【摘要】 以聚苯乙烯磺酸钠(PSS)掺杂CaCO3微球为模板,利用逐层(LBL)自组装技术将聚二烯丙基二甲基氯化铵(PDDA)和锂藻土(Laponite)组装到微球表面,得到了核壳型载药微球。通过扫描电镜(SEM)、透射电镜(TEM)、zeta-电位分析仪、X射线衍射分析仪(XRD)、傅立叶变换红外光谱仪(FT-IR)以及紫外-可见分光光度计(UV)等对微球形貌、结构和载药释药性能进行表征。实验结果表明,CaCO3微球合成过程中,PSS不仅调控了CaCO3的形状,也改变了CaCO3晶型,即由方解石晶型转变为球霰石晶型;在负载布洛芬(IBU)的CaCO3微球表面,通过层层自组装法得到核壳型载药微球。去除模板CaCO3后的微囊结构表明聚电解质和粘土成功地组装在微球表面;壳层中的聚电解质能够有效地延缓药物的释放,而锂藻土对药物的释放具有阻隔作用,能进一步延长药物的释放时间。更多还原

【Abstract】 Core-shell drug loaded microspheres were prepared by the layer-by-layer self-assembly technique in which sodium polystyrene sulfonate(PSS),poly(diallyl dimethyl ammonium chloride)(PDDA) and clay particles(laponite) were alternatively adsorbed on the calcium carbonate(CaCO3) template particles.PSS was also used in the preparation of CaCO3 template to control its structure.Ibuprofen(IBU) as model drug was then loaded in the pore of CaCO3 through physical absorption.At last the polyelectrolytes and/or laponite particles were assembly on the drug loaded CaCO3 particles to block the drug releasing.The laponite could be dispersed into monolayer round sheet with the diameter and thickness about 25nm and 1nm respectively in the water,which used in the shell of microspheres here to promote the properties of drug releasing.The morphology,structure and drug release property of the microspheres were characterized by the scanning electron microscope(SEM),the transmission electron microscope(TEM),zeta potential analyzer,X-ray diffraction(XRD),Fourier transform infrared spectra(FT-IR) and ultraviolet spectrophotometer(UV).The results showed that PSS played an important role in the synthesis of CaCO3 microspheres,by which not only the spherical morphology was controlled,but also its crystal type was changed from calcite to vaterite.The IBU loading in CaCO3 could reach 28.6mg/g.The thin shell of polyelectrolyte or polyelectrolyte/laponite could be formed on the surface of CaCO3 by layer-by-layer assembly,which was verified by the polyelectrolyte/laponite microcapsules obtained after removing the core of CaCO3.The result of cumulative drug releasing showed that the shell of polyelectrolyte and laponite particles could effectively extend the time of drug releasing.更多还原