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Synthetic Macromolecules (synthetic + macromolecule)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Precision Polymers: Monodisperse, Monomer-Sequence-Defined Segments to Target Future Demands of Polymers in Medicine

ADVANCED MATERIALS, Issue 32-33 2009
L. Hartmann
Abstract The established technology platforms of solid-phase-supported oligopeptide and oligonucleotide synthesis can be expanded to access fully synthetic macromolecules, preserving both the monodisperse character and the defined monomer sequence. Precision polymers are sequentially assembled from a library of functional building blocks, enabling one to program interaction capabilities or generate functions by sequence-specific positioning of functionalities. Examples are provided, showing that these monodisperse macromolecules can be conjugated to oligonucleotides, oligopeptides, or poly(ethylene glycol)s. The resulting model systems can contribute to the understanding of complex biomedical-related processes. Due to the absence of chemical and molecular-weight distributions in these multifunctional segments, exact correlation of the monomer sequence and (bio)properties is attainable. This is demonstrated by the design of carrier systems that exhibit fine-tuned interactions with plasmid DNA, actively controlling important steps in DNA delivery and transfection, such as polyplex formation, DNA compression, and release of the cargo. [source]

Drug targeting by macromolecules without recognition unit?

JOURNAL OF MOLECULAR RECOGNITION, Issue 5 2003
Ferenc Hudecz
Abstract his review will summarize available information on the ability of macromolecular conjugates containing no specific recognition motifs to deliver anthracyclines (daunomycin, adriamycin) or methotrexate to target cells such as tumour cells or macrophages. Conjugates with natural (proteins, DNA, carbohydrates) and synthetic macromolecules (linear and branched chain poly-,-amino acids, non-biodegradable DIVEMA, HPMA etc.) will be reviewed. Experimental data from several laboratories indicate that these conjugates are taken up by cells mainly by fluid-phase or adsorptive endocytosis. It is believed that these processes do not involve ,specific receptors'. Two examples of methotrexate and daunomycin conjugates will be discussed to show the effect of the chemical structure of branched chain polypeptides on the uptake and antitumour or antiparasitic (Leishmania donovani infection) efficacy of conjugates. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Biological,synthetic hybrid block copolymers: Combining the best from two worlds

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 1 2005
Harm-Anton Klok
Abstract Although biopolymers and synthetic polymers share many common features, each of these two classes of materials is also characterized by a distinct and very specific set of advantages and disadvantages. Combining biopolymer elements with synthetic polymers into a single macromolecular conjugate is an interesting strategy for synergetically merging the properties of the individual components and overcoming some of their limitations. This article focuses on a special class of biological,synthetic hybrids that are obtained by site-selective conjugation of a protein or peptide and a synthetic polymer. The first part of the article gives an overview of the different liquid-phase and solid-phase techniques that have been developed for the synthesis of well-defined, that is, site-selectively conjugated, synthetic polymer,protein hybrids. In the second part, the properties and potential applications of these materials are discussed. The conjugation of biological and synthetic macromolecules allows the modulation of protein binding and recognition properties and is a powerful strategy for mediating the self-assembly of synthetic polymers. Synthetic polymer,protein hybrids are already used as medicines and show significant promise for bioanalytical applications and bioseparations. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1,17, 2005 [source]

Theoretical design of bioinspired macromolecular electrets based on anthranilamide derivatives

BIOTECHNOLOGY PROGRESS, Issue 4 2009
M. K. Ashraf
Abstract Polypeptide helices possess considerable intrinsic dipole moments oriented along their axes. While for proline helices the dipoles originate solely from the ordered orientation of the amide bonds, for 310, and ,-helices the polarization resultant from the formation of hydrogen-bond network further increases the magnitude of the macromolecular dipoles. The enormous electric-field gradients, generated by the dipoles of ,-helices (which amount to about 5 D per residue with 0.15 nm residue increments along the helix), play a crucial role in the selectivity and the transport properties of ion channels. The demonstration of dipole-induced rectification of vectorial charge transfer mediated by ,-helices has opened a range of possibilities for applications of these macromolecules in molecular and biomolecular electronics. These biopolymers, however, possess relatively large bandgaps. As an alternative, we examined a series of synthetic macromolecules, aromatic oligo- ortho -amides, which form extended structures with amide bonds in ordered orientation, supported by a hydrogen-bond network. Unlike their biomolecular counterparts, the extended ,-conjugation of these macromolecules will produce bandgaps significantly smaller than the polypeptide bandgaps. Using ab initio density functional theory calculations, we modeled anthranilamide derivatives that are representative oligo- ortho -amide conjugates. Our calculations, indeed, showed intrinsic dipole moments oriented along the polymer axes and increasing with the increase in the length of the oligomers. Each anthranilamide residue contributed about 3 D to the vectorial macromolecular dipole. When we added electron donating (diethylamine) and electron withdrawing (nitro and trifluoromethyl) groups for n- and p-doping, respectively, we observed that: (1) proper positioning of the electron donating and withdrawing groups further polarized the aromatic residues, increasing the intrinsic dipole to about 4.5 D per residue; and (2) extension of the ,-conjugation over some of the doping groups narrowed the band gaps with as much as 1 eV. The investigated bioinspired systems offer alternatives for the development of broad range of organic electronic materials with nonlinear properties. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source]