A complex micelle as a hemoglobin functional model with the biaoactive function of reversible oxygen transfer has been constructed through the hierarchical assembly of the diblock copolymer poly（ethylene glycol）-blo...A complex micelle as a hemoglobin functional model with the biaoactive function of reversible oxygen transfer has been constructed through the hierarchical assembly of the diblock copolymer poly（ethylene glycol）-block- poly（4-vinylpyridine-co-N-heptyl-4-vinylpyridine） （PEG-b-P（4VP-co-4VPHep））, tetrakis（4-sulfonatophenyl）porphinato iron（II） （Fe（II）TPPS） and β-cyclodextrin （β-CD）. The μ-oxo dimer of Fe（II）TPPS was successfully inhibited because the Fe（II）TPPS was included into the cavities of β-CDs through host-guest interaction. Fe（II）TPPS coordinated with pyridine groups functions as the active site to reversibly bind dioxygen. In adition, the host-guest inclusion （β-CD/Fe（II）TPPS） was encapsulated in the hydrophobic core of the complex micelle and tightly fixed by P4VP chains. The hydrophilic PEG blocks stretched in aqueous solution to constitute the shells which stabilize the structure of the complex micelle as well as endow the complex micelle with sufficient blood circulation time. Dioxygen can be bound to the Fe（II）TPPS located in the confined space and excellent reversibility of the binding-release process of dioxygen can be achieved. The quaternary amine N-heptyl-4-vinylpyridine can coerce abundant S2O4^2- ions into the core of the complex micelle to facilitate the self-reduction process. Dioxygen adducts （Fe（II）TPPS（O2）） were effectively protected by the double hydrophobic barriers constructed by the cavity of the cyclodextrin and the core of the complex micelle which enhances the ability to resist nucleophilic molecules. Therefore, the rationally designed amphiphilic structure can work as a promising artificial O2 carrier. Potentially, the complex micelle can be expected to improve the treatment of diseases linked with hypoxia.展开更多
Over the past decade, biopolymers have gained great interests especially in biomedicine due to their physical properties and/or chemical structures changes in response to external stimuli in a certain time fiarne or a...Over the past decade, biopolymers have gained great interests especially in biomedicine due to their physical properties and/or chemical structures changes in response to external stimuli in a certain time fiarne or at a specific location. Among them, poly（β-amino ester）s, methacrylate-based block copolymers and polypeptide with tertiary amine groups have been extensively studied and exhibit pH sensitive properties due to the protonation of tertiary amine groups. The pH values in normal organs, tissues, and subcellular compartments are always different from those in pathological tissues. These interesting properties allow their applications in a variety of fields ranging from diagnosis and therapeutics of diseases. Here, we review the recent progress of poly（β-amino ester）s, methacrylate-based block copolymers and polypeptide with tertiary amine groups and their applications in drug delivery and bioimaging.展开更多
文摘A complex micelle as a hemoglobin functional model with the biaoactive function of reversible oxygen transfer has been constructed through the hierarchical assembly of the diblock copolymer poly（ethylene glycol）-block- poly（4-vinylpyridine-co-N-heptyl-4-vinylpyridine） （PEG-b-P（4VP-co-4VPHep））, tetrakis（4-sulfonatophenyl）porphinato iron（II） （Fe（II）TPPS） and β-cyclodextrin （β-CD）. The μ-oxo dimer of Fe（II）TPPS was successfully inhibited because the Fe（II）TPPS was included into the cavities of β-CDs through host-guest interaction. Fe（II）TPPS coordinated with pyridine groups functions as the active site to reversibly bind dioxygen. In adition, the host-guest inclusion （β-CD/Fe（II）TPPS） was encapsulated in the hydrophobic core of the complex micelle and tightly fixed by P4VP chains. The hydrophilic PEG blocks stretched in aqueous solution to constitute the shells which stabilize the structure of the complex micelle as well as endow the complex micelle with sufficient blood circulation time. Dioxygen can be bound to the Fe（II）TPPS located in the confined space and excellent reversibility of the binding-release process of dioxygen can be achieved. The quaternary amine N-heptyl-4-vinylpyridine can coerce abundant S2O4^2- ions into the core of the complex micelle to facilitate the self-reduction process. Dioxygen adducts （Fe（II）TPPS（O2）） were effectively protected by the double hydrophobic barriers constructed by the cavity of the cyclodextrin and the core of the complex micelle which enhances the ability to resist nucleophilic molecules. Therefore, the rationally designed amphiphilic structure can work as a promising artificial O2 carrier. Potentially, the complex micelle can be expected to improve the treatment of diseases linked with hypoxia.
文摘Over the past decade, biopolymers have gained great interests especially in biomedicine due to their physical properties and/or chemical structures changes in response to external stimuli in a certain time fiarne or at a specific location. Among them, poly（β-amino ester）s, methacrylate-based block copolymers and polypeptide with tertiary amine groups have been extensively studied and exhibit pH sensitive properties due to the protonation of tertiary amine groups. The pH values in normal organs, tissues, and subcellular compartments are always different from those in pathological tissues. These interesting properties allow their applications in a variety of fields ranging from diagnosis and therapeutics of diseases. Here, we review the recent progress of poly（β-amino ester）s, methacrylate-based block copolymers and polypeptide with tertiary amine groups and their applications in drug delivery and bioimaging.
