Article

Self-immolative polymers.

School of Pharmacy, University of Nottingham, Nottingham, UK.
Angewandte Chemie International Edition (Impact Factor: 11.34). 10/2008; 47(41):7804-6. DOI: 10.1002/anie.200802474
Source: PubMed
1 Bookmark
 · 
281 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Inspired by the spontaneous cyclization of ornithine in peptides, polyesters containing protected ornithine (Orn) side chains along the backbone were synthesized and shown to degrade rapidly upon deprotection through intramolecular cyclization. A new ornithine-based poly(ester amide) PEA 1 and a lysine-based control PEA 2, both bearing the light-sensitive protecting group o-nitrobenzyl alcohol (ONB), were synthesized. Tert-butyl carbamate (Boc)-protected versions 1-Boc and 2-Boc were also synthesized for proof of concept. GPC confirmed that 1-Boc degrades over 40 times faster than 2-Boc following deprotection into the designed intramolecular cyclization products. Finally, TEM visualization of particles made from 1 encapsulating iron oxide nanoparticles reveals complete disruption of nanoparticles and release of payload within a day upon UV irradiation. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3783–3790
    Journal of Polymer Science Part A Polymer Chemistry 09/2013; 51(18):3783-3790. · 3.54 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Biological systems rely on recyclable materials resources such as amino acids, carbohydrates and nucleic acids. When biomaterials are damaged as a result of aging or stress, tissues undergo repair by a depolymerization-repolymerization sequence of remodelling. Integration of this concept into synthetic materials systems may lead to devices with extended lifetimes. Here, we show that a metastable polymer, end-capped poly(o-phthalaldehyde), undergoes mechanically initiated depolymerization to revert the material to monomers. Trapping experiments and steered molecular dynamics simulations are consistent with a heterolytic scission mechanism. The obtained monomer was repolymerized by a chemical initiator, effectively completing a depolymerization-repolymerization cycle. By emulating remodelling of biomaterials, this model system suggests the possibility of smart materials where aging or mechanical damage triggers depolymerization, and orthogonal conditions regenerate the polymer when and where necessary.
    Nature Chemistry 07/2014; 6(7):623-8. · 23.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Self-immolative polymers (SIPs) are unique macromolecules that are able to react to multiple types of environmental influences by giving amplified response outputs. When triggering moieties installed at SIP chain ends are activated by their corresponding stimuli, a spontaneous head-to-tail depolymerization ensues, often involving multitopic release of small molecules. SIP designs have evolved a high degree of modularity in each of their functional components, enabling a broad range of utility and applications-driven tuning. In this Perspective, we summarize and discuss recent progress in this nascent area of research, including (i) synthesis of different types of SIPs, (ii) design and evaluation of triggering moieties, (iii) depolymerization mechanisms and kinetics, (iv) applications of SIPs, and (v) outlook and challenges facing the field.
    Macromolecules 09/2012; 45(18):7317-7328. · 5.93 Impact Factor

Full-text (2 Sources)

Download
78 Downloads
Available from
May 31, 2014