论文部分内容阅读
Novel interior-hollow poly (acrylic acid)-poly (N-isopropylacrylamide) (PAA-PNIPAm) microcapsules with thermo and pH dual-responsive controlled-released property are reported.Firstly,the hydropropylcellulose (HPC)-PAA template particles were synthesized by polymerization of acrylic acid monomers in HPC aqueous solution due to the hydrogen bonding.Secondly,the core-shell HPC-PAA-PNIPAm composite particles were formed through precipitation polymerization of the cross-linked PNIPAm shell onto the surface of HPC-PAA template particles.Finally,the interior-hollow PAA-PNIPAm microcapsules were successfully achieved after merely adjusting the pH of suspension to selectively remove HPC.Furthermore,Doxorubicin hydrochloride (Dox) was selected as a model drug to investigate their performances as drug carriers.On one hand,the microcapsules could favorably encapsulate Dox in the force of electrostatic interaction,resulting in excellent loading capacity.On the other hand,the release of Dox-loaded PAA-PNIPAm microcapsules showed a slow-sustainable feature,and the controlled-drug-release phenomenon was simultaneously detected to be related with external temperature and pH,behaving thermo and pH dual-controlled release.Considering the simple and mild preparation procedure,peculiar interior-hollow structure and high drug loading capacity,as well as the desired stimuli-responsive controlled-released property,the obtained PAA-PNIPAm microcapsules might be applied as promising intelligent drug carriers for drug delivery system.