A novel biocompatible polymer was prepared by grafting the derivate of β-cyclodextrin （6-SH-β-CD） onto poly（3,4-dihydroxycinnamic acid） （PDHCA） via Michael addition. PDHCA-β-CD nanoparticles were prepared by ...A novel biocompatible polymer was prepared by grafting the derivate of β-cyclodextrin （6-SH-β-CD） onto poly（3,4-dihydroxycinnamic acid） （PDHCA） via Michael addition. PDHCA-β-CD nanoparticles were prepared by the self-assembly of amphiphilic PDHCA-β-CD polymer with N,N-dimethylformamide （DMF） as good solvent and water as poor solvent. The PDHCA-β-CD nanoparticles were monodispersed with spherical morphology as shown in the scanning electron microscopic （SEM） images in accord with the result of dynamic light scattering （DLS） measurement. The size of the nanoparticles could be controlled from 60 to 180 nm by tuning the grafting degree （GD） of PDHCA-β-CD polymer and also significantly influenced by the amount of water used during the process. These as-prepared nanoparticles were stable without any significant change in the particle size after six-months＇ storage and even after being irradiated by UV at 2〉280 nm for hours. The formation mechanism of PDHCA-β-CD nanoparticles was explored. The content of doxombicin （DOX） loaded onto the nanoparticles was up to 39% with relatively high loading efficiency （approximately 78.8% of initial DOX introduced was loaded）. In vitro release studies suggested that DOX released slowly from PDHCA-β-CD nanoparticles. These features strongly support the potential of developing PDHCA-β-CD nanoparticles as carriers for the controlled delivery of drug.展开更多
The methyl methacrylate(MMA) reversible addition-fragmentation chain transfer(RAFT) miniemulsion polymerization in the presence of β-cyclodextrin(β-CD) was investigated. β-CD is found to act both as an efficient so...The methyl methacrylate(MMA) reversible addition-fragmentation chain transfer(RAFT) miniemulsion polymerization in the presence of β-cyclodextrin(β-CD) was investigated. β-CD is found to act both as an efficient solubilizer for RAFT agent(2-cyanopro-2-yl dithiobenzoate) and as a stabilizer for heterogeneous polymerization. The RAFT miniemulsion polymerizations with or without β-CD were compared in terms of kinetics and the molecular weight distribution. The problem of poor latex stability was observed in this system. A good result of the control over RAFT miniemulsion polymerization of MMA was obtained with β-CD. The increase of the molecular weight of poly(methyl methacrylate) shows a linear relationship with the monomer conversion. The polydispersity index of the polymer with β-CD(PDI=1.18—1.21) is smaller than that without β-CD. TEM photographs showed that the PMMA particles produced with β-CD had smooth surfaces and uniform particle size. Higher amount of sodium dodecyl sulfate and hexadecane was found in favor of improving the controllability of the system. Oil soluble initiator is beneficial to the controllability of the polymerization.展开更多
基金This research was supported by the National Nattlral Science Foundation of China （No. 51173072）, the Fun- damental Research Funds for the Central Universities （JUSRP51408B） and Jiangsu Province Joint Innovation Funds （BY2014023-12）.
文摘A novel biocompatible polymer was prepared by grafting the derivate of β-cyclodextrin （6-SH-β-CD） onto poly（3,4-dihydroxycinnamic acid） （PDHCA） via Michael addition. PDHCA-β-CD nanoparticles were prepared by the self-assembly of amphiphilic PDHCA-β-CD polymer with N,N-dimethylformamide （DMF） as good solvent and water as poor solvent. The PDHCA-β-CD nanoparticles were monodispersed with spherical morphology as shown in the scanning electron microscopic （SEM） images in accord with the result of dynamic light scattering （DLS） measurement. The size of the nanoparticles could be controlled from 60 to 180 nm by tuning the grafting degree （GD） of PDHCA-β-CD polymer and also significantly influenced by the amount of water used during the process. These as-prepared nanoparticles were stable without any significant change in the particle size after six-months＇ storage and even after being irradiated by UV at 2〉280 nm for hours. The formation mechanism of PDHCA-β-CD nanoparticles was explored. The content of doxombicin （DOX） loaded onto the nanoparticles was up to 39% with relatively high loading efficiency （approximately 78.8% of initial DOX introduced was loaded）. In vitro release studies suggested that DOX released slowly from PDHCA-β-CD nanoparticles. These features strongly support the potential of developing PDHCA-β-CD nanoparticles as carriers for the controlled delivery of drug.
文摘The methyl methacrylate(MMA) reversible addition-fragmentation chain transfer(RAFT) miniemulsion polymerization in the presence of β-cyclodextrin(β-CD) was investigated. β-CD is found to act both as an efficient solubilizer for RAFT agent(2-cyanopro-2-yl dithiobenzoate) and as a stabilizer for heterogeneous polymerization. The RAFT miniemulsion polymerizations with or without β-CD were compared in terms of kinetics and the molecular weight distribution. The problem of poor latex stability was observed in this system. A good result of the control over RAFT miniemulsion polymerization of MMA was obtained with β-CD. The increase of the molecular weight of poly(methyl methacrylate) shows a linear relationship with the monomer conversion. The polydispersity index of the polymer with β-CD(PDI=1.18—1.21) is smaller than that without β-CD. TEM photographs showed that the PMMA particles produced with β-CD had smooth surfaces and uniform particle size. Higher amount of sodium dodecyl sulfate and hexadecane was found in favor of improving the controllability of the system. Oil soluble initiator is beneficial to the controllability of the polymerization.
