RESUMO
Covalent or noncovalent linked polymers with stimuli-responsive properties have been well researched as a kind of advanced functional materials. However, little effort has been devoted to establishing a bridge for switching between covalent polymers and noncovalent polymers. Actually, such unitive system is promising because it can combine their chemical advantages of two types of polymers in a single and tunable platform. Herein, by taking advantage of reversible photodimerization of coumarins and host-guest assemblies with γ-cyclodextrin (γ-CD), we demonstrate a simple and effective way to construct a dual-modality supramolecular polymer, which can be switched between a noncovalent polymer and its corresponding covalent polymer in response to light stimuli. Moreover, this unique switchable polymer can also be employed to construct a dual-stimuli responsive supramolecular hydrogel with the surfactant cetyl trimethylammonium bromide (CTAB). This methodology establishes a bridge between the two "polymer mansions" and is promising to open a new class of photoswitchable materials.
Assuntos
Polímeros/química , Cumarínicos/química , Substâncias Macromoleculares/química , Estrutura Molecular , Processos Fotoquímicos , gama-Ciclodextrinas/químicaRESUMO
Mixed polydiacetylene (PDA) liposomes functionalized on their surface with a fluorescent pentalysine peptide derivative and histidine in a ratio of 1:9 can identify bacterial lipopolysaccharide (LPS). Upon photopolymerization of the self-assembled liposomes the initial fluorescence of the peptide-diacetylene amphiphiles is quenched. Interaction with LPS in aqueous solution or on the surface of E. coli DH5α restores the fluorescence. This increase in fluorescence is selective for LPS relative to other negatively charged analytes including nucleotides and ctDNA. This simple turn-on fluorescent sensor allows detecting LPS even at low micromolar concentrations.
Assuntos
Fluorescência , Lipopolissacarídeos/análise , Lipossomos/química , Peptídeos/química , Polímeros/química , Poli-Inos/química , Escherichia coli , Polímero Poliacetilênico , Sensibilidade e EspecificidadeRESUMO
Peptide functionalized polydiacetylene (PDA) micelles encapsulated with camptothecin (CPT) kill ovarian cancer cells by the lysosome release of anticancer drug CPT. Moreover, the sub-30 nm PDA micelles penetrate efficiently into a tumor for enhanced therapeutic efficacy.
Assuntos
Antineoplásicos/administração & dosagem , Camptotecina/administração & dosagem , Micelas , Neoplasias Ovarianas/tratamento farmacológico , Polímeros/administração & dosagem , Poli-Inos/administração & dosagem , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Camptotecina/farmacocinética , Camptotecina/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Camundongos , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Neoplasias Ovarianas/patologia , Polímero Poliacetilênico , Polímeros/química , Poli-Inos/química , Relação Estrutura-AtividadeRESUMO
Polydiacetylene (PDA) micelles have been widely used to deliver anticancer drugs in the treatment of a variety of tumours and for imaging living cells. In this study, we developed an effective strategy to directly conjugate magainin II (MGN-II) to the surface of PDA micelles using a fluorescent dye. These stable and well-defined PDA micelles had high cytotoxicity in cancer cell lines, and were able to reduce the tumour size in mice. The modified PDA micelles improved the anticancer effects of MGN-II in the A549 cell line only at a concentration of 16.0 µg mL(-1) (IC50). In addition, following irradiation with UV light at 254 nm, the PDA micelles gave rise to an energy transfer from the fluorescent dye to the backbone of PDA micelles to enhance the imaging of living cells. Our results demonstrate that modified PDA micelles can not only be used in the treatment of tumors in vitro and in vivo in a simple and directed way, but also offer a new platform for designing functional liposomes to act as anticancer agents.