino function on the chitosan by the use of an activated chitosan species. In another embodiment, the conjugate comprises a chitosan moiety or a derivative thereof and a polyethylene glycol moiety or a derivative thereof which are bonded together, the chitosan portion of the conjugate having a molecular weight in the range of from 10 kilodaltons to 1000 kilodaltons.

Abstract: A composition for delivering a biologically active polyanionic molecule comprising a linear polymer with a backbone comprising amido and tertiary amino groups arranged regularly on the backbone and biologically active polyanionic molecule bound to the polymer. Preferably, the linear polymer comprises a poly(amidoamine). Preferably, the biologically active polyanionic molecule is a nucleic acid, more preferably a DNA. The compositions are useful for delivering nucleic acids to a cell in a cell transformation, transfection or gene therapy method.

Abstract: Polyesterpolycarbonates of formula (I) ##STR1## wherein a is an integer from 2 to 300; R.sub.1 and R.sub.2, which can be the same or different, are each a polyester residue of formula (II) ##STR2## with x and y being integers from 0 to 100, and the ratio of (x/x+y)*100 being between 0 and 100, with the proviso that x and y are not 0 at the same time; R.sub.3 and R.sub.4 being aliphatic hydrocarbon residues of 1 to 4 carbon atoms; R.sub.5 being an aliphatic hydrocarbon residue having from 2 to 18 carbon atoms or a cycloaliphatic hydrocarbon residue having from 3 to 8 carbon atoms; or a polyoxyalkylene residue of formula (III): ##STR3## wherein R.sub.6 is hydrogen or methyl, n is an integer from 1 to 3 and m is an integer from 1 to 200; and the two --R.sub.3 --COO and --R.sub.4 --COO groups are randomly distributed in the polyester residue, with the polyesterpolycarbonates of formula (I) having an intrinsic viscosity of greater than 0.45 dl/g when measured in chloroform at 32.degree. C.

Abstract: Polycarbonates of formula (I) wherein a is an integer from 2 to 300; R.sup.1 and R.sup.2 are the same or different and are independently a polyester residue of formula (III) wherein x and y are integers from 1 to 50, R.sup.4 and R.sup.5, which are the same or different, are aliphatic straight or branched hydrocarbon chains having from 1 to 4 carbon atoms, R.sup.6 is an aliphatic or alicyclic straight or branched chain having from 2 to 18 carbon atoms, or a polyoxyalkylene residue of formula (II), the two groups --R.sup.4 --COO and --R.sup.5 --COO being randomly distributed in the polyester residue, x and y being in any possible ratio from 0 to 100, are synthesized by reacting dihydroxy compounds with 1,1'-carbonyldiimidazole. They are useful for the preparation of bioerosible matrices for biologically active compounds.